Principles of Radiology, Viva Voce Examination Notes, Question And Answers

Principles of Radiology, Imaging, Viva Voce Examination

Principles of Radiology, Imaging, Viva Voce Examination Introduction

One of the sessions in the undergraduate and postgraduate examinations is questions on plain X-rays and images.

More and more images such as ultrasound, CT scan, MRI, and PET scan, ethave been used in the evaluation of patients.

Read And Learn More: Surgery of Urology Notes

These investigations are done to achieve evidence-based science and surgery. Several CT images have been included in the book.

Students are requested to study the principles behind these investigations so as to understand the investigations properly.

This is only an exercise for you to perform better in the final examination.

Plain X-Rays

When a plain X-ray is projected look carefully and identify the side—right or left. To give an example, if fundic air bubble is seen and cardiac shadow is seen it is on the left side. Similarly, because of the liver, diaphragm on the right side is usually elevated compared to the left side.

• Look at the bony cage—clavicle, ribs, sternum, vertebrae.
• Chest X-ray is taken always PA view so as to avoid sternal shadow.
• Then look at the soft tissue shadows—in the lungs, oesophageal shadow, cardiac shadow for any cardiomegaly and aortic shadow for any prominence
• A Few examples are given below which are commonly asked questions.

Plain X-Ray Chest PA View Showing Collection Of Free Gas Under The Right Dome Of The Diaphragm

• Normally, fundic air bubble is present on the left side.
• Hence, importance is given to the gas on the right side.

Question 1. What are the causes of free gas under the right dome of the diaphragm?
Answer:

• Perforation of hollow viscus. Examples Duodenal ulcer, gastric ulcer, enteric ulcer, Meckel’s diverticulum, Malignant ulcers—colonic, gastric, perforation of the tuberculous ulcer—ileum
• Abdominal stab injury, laparotomy
• Tubal insufflation test done for tubal patency—not done nowadays

Question 2. Is there any other finding in the X-ray?
Answer: Ground glass appearance indicates significant fluid in the peritoneal cavity.

Question 3. How do you manage a case of perforated duodenal ulcer?
Answer:

• With antibiotic coverage, Ryle’s tube aspiration and early resuscitation with intravenous fluids, exploratory laparotomy is done. The site of perforation is identified which is in the first part of the duodenum. The perforation is closed by using nonabsorbable sutures. Omentum can be used to reinforce the suture line. This is called Roscoe Graham operation. Tube drain is used to drain peritoneal cavity.

Question 4. Will you do elective surgery such as GJ and vagotomy or HSV at this stage?
Answer: Since the general condition of the patient will be very poor at this acute stage because of hypovolaemic and septic shock, elective surgery is not done.

Question 5. What are the stages of duodenal ulcer perforation?
Answer:

• Stage of chemical peritonitis
• Stage of illusion or delusion
• Stage of bacterial peritonitis

Plain X-Ray Abdomen Showing Multiple Gas And Fluid Levels

Question 1. What is the diagnosis?
Answer: Since jejunal loops are prominently seen and loops are centrally located, it is probably terminal ileal obstruction.

Question 2. What are the common causes of terminal ileal obstruction?
Answer:

• Tuberculous stricture
• Bands—congenital
• Adhesions
• ‘Worm ball’ in children
• Obstructed hernia

Question 3. How do you identify jejunum, ileum and colon in a plain X-ray?
Answer:

• Jejunum—valvulae conniventes—regularly placed mucosal folds placed opposite to each other.
• Ileum—no character—characterless loop of Wangensteen.
• Colon—haustrations—a large incomplete mucosal folds not placed opposite to each other.

Question 4. How do you treat tuberculous strictures?
Answer: Resection and end-to-end anastomosis.

Question 5. Can any other surgical procedure be done?
Answer: Stricturoplasty (like pyloroplasty), if there is a single stricture.

Plain X-Ray Abdomen Showing Radio-Opaque Shadow In The Right Upper Abdomen

Question 1. What is the diagnosis?
Answer: Probably renal stone

Question 2. Why is it not a gallstone?
Answer:

• The location of the stone is at lower level when compared to gallstone.
• The shape of the stone suggests that it is a stone in the pelvis growing within calyces.

Question 3. What do you call such a stone?
Answer: Staghorn calculus

Question 4. What type of X-ray is ideal to distinguish renal stone from gallbladder stone?
Answer: Lateral view

Question 5. What will be the findings in case of renal stones in a lateral picture?
Answer: Renal stones are found superimposed on vertebral bodies. On the other hand, gallstones are found anterior to it.

Plain X-Ray Abdomen Showing Radio-Opaque Shadow In The Region Of Gallbladder

Question 1. What is the diagnosis?
Answer: It is gallstone because in the lateral picture it is in front of vertebral column

Question 2. What percentage of gallstones are visible in a plain X-ray?
Answer: Only 10%

Question 3. What is the reason for that?
Answer: The calcium content in gallstones is very less.

Question 4. What are the causes of radio-opaque shadow in the abdomen?
Answer:

• Gallstones
• Renal stones
• Pancreatic stones
• Renal tuberculosis
• ‘Chip’ fracture of the transverse process of the vertebrae
• Calcified lymph nodes—tuberculosis
• Faecoliths
• Phleboliths

Question 5. What is the treatment of symptomatic gallstones?
Answer: Cholecystectomy

X-Ray Chest Pa View Showing Multiple Round Shadow In Both Lung Fields

Question 1. What is the diagnosis?
Answer: Bilateral chest secondaries

Question 2. What are they called?
Answer: Cannonball secondaries

Question 3. Why are secondaries in the lung round?
Answer: The lung is an elastic tissue, it has resilience. Hence, during the act of inspiration and expiration, equal amount of pressure is exerted on secondaries, which are growing. Hence, they tend to become round.

Question 4. What are the common causes of chest secondaries?
Answer:

• Carcinoma breast
• Carcinoma testis
• Malignant melanoma
• Hepatoma
• Renal cell carcinoma
• Sarcoma

Question 5. Is there any other differential diagnosis?
Answer:

• Miliary tuberculosis: The shadows will be very small and numerous.

