surgical diagnostic technique

1. Surgical diagnostic
process &techniques
Dr. Md. Nazmus Sakib
Junior Consultant
Sakibs23@gmail.com

2. • Appropriate surgical management of the patient relies
on correct surgical diagnosis.
• Besides clinical symptoms and signs, there are some
condition which needs supplementary investigation
for confirmation of the diagnosis.

3. Some basic principles
• Choice of investigation depends on equipment availability,
expertise, cost as well as clinical presentation.
• Simplest and cheapest investigations should be chosen
first.
• Keep in mind about the diagnostic hazards, potential
complications and limitation of the techniques
• If any uncertainty go for multidisciplinary team meeting.

4. Purpose of investigation
• For confirmation of diagnosis
• To exclude the differentials
• To assess the exact extent of diseases (staging)
• For treatment purpose (fitness for anesthesia)
• Detection of recurrence of the disease
• Follow-up purpose

5. Investigations
Basic biochemical &
haematological
Imaging
Advanced
Genetic analysis
Tissue & molecular
diagnosis

6. Tissue and molecular diagnosis
Tissue diagnosis could be done from
• FNA
• Biopsy
• Sputum
• Body fluid
• Washing, brushing and scrape material

7. FNA, Biopsy, wedge biopsy, core
biopsy-all these are technique of
taking tissue for histological
examination

8. • In FNA 23G or 25G needle is used.
• In core biopsy 11G or 13G needle is used.
• Wedge biopsy: Triangular area of tissue from both
healthy and unhealthy area.

9. Reasons for analysis of tissue
 Diagnosis
● Confirmation/rejection of a clinical diagnosis
● Additional diagnoses
● Classification of neoplasia
● Classification of non-neoplastic disease
 Staging of malignancy
 Prognosis

10.  Management
● Selection of therapy
● Assessment of response to treatment
 Cancer screening programmes and related programmes
● Cervical, bowel, breast, infammatory bowel disease,
Barrett’s oesophagus
 Clinical trial support
 Audit

11. Is it possible that FNAC is positive without
malignancy???
False positive for malignancy
• Interchanged samples
• Contamination
• Interpretative error
• Treatment-induced change, e.g. Radiotherapy
• Ulceration

12. FNAC may be negative in the presence of
malignancy
• Failure or inability to obtain representative tissue
from the intended area
• Scanty sample
• Non viable tissue
• Improper staining
• Blood tap

13. Which one is better???
FNAC vs Core
Biopsy

14. Frozen section technique
Inform department of pathology prior to surgery
Fresh representative part of tissue send to Pathology
Department from OT
Patient remain under anaesthesia
In Pathology dept this tissue is freezed at -40°C
Sectioned for microscopic examination

15. After staining microscopic examination is done
Report is prepared
Report is sent over telephone to OT

16. Frozen section
Advantages
 Quick diagnosis
Disadvantages
 Poorer quality sections
 Potential reduction in accuracy and
precision of histological diagnosis
 Labour intensive
 Disruptive
 Risk of infection
 Small sample required
 Some tissue types difficult to
process

17. Imaging
Non-invasive
 Ultrasound scanning (USS)
 Magnetic resonance imaging (MRI)
Invasive
 X ray
 Computed tomography scan (CT scan)
 Radio scintigraphy

18. Others
• Endoscopy, colonoscopy
• Capsule endoscopy
• Chromo endoscopy
• Hybrid method –
 Endoscopic Retrograde Cholangio
Pancreatography (ERCP)
Endoscopic ultrasound(EUS)
Image guided FNAC

19. Last but no the least
Diagnostic laparotomy
or
Diagnostic laparocopy

20. Ultrasound

22. It relies on high-frequency sound waves generated by a
transducer containing piezoelectric material. The
generated sound waves are reflected by tissue interfaces
and, by ascertaining the time taken for a pulse to return
and the magnitude and direction of a pulse, it is possible
to form an image. Medical ultrasound uses frequencies
in the range 3–20 MHz. The higher the frequency of the
ultrasound wave, the greater the resolution of the
image, but the less depth of view from the skin.

