Radiology AIIMS NOV 2013

Q-1. Neonate with seizures, investigation to be done is
a) Trans-cranial USG
b) MRI brain
c) CT head
d) Skull radiography

Answer: Trans-cranial USG
Explanation:
Investigations that should be considered in all neonates with seizures include blood sugar, hematocrit, bilirubin, serum electrolytes, arterial blood gas, anion gap, cerebrospinal fluid (CSF) examination, cranial ultrasound (US) and electroencephalography (EEG).
Neuro-sonography should be done in all infants with seizures.
Neuro-sonography is an excellent tool for detection of intra-ventricular and parenchymal hemorrhage but is unable to detect SAH and sub-dural hemorrhage.
A CT and MRI scan should be done in all infants where an etiology is not available after the first line of investigations.

Q-2 Radiologically, increased pulmonary blood flow is indicated by all except
a) Diameter of descending pulmonary artery >16 mm
b) Kerley b lines
c) Diameter of 2 peripheral arteries > accompanying bronchus
d) More than 6 vessels in outer 1/3rd

Answer: Diameter of 2 peripheral arteries > accompanying bronchiole
Explanation:
Pulmonary hypertension:
Vascular signs:
Widest short-axis diameter of main pulmonary artery ≥29 mm
Diameter ratio of main pulmonary artery to ascending aorta >1
Segmental artery to bronchus ratio >1 in three lobes
Diameter of left + right pulmonary artery >16 mm
Enlargement of bronchial systemic arteries to >1.5 mm
Kerley B lines: Best seen at costophrenic angles
Horizontal non branching 1-2 mm thick 1-3 cm long lines at lung base and perpendicular to pleural surface due to thickening of interlobular septa caused by
Pulmonary venous hypertension (MS, LVF)
Lymphatic obstruction (Pneumoconiosis, sarcoidosis and lymphangitis carcinomatosis
Interstial pneumonitis

Q-3. Stratosphere sign in M mode USG seen in
a) Cardiac tamponade
b) Pneumothorax
c) Hemothorax
d) Pulmonary effusion

Answer: Pneumothorax
Explanation:
USG signs between two ribs with posterior shadowing behind them and the pleural line in between:
The bat sign:
This is typically called ‘the bat sign’ where the periosteum of the ribs represents the wings and the bright hyper-echoic pleural line in between them represents the bats’ body.
It is in between these two rib landmarks that the two layers of pleura, parietal and visceral, are seen sliding across one another.
The presence of pleural sliding is the most important finding in normal aerated lung.
Lung sliding:
Lung sliding corresponds to the to-and-fro movement of the visceral pleura on the parietal pleura that occurs with respiration. The use of M-mode USG, which detects motion over time, provides more evidence that the pleural line is sliding.
Seashore sign:
The M-mode cursor is placed over the pleural line and two different patterns are displayed on the screen: The motionless portion of the chest above the pleural line creates horizontal ‘waves and the sliding below the pleural line, creates a granular pattern, the ‘sand’. The resultant picture is one that resembles waves crashing in onto the sand and is therefore called the ‘seashore sign’ and is present in normal lung.
B-lines or comet-tail artifacts:
‘B-lines’ or ‘comet-tail artifacts’ are reverberation artifacts that appear as hyper-echoic vertical lines that extend from the pleura to the edge of the screen without fading.
Excessive ‘B-lines’, especially in the anterior lung, are abnormal and are usually indicative of interstitial edema.
Stratosphere sign:
In a pneumothorax, there is air present that separates the visceral and parietal pleura and prevents visualization of the visceral pleura. In this situation, lung sliding is absent.
The resultant M-mode tracing in a pneumothorax will only display one pattern of parallel horizontal lines above and below the pleural line, exemplifying the lack of movement. This pattern resembles a ‘barcode’ and is often called the ‘stratosphere sign’
Lung-point sign:
The ‘lung-point sign’ occurs at the border of a pneumothorax. It is due to sliding lung intermittently coming into contact with the chest wall during inspiration and is helpful in determining the actual size of the pneumothorax. The ‘lung-point sign’ is 100% specific for pneumothorax and defines its border.

Q-4. Most accurate and safe for diagnosis of pregnancy in 6 weeks amenorrhea
a) USG showing fetal cardiac activity
b) Doppler
c) Urine for pregnancy
d) Amniocentesis

Answer: USG showing fetal cardiac activity
Explanation:
USG in early pregnancy:
The gestational sac can sometimes be visualized as early as four and a half weeks of gestation (approximately two and a half weeks after ovulation) and the yolk sac at about five weeks gestation.
The embryo can be observed and measured by about five and a half weeks.
The heartbeat may be seen as early as 6 weeks, and is usually visible by 7 weeks gestation.
Coincidentally, most miscarriages also happen by 7 weeks gestation.
The rate of miscarriage, especially threatened miscarriage, drops significantly if normal heartbeat is detected.

Q-5. Symptomatic spinal injury without radiological evidence is most commonly found in
a) Children
b) Elderly
c) Young adults
d) Teenagers

Answer: Children
Explanation:
SCIWORA (Spinal cord injury without radiographic abnormality) was first developed and introduced by Pang and Wilberger who used it to define “clinical symptoms of traumatic myelopathy with no radiographic or computed tomographic features of spinal fracture or instability” and mostly affects children.
SCIWORA lesions are found mainly in the cervical spine but can also be seen, although much less frequently, in the thoracic or lumbar spine.
Important point:
SCIWORA can be an indication for MRI when there is a persisting, objective myelopathy after a traumatic event with normal plain film and CT findings.

Q-6. FAST stands for
a) Focused assessment with sonography for trauma
b) Fast assessment with sonography for trauma
c) Fast assessment with sonography and tomography
d) Focused abdominal sonography for trauma

Answer: Focused assessment with sonography for trauma
Explanation:
Focused assessment with sonography for trauma (FAST) is an important and valuable diagnostic alternative to diagnostic peritoneal lavage and CT that can often facilitate a timely diagnosis for patients with blunt abdominal trauma.
The primary FAST examination classically includes the sub-xiphoid window of the heart to denote pericardial fluid. Indications for FAST include evaluation of the torso for free fluid suggesting injury to the peritoneal, pericardial, and pleural cavities, particularly in cases of trauma. FAST examination may be used to evaluate the lungs for pneumothorax.