X-Ray Cervical Vertebrae With Upper Ribs Showing Bilateral Cervical Ribs

Question 1. What is a cervical rib?
Answer: It is an extra rib arising from 7th cervical vertebra.

Question 2. What are 4 types of cervical rib?
Answer:

• Incomplete bony
• Complete bony with anterior expanded bony end.
• Partly fibrous, partly bony
• Complete fibrous band

Question 3. What variety gives rise to vascular symptoms?
Answer: The fibrous band variety

Question 4. What is your finding here?
Answer: On the right side, it is complete variety and on the left side, it is incomplete.

Question 5. If the cervical rib is symptomatic, what is the treatment?
Answer: Extraperiosteal excision of the cervical rib which means removal of the rib along with the periosteum. Some surgeons also do cervical sympathectomy to decrease the vasomotor tone of vessels.

X-Ray Lateral View Of The Skull Showing A Large Swelling With Erosion In The Pericranium

Question 1. What is the diagnosis?
Answer: Secondary deposit in the skull

Question 2. Why is it not a lipoma or neurofibroma?
Answer: Erosion of the bone is seen in malignancy, not in benign tumours.

Question 3. If this patient is a female aged 40 years, what are the causes?
Answer:

• Follicular carcinoma thyroid
• Carcinoma of the breast
• Renal cell carcinoma

Question 4. What is the treatment if this is follicular carcinoma thyroid?
Answer: Near total/total thyroidectomy followed by radioiodine therapy and external radiotherapy for metastasis in bones.

Question 5. How do you diagnose follicular carcinoma thyroid histologically?
Answer: Angioinvasion and capsular invasion (lobectomy– total thyroidectomy).

Plain X-Ray Abdomen Showing Extensive Calcification In The Region Of Pancreas

Question 1. What is the diagnosis?
Answer: Chronic pancreatitis

Question 2. Why do you say so?
Answer: Extensive calcification involving head, body and tail of pancreas.

Question 3. What other investigation can be done here, which is used for therapeutic purpose?
Answer: ERCP-stent can be placed-one of the methods of treatment of chronic pancreatitis.

Question 4. What are the manifestations of chronic pancreatitis?
Answer: Severe abdominal pain, diabetes, steatorrhoea, multiple strictures.

Question 5. If pancreatic duct is dilated more than 8 mm in a patient with severe abdominal pain with chronic pancreatitis, what is the treatment?
Answer: Longitudinal pancreaticojejunostomy—Puestow’s operation. In this operation, pancreatic duct is laid open, strictures are divided, and the duct is anastomosed to jejunum.

Barium Studies

• This is the study of the gastrointestinal tract by instillation/ingestion of barium suspension made up of/made from pure barium sulphate.

Barium Swallow

• It is the contrast study from the oral cavity up to the fundus of the stomach.

Barium Studies Indications:

• Dysphagia and obstruction, odynophagia, assessment of mediastinal masses, motility disorders of the oesophagus—achalasia, scleroderma

Relative Contraindications:

• Tracheo-oesophageal fistula, perforation.

Barium Studies Procedure:

• One mouthful of contrast media is given and the act of deglutition is observed fluoroscopically. After a mouthful of barium, films are exposed to the region of interest.

Interpretation of Study:

• Malignant obstructions are seen as annular constrictions, shouldering cranial and caudal to the lesion, mucosal destruction, ulceration and fistulae formation.
• Benign strictures are long segment narrowings with no mucosal abnormalities.
• Achalasia cardia is evident as ‘rat tail’ appearance of the lower end of the oesophagus, with gross dilatation of the oesophagus proximally and thin streaks of contrast entering the stomach.
• Scleroderma shows dilatation, atonicity, poor or absent peristalsis and free gastro-oesophageal reflux.

Barium Swallow Showing Intrinsic, Irregular, And Persistent Filling Defect In The Lower Oesophagus

Question 1. What is the diagnosis?
Answer: Carcinoma lower one-third of the oesophagus.

Question 2. What are the other findings?
Answer: Proximal shouldering is very characteristic of malignancy.

Question 3. How do you confirm the diagnosis?
Answer: Oesophagoscopy and biopsy

Question 4. If the biopsy report is adenocarcinoma, what is the treatment?
Answer:

• Operable—oesophagogastrectomy
• Inoperable—to relieve Dysphagia, Self Expandable Metallic stents (SEMS) can be introduced, and surgery can be avoid

Question 5. What are the premalignant conditions?
Answer:

• Achalasia cardia
• Reflux oesophagitis
• Corrosive stricture
• Plummer-Vinson syndrome

Barium Swallow Showing Extensive And Irregular Filling Defect Involving Middle One-Third Of Oesophagus

Question 1. What is the diagnosis?
Answer: Carcinoma middle one-third of the oesophagus

Question 2. How do you confirm the diagnosis?
Answer: Oesophagoscopy and biopsy

Question 3. What will be the biopsy report?
Answer: Squamous cell carcinoma

Question 4. What other investigations are necessary in such a case?
Answer: Bronchoscopy, CT scan of the chest and endosonography are important investigations.

Question 5. Looking at this advanced lesion, what is probably the best treatment for this patient?
Answer: Chemotherapy and radiotherapy followed by dilatation of the oesophagus, since chances of fibrosis and narrowing of the lumen following radiotherapy are high.

Barium Meal

This is the radiological study of the oesophagus, stomach, duodenum and proximal jejunum.

Barium Studies Indications:

• Symptoms of vomiting, epigastric pain, heart burn, dyspepsia
• Upper abdominal mass
• Gastrointestinal haemorrhage
• Gastric or duodenal obstruction
• Malignancies

Barium Studies Contraindications:

• Suspected perforation
• Suspicion of aspiration
• Large bowel obstruction

Barium Studies Procedure:

An undiluted barium suspension is given and deglutition is seen under fluoroscopy. Once barium reaches the stomach, the patient is rotated so as to coat the entire stomach and filming is done. More barium is given to distend the stomach wall. Filming is done as contrast enters the duodenum and opacifies the proximal jejunum.

