The term acute abdomen defines a clinical syndrome characterized by the sudden onset of severe abdominal pain requiring emergency medical or surgical treatment.
It is one of the most frequent reasons for presentation of an adult to the emergency department, ranging from 4% to 10% of admissions.
A prompt and accurate diagnosis is essential to minimize morbidity and mortality in these patients.
The differential diagnosis includes a spectrum of infectious, inflammatory, ischemic, obstructive, hemorrhagic, and neoplastic disorders.
The acute abdomen can also reflect extra-abdominal conditions, including cardiac, pulmonary, endocrine, or metabolic disorders.
Imaging assessment of malignant focal and diffuse liver lesions from Ultrasound to Mri with overview of interventional modalities and diagnostic snippets,
Initially in my lectures you can see that I have talked about Approach to Pain in abdomen, now we will learn what imaging should be done and why as per case to case basis. CT or USG or X-ray !!
Imaging assessment of malignant focal and diffuse liver lesions from Ultrasound to Mri with overview of interventional modalities and diagnostic snippets,
Initially in my lectures you can see that I have talked about Approach to Pain in abdomen, now we will learn what imaging should be done and why as per case to case basis. CT or USG or X-ray !!
New Predictors for Periampullary Resectabilityasclepiuspdfs
Background: Periampullary tumor involves ampullary, pancreatic, biliary and duodenal mucosa, and pancreaticoduodenectomy considered the curative option. Hence, imaging evaluation to describe the lesion is important. Furthermore, certain specific features could help in pre-operative prediction of resectability for periampullary cancers. The aim of this study is to find out any specific perioperative predictor of resectability on periampullary cancers. Patients and Methods: This is an observational cross-sectional hospital-based study done in tertiary hospital, a total of 79 patients were included in the study. Variables such as age, gender, symptoms (back pain, jaundice, etc.), investigations (bilirubin, alkaline phosphatase, etc.), and imaging (Triphasic computed tomography [CT], magnetic resonance cholangiopancreatography, endoscopic ultrasonography, etc.) were studied and the data collected and analyzed using SPSS 20. Results: Male was slightly predominant and male to female ratio was 1:0.9. The mean age was 50 years (SD ±6.54). Triphasic CT abdomen pancreatic protocol was the most effective modality of investigation. High bilirubin (>10 mg/dl) and back pain were statistically significant among patients with unresectable tumor. Conclusions: Back pain and high bilirubin could be helpful in pre-operative prediction of operability of periampullary cancers.
Indications to CTC are increasing
CTC is recommended in all cases of unfeasibility of colonoscopy
CTC is not ready for mass screening but is ideal for screening on an individual basis.
Inflammatory Bowel Disease ( Pathogensis & Steps of Diagnosis and Management) For Resident at Gastroenterology and Hepatology department at Kafrelsheikh by Dr/ Mohammed Hussien ( Assistant Lecturer).
Scans and Ovarian Cancer: Everything You Want to Knowbkling
When you’re diagnosed with ovarian cancer, scans become an inevitable part of life. But what are the differences between the imaging tests? When should which scans be used? What about the pros and cons of each test? Join Dr. Kevin Holcomb, Vice-Chair of Gynecology and member of the Division of Gynecologic Oncology at Weill Cornell Medicine, and Dr. Elisabeth O’Dwyer, Instructor in Radiology at Weill Cornell Medicine and Assistant Attending Radiologist at NewYork-Presbyterian Hospital-Weill Cornell Campus, as they help make sense of it all.
Practical Points in Emergency CT for Emergency PhysiciansRathachai Kaewlai
The handout describes some brief practical points on emergency CT, particularly for emergency physicians. They include imaging utilisation trends, radiation dose, contrast reaction, contrast-induced nephropathy, use of oral contrast medium and some caveats on emergency CT (esp. abdomen)
While the role of radiation therapy in carcinoma cervix management is undauntable for all stages. Recurrent carcinoma cervix need a lot of personalisation
Congenital Anomalies of the Kidney & Urinary TractAbhineet Dey
Congenital anomalies of the kidney and urinary tract (CAKUT) represent a broad range of disorders that result from developmental abnormalities of the lower urinary tract, urinary collecting system, disrupted embryonic migration of the kidney(s), or abnormal renal parenchymal development.
Despite significant variation in phenotype and clinical implications, CAKUT shares a common genetic basis and molecular signaling that affect kidney development.
Diagnostics in Inflammatory Bowel Disease (IBD): UltrasoundAbhineet Dey
Intestinal ultrasound has a good accuracy in the diagnosis of Crohn's disease, as well as in the assessment of disease activity, extent, and evaluating disease-related complications, namely strictures, fistulae, and abscesses.
Even though not fully validated, several scores have been developed to assess disease activity using ultrasound. Importantly, intestinal ultrasound can also be used to assess response to treatment. Changes in ultrasonographic parameters are observed as early as 4 weeks after treatment initiation and persist during short- and long-term follow-up. Additionally, Crohn's disease patients with no ultrasound improvement seem to be at a higher risk of therapy intensification, need for steroids, hospitalisation, or even surgery.
Similarly to Crohn's disease, intestinal ultrasound has a good performance in the diagnosis, activity, and disease extent assessment in ulcerative colitis patients. In fact, in patients with severe acute colitis, higher bowel wall thickness at admission is associated with the need for salvage therapy and the absence of a significant decrease in this parameter may predict the need for colectomy.
Short-term data also evidence the role of intestinal ultrasound in evaluating therapy response, with ultrasound changes observed after 2 weeks of treatment and significant improvement after 12 weeks of follow-up in ulcerative colitis.
Beyond LFT - A Radiologist’s Guide to the Liver Blood TestsAbhineet Dey
Abnormal liver blood test results are often the first indicator of hepatobiliary disease and a common indication for abdominal imaging with US, CT, or MRI.
Most of the disease entities can be categorized into hepatocellular or cholestatic patterns, with characteristic traits on liver blood tests. Each pattern has a specific differential, which can help narrow the differential diagnosis when combined with the clinical history and imaging findings.
Overall, integrating liver blood test patterns with imaging findings can help the radiologist accurately diagnose hepatobiliary disease, especially in cases where imaging findings may not allow differentiation between different entities.
Imaging of the Biliary System and its DisordersAbhineet Dey
Clinical data such as history, physical examination, and laboratory tests are useful in identifying patients with biliary obstruction and biliary sources of infection. However, if intervention is planned, noninvasive imaging is needed to confirm the presence, location, and extent of the disease process.
Currently, the most commonly available and used noninvasive modalities are ultrasound (US), computed tomography (CT), magnetic resonance (MR), and nuclear medicine hepatobiliary scintigraphy (HIDA).
Imaging plays a key role in the diagnosis of diseases of the trachea, bronchi and small airways. The technical advances relating to CT, and in particular the ability to rapidly acquire a volume of data with multidetector CT, has revolutionised the investigation of patients with suspected airway disease.
Tracheal abnormalities can be due to intrinsic or extrinsic causes and may be focal, multifocal or diffuse. CT is now the investigation of choice for suspected bronchiectasis. Asthma remains a clinical diagnosis, but advances in CT technology now allow quantitative assessment of the bronchial wall and this is providing insights into the nature of airway remodelling that occurs in asthma.
Small airways (for practical purposes the bronchioles) are numerous and thus clinical tests are insensitive in detecting disease. This has increased the role and importance of CT in identifying either of the two main categories of small airway disease—constrictive bronchiolitis and exudative bronchiolitis.