23. Some modification of USG
• Doppler study
• Echocardiogram
• Endo USG

25. • Focused Abdominal Sonogram for Trauma patient
(FAST)
• Extended Focused Abdominal Sonogram for Trauma
patient (eFAST)

27. Wilhelm Conrad Roentgen was a German mechanical engineer
and physicist, who on 8th November, 1895 produced and detected
electromagnetic radiation in a wavelength range known as X ray,
an achievement that earned him inaugural Nobel Prize in 1901.

28. Basic Mechanism of X ray
X ray emitted from an x ray source are absorbed to
varying degree by different materials and tissues and
therefore causes different degree of blackening on
radiographic film. In general higher density tissue
results in greater reduction in the number of X ray
photon and reduces the amount of blackening.

30. Manipulation of X ray system
• Mammography
• Contrast X ray
Intra venous contrast- Intravenous Urography
Oral contrast- Barium meal x ray

31. Advantage
 Cheap
 Universally available
 Easily reproducible
 Comparable with prior examination
 Relatively low dose ionising radiation
Disadvantages
 Lack of soft tissue evaluation

32. In case of Acute Abdomen plain X ray
abdomen is the most important & frequently
used imaging in our clinical practice.

34. Computed tomography
• CT scanners consist of a gantry containing the x-ray
tube, filters and detectors, which revolve around the
patient, acquiring information at different angles and
projections. This information is then mathematically
reconstructed to produce a two-dimensional grey-
scale image of a slice through the body. This
technique overcomes the problem of superimposition
of different structures.

36. It is possible to produce reconstructed image by
CT scanner

37. Strengths
• High spatial and contrast resolution
• Contrast resolution enhanced by ability to image in
multiple phases, including arterial, venous and delayed
• Rapid acquisition of images in one breath-hold
• Imaging of choice for the detection of pulmonary
masses
• Allows global assessment of the abdomen and pelvis

38. • Excellent for liver, pancreatic, renal and bowel pathology
• Three-dimensional reconstruction allows complex fracture
imaging
• Multiplanar reconstruction and three-dimensional imaging,
e.g. CT angiography and colonoscopy
• Ability to guide intervention such as percutaneous biopsy
and drainage

39. Weaknesses
• High radiation dose
• Poor soft-tissue resolution of the peripheries and
superficial structures
• Patient needs to be able to lie fat and still
• Less readily available than plain films and ultrasound

40. Magnetic Resonance Imaging
• MRI relies on the fact that nuclei containing an odd
number of protons have a characteristic motion in a
magnetic field (precession) and produce a magnetic
moment as a result of this motion. In a strong uniform
magnetic field such as an MRI scanner, these nuclei
align themselves with the main magnetic field and
result in a net magnetic moment. A brief radiofrequency
pulse is then applied to alter the motion of the nuclei.

41. • Once the radiofrequency pulse is removed, the nuclei
realign themselves with the main magnetic field
(relaxation) and in the process emit a radiofrequency
signal that can be recorded, spatially encoded and used to
construct a grey-scale image. The specific tissue
characteristics define the manner and rate at which the
nuclei relax. This relaxation is measured in two ways,
referred to as the T1 and T2 relaxation times. The
relaxation times and the proton density determine the
signal from a specific tissue.

43. Uses
• Staging
• MRCP
• R angiography
• Breast malignancy
• Pelvic malignancy
• Cardiac imaging
• MR enterography
• Diffusion-weighted imaging

44. MRI of spine

45. Strengths
• No ionising radiation
• Excellent soft-tissue contrast
• Best imaging technique for
• Intracranial lesions
• Spine, Bone marrow and joint lesions

46. Absolute contraindications
• Ocular metallic foreign bodies
• Cochlear implants
• Cranial aneurysm clips
Relative contraindications
• Pacemakers
• First trimester of pregnancy
• Claustrophobia

47. Radiation Hazard

48. Ultra Sonogram Hypo-echoic
Hyper-echoic
X-ray Radio-opaque
Radio lucent
CT scan Hypo dense
Hyper dense
Iso-dense
MRI Hypo intense
Hyper intense