Interpretation of Study:

1. A hiatus hernia is evident as the presence of the stomach above the oesophageal hiatus. In addition, gastroesophageal reflux will be evident. Mucosal ulceration and strictures may be demonstrable in long-standing cases.
2. Gastric and duodenal ulcers appear as projections from the normal contour with pooling of contrast. Benign ulcers usually project out and have the mucosal folds radiating up to the edge of the ulcer. Deformity of the stomach and duodenal cap are seen in chronic stages.
3. Bezoars of stomach are seen as radiolucent masses in the stomach and the barium fills the crevices between the particles forming a characteristic appearance.
4. Infantile hypertrophic pyloric stenosis: Thin streak of barium is seen extending across the pylorus— indentation of barium-filled antrum is seen.
5. Persistent, irregular filling defect is seen in carcinoma of the stomach.

Barium Meal Contrast Opacified Stomach Demonstrating A Projection From Lesser Curvature

Question 1. What is the diagnosis?
Answer: Benign gastric ulcer

Question 2. What is the finding called?
Answer: Niche

Question 3. Will you do a biopsy?
Answer: Yes because 1–2% of gastric ulcers can turn into malignancy

Question 4. What is the treatment of benign gastric ulcer?
Answer: Avoid irritants such as smoking, spicy food, alcohol and drugs such as non-steroidal anti-inflammatory drugs.

Question 5. Mention complications of gastric ulcer.
Answer: Bleeding, teapot deformity, hourglass contracture, perforation and carcinoma.

Barium Meal Showing Intrinsic, Irregular, And Persistent Filling Defect Involving Pyloric Antrum

Question 1. What is the diagnosis?
Answer: Carcinoma pyloric antrum

Question 2. How do you confirm the diagnosis?
Answer: Gastroscopic biopsy

Question 3. What will be the biopsy report?
Answer: Adenocarcinoma

Question 4. What is the treatment, if it is operable?
Answer: Subtotal gastrectomy

Question 5. What structures are removed in the operation?
Answer: Growth along with 60–70% of distal stomach, omentum, removal of primary of group of lymph nodes along the lesser and greater curvature, and in the vicinity of major blood vessels followed by gastrojejunal anastomosis—D2 gastrectomy.

Barium Meal X-Ray Showing Enormous Dilatation Of The Stomach And Failure Of Barium To Fill Into The Distal Intestine

Question 1. What is the diagnosis?
Answer: Gastric outlet obstruction due to chronic cicatrized duodenal ulcer (pyloric stenosis is an old terminology).

Question 2. Why is it not due to carcinoma pyloric antrum?
Answer: There is no filling defect in the pyloric antrum.

Question 3. How do you treat this case?
Answer: With a preoperative stomach wash, adequate intravenous fluids, total truncal vagotomy with GJ is the treatment of choice.

Question 4. Why GJ and vagotomy?
Answer: After vagotomy, motility of the stomach is lost and in pyloric stenosis, there is already obstruction at the pyloric antrum. Hence, gastrojejunostomy is the drainage procedure of choice.

Question 5. Why not pyloroplasty or highly selective vagotomy?
Answer: Pylorus is scarred and deformeHence, it is not safe to do pyloroplasty. HSV is contraindicated in the presence of pyloric obstruction.

Small Bowel Enema Or Enteroclysis

This is the radiological study of the small bowel (from the jejunum to the ileocecal junction) by intubation of the jejunum and instillation of contrast media through the tube. This investigation has replaced barium meal follow-through.

Barium Studies Procedure:

• The Bilbao Dotter tube is inserted with the guide wire through one of the nostrils and advanced caudally with the swallowing action till the tip reaches the stomach. The tube is then advanced through the antrum of the stomach to the pyloric canal. Then it is advanced under fluoroscopic guidance to about 4–5 cm distal to the Treitz ligament (duodenojejunal junction).
• 200 ml barium suspension is injected at a rate of 75 ml/min followed by 5% of methylcellulose at a rate of 100 ml/min. The head of the barium column is followed with intermittent fluoroscopy and films exposed wherever necessary.
• Ileocaecal spot films are taken when the junction is opacified and distended.

Interpretation of Study:

1. Normal small bowel shows a decrease in calibre from jejunum to ileum and the change of prominent valvulae conniventes to featureless ileum is evident.
2. Malignancies and lymphomas show evidence of strictures, proximal dilatations and mucosal abnormality. Large mesenteric nodal masses displace the bowel loops.
3. Strictures and ulceration of terminal ileum: Dilatation of the segment proximal to the narrowed segment and conical shrunken caecum are seen in ileocaecal tuberculosis. In later stages, ileal strictures, fistulae, may be seen.

Barium Studies Complications:

Perforation, inspissation of barium, transient bacteraemia.

One example of small bowel enteroclysis or small bowel enema:

Small Bowel Enema Showing Stricture Terminal Ileum

Question 1. What is the diagnosis?
Answer: Most probably intestinal tuberculosis.

Question 2. What are the nature of the strictures in tuberculosis?
Answer: Transverse

Question 3. How do you confirm the diagnosis?
Answer: CT enterography can be done. Later balloon enteroscopy is done and biopsy can be taken.

Question 4. What is the treatment?
Answer: Single stricture can be treated by stricturoplasty and multiple strictures are treated by resection anastomosis.

Question 5. What are the complications of tubercular stricture?
Answer: Intestinal obstruction, perforation peritonitis.

Barium Enema

This is the radiographic study of the large bowel by administration of contrast media through the rectum

Barium Studies Types:

Single contrast barium enema and double contrast barium enema.

Barium Studies Indications:

Change in bowel habit, melaena, mass suspected to be arising from colon.

Barium Studies Contraindications:

Toxic megacolon, pseudomembranous colitis, rectal biopsy done recently (procedure withheld for 7 days).

Barium Studies Procedure:

• The bowel is prepared with low residue diet, purgation and cleansing water enemHigh density barium suspension is allowed to flow up to the ileocaecal junction and reflux into the terminal ileum. Single contrast filming is done. The patient is asked to evacuate the barium and a post-evacuation film is taken. Once barium is evacuated properly, air insufflation is carried out so as to distend colon up to the ileocaecal junction.
• Filming is done to demonstrate the double contrast of large bowel with additional spots of hepatic, splenic flexures and rectosigmoid junction in oblique positions so as to open up these regions.