Sarcoidosis from head to toe: What the radiologist needs to knowAbhineet Dey
Sarcoidosis is a multisystem granulomatous disorder characterized by development of noncaseating granulomas in various organs.
Clinical features are often nonspecific, and imaging is essential to diagnosis.
Abnormalities may be seen on chest radiographs in more than 90% of patients with thoracic sarcoidosis. Symmetric hilar and mediastinal adenopathy and pulmonary micronodules in a perilymphatic distribution are characteristic features of sarcoidosis. Irreversible pulmonary fibrosis may be seen in 25% of patients with the disease.
Although sarcoidosis commonly involves the lungs, it can affect virtually any organ in the body.
Computed tomography (CT), magnetic resonance (MR) imaging, and positron emission tomography/CT (PET/CT) are useful in the diagnosis of extrapulmonary sarcoidosis, but imaging features may overlap with those of other conditions.
Familiarity with the spectrum of multimodality imaging findings of sarcoidosis can help to suggest the diagnosis and guide appropriate management.
This presentation aims to give a foundational knowledge in the art of radiological interpretation of the chest radiograph.
It includes some of the important anatomical structures visible on a chest X-ray along with technical aspects regarding image aquisition in correlation with lateral views and cross-sectional imaging to give a more complete sense of the structures in view.
Journal presentation: Brink, J. A., & Hricak, H. (2023). Radiology 2040. Radiology, 306(1), 69–72. https://doi.org/10.1148/radiol.222594
This editorial describes a variety of anticipated changes in the science and practice of radiology, some of which will appear almost inevitably and some of which the imaging community will only be able to achieve through vision and intense determination.
Case study on Varicose Veins & Venous UlcersAbhineet Dey
A clinically based study of a case of Varicose Veins & Venous Ulcers.
Moderator:
Dr M. K. Mazumdar
Asst. Professor,
Dept. of Obstetrics and Gynaecology,
Gauhati Medical College & Hospital
Presented by:
29: Abhineet Dey
30: Devasree Kalita
31: Parishmita Sharma
32: Samadrita Borkakoty
33: Ankur Jain
34: Dhurjyoti Nath
35: Mousumi Mehtaz
Students of 8th Semester,
Gauhati Medical College & Hospital, Guwahati, Assam
Case Study on Intrauterine Growth RestrictionAbhineet Dey
A clinically based study of a case of Intrauterine Growth Restriction (IUGR) or Foetal Growth Restriction (FGR).
Moderator:
Dr M. K. Mazumdar
Asst. Professor,
Dept. of Obstetrics and Gynaecology,
Gauhati Medical College & Hospital
Presented by:
29: Abhineet Dey
30: Devasree Kalita
31: Parishmita Sharma
33: Ankur Jain
34: Dhurjyoti Nath
35: Mousumi Mehtaz
42: Liza Hazarika
Students of 8th Semester,
Gauhati Medical College & Hospital, Guwahati, Assam
Immediate or Type I hypersensitivity is a rapid immunological reaction occurring in a previously sensitized individual that is triggered by the binding of an antigen to IgE antibody on the surface of mast cells.
Amyloidosis is a condition associated with a number of inherited and inflammatory disorders in which extracellular deposits of fibrillar proteins are responsible for tissue damange and functional compromise. (Robbins Basic Pathology, 9th Edition)
The following slideshow deals with the classification of Amyloidosis:
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
3. Acute abdomen
Acute abdominal pain in a subgroup of patients who are seriously ill and
have abdominal tenderness and rigidity.
4. Diagnostic conundrum
• The differential diagnosis for abdominal pain is broad, encompassing
gastrointestinal, gynecologic, urologic, vascular, and musculoskeletal conditions.
• A confident and accurate diagnosis can be made solely on the basis of medical
history, physical examination, and laboratory test findings in only a small
proportion of patients.
• The clinical manifestations of the various causes of acute abdominal pain usually
are not straightforward.
• For proper treatment, a diagnostic work-up that enables the clinician to
differentiate between the various causes of acute abdominal pain is important, and
imaging plays an important role in this process.
5. ACR Appropriateness Criteria
• Evidence-based guidelines to help physicians make the most appropriate
imaging decisions for specific clinical conditions.
• The ACR Appropriateness Criteria for abdominal imaging are based primarily on
the location of pain. For most locations, the ACR provides several clinical
variants (e.g., presence or absence of fever, leukocytosis, pregnancy) and outlines
the appropriate imaging for each scenario.
• This presentation includes one clinical variant for each pain location; tables for all
clinical variants are available at https://acsearch.acr.org/list
6. Imaging modalities
Imaging plays an important role in the management of patients because
clinical evaluation results can be inaccurate.
7. Conventional radiography
• Conventional radiography is commonly the initial imaging examination performed
in the diagnostic work-up of patients who present with acute abdominal pain to the
ED.
• This examination is widely available, can be easily performed in admitted patients,
and is used to exclude major illness such as bowel obstruction and perforated
viscus.
• Conventional radiography includes supine and upright conventional abdominal
radiography and upright chest radiography.
8. Conventional radiography
• The accuracy values for conventional
radiography in the diagnostic work-up of
patients with acute abdominal pain are
not convincing.
• However, it is widely available in the
ambulatory setting and is often the initial
imaging test for evaluation of outpatients
with abdominal pain.
• Conventional radiography has been
reported to have good accuracy in the
following conditions however:
• Bowel obstruction
• Perforated viscus
• Urinary tract calculi
• Foreign bodies
In a recent study*, however, only the
sensitivity for the diagnosis of bowel
obstruction was significantly higher after
conventional radiograph evaluation
* van Randen A, Lameris W, Bossuyt PM, Boermeester MA, Stoker J. Comparison of accuracy of ultrasonography and computed tomography in patients
with acute abdominal pain at the emergency department [abstr]. In: Radiological Society of North America scientific assembly and annual meeting
program. Oak Brook, Ill: Radiological Society of North America, 2009; 519.
9. Ultrasonography (USG)
• US is another imaging modality commonly used in the diagnostic work-up of
patients with acute abdominal pain.
• With US, the abdominal organs and the alimentary tract can be visualized. Curved
(3.5–5.0-MHz) and linear (5.0–12.0-MHz) transducers are used most commonly,
with frequencies depending on the application and the patient’s stature
• Graded-compression procedure: Interposing fat and bowel can be displaced or
compressed by means of gradual compression to show underlying structures. This
is the most common US technique used to examine patients with acute abdominal
pain
• Furthermore, if the bowel cannot be compressed, the non-compressibility itself is
an indication of inflammation.
10. Ultrasonography (USG)
Advantages
• Wide availability in the ED
• Lower costs
• Absence of radiation exposure
• Real-time dynamic examination: Can
reveal presence/absence of peristalsis
and depict blood flow
• Clinical tool: US findings can correlate
with the point of maximal tenderness.
Disadvantages
• Operator dependent
• Patient dependent: Patient body
habitus, cooperation
• Bowel gas shadow can obscure findings
11. Computed tomography (CT)
• The CT technique used to examine patients with acute abdominal pain generally
involves scanning of the entire abdomen after intravenous administration of an
iodinated contrast medium
• Although rectal or oral contrast material may be helpful in differentiating fluid-
filled bowel loops from abscesses in some cases, the use of oral contrast material
can markedly increase the time these patients spend in the ED. *
* Huynh LN, Coughlin BF, Wolfe J, Blank F, Lee SY, Smithline HA. Patient encounter time intervals in the evaluation of emergency department
patients requiring abdominopelvic CT: oral contrast versus no contrast. Emerg Radiol 2004;10:310–313.
