Radiology: AIIMS May 2015

Q-1. Investigation of choice in stress fracture
a) MRI
b) CT
c) Bone scan
d) X-ray

Answer: MRI
Stress fractures are a common overuse injury among athletes.
Magnetic resonance imaging (MRI) is being used increasingly as the investigation of choice for stress fractures. The typical findings on MRI are of periosteal and marrow edema, as well as fracture line.

Q-2. Immediate investigation of choice for acute appendicitis in a child
a) USG
b) CT scan
c) Barium enema
d) X-ray

Answer: USG
Ultrasound with its lack of ionizing radiation should be the investigation of choice in young patients, and is effective in competent hands in identifying abnormal appendixes (A non-compressible and thickened), especially in thin patients.
CT scanning is more sensitive and specific than ultrasound when diagnosing acute appendicitis.
Most useful predictors of acute appendicitis on CT are enlarged appendix, appendiceal wall thickening, peri-appendiceal fat stranding, and appendiceal wall enhancement.

Q-3. Best non-invasive test for myocardial viability
a) Echo cardiograph
b) PET
c) MRI
d) Thallium 201 Scan

Answer: PET
Viable myocardium is myocardium which due to ischemia does not contract normally at rest but has the potential to recover its function, either by itself over time or after revascularization.
PET is generally regarded as the gold standard for the assessment of myocardium viability. PET identifies ischemic or hibernating myocardium in 10-20 % of the regions that would be classified as fibrotic or infracted by thallium and technetium labeled compounds.

Q-4. Judet view of X-ray is for
a) Pelvis
b) Calcaneum
c) Scaphoid
d) Spine

Answer: Pelvis
The entire pelvis is demonstrated on each oblique Judet view.
The Judet view demonstrates acetabular fractures and hip dislocation.

Q-5. Shenton line present in
a) Knee
b) Shoulder
c) Elbow
d) Hip

Answer: Hip
Shenton’s line is an imaginary line drawn along the inferior border of the superior pubic ramus (superior border of the obturator foramen) and along the infero-medial border of the neck of femur.
Break in Shenton’s line:
Fracture of neck of femur
Posterior dislocation of hip
Developmental dysplasia of the hip
Congenital dislocation of hip

Q-6. Patient with tachyarrhythmia is on implantable cardio-verter defibrillator. He develops shock. Best method to know the position and integrity of ICD
a) Contrast CT
b) MRI
c) USG
d) Plain Radiograph

Answer: Plain Radiograph
Implantable cardioverter-defibrillator (ICD):
ICD systems consist of a pulse generator and pacing leads.
Endocardial leads are inserted trans-venously and advanced to the right ventricle, where they are implanted into the myocardial tissue.
The pulse generator is placed subcutaneously or sub-muscularly in the chest wall.
Chest radiography is the preferred imaging modality to evaluate ICD’s anatomic location, lead wire integrity, and help in identifying several complications.
Important point:
An implantable cardioverter-defibrillator (ICD) is a specialized device designed to directly treat a cardiac tachydysrhythmia, while a permanent pacemaker is an implanted device that provides electrical stimuli, thereby causing cardiac contraction when intrinsic myocardial electrical activity is inappropriately slow or absent.

Q-7. Investigation of choice for biliary atresia in a 2 months old child is
a) Hepatic scintigraphy
c) USG

Answer: Hepatic scintigraphy
Ultra-sonography is often the initial investigation in patients with suspected biliary atresia, followed by hepato-biliary scintigraphy, a study that has been used effectively for many years.
If the diagnosis remains elusive after these studies, magnetic resonance cholangiopancreatography (MRCP) may be helpful.
Percutaneous liver biopsy is most valuable procedure in the evaluation of neonatal hepato-biliary diseases and provides the most reliable discriminatory evidence.

Q-8. Contrast filled apace in myelo-graphy, lesion is
Expansion of the space on myelo-graphy is seen in
a) Extra-dural
b) Intra-dural but extra-medullary
c) Intra-medullary
d) Intra-dural

Answer: Intra-dural but extra-medullary
Characteristic findings in Myelo-graphy:
Extra-dural block: Feathered appearance
Intra-dural extra-medullary block: Widening of sub-arachnoid space with Meniscus sign
Intra-dural intra-medullary block: Widening of the cord and Trouser leg appearance

Q-9. Most accurate and safe method to diagnose viable pregnancy at 6 weeks
a) Fetal Cardiac Doppler Study
b) USG of fetal cardiac activity
c) Per-vaginal examination correspond size of uterus is 6 weeks
d) UPT

Answer: USG of fetal cardiac activity
Trans-vaginal ultra-sound is the most accurate means of confirming intra-uterine pregnancy and gestational age during the early first trimester.
Important points:
The standard trans-abdominal scanning using lower frequencies with relatively poorer axial resolution is unsuitable for imaging first trimester conceptus.
High frequency trans-vaginal probe has opened entirely new possibilities to study in detail the early gestation.