Interpretation of Study A few examples are:

1. Ulcerative colitis:
   1. Loss of haustral pattern, fine granularity of mucosa
   2. Strictures, pipe stem colon, increase in presacral space
2. Malignant lesions:
   1. Circumferential/eccentric growth narrowing the lumen
   2. Hold up of barium proximal to the lesion, mucosal abnormality—ulcerations
3.  Tuberculosis: Ileocaecal region is the commonest site. Deformed, elevated caecum, stricture and ulceration involving ascending colon and ileum.
4. Crohn’s disease: Multiple ulcerations, thickening and distortion of valvulae conniventes, short or long strictures, cobblestone pattern and separation of bowel loops are the
5. Malabsorption: Dilution of barium, segmentation of the column of barium, ‘Moulage sign’ (barium in a featureless tube) and jejunal dilatation are the findings

Barium Enema Showing The Left Colon Transverse Colon And A Part Of Ascending Colon

Question 1. What is the diagnosis?
Answer: Ileocolic intussusception

Question 2. Why do you say so?
Answer: The ‘claw-like ending or pincer ending is typical of intussusception.

Question 3. What are the causes of intussusception in adults?
Answer:

• Submucous lipoma, or polyps
• Meckel’s diverticulum
• Growth in the caecum
• Leiomyoma of the ileum

Question 4. In a child, what are the causes?
Answer: Weaning of the diet or viral infection.

Question 5. What is the treatment of adult intussusception?
Answer: Resection because there is a precipitating cause.

Barium Enema Showing Intrinsic Irregular And Persistent Filling Defect In The Ascending Colon

Question 1. What is the diagnosis?
Answer: Carcinoma ascending colon

Question 2. What is the confirmatory investigation?
Answer: Colonoscopy and biopsy

Question 3. What is the report, if it is carcinoma?
Answer: Adenocarcinoma

Question 4. What is the treatment?
Answer: Right radical hemicolectomy, if it is operable. Structures removed in this operation include terminal ileum (6–8 cm), caecum including appendix, ascending colon and 1/3rd of right transverse colon. If it is inoperable, part of ileum is anastomosed to the transverse colon to prevent or relieve intestinal obstruction (side to side). One need not remove two feet of ileum.

Question 5. What is the differential diagnosis?
Answer:

1. Ileocaecal tuberculosis: In this condition:
   1. The irregular filling defect is not seen.
   2. The caecum is usually pulled up and then ileocaecal angle becomes obtuse.

Barium Enema Showing Loss Of Haustrations In The Left Colon, Small And Multiple, Regular Filling Defects Due To Pseudopolyposis

Question 1. What is the diagnosis?
Answer: Ulcerative colitis.

Question 2. What is pseudopolyposis?
Answer: An attempt at healing in between the ulcers produces granulation tissues which have the appearance of polyps. Hence, pseudopolyposis.

Question 3. What are the dangerous complications of ulcerative colitis?
Answer: Haemorrhage, toxic megacolon, perforation and malignancy.

Question 4. What are the drugs used in the treatment of ulcerative colitis?
Answer: Salazopyrines and corticosteroids

Question 5. What are the surgical treatments?
Answer:

• Total colectomy with permanent ileostomy. OR
• Total colectomy, the creation of a pouch with anastomosis of the pouch to the anal canal.

Barium Enema Showing Pulled-Up Caecum

Question 1. What is the diagnosis?
Answer: Ileocaecal tuberculosis

Question 2. Why caecum is pulled up?
Answer: Involved caecum and ascending colon are contracted and fibrosed resulting in caecum in a higher position.

Question 3. What are the other signs you will look for in this case?
Answer: Narrowing of terminal ileum (Fleischner’s sign), fibrotic terminal ileum opening into the contracted caecum (Stierlin’s sign).

Question 4. What about ileocaecal angle?
Answer: Normal angle is acute. In this case, it becomes obtuse.

Question 5. What are the surgical treatments?
Answer: If obstruction is present, better to do limited colectomy followed by anti-tuberculous treatment.

Angiography

Angiography Definition:

This is the study of blood vessels by injection of a contrast medium containing iodine into the vessel. For lower limbs, femoral artery is selected because it is superficial and easily palpable. It is punctured under local anaesthesiToday majority of the cases undergoCT angiogram. In CT angiogram, iodine-based contrast is injected through the intravenous line, thus avoiding a direct puncture of artery, thus avoiding complications such as pseudoaneurysm formation, bleeding, etc.

Investigation is designed to increase the absorption of X-ray photons and thereby enhancing the image contrast of blood vessels and well-perfused tissues.

Angiography Indications:

1. Primary vascular diseases such as vaso-occlusive disease, aneurysm, arteriovenous malformation (AVM).
2. Vascularity assessment of a tumour.
3. Congenital vascular conditions such as coarctation.
4. Percutaneous interventional vascular procedures.

Angiography Contraindications:

1. Bleeding tendencies
2. Skin infections at site of entry
3. Cardiovascular disease such as recent myocardial infarction, overt congestive cardiac failure.
4. Hepatic failure

Angiography Procedure:

• Local anaesthesia at site of puncture is preferred except in children or restless patients, wherein general anaesthesia is preferreUsing a Seldinger needle the artery is punctured.
• The catheter of appropriate dimension is placed into the artery and negotiated into the desired vessel to be studie

Puncture Sites:

The femoral artery, axillary artery and brachial artery.

Interpretation of Study:

1. Aneurysms are seen as focal dilatations of vessel or projecting from the main vessel through a neck.
2. Tumour vessels show abnormal branching pattern, vascular encasement, displacement, arteriovenous shunting and pooling of contrast in the lesion.
3. AVM shows evidence of a dilated feeding artery/ abnormal blush and early draining vein.
4. Vascular occlusions are seen as abrupt or gradual tapering of vessel with collateral supply distally.

Angiography Complications:

• Damage to arterial walls at the site of puncture
• Severe hypotensive reactions
• Thrombosis of arteries, catheter clot embolus, haematoma at puncture site
• Vagal inhibition
• Allergic reactions to contrast
• Damage to nerves and to organs

Retrograde Angiography Showing Occlusion Of Femoral Artery On The Left Side

Question 1. What is the technique employed in this angiography?
Answer: Seldinger’s technique—percutaneous, transfemoral, retrograde.