12. Computed tomography (CT)
• Exposure to ionizing radiation is a disadvantage of CT.
• The effective radiation dose for abdominal CT is approximately 10 mSv. In
comparison, the annual background radiation dose in the United States is
approximately 3 mSv.
• A 10-mSv CT examination performed in a 25-year old person is associated with an
estimated risk of induced cancer of one in 900 individuals and a risk of
induced fatal cancer of about one in 1800 individuals*. For older individuals,
these risks are considerably lower. These risks should be weighed against the direct
diagnostic benefit and related to the lifetime cancer risk
* The 2007 recommendations of the International Commission on Radiological Protection. ICRP publication 103. Ann ICRP 2007; 37:1–332.
13. Magnetic resonance (MR)
• MR imaging has demonstrated promising accuracy for the assessment and
diagnosis of appendicitis, albeit in a relatively small series of patients, who often
were pregnant. MR imaging is also accurate in the diagnosis of diverticulitis. MR
imaging is more accurate than CT for the diagnosis of acute cholecystitis and the
detection of common bile duct stones.
• At this time, MR imaging is used in only select cases at many institutions, primarily
after US yields nondiagnostic findings in pregnant women.
• MR imaging has contraindications, including claustrophobia, which may prevent
MR imaging from being performed.
* Oto A. MR imaging evaluation of acute abdominal pain during pregnancy. Magn Reson Imaging Clin N Am 2006;14:489–501. 35.
* Oh KY, Gilfeather M, Kennedy A, et al. Limited abdominal MRI in the evaluation of acute right upper quadrant pain. Abdom Imaging 2003;28:643–651. 36.
* Aube C, Delorme B, Yzet T, et al. MR cholangiopancreatography versus endoscopic sonography in suspected common bile duct lithiasis: a prospective,
comparative study. AJR Am J Roentgenol 2005;184:55–62. 37.
* Stoker J. Magnetic resonance imaging and the acute abdomen. Br J Surg 2008;95: 1193–1194.
14. Imaging
Recommendations
Imaging Recommendations for
Evaluating Select Causes of Acute
Abdominal Pain in Adults
Cartwright, S. L., & Knudson, M. P. (2015).
Diagnostic imaging of acute abdominal pain in
adults. American family physician, 91(7), 452–
459.
16. ACR Appropriateness Criteria
Initial imaging of right upper quadrant (RUQ) pain
Expert Panel on Gastrointestinal Imaging, Russo, G. K., Zaheer, A., Kamel, I. R., Porter, K. K., Archer-Arroyo, K., Bashir, M. R., Cash, B. D., Fung, A.,
McCrary, M., McGuire, B. M., Shih, R. D., Stowers, J., Thakrar, K. H., Vij, A., Wahab, S. A., Zukotynski, K., & Carucci, L. R. (2023). ACR Appropriateness
Criteria® Right Upper Quadrant Pain: 2022 Update. Journal of the American College of Radiology : JACR, 20(5S), S211–S223.
https://doi.org/10.1016/j.jacr.2023.02.011
17. Acute cholecystitis
• Acute cholecystitis is a primary diagnostic consideration in patients presenting
with new-onset right upper quadrant pain.
• The prevalence of acute cholecystitis is approximately 5% in patients who present
with acute abdominal pain to the ED.
• Diagnostic clinical triad:
1. Right upper quadrant tenderness
2. Elevated body temperature
3. Elevated WBC count
However, this triad was present in only 8% of patients in a prospective series
* Lameris W, van Randen A, Ten Hove W, Bossuyt PM, Boermeester MA, Stoker J. The clinical diagnosis of acute cholecystitis is unreliable
[abstr]. In: Radiological Society of North America Scientific Assembly and Annual Meeting Program. Oak Brook, Ill: Radiological Society of
North America, 2008;110.
18. Tokyo Guidelines 2018/2013 (TG18/TG13)
A. Local signs of inflammation:
1. Murphy's sign
2. RUQ mass/pain/tenderness
B. Systemic signs of inflammation:
1. Fever
2. Elevated CRP
3. Elevated WBC count
C. Imaging findings: Imaging findings characteristic of acute cholecystitis
• Suspected diagnosis: One item in A + one item in B
• Definite diagnosis: One item in A + one item in B + C
19. Acute cholecystitis: USG
According to ACR appropriateness criteria, US is considered the most appropriate
imaging modality for patients suspected of having acute calculous cholecystitis.
FINDINGS:
• Sonographic Murphy sign (tenderness elicited by pressing the gallbladder with
the ultrasound probe)
• Thickened gallbladder wall (>4 mm; if the patient does not have chronic liver
disease and/or ascites or right heart failure)
• Enlarged gallbladder (long axis diameter > 8 cm, short axis diameter > 4 cm)
• Incarcerated gallstone, debris echo, pericholecystic fluid collection
• Sonolucent layer in the gallbladder wall, striated intramural lucencies, and
Doppler signals.
20. Typical ultrasound images of acute cholecystitis. (a) Pericholecystic fluid. Pericholecystic fluid is demonstrated to the
left side of the gallbladder. Gallstones and debris are also seen in the gallbladder. (b) An intraluminal flap seen in a
gangrenous cholecystitis. A linear echogenic line representing the intraluminal flap is demonstrated
Yokoe, M., Hata, J., Takada, T., Strasberg, S.M., Asbun, H.J., Wakabayashi, G., Kozaka, K., Endo, I., Deziel, D.J., Miura, F., Okamoto, K., Hwang, T.-L., Huang, W.S.-W.,
Ker, C.-G., Chen, M.-F., Han, H.-S., Yoon, Y.-S., Choi, I.-S., Yoon, D.-S., Noguchi, Y., Shikata, S., Ukai, T., Higuchi, R., Gabata, T., Mori, Y., Iwashita, Y., Hibi, T., Jagannath,
P., Jonas, E., Liau, K.-H., Dervenis, C., Gouma, D.J., Cherqui, D., Belli, G., Garden, O.J., Giménez, M.E., de Santibañes, E., Suzuki, K., Umezawa, A., Supe, A.N., Pitt, H.A.,
Singh, H., Chan, A.C.W., Lau, W.Y., Teoh, A.Y.B., Honda, G., Sugioka, A., Asai, K., Gomi, H., Itoi, T., Kiriyama, S., Yoshida, M., Mayumi, T., Matsumura, N., Tokumura,
H., Kitano, S., Hirata, K., Inui, K., Sumiyama, Y. and Yamamoto, M. (2018), Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholecystitis
(with videos). J Hepatobiliary Pancreat Sci, 25: 41-54. https://doi.org/10.1002/jhbp.515
21. Typical ultrasound images of acute cholecystitis. (a) Color Doppler images of acute cholecystitis. Increased
intraluminal blood flow is demonstrated. However, it is not always easy to estimate the intraluminal flow since the sensitivity
of color Doppler imaging is influenced by several factors such as the settings of the filter, velocity range, frequency of the
ultrasound beam, the patients’ constitutions, and the limitations of the equipment. (b) Superb Microvascular Imaging of acute
cholecystitis. Superb Microvascular imaging, which is more sensitive than the conventional color Doppler in the detection
of blood flow, shows the increased intraluminal flow of the gallbladder in a patient with acute cholecystitis. Still, the same
problem as described in the figure legend of (a) remains so it is difficult to make use of these Doppler imagings as an
objective method for the diagnosis of acute cholecystitis
Yokoe, M., Hata, J., Takada, T., Strasberg, S.M., Asbun, H.J., Wakabayashi, G., Kozaka, K., Endo, I., Deziel, D.J., Miura, F., Okamoto, K., Hwang, T.-L., Huang, W.S.-W.,
Ker, C.-G., Chen, M.-F., Han, H.-S., Yoon, Y.-S., Choi, I.-S., Yoon, D.-S., Noguchi, Y., Shikata, S., Ukai, T., Higuchi, R., Gabata, T., Mori, Y., Iwashita, Y., Hibi, T., Jagannath,
P., Jonas, E., Liau, K.-H., Dervenis, C., Gouma, D.J., Cherqui, D., Belli, G., Garden, O.J., Giménez, M.E., de Santibañes, E., Suzuki, K., Umezawa, A., Supe, A.N., Pitt, H.A.,
Singh, H., Chan, A.C.W., Lau, W.Y., Teoh, A.Y.B., Honda, G., Sugioka, A., Asai, K., Gomi, H., Itoi, T., Kiriyama, S., Yoshida, M., Mayumi, T., Matsumura, N., Tokumura,
H., Kitano, S., Hirata, K., Inui, K., Sumiyama, Y. and Yamamoto, M. (2018), Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholecystitis
(with videos). J Hepatobiliary Pancreat Sci, 25: 41-54. https://doi.org/10.1002/jhbp.515
22. Acute cholecystitis: CT
CT findings
• Thickened gallbladder wall
• Pericholecystic fluid collection
• Enlarged gallbladder
• Linear high-density areas in the
pericholecystic fat tissue
Complications
• Perforation/abscess formation,
• Hemorrhage
• Gas (in diabetic patients with
emphysematous cholecystitis)
• Wall gangrene
Computed tomography (CT) is not used for the initial evaluation of right upper quadrant pain.
