Imaging techniques play a crucial role in the diagnosis, preparation, and follow-up of surgical patients, utilizing methods such as X-rays, fluoroscopy, ultrasound, CT, MRI, and radionuclide scans. Each method has its advantages and limitations, with X-rays being cost-effective but using ionizing radiation, while MRI offers detailed imaging without radiation. The application of these imaging modalities is essential in various surgical conditions including acute abdomen, trauma, and tumor assessment.

1. Imaging in Surgery

2. Introduction
-Imaging is a veritable tool in surgical patients.
-Radiological investigations remain vital to the diagnosis, preparation and follow
up of patients .

3. Uses
# To aid in diagnosis of a surgical disorder
# To guide a surgical procedure
# Monitoring
# Interventional radiological techniques

4. Imaging Techniques
X rays
Fluoroscopy
Ultrasound
CT
MRI
Nuclear medicine

5. Radiography
- Oldest and commonest imaging technique
- Uses ionising radiations
- Parts : X ray tube , collimator, table , film
- Principle : X-rays emitted from an X-ray source are absorbed to varying
degrees by different materials and tissues and therefore causes different
degree of darkening of radiographic films , resulting in an image

7. Advantages
- cheap
- Available
- Short developing time
- Good for assessing bone

8. Disadvantages
- ionising radiation
- Poor soft tissue contrast

10. Fluroscopy
- uses X-rays like in conventional radiographs. However, a fluorescent
screen,image intensifier and a video converter is used
- Allows for real time imaging
- Higher dose of radiation
- Extensive use in functional studies , interventional radiology and imagine
guidance

12. Ultrasound
- Second most common method of imaging
- Relies on high frequency sound waves generated by a transducer containing
piezoelectric material
- Principle : Generated sound waves are reflected by tissue interfaces and by
ascertaining the direction and time taken for a pulse to return it is possible to
form an image

16. CT scan
- Method of cross sectional imaging
- CT uses a computer to create an image from an integration of multiple X-rays
exposures taken in a circle round the patient
- Heavy ionising radiation dose
- Parts : Gantry, X-ray source,detectors table

19. MRI
- Newest of the imaging techniques
- Does not use ionising radiation
- Parts : magnet , radio frequency coil , table
- Principle : Body tissues consist of protons and electrons. In a strong uniform
magnetic field such as a MRI scanner , these nuclei align themselves with the
main magnetic field.A brief radio frequency pulse is applied to alter the motion
of nuclei. When removed , the nuclei realign with the main magnetic
field,emitting energy.

20. T1- fat, methemoglobin, mucinous
fluid appear white.
Important for delineating anatomy
T2- fat, water and most
pathological fluid appear white.
Highlights pathology better

24. Radionuclide scan
- A radioactive element (radionuclide) is administered as a radio
pharmaceutical agent and a detector ( gamma camera ) is used to record and
localise the emission ( gamma ray ) and thus form an image
- Agents : technetium,gallium,thallium,iodine
- These are usually labelled for organ specificity

25. PET scan
- An extension of radionuclide studies
- Same principle but uses substances that emit positron and not gamma rays
- Agent : 18F-2Fluoro-2deoxy-D glucose ( FDG)

28. Others
- CONTRAST STUDIES
- * positive , negative and combine
- * Radiocontrast
- * MRI contrast
- * USS contrast
- SPECT

29. Application in surgery
- Acute abdomen : Bowel obstruction, perforation , ischemia , GIT
haemorrhage , inflammatory lesions.
Modalities:- Chest X-ray , abdominal X-ray , USS , CT scan , MRI
- Trauma : USS , CT , MRI
- Masses : USS , Contrast studies , CT , MRI

30. THANK YOU