Question 2. What is the probable cause in our country?
Answer: Buerger’s disease (thromboangiitis obliterans).

Question 3. Why do you say so?
Answer: Buerger’s disease affects medium-sized vessels and narrowing of femoral artery is segmental in this radiograph.

Question 4. What is the surgical treatment for Buerger’s disease?
Answer: Lumbar sympathectomy

Question 5. How does lumbar sympathectomy help these patients?
Answer: By reducing the sympathetic tone of the lower limb, arterioles and capillaries get dilated allowing cutaneous ulcers to heal.

Question 6. If patient is 65 years old, what diagnosis you would have considered? What is the treatment in such cases?
Answer: Atherosclerosis. Femoropopliteal bypass.

CT Angiogram Showing Femoral Artery And Its Branches

Question 1. What is the technique employed in this angiography?
Answer: It is CT angiogram.

Question 2. What is the indication?
Answer: Patient with severe claudication with or without ulcers as in atherosclerotic disease.

Question 3. What are the findings?
Answer: In the first film, superficial femoral artery is narrowed and in the second picture, you can see dye flowing freely after dilatation—angioplasty. It is done by a balloon dilatation using 6 or 7 mm and stent of the same size is useStents used are nitinol stents.

Question 4. How angioplasty is done?
Answer: Under local anaesthesia, thin catheter is advanced into the femoral artery and with help of balloon it is dilated followed by a small stent is placed.

Question 5. What is the usual site of obstruction of femoral artery?
Answer: It is in the hiatus of adductor magnus—Hunterian canal.

Ultrasonography

Ultrasonography Principle:

This imaging modality is based on the piezoelectric effect which is the property of certain substances to convert electrical energy to sound energy. These are the active portions of the ultrasonic transducers. The commonly used substance in the transducer is lead zirconate titanate (PZT).

Ultrasonography Applications:

• An ultrasonic beam of high frequency gives excellent resolution images of only superficial structures. This is used for study of musculoskeletal system, joints, thyroid, scrotum, etFor imaging deeper structures of abdomen, a low frequency probe with greater penetrancy is use

Interpretation of Images:

• Images are dependent on the intensity of echoes received back by the transducer.
• Structures which reflect all the sound waves back are depicted as bright echoes and termed hyperechoic.
• Structures which reflect moderate level of sound waves appear as uniform grains and are termed isoechoic.
• Fluid-filled structures which transmit all the sound waves, do not reflect any echoes and are termed hypoechoic.
• The reflection of sound waves in the form of echoes depends on the density of the organ and the transmission of sound through the same.

Advantages of Ultrasonography:

1. It is a cost-effective investigation.
2. It is widely available.
3. Noninvasive.
4. Owing to the relatively small size of the apparatus, it is fairly portable, and can thus be brought to the bedside of the moribund patient.
5. It does not involve the use of ionising radiation, and can, therefore, be safely used in a pregnant patient and can be repeatedly used as a follow-up modality.

Limitations of Ultrasonography

1. Its use is limited in thorax.
2. Limited use in the abdomen when there is gaseous distension.
3. Operator expertise is all important.
4. It cannot image bone.

Computed Tomography (CT)

This is an imaging procedure where detailed information is obtained from thin sections in collimated X-rays.

Computed Tomography Indications:

• Structural evaluation of intracranial lesions
• Detailed evaluation of lung, mediastinal pathologies

• Intra-abdominal and pelvic masses where exact site of origin and relation to adjacent structures can be evaluated.
• Extra-osseous and soft tissue extension of bone tumours.
• Vascularity of the normal organ and the abnormal tissue can be evaluated and compared.

Contraindications (Relative):

• Pregnancy
• Restless patients

Interpretation of Images:

• Structures imaged appear densely white to densely black depending on the absorption of X-rays and the emerging resultant X-rays which are detecteThe composite picture is actually a collection of Hounsfield numbers. Each Hounsfield number being assigned a specific shade of grey, thus producing a picture that might be easily understoo

Some of the common densities to be encountered in practice are as follows (Hounsfield units = HU):

• Air – –1000 HU
• Fat – –50 to –100 HU
• Water – 0 HU
• CSF – 0 to +3 HU
• White matter – +22 to +32 HU
• Grey matter – +36 to +46 HU
• Clotted blood – +60 to +80 HU
• Calcification bone – +80 to +1000 HU

In order to increase the contrast that may exist between the structures in the body, intravenous contrast (iodine-containing) is administered to tissues to show enhancement of their density and various pathologies also show fairly characteristic contrast uptake patterns.

• In abdominal scanning, oral contrast is administered to the patient before the procedure, to enable the operator to accurately separate the bowel loops from the other intra-abdominal structures.
• The advantages of CT over conventional radiology are that it can visualise extremely small pathology, not evident on conventional films, is cost-effective as multiple X-ray films and procedures can be avoide It is noninvasive and the radiation levels applied to the patient are extremely low.

Virtual Colonoscopy

• It is a recently developed technique that uses a CT scanner and computer virtual reality software to look inside the body without having to insert a long tube (conventional colonoscopy) into the colon or without having to fill the colon with liquid barium (barium enema).
• More formally known as three-dimensional CT colonography, the virtual procedure allows radiologists to obtain 3D images from different angles, providing a sort of movie of the colon’s interior without having to insert an endoscope into the bowel.

Virtual Colonoscopy Advantages

• Noninvasive procedure, well-tolerated by patient
• Requires no sedation, less time-consuming
• Useful in elderly who are frail and infirm
• Useful when a tumour is large enough to block passage of scope.

Virtual Colonoscopy Disadvantages

• Exposure to radiation, less detail of inner lining of colon
• Small polyps are located more reliably by colonoscopy
• Strictly a diagnostic procedure (unlike colonoscopy).

Contrast-Enhanced (Ce) Ct Abdomen Showing Mass In The Right Iliac Fossa

Question 1. What is this investigation?
Answer: Contrast enhanced CT scan

Question 2. How to interpret the CT scan?
Answer: Structures imaged appear as densely white or black.