It may be considered in patients with inconclusive ultrasonography or cholescintigraphy
results or to help guide surgical planning.
23. Typical computed tomography (CT) images of gangrenous cholecystitis. Woman in her 70s with gangrenous
cholecystitis (acute acalculous cholecystitis). Dynamic contrast-enhanced CT (a, plain; b, early phase; c, equilibrium phase).
Enlargement of the gallbladder, thickening of the gallbladder wall, and edematous lesions beneath the gallbladder
serosa are evident on plain CT (arrows). On contrast-enhanced CT (b,c), irregularity of the gallbladder wall and the
partial lack of contrast enhancement can be seen (arrows) as the characteristic appearance of gangrenous cholecystitis.
Transient early-phase staining of the hepatic parenchyma (b) and edematous changes to the hepatoduodenal
ligament (c, arrowhead) are also apparent, suggesting the spread of inflammation
Yokoe, M., Hata, J., Takada, T., Strasberg, S.M., Asbun, H.J., Wakabayashi, G., Kozaka, K., Endo, I., Deziel, D.J., Miura, F., Okamoto, K., Hwang, T.-L., Huang, W.S.-W.,
Ker, C.-G., Chen, M.-F., Han, H.-S., Yoon, Y.-S., Choi, I.-S., Yoon, D.-S., Noguchi, Y., Shikata, S., Ukai, T., Higuchi, R., Gabata, T., Mori, Y., Iwashita, Y., Hibi, T., Jagannath,
P., Jonas, E., Liau, K.-H., Dervenis, C., Gouma, D.J., Cherqui, D., Belli, G., Garden, O.J., Giménez, M.E., de Santibañes, E., Suzuki, K., Umezawa, A., Supe, A.N., Pitt, H.A.,
Singh, H., Chan, A.C.W., Lau, W.Y., Teoh, A.Y.B., Honda, G., Sugioka, A., Asai, K., Gomi, H., Itoi, T., Kiriyama, S., Yoshida, M., Mayumi, T., Matsumura, N., Tokumura,
H., Kitano, S., Hirata, K., Inui, K., Sumiyama, Y. and Yamamoto, M. (2018), Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholecystitis
(with videos). J Hepatobiliary Pancreat Sci, 25: 41-54. https://doi.org/10.1002/jhbp.515
25. Emphysematous Cholecystitis
(A) Coronal CT—intramural gas (arrows); (B) US—intraluminal gas appears as a bright curvilinear echogenic
band (arrow) with ‘dirty’ shadowing.
26. Acute cholecystitis: MR
• Magnetic resonance imaging (MRI) may be useful for evaluating acute cholecystitis,
with a sensitivity (85%) and specificity (81%) similar to that of ultrasonography.
• MRI can be used in patients with equivocal ultrasonography findings or to visualize
hepatic and biliary abnormalities that cannot be characterized on ultrasonography.
* Kiewiet JJ, Leeuwenburgh MM, Bipat S, Bossuyt PM, Stoker J, Boermeester MA. A systematic review and meta-analysis of diagnostic
performance of imaging in acute cholecystitis. Radiology. 2012; 264(3):708-720.
27. Acute cholecystitis: Differentials
Liver abscess
Pyogenic liver abscesses may be idiopathic
or may result from seeding from infection
in the biliary tract, from the luminal
gastrointestinal tract or from the
portal/mesenteric venous system.
• USG: Round or oval hypoechoic mass
or masses, which may contain low-level
echoes.
• CT/MRI: Enhancing wall with
peripheral zone of edema
These findings are not universally present
Rupture of hepatocellular carcinoma
Spontaneous rupture of a hepatocellular
carcinoma with associated
hemoperitoneum is a frequent
complication in countries with a high
incidence of this tumor
Hepatocellular carcinoma usually is highly
vascular, and tumor necrosis with
associated hepatic capsular rupture and
rupture of vessels within the tumor is the
presumed etiology.
Differential diagnosis includes
spontaneous hemorrhage within a hepatic
adenoma or a hepatic metastasis
28. Hepatic abscess
Ultrasound (left image) shows a heterogeneously hypoechoic lesion corresponding to a hypodense lesion with
foci of gas on non-contrast CT (middle image). This lesion was heterogeneously T2 hyperintense on MRI (right
image) with enhancement and restricted diffusion (not shown).
30. Splenic pathology
Splenic infarction
Splenic infarction may be focal and less
commonly global.
• Etiology:
Secondary to bland or septic emboli to the
spleen
Marked splenomegaly with outgrowth of the
splenic blood supply
Pancreatitis
• Typical infarcts are wedge-shaped and
hypoattenuating on CT
Splenic abscess
Most splenic abscesses are secondary to
hematogenous dissemination of infection
and are seen primarily in
immunocompromised individuals and IV
drug abusers.
• On CT, splenic abscesses demonstrate
low attenuation centrally with an
enhancing rim and occasionally have
central gas.
31. Splenic abscess
73-year-old man with left upper
quadrant pain, fever, and
leukocytosis.
Transaxial contrast-enhanced CT
image shows a gas-containing
fluid collection in the spleen. A
drainage catheter was placed
percutaneously, and cultures grew
Escherichia coli
32. Splenic Arterial Infarcts
Arterial emboli commonly result in peripheral well-defined wedge-shaped lesions, as shown here on an
axial image (A). Coronal image (B) of the same CT showing the same infarct in the upper pole and another
smaller infarct in the lower pole. Multiple small hypodense lesions in this spleen represent micro-abscesses.
Emboli causing infarcts are therefore likely septic emboli.
33. Gastric pathology
The diagnosis of gastric pathology is best
established by endoscopy, although
patients may present with left or right
upper abdominal pain, and with other non-
specific signs and symptoms, and CT may
reveal the diagnosis when it is not clinically
suspected.
Acute gastric disorders include gastritis
and ulcer.
CT findings
• Focal or diffuse gastric wall
thickening,
• Increased mucosal enhancement
• Submucosal edema
• Peri-gastric inflammatory changes.
• Focal ulceration with or without
perforation (generally benign but
occasionally of malignant etiology)
34. Gastric ulcer
(A) Axial CT image showing benign ulcer (arrow) along the lesser curvature with a crater and surrounding
smooth mound. (B) Axial CT shows perforated gastric ulcer in the posterior gastric antrum with leaking contrast
(arrow), focal wall thickening and adjacent fat stranding.
36. Acute pancreatitis
• Pancreatitis is inflammation of the pancreas, which may be due to a variety of
etiologies that share a final common pathway of premature activation of pancreatic
enzymes and resultant autodigestion of pancreatic parenchyma.
• On initial clinical evaluation, pancreatitis frequently is confused with other
disorders, and amylase and lipase levels may either be pending or not obtained.
Therefore it is important for the radiologist to identify pancreatitis, usually on CT
but occasionally on sonography, when the diagnosis is not suspected clinically.
• The vast majority of cases are due to gallstones or alcohol abuse. Less common
etiologies include trauma, interventional pancreatobiliary procedures, medications,
elevated triglycerides, congenital anomalies (i.e., pancreas divisum, annular
pancreas, absent dorsal pancreas), and underlying tumor.
37. Revised Atlanta
Classification
Revised Atlanta classification of acute
pancreatitis (2012) is an international
multidisciplinary classification of the
severity of acute pancreatitis, updating
the 1992 Atlanta classification.
It attempts to better characterize the
disease process, to standardize
terminology—including the
description of cross-sectional imaging
findings—and to provide better
correlation with prognosis.
Trikudanathan, G., Wolbrink, D., van Santvoort, H., Mallery, S., Freeman, M., & Besselink, M. (2019).
Current Concepts in Severe Acute and Necrotizing Pancreatitis: An Evidence-Based Approach.
Gastroenterology, 156(7), 1994-2007.e3. doi: 10.1053/j.gastro.2019.01.269
38. Modified CT severity index (CTSI)
Balthazar grade
Grade CT findings Score
A Normal CT 0
B Focal/diffuse pancreatic
enlargement
1
C Pancreatic gland abnormalities
and peri pancreatic
inflammation
2
D 1 Fluid collection 3
E ≥ 2 fluid collections and/or gas
bubbles in/adjacent to
pancreas
4
Pancreatic necrosis score
CT findings Score
No necrosis 0
< 30% necrosis 2
30-50% necrosis 4
> 50% necrosis 6
CT severity index (CTSI) combines the Balthazar grade (0-4 points) with the extent of
pancreatic necrosis (0-6 points) on a 10-point severity scale.
39. Modified CT severity index (CTSI)
DISEASE STRATIFICATION
• Mild (interstitial) pancreatitis : CTSI 0-2
• Balthazar B or C, without pancreatic or extra-pancreatic necrosis
• Intermediate (exudative) pancreatitis: CTSI 4-6
• Balthazar D or E, without pancreatic necrosis; peripancreatic collections are due to
extra-pancreatic necrosis
• Severe (necrotizing) pancreatitis: CTSI 8-10
• Necrosis of the pancreas (non-enhancing areas in the pancreas on contrast-enhanced
CT)
40. Acute pancreatitis
Contrast-enhanced axial CT (left image) demonstrates diffuse pancreatic enlargement and peripancreatic edema. The
pancreatic parenchyma enhances uniformly, without evidence for necrosis. Transverse ultrasound (right image) of
the head and body of the pancreas shows a diffusely enlarged, heterogeneous pancreas (arrows) due to pancreatic
edema.
Ultrasound case courtesy Julie Ritner, MD, Brigham and Women’s Hospital, Boston
41. Chronic pancreatitis
Two identical abdominal radiographs showing pancreatic calcification. There are
multiple irregular foci of calcification projected over the midline in the rough shape of
the pancreas. The right radiograph shows the pancreatic calcifications marked in
yellow
43. ACR Appropriateness Criteria
Initial imaging of right lower quadrant (RLQ) pain
Expert Panel on Gastrointestinal Imaging, Kambadakone, A. R., Santillan, C. S., Kim, D. H., Fowler, K. J., Birkholz, J. H., Camacho, M. A., Cash, B. D., Dane,
B., Felker, R. A., Grossman, E. J., Korngold, E. K., Liu, P. S., Marin, D., McCrary, M., Pietryga, J. A., Weinstein, S., Zukotynski, K., & Carucci, L. R. (2022).
ACR Appropriateness Criteria® Right Lower Quadrant Pain: 2022 Update. Journal of the American College of Radiology : JACR, 19(11S), S445–S461.
https://doi.org/10.1016/j.jacr.2022.09.011
44. Acute appendicitis
• The starting symptom is generally nondescriptive visceral pain in the periumbilical
region, followed by nausea & vomiting. When the disease progresses, the pain
typically migrates to the right lower quadrant because of more localized peritoneal
inflammation.
• US performed as the initial diagnostic test, with CT performed only secondarily,
after US has yielded nondiagnostic findings.
• However, US can be limited by gas-filled bowel, which may obscure the underlying
abnormality and thus necessitate secondary CT in many individuals
45. Acute appendicitis
US remains the initial imaging examination,
despite its poor sensitivity and specificity
in this clinical setting.
In the evaluation of suspected appendicitis
in children (and in selected nonpregnant
women of childbearing age), US is
considered the initial examination of
choice, if available, although CT has a
higher accuracy.
Primary US criteria
• Swollen, non-compressible appendix
>7 mm in diameter (appendix can be
larger than 6 mm in transverse diameter
and can still be normal on CT),
• Target configuration
• Pain corresponding to the site of the
appendix.
• Other findings: Appendicolith or
multiple appendicolith
46. Acute appendicitis
(a–c) Ultrasonography of acute appendicitis in a 12-year-old girl. Oblique and transverse views show a
swollen appendix (diameter 10 mm), with a target configuration
47. Acute appendicitis: CT
Uncomplicated appendicitis
• Enlarged (> 6 mm) appendix (high
PPV)
• Adjacent fat infiltration (high
sensitivity)
• Visualization of appendicoliths (low
PPV because these may also be present in
individuals who do not have
appendicitis)
Perforated appendicitis
• Extraluminal gas, abscess
• Focal appendiceal wall defect
• Small-bowel obstruction (SBO)
* Daly CP, Cohan RH, Francis IR, Caoili EM, Ellis JH, Nan B. Incidence of acute appendicitis in patients with equivocal CT findings. AJR Am J Roentgenol
2005;184:1813–1820.
* Rao PM. Cecal apical changes with appendicitis: diagnosing appendicitis when the appendix is borderline abnormal or not seen. J Comput Assist Tomogr
1999;23: 55–59.
* Pereira JM, Sirlin CB, Pinto PS, Jeffrey RB, Stella DL, Casola G. Disproportionate fat stranding: a helpful CT sign in patients with acute abdominal pain.
RadioGraphics 2004;24:703–715.
* Bixby SD, Lucey BC, Soto JA, Theysohn JM, Ozonoff A, Varghese JC. Perforated versus nonperforated acute appendicitis: accuracy of multidetector CT
detection. Radiology 2006;241:780–786.
* Horrow MM, White DS, Horrow JC. Differentiation of perforated from nonperforated appendicitis at CT. Radiology 2003; 227:46–51.