Question 3. What is the name used to the picture in terms of number of units?
Answer: Hounsfield units

Question 4. Why do you give contrast?
Answer: This is to increase the density between various structures. E x a m p l e : Aorta appears bright with contrast.

Question 5. What are the precautions?
Answer: Pregnancy is a contraindication. Iodine containing contrast can give rise to nephropathy. Allergy to contrast can happen. Hence, dehydration should be correcteSerum creatinine should be checked before contrast.

Question 6. When do you use oral contrast?
Answer: While studying abdominal viscera, e.g. if leak is suspected.

Question 7. What is the finding here?
Answer: It is showing a hypodense lesion in the right iliac fossa.

Question 8. What is the diagnosis?
Answer: Mostly carcinoma caecum

Question 9. Why do you say so?
Answer: Anatomically it is a lesion occupying the right iliac fossa involving caecum.

Question 10. How do you describe this?
Answer: It is a hypodense mass with solid and cystic areas. Cystic areas represent tumour degeneration.

Question 11. What else is seen in this picture?
Answer: Fat planes between the mass and the abdominal wall is obliterated.

Question 12. What is the importance of that?
Answer: Probably it is infiltrating the abdominal wall.

Question 13. Why do you want to know this information?
Answer: At surgery, the involved portion of the abdominal wall has to be removed.

Question 14. How do you confirm the diagnosis?
Answer: Colonoscopy and biopsy

Question 15. What will be the report expected?
Answer: In majority of the cases it is adenocarcinoma

Question 16. What is the treatment, if it is operable?
Answer: Right radical hemicolectomy

Question 17. If it is inoperable, what is the treatment?
Answer: Palliative ileo-transverse anastomosis

Cect Showing Hypodense Lesion With Air Pockets In The Left Subphraenic Space

Question 1. What are the findings in this film?
Answer: About 5 cm sized hypodense lesion with air-filled lesion.

Question 2. What is the most likely diagnosis?
Answer: Abscess

Question 3. What are causes of abscess in that location?
Answer: Pancreatic necrosis, posterior gastric perforations, ruptures liver abscess

Question 4. Left posterior subphrenic space is called as what?
Answer: Lesser sac

Question 5. What is the treatment?
Answer: Ultrasound-guided per cutaneous aspiration of pus.

Cholangiogram Or Ercp Or Mrcp

Cholangiogram/Ercp/Mrcp Introduction:

These are used in the evaluation of biliary tract and pancreas. Details have been given in the gallbladder and pancreas chapter. T-tube cholangiogram is used following open choledochotomy. ERCP is preferred for evaluation of lower biliary obstructions, classical example being stones in the CBMRCP is used in the evaluation of high bile duct strictures or obstructions. A few examples are given below.

T-Tube Cholangiography Showing A Filling Defect In The Lower End Of The Common Bile Duct (CBD)

Question 1. What is the diagnosis?
Answer: Postcholecystectomy—residual stone in the CBD

Question 2. What is the surgery done for this patient?
Answer: Cholecystectomy and choledocholithotomy

Question 3. Why do you insert a T-tube after CBD exploration?
Answer: In case of distal obstruction by a residual stone, the bile starts leaking from the suture line on the CBD and may result in biliary peritonitis. In such situations, T-tube helps in drainage of the bile.

Question 4. What material is T-tube made of?
Answer: Latex

Question 5. How do you treat this patient in order to extract the stone?
Answer: Endoscopic sphincterotomy and extraction of the stone.

Ercp Showing Filling Of The Dye In The Duodenum Lower Cbd And Partial Filling Of Intrahepatic Bile Duct Radicals. Also 3 Clips Are Visible Along The Length Of Common Hepatic Duct. The Gallbladder Is Not Visualized

Question 1. What is the diagnosis?
Answer: Postcholecystectomy—stricture common hepatic duct/common hepatic duct.

Question 2. What is the type of injury is this?
Answer: Strasberg D—probably a lateral injury due to partial clips.

Question 3. What is the next investigation?
Answer: CET is done to know any significant bile collection/ biloma—if present and if sepsis is present, better to explore.

Question 4. How do you treat this patient in order to eliminate sepsis?
Answer: Explore, drain the bile, remove clips, if possible insert T-tube drain, Morrison’s pouch and come out

Question 5. In cases of complete transections, how do you treat?
Answer: If detected on table, do primary repair—hepaticojejunostomy. If detected later, assess for sepsis— treat it, improve nutrition and surgery can be done 4 to 6 weeks later.

Magnetic Resonance Imaging (MRI)

Magnetic Resonance Imaging Principle:

• Certain atomic nuclei, which possess unpaired protons or neutrons, have an inherent spin. The nucleus is positively charged and therefore creates a small magnetic field around itself, when it spins. The human body contains in abundance such spinning nuclei in the atoms of hydrogen which is found in water and lipids.
• When the tissues containing these nuclei are within a strong magnetic field, the nuclei tend to align themselves along the lines of the force. The spinning protons now tend to precess, i.e. wobble about the axis of the main magnetic fielNow a radiofrequency (RF) is applied, being of the same frequency as the processing but at right angles to the main magnetic fielThis excites the protons at low energy states into higher energy states. Thus, an absorption of energy takes place, which is used, as the excited protons ‘relax’ back to their original energy level when the radiofrequency is switched off. The relaxation of protons back to equilibrium and lower energy state is termed spinlattice relaxation or longitudinal relaxation. It is exponential and referred to by the time constant T1.
• When the RF pulse is applied the protons process together in synchronism or in phase with each other.
• During relaxation, however, they go quickly out of phase due to small variations in local magnetic fields. This loss of phase is termed spin-spin relaxation or transverse relaxation. It is also an exponential and referred to by the time constant T2. Depending on the type of tissue under study, the T1 and T2 relaxation times will differ, thus giving rise to differences in the image.

The MRI image depends upon four main factors:

1. The T1 relaxation time
2. The T2 relaxation time
3. The proton density
4. The blood flow

Depending on the characteristics of the above four parameters, the signal intensity of the image will vary, thus deciding the appearance that any given tissue will finally cast.