48. Acute appendicitis
Axial CT image obtained after
intravenous administration of contrast
medium in 39- year-old woman with
classic clinical manifestations of
appendicitis shows retrocecal
inflamed appendix (arrow) with
thickened wall and some
surrounding infiltration.
The appendix could not be
visualized at US because of
overlying (bowel) gas. Appendicitis
was confirmed at surgery and
histopathologic analysis.
C: Cecum.
49. Acute appendicitis: MR
• Non-contrast MRI is being used increasingly in pregnant patients after
nondiagnostic US and has demonstrated high accuracy for diagnosis and exclusion
of appendicitis and for identification of alternative diagnoses.
• CT should be reserved as a third-line examination, used only if needed.
50. Acute appendicitis
Axial fat-saturated half-Fourier
acquisition with single-shot turbo
spin-echo MR image (1900/72
[repetition time msec/echo time
msec]) obtained in 28-year-old
woman who was at 18 weeks
gestation, was clinically suspected of
having appendicitis, and had
nondiagnostic US findings.
Image shows thickened retrocecal
appendix (arrow) with increased
signal intensity and minimal
infiltration of surrounding fat.
Fundus uteri is seen directly anterior
to the aorta. The diagnosis of
appendicitis was confirmed at surgery.
51. Acute appendicitis: Differentials
Common alternative conditions
• Crohn disease
• Right-sided colitis or diverticulitis
• Women: Pelvic inflammatory disease
(PID), ovarian cysts (and their
complications including rupture,
hemorrhage, and torsion)
Other alternative conditions
• Omental infarction (can present with
upper or mid right abdominal pain)
• Epiploic appendagitis
• Small bowel diverticulitis (ileal or
Meckel’s)
52. Ovarian torsion
Axial CT scan obtained after
intravenous contrast medium
administration in 24-year old woman
with right lower quadrant pain, a
clinical differential diagnosis of
gynecologic disorder (tubo-ovarian
abscess, pelvic inflammatory disease,
ovarian torsion) or appendicitis, and
inconclusive US findings shows a
normal appendix (straight arrow) and
an enlarged right ovary
(arrowheads), which most likely is
due to tubo-ovarian abscess or ovarian
torsion.
Free fluid and some thickening of
the peritoneum (curved arrows) are
also visible. Laparoscopy revealed
ovarian torsion.
53. Right-sided
diverticulitis
Axial CT images in 25-year-old
woman suspected of having
appendicitis.
At US, the appendix was not well
visualized; therefore, CT was
performed after intravenous contrast
medium administration. (a) Image
shows right-sided diverticulitis,
indicated by right-sided colon
diverticula (arrow) and fecalith
with thickened wall, wall
enhancement, and adjacent fat
infiltration (arrowheads). (b) Image
shows some secondary wall thickening
of the adjacent appendix (arrow), with
air in the lumen. Only some secondary
changes— and no appendicitis—are
seen.
54. Left lower quadrant
The ACR recommends CT as the initial imaging test for the evaluation of left
lower quadrant pain
55. ACR Appropriateness Criteria
Initial imaging of left lower quadrant (LLQ) pain
Expert Panel on Gastrointestinal Imaging:, Galgano, S. J., McNamara, M. M., Peterson, C. M., Kim, D. H., Fowler, K. J., Camacho, M. A., Cash, B. D., Chang,
K. J., Feig, B. W., Gage, K. L., Garcia, E. M., Kambadakone, A. R., Levy, A. D., Liu, P. S., Marin, D., Moreno, C., Pietryga, J. A., Smith, M. P., Weinstein, S., …
Carucci, L. R. (2019). ACR Appropriateness Criteria® Left Lower Quadrant Pain-Suspected Diverticulitis. Journal of the American College of
Radiology : JACR, 16(5S), S141–S149. https://doi.org/10.1016/j.jacr.2019.02.015
56. Acute colonic diverticulitis
• Diverticulitis is acute inflammation of an obstructed colonic diverticulum, leading
to diverticular wall ischemia and microperforation.
• Acute colonic diverticulitis is the second most common cause of acute abdominal
pain and the most common cause of left lower quadrant pain in adults.
• Diverticulitis is often diagnosed clinically without radiologic examination, but
imaging should be considered if the diagnosis is unclear or if complications (e.g.,
abscess, fistula, obstruction, perforation) are suspected.
• CT is the primary modality for diagnosis, triage, and evaluation of severity and
complications, according to guidelines of the American Society of Colorectal
Surgeons
58. Modified Hinchey Classification
Stage Characteristics
Uncomplicated diverticulitis
0 Mild clinical diverticulitis
1a Confined pericolic inflammation, no abscess
Complicated diverticulitis
1b Confined pericolic inflammation with local abscess
2 Pelvic, retroperitoneal, or distant intraperitoneal abscess
3 Generalized purulent peritonitis, no communication with bowel lumen
4 Feculent peritonitis, open communication with bowel lumen
Kaiser AM, Jiang JK, Lake JP, et al. The management of complicated diverticulitis and the role of computed tomography. Am J
Gastroenterol 2005;100:910–917.
60. Complicated
diverticulitis
Axial CT shows a large diverticulum
arising from the sigmoid colon
containing enteric contrast (yellow
arrow), with surrounding
mesenteric fat stranding. A few
adjacent locules of extraluminal gas
(red arrow) are present.
61. Acute colonic diverticulitis: Differential
Colorectal cancer
• Pericolonic lymph nodes
• Luminal mass
Diverticulitis
• Pericolonic inflammation
• Continuous (> 10 cm) segment
involvement
However, these signs are not very accurate, and cancer can be missed
Therefore, endoscopy and biopsy are often required to make this differentiation after
the clinical symptoms have resolved— often after 6 weeks.
62. Colorectal cancer
(a, b) Axial CT images obtained after
intravenous, oral, and rectal contrast
material administration in 46-year-
old man with 2-year history of
abdominal pain and recent
progressive acute abdominal pain.
He had not defecated for the past 2
days and had experienced weight loss
of 12 kg during the past year. Acute
diverticulitis was clinically suspected,
with colorectal cancer as a differential
diagnosis.
Images show (a) apple-core stenosis
(arrow) of the sigmoid colon caused by
colorectal cancer and (b) proximal
prestenotic dilatation of descending
colon and cecum (arrow).
63. Epiploic appendagitis
Epiploic appendagitis is a relatively
common, self-limiting condition, in which
an appendage of fat along the external
aspect of the colon, left side much more
common than right, undergoes torsion,
with subsequent venous thrombosis.
CT findings
• Swollen, ovoid, 1.5–3.5 cm fat-
containing focus with peripheral
thickening and associated
inflammation
• Adjacent colon is usually normal or
nearly normal.
65. Left lower quadrant pain: Differentials
• Colitis
• Bowel ischemia
• Functional colonic disorders (especially constipation and also obstruction from a
variety of other etiologies)
• Urinary tract infection (UTI)
• Gynecologic disease
66. Pseudomembranous colitis
Axial (left image) and coronal (right image) contrast-enhanced CT demonstrates diffuse bowel wall
edema and mucosal enhancement of the entire colon (accordion sign) with pericolonic stranding
and mesenteric vasculature engorgement, consistent with pseudomembranous colitis in this patient
with fever, leukocytosis, and a positive C. diff. culture.
67. Acute non-localized pain
Differential diagnosis of acute nonlocalized abdominal pain is broad.
CT is typically the imaging modality of choice if there is significant concern
for serious pathology or if the diagnosis is unclear from history, physical
examination, and laboratory testing
68. ACR Appropriateness Criteria
Initial imaging of acute non-localized abdominal pain
Chang, K., Scheirey, C., Fowler, K., Therrien, J., Kim, D., WB, A.-R., Camacho, M., Cash, B., Garcia, E., Kambadakone, A., Lambert, D., Levy, A., Marin, D.,
Moreno, C., Noto, R., Peterson, C., Smith, M., Weinstein, S., & Carucci, L. (2018). ACR Appropriateness Criteria Acute Nonlocalized Abdominal
Pain. Journal of the American College of Radiology https://doi.org/10.1016/j.jacr.2018.09.010
69. Diffuse abdominal pain: Common causes
Gastroenteritis
• CT findings often are normal
• Mild bowel wall thickening and
increased intraluminal fluid
Colitis
• Varying degrees of colonic wall
thickening/edema
• Inflammation of the adjacent fat
Any disorder that involves a large portion of the gastrointestinal tract or irritates the peritoneum
can cause diffuse abdominal pain. The most common disorder is gastroenteritis
70. Bowel obstruction
Bowel obstruction is a relatively frequent cause of acute abdominal pain.
The majority of patients found to have bowel obstruction after they present
to the ED have an small bowel obstruction (SBO).
71. Gastric obstruction
Abdominal radiograph showing a
gas‐filled dilated stomach.
There is a loop of stomach‐shaped
distended bowel in the upper
abdomen. On the right side of the
abdomen, you can see that the
duodenum is partially distended as
valvulae conniventes are seen.
The findings are suggestive of a
proximal small bowel obstruction,
possibly in the region of the distal
duodenum or proximal jejunum.
72. Small bowel obstruction (SBO)
Primary presentation
• Combination of vomiting, distended
abdomen, and increased bowel sounds is
suggestive of SBO
This has a positive predictive value of 64% *
Patient characteristics & risk factors
• Previous abdominal surgery
• Age older than 50 years
• History of constipation
* Bohner H, Yang Q, Franke C, Verreet PR, Ohmann C. Simple data from history and physical examination help to exclude bowel obstruction and to avoid
radiographic studies in patients with acute abdominal pain. Eur J Surg 1998;164:777–784.
73. Small bowel obstruction (SBO)
• For adequate treatment, it is important to identify the cause (eg, adhesion,
neoplasm, or hernia) and severity of the obstruction.
• An obstruction can be partial or complete and complicated by ischemia, especially
in the case of closed loop obstruction (strangulation).
• Radiography has long been the primary imaging modality of choice for patients
suspected of having bowel obstruction.
* 69% sensitivity and 57% specificity
• CT has the best reported accuracy for the diagnosis of SBO
* 94% sensitivity and 96% specificity
* Maglinte DD, Balthazar EJ, Kelvin FM, Megibow AJ. The role of radiology in the diagnosis of small-bowel obstruction. AJR Am J Roentgenol 1997;168:1171–
1180. 77.
* Megibow AJ. Bowel obstruction: evaluation with CT. Radiol Clin North Am 1994;32: 861–870.
74. Small bowel
obstruction (SBO)
Upright conventional abdominal
radiograph obtained in 59-year-old
man who had abdominal pain and a
distended abdomen at clinical
evaluation, as well as a history of SBO
3 years ago, for which he was treated
conservatively,
Radiography shows distended small-
bowel loops and air-fluid levels
(arrowheads), consistent with SBO.
The previous obstruction was most
likely caused by adhesions because the
patient had previously undergone
appendectomy. This patient was again
treated conservatively.
75. ACR Appropriateness Criteria: SBO
Complete or high-grade SBO
Abdominopelvic CT with intravenous
contrast medium
Low-grade or intermittent SBO
Several CT techniques appropriate:
• Abdominopelvic CT with barium or
water as the contrast agent, CT
enteroclysis
• Conventional: Follow-through,
conventional enteroclysis
76. Small bowel obstruction (SBO): CT
• Clear change in bowel diameter: Distended loops proximal to transition point &
collapsed loops distal to transition point
• Small-bowel feces sign (helpful sign for identifying the point of obstruction):
Feces-like material in the distended small bowel
• Transition point should be scrutinized for the cause of the obstruction adhesion,
neoplasm, hernia, or inflammatory disorder
• Because SBO is most often due to adhesions, which are usually not visible at CT, in
most patients, no cause will be identified at CT. In this setting, the diagnosis of SBO
due to adhesions is made by means of exclusion.
77. Small bowel
obstruction (SBO)
Sagittal reconstructed CT image in 47-
year-old woman who had a history of
lysis of adhesions and presented
with cramping pain of 2 days
duration, nausea, and vomiting
shows the transition point (arrow)
and the small-bowel feces sign
(arrowheads) proximal to the
transition point. No mass is visible,
and the diagnosis is obstruction by
adhesions. The patient was treated
conservatively with a successful
outcome.
78. Closed-loop small
bowel obstruction
62-year-old man with metastatic
colon cancer who presented with
severe abdominal pain, nausea, and
vomiting.
Transaxial contrast-enhanced CT
image shows a fluid-filled, distended
loop of small bowel in the left mid-
abdomen. Mesenteric edema and
mild wall thickening indicate bowel
ischemia. Note the two adjacent
collapsed segments of small bowel
(arrows), where the loop of small
bowel had entered an internal hernia
79. Small bowel obstruction (SBO): USG
US reportedly has good accuracy (81%) in the diagnosis of bowel obstruction *.
However the ACR states that US is the least appropriate imaging modality when high-
or low-grade SBO is suspected.
• Fluid-filled loops easily visualized
• Visualizing peristaltic movement: Differentiate between mechanical obstruction
and paralytic ileus
Gas-filled loops may obscure the underlying abnormality, which has important
treatment management–related implications. Obstruction is difficult to stage
accurately.
Overall, CT can be considered the primary imaging technique for patients suspected
of having SBO.
Schmutz GR, Benko A, Fournier L, Peron JM, Morel E, Chiche L. Small bowel obstruction: role and contribution of sonography. Eur Radiol
1997;7:1054–1058
80. Large bowel obstruction (LBO)
Common causes
• Colorectal cancer (60% cases)
• Sigmoid volvulus (10%–15% cases)
• Diverticulitis (10% cases)
Clinical features
• Abdominal pain
• Constipation
• Abdominal distention
These are not very specific and therefore,
clinical diagnosis is often incorrect.
81. Large bowel
obstruction (LBO): XR
Abdominal radiograph showing dilated
large bowel.
The large bowel is visible as there is
gas (black) within with a distension of
>5.5 cm, circumferential location and
visible haustra.
82. Large bowel obstruction (LBO): CT
• Traditionally, conventional radiography has been the initial imaging examination
performed.
• CT is the imaging modality of choice in the diagnosis of LBO. It can be used to
identify the cause of the obstruction, the level of obstruction, and the presence of a
complicated obstruction (eg, strangulation).
96% sensitivity and 93% specificity
FINDINGS:
• Dilated colon (colon diameter > 5.5 cm, cecum diameter > 10 cm)
• Colon filled with feces, gas, and fluid proximal to an abrupt transition point, after
which the colon is collapsed distally
Frager D, Rovno HD, Baer JW, Bashist B, Friedman M. Prospective evaluation of colonic obstruction with computed tomography. Abdom
Imaging 1998;23:141–146.
83. Sigmoid volvulus
Abdominal radiograph showing a
sigmoid volvulus.