Advantages of MRI:

1. It is non-invasive.
2. It does not involve the use of ionising radiation. Hence, it is safe in that respect.
3. It gives high intrinsic contrast.
4. Direct transverse, sagittal and normal imaging possible.
5. No bone/air artefact.
6. It has no known biological hazard.

Disadvantages of MRl:

1. The imaging time is long. Hence, movement of the patients may produce artefacts.
2. Due to variety of protocol options during scanning, the final image is highly operator-dependent and this requires expert technical staff.
3. Expensive
4. Poor bone and calcium detail
5. Patients with pacemakers, metallic implants and critically ill patients cannot be scanne

Mri Showing Stones In The CBD

Question 1. What structures are seen here?
Answer: Intrahepatic radicles, common bile duct and duodenum.

Question 2. What are the findings?
Answer: Filling defects are seen as dark shadows in the CBD.

Question 3. What is the final diagnosis?
Answer: Choledocholithiasis

Question 4. What are the advantages of MRI?
Answer: It is non-ionizing and no contrast is used.

Question 5. How do you treat this condition?
Answer: ERCP, basketting of stones followed by laparoscopic cholecystectomy.

Mri Of The Thigh

Question 1. Name this investigation.
Answer: Magnetic resonance imaging

Question 2. What are the principles of MRI?
Answer:

• Certain atomic nuclei, which possess unpaired protons or neutrons, possess an inherent spin. The nucleus is positively charged and, therefore, creates a small magnetic field around itself, when it spins. The human body contains in abundance such spinning nuclei in the atoms of hydrogen, which is found in water and lipids.

Question 3. What are the chief advantages of MRI over CT scan?
Answer: It is noninvasive and does not involve the use of ionising radiation. Hence, it is safe.

Question 4. What are the disadvantages of MRI?
Answer:

• The imaging time is long. Hence, movement of the patients may produce artefacts.
• Expensive
• Patients with pacemakers, metallic implant and critically ill patients cannot be scanned.
• Claustrophobia

Question 5. What does this picture show?
Answer: A hyperintense mass occupying the thigh region.

Question 6. What is the diagnosis?
Answer: Soft tissue sarcoma

Question 7. How do you confirm the diagnosis?
Answer: Trucut biopsy

Question 8. Why not FNAC?
Answer: FNAC cannot diagnose the type of sarcoma

Question 9. What are common tumours in this location?
Answer: Malignant fibrous histiocytoma (MFH) and liposarcoma.

Question 10. What is the treatment?
Answer: Wide excision with 2–3 cm margin.

Few MRI images:

Positron Emission Tomography (PET scan)

• PET scan is a medical imaging technique that combines computed tomography (CT) and nuclear scanning. It is used to determine the metabolic or biochemical activity in the brain, heart and other organs by tracking the movement and concentration of a radioactive tracer injected into the blood stream.
• A camera records the tracer’s signal as it travels through the body and collects information about the organs. A computer then converts the signals into 3D images of the examined organ, which provide a clear view of an abnormality.
• One of the main differences between PET scan and other imaging tests like CT or MRI is that the PET scan reveals the cellular level metabolic changes occurring in an organ and functional changes at cellular level. A PET scan often detects these changes very early, whereas CT or MRI detect changes a little later as the disease begins to cause structural changes in organs or tissues.
• Positron emission tomography (PET-CT) constitutes major progress in management of cancer patients for the initial diagnosis, staging and follow-up of various malignancies. PET-CT is also useful in the follow-up of patients following chemotherapy or surgical resection of tumour, since, most of them have a confusing appearance at CT or MR imaging due to postoperative changes or scar tissue

Positron Emission Tomography (PET) Scan

Question 1. Name this investigation.
Answer: PET-CT scan

Question 2. What is a PET scan?
Answer: Positron emission tomography

Question 3. What is the most commonly used positron emitting radionuclide?
Answer: Fluoro-deoxyglucose (FDG)

Question 4. What are the chief uses of PET scan?
Answer: For myocardial perfusion and viability, detection of metastasis from cancer—carcinoma lung, colon, nasopharynx, etc.

Question 5. What are the disadvantages?
Answer: Very expensive and limited availability

Question 6. What does this picture show?
Answer: Hilar mass with a nodule anteriorly on the left side of pleura

Question 7. What may be the diagnosis?
Answer: Carcinoma lung

Question 8. How do you confirm the diagnosis?
Answer: Bronchoscopy and biopsy

Question 9. If the report is adenocarcinoma lung, what is the next step?
Answer: To stage the disease by whole body bone scan, PET scan, and CT scan.

Question 10. If confined to lung, what is the treatment?
Answer: Lobectomy/pneumonectomy.

Interventional Radiology

The role of radiology was limited as only a diagnostic art until mid 1970s. However, now radiology has taken on an exciting new aspect and has entered the field of interventional radiology. Two main types of interventional procedures: Vascular and nonvascular.

Vascular:

1. Angioplasty: This is performed by the use of intraluminal balloon catheters and may be performed for almost any diseased vessel in the body. The more commonly treated vessels are the coronaries, renal arteries, peripheral limb vessels, etc.
2. Embolisation: This procedure is performed either preoperatively to reduce the vascularity of certain tumours, or as a curative treatment for vascular malformations, aneurysms, GI bleeding, etTemporary embolisation may be achieved by using gel foam or autologous clots and permanent embolisation by using balloons, steel coils, ethanol, etInferior vena cava (IVC) umbrella placement, IVC membranotomy are also done.
3. Intravascular ultrasound: The use of ultrasound inside a blood vessel to visualise the interior of the vessel in order to detect problems inside the blood vessel.
4. Stent placement: A tiny, expandable coil, called a stent, is placed inside a blood vessel at the site of a blockage. The stent is expanded to open up the blockage.
   • Important types of stents and stent selection: Self-expanding stents are compressed within a catheter device and released by removing a constraining sheath or membrane. The final diameter of the stent is a function of the outward elastic load of the stent and the inward recoil of the elastic wall.
   • Balloon expandable stents are mounted on angioplasty balloons in a compressed state and then deployed by balloon inflation. These stents retain the diameter imposed by angioplasty balloon unless externally compressed.
5. Foreign body extraction: The use of a catheter inserted into a blood vessel to retrieve a foreign body in the vessel.
6. Needle biopsy: A small needle is inserted into the abnormal area in almost any part of the body, guided by imaging techniques, to obtain a tissue biopsy. This type of biopsy can provide a diagnosis without surgical intervention.
7. Blood clot filters: A small filter is inserted into a blood clot to catch and break up blood clots.
8. Injection of clot-lysing agents: Clot-lysing agents, such as tissue plasminogen activator (tPA) are injected into the body to dissolve blood clots, thereby increasing blood flow to the heart or brain.
9. Catheter insertions: A catheter is inserted into large veins for giving chemotherapy drugs, nutritional support, and haemodialysis. A catheter may also be inserted prior to bone marrow transplantation.
10. Cancer treatment: Administering cancer medications directly to the tumour site.

Nonvascular:

1. Hepatobiliary: Percutaneous transhepatic biliary drainage (PTBD) is widely accepted in cases of biliary obstruction, along with percutaneous biliary calculus removal. Biliary stent placement across a malignant lesion is widely being done in inoperable cases as a palliative procedure.
2. Urinary: Percutaneous nephrostomy, percutaneous stenting and percutaneous nephrolithotomy are being performed.
3. Guided biopsy: Fluoroscopy, ultrasound or CTguided biopsy of various lesions are now part of routine technique.
4. Other interventional procedures: Percutaneous gastrostomy, catheter drainage of abscesses, pseudocysts, ultrasound-guided intrauterine foetal surgeries, etc.

Advantages of Interventional Procedures:

1. Patient compliance is high as surgery is avoided.
2. Cost-effectiveness is high.
3. Infection rates are low.
4. Can be repeated as it is relatively noninvasive.
5. Certain untreatable conditions are treated palliatively with interventional procedures.

Principles of Radiology, Imaging, Viva Voce Examination Multiple Choice Questions

Question 1. Niche and a notch mark is an absolute contraindication for myelography

1. Chronic duodenal ulcer
2. Chronic gastric ulcer
3. Carcinoma stomach
4. Stromal tumour

Answer: 2. Chronic gastric ulcer

Question 2. Trifoliate/clover deformity is diagnostic of:

1. Chronic duodenal ulcer
2. Chronic gastric ulcer
3. Carcinoma stomach
4. Stromal tumour

Answer: 1. Chronic duodenal ulcer

Question 3. The substance used in barium studies is:

1. Barium chloride
2. Barium sulphate
3. Barium carbonate
4. Barium sulphide

Answer: 2. Barium sulphate

Question 4. Barium follows through extends up to:

1. Proximal duodenum
2. Fundus of the stomach
3. Ileocaecal junction
4. Proximal jejunum

Answer: 3. Ileocaecal junction

Question 5. Which of the following is a contraindication for barium study?

1. Dysphagia and odynophagia
2. Motility disorders of the GIT
3. Perforation of gastric mucosa
4. Assessing mediastinal masses

Answer: 3. Perforation of gastric mucosa

Question 6. Achalasia cardia shows the following findings on barium swallow except:

1. Shouldering effect cranial and caudal to the lesion
2. Rat tail appearance of lower end of the oesophagus
3. Gross dilatation of the proximal oesophagus
4. Thin streaks of contrast entering the stomach

Answer: 1. Shouldering effect cranial and caudal to the lesion

Question 7. ‘Moulage’ sign (barium in a featureless tube) is a feature of:

1. Crohn’s disease
2. Intestinal TB
3. Ulcerative colitis
4. Malabsorption

Answer: 4. Malabsorption

Question 8. Which of the following statements is false?

1. Angiographic studies use ¹²³I as contrast substance
2. Enteroclysis is done for mechanical obstruction of the intestine
3. Peripheral venography done for deep vein thrombosis uses 125I
4. Papilloedema is an absolute contraindication for myelography

Answer: 1. Angiographic studies use 123I as contrast substance

Question 9. Which of the following statements is false?

1. Ultrasound is based on the principle of piezo-electric effect, the most common substance used in ultrasonic transducers being lead zirconate titanate (PZT)
2. MRI uses ionising radiation, hence it is unsafe
3. Patients with pacemakers and critically ill patients cannot be scanned using MRI
4. CT scan gives good bone and calcium detail

Answer: 2. MRI uses ionising radiation, hence it is unsafe

Question 10. The most common side effect of peripheral venography is:

1. Complications due to contrast
2. Tissue necrosis
3. Thrombophlebitis
4. Pulmonary embolism due to dislodged clot

Answer: 1. Complications due to contrast

Question 11. Which of the following statements is false about PET scan?

1. PET scan uses protons for radiological examination
2. It combines CT and nuclear scanning
3. It detects changes at the cellular level
4. It helps in early detection of changes in various pathologies.

Answer: 1. PET scan uses protons for radiological examination

Question 12. BI-RADS score of 5 indicates which of the following?

1. Normal mammogram, no evidence of cancer
2. Mammogram normal, some evidence of cancer present
3. Suspicious findings on mammogram, 20–35% chance of cancer
4. Mammogram findings highly suspicious, 95% chance of cancer

Answer: 4. Mammogram findings highly suspicious, 95% chance of cancer

Question 13. The following statements about virtual colonoscopy are true except:

1. It is also called CT pneumocolon, purely diagnostic
2. It is invasive, requires sedation and contraindicated in elderly
3. It involves exposure to radiation
4. It cannot identify polyps measuring between 2 and 10 mm

Answer: 2. It is invasive, requires sedation and contraindicated in elderly

Question 14. Which of the following in future may be a gold standard test for screening of colorectal cancer?

1. PET scan
2. Sigmoidoscopy and colonoscopy
3. MRI
4. Virtual colonoscopy

Answer: 4. Virtual colonoscopy

Question 15. The following is true about MRI except:

1. It is noninvasive
2. Gives high intrinsic contrast
3. Imaging possible in transverse, sagittal and normal views
4. Bone/air artefact can be a problem

Answer: 4. Bone/air artefact can be a problem