There is a ‘coffee bean’–shaped loop
of distended bowel crossing the
midline and extending to the right
upper quadrant. There is a general lack
of haustra. The proximal large bowel is
somewhat distended secondary to the
obstruction from the volvulus.
84. Cecal volvulus
Abdominal radiograph showing a
caecal volvulus.
There is a rounded comma‐shaped
loop of distended large bowel in the
centre of the abdomen with haustra
seen within. The remainder of the
colon distal to the caecal volvulus
(obstruction) is collapsed.
85. Cecal volvulus
Transverse CT image (a) and coronal
CT reformation (b) demonstrate a
markedly dilated cecum (C) located in
the midline and left lower abdomen
and upper pelvis. The arrow points to
the area of colonic twisting. Note the
dilated small bowel loops, due to the
proximal colonic obstruction
86. Perforated viscus
• Because the clinical symptoms of free perforation are associated with the
underlying cause of the perforation, the clinical presentations of patients with
perforated viscus are quite variable.
• Besides the variable symptoms of the underlying mechanism, a rigid abdomen
usually is present. Recognizing a perforation and establishing the cause and site of
the perforation can yield crucial information for the surgeon.
88. Contained perforated diverticulitis
Axial CT images obtained in (a) abdominal and (b) lung window settings after intravenous contrast medium
administration in 71-year-old woman who had a 2-day history of left lower quadrant pain and was
suspected of having diverticulitis show diverticulitis of the sigmoid colon with a contained perforation
(arrow) and infiltration of pericolic fat. The patient was treated conservatively with antibiotics
Among patients who are evaluated for possible acute diverticulitis, only 1%–2% have
free perforation*
* Jacobs DO. Clinical practice: diverticulitis. N Engl J Med 2007;357:2057–2066.
89. Perforated duodenal ulcer
Axial CT images obtained after intravenous administration of contrast medium in 54-year-old woman who
presented to the ED with acute periumbilical abdominal pain that radiated to the back. The abdominal
pain started after the woman ingested a nonsteroidal anti-inflammatory drug. (a) Image obtained in lung
window setting shows free intraperitoneal air (arrow). (b) Image shows wall thickening at the duodenal
bulb and evidence of perforation (arrow), with adjacent soft-tissue infiltration and air bubbles
(arrowhead). A diagnosis of perforated duodenal ulcer was made and confirmed at surgery.
90. Bowel ischemia
Presentation
PRIMARY SYMPTOM:
• Short clinical history of prominent
abdominal pain
OTHER SYMPTOMS:
• Nausea & vomiting
• Diarrhea
• Distended abdomen
All of these symptoms are nonspecific.
A diagnosis of bowel ischemia is often made
after the more frequently occurring diagnoses
with similar associated symptoms are
excluded.
Risk factors
Bowel ischemia should be considered in the
following:
• Elderly patients with known
cardiovascular disease (eg, atrial
fibrillation)
• Younger patients with diseases that cause
inadequate mesenteric blood flow:
Vasculitis, hereditary or familial coagulation
disorders such as antiphospholipid
syndrome, and protein C or S deficiency.
91. Bowel ischemia: Biphasic CT
Arterial phase CT
• Evaluating the celiac trunk and the
mesenteric arteries
Venous phase CT
• Show occlusions of mesenteric arteries,
but it predominantly enables evaluation
of the mesenteric veins, bowel wall, and
other causes of acute abdominal pain
92. Bowel ischemia: CT
Specific CT findings
• Clear sign of mesenteric ischemia:
Occluded mesenteric arteries or venous
thrombus
• Thickened bowel wall (> 3 mm): Because
of mural edema, hemorrhage, congestion, or
superinfection. Thickening owing to edema,
congestion, or hemorrhage is a frequent
finding of venous obstruction.
• Bowel wall hypoattenuation (edema)
• Bowel wall hyperattenuation
(hemorrhage)
• Target sign: Abnormal bowel wall
enhancement
• Absence of bowel wall enhancement
(highly specific but often missed)
Other findings
• Impending perforation: Paper-thin bowel
wall
• Irreversible ischemia: Luminal dilatation
and fluid levels (fluid exudation of the
ischemic bowel segments)
93. Bowel ischemia
Multiplanar reformatted abdominal CT
images obtained in (a) soft-tissue and (b)
lung windows after intravenous
administration of contrast material in 59-
year-old woman with nausea and
vomiting who had undergone sigmoid
colon resection for a gastrointestinal
stromal tumor 5 days earlier. A
distended abdomen identified at physical
examination and an increasing C-reactive
protein level were noted.
Images show portovenous gas (straight
arrows) in the periphery of the liver and
pneumatosis (curved arrows). The bowel
wall (arrowheads) is thickened and
enhanced. On the basis of these CT
findings, bowel ischemia was considered.
However, the clinical findings were more
suggestive of bacterial translocation. The
patient responded well to treatment with
antibiotics.
Images courtesy of Ludo F.M. Beenen, MD, Academisch Medisch Centrum, Universiteit van
Amsterdam, Amsterdam, the Netherlands
94. Bowel ischemia
secondary to SMA
thrombosis
52-year-old man with 4-day history
of severe diffuse abdominal pain.
Transaxial (a, b) and sagittal curved
planar reformatted (c) contrast-
enhanced CT images demonstrate
thrombosis of the superior
mesenteric artery (large white
arrow). Note the bowel pneumatosis
(small black arrow) and gas within the
mesenteric veins (small white arrow)
indicative of bowel ischemia
95. Conclusion
The clinical findings–based diagnosis rendered in patients with acute abdominal pain
is often inaccurate. Therefore, imaging plays an important role in the treatment of
patients with acute abdominal pain.
Because US and CT are widely available, radiography is rarely indicated for the
examination of patients with acute abdominal pain, with the exception of select
patients groups
96. Reference
Books
• Adam, A., Dixon, A. K., Gillard, J. H., &
Schaefer-Prokop, C. M. (2021). Grainger &
Allison’s Diagnostic Radiology: A textbook
of medical imaging. Elsevier.
• Diseases of the Abdomen and Pelvis
2018-2021. (2018). IDKD Springer Series.
doi: 10.1007/978-3-319-75019-4
• Mandell, J. (2013). Core Radiology: A
Visual Approach to Diagnostic Imaging.
Cambridge: Cambridge University Press.
doi:10.1017/CBO9781139225762
Journals
• Stoker, J., van Randen, A., Laméris, W., &
Boermeester, M. A. (2009). Imaging
Patients with Acute Abdominal Pain.
Radiology, 253(1), 31-46.
https://doi.org/10.1148/radiol.25310903
02
• Cartwright, S. L., & Knudson, M. P. (2015).
Diagnostic imaging of acute abdominal
pain in adults. American family physician,
91(7), 452–459.
The ACR Appropriateness Criteria recommend ultrasonography as the initial imaging test for patients presenting with right upper quadrant pain
The ACR Appropriateness Criteria recommend CT as the initial imaging test of choice for patients presenting with right lower quadrant pain
A meta-analysis of six studies from 1994 to 2005 found that CT has better sensitivity and specificity (91% and 90%, respectively) than ultrasonography (78% and 83%, respectively) for detecting acute appendicitis15 (Figure 2). CT also provides more consistent results than ultrasonography,5 because ultrasonography is a highly operator-dependent technique that varies based on the skill and experience level of the technologist and radiologist.
Perforation of a peptic ulcer is now less frequent because of the availability of adequate medical therapy for peptic ulcer disease.