Q-31. Which of the following is the most common cause of sclerotic skeletal metastasis in the female patient?
a) Carcinoma breast
b) Carcinoma ovary
c) Endometrial carcinoma
d) Melanoma
Answer: Carcinoma breast
Explanation:
Primary carcinomas that frequently metastasize to bone
Four lesions comprise 80% of all metastases to bone
Breast (70% of bone mets in women)
Lung
Prostate (60% of all bone mets in men)
Kidney
Most Common Tumors to Metastasize to Bone
Tumor————Appearance
Prostate———- Blastic
Breast————- Mixed
Lung————— Predominantly lytic
Renal Cell Ca—— Predominantly lytic
Q-32. Investigation of choice for detection and characterization of interstitial lung disease is
a) MRI
b) Chest X-ray
c) High resolution CT scan
d) Ventilation perfusion scan
Answer: High resolution CT scan
Explanation:
HRCT thorax is the best mode of investigation to diagnose interstitial lung disease.
A lung biopsy is required if the clinical history and imaging are not clearly suggestive of a specific diagnosis or malignancy cannot otherwise be ruled out.
Q-33. Which of the following is the most common cause of a mixed cystic and solid supra-sellar mass seen on cranial MR scan of a 10 old child?
a) Pituitary adenoma
b) Cranio-pharyngioma
c) Optic chiasmal glioma
d) Germinoma
Ans: Cranio-pharyngioma
Explanation:
Cranio-pharyngioma is histologically benign neuro-epithelial tumors of the CNS that is predominately observed in children aged 5-10 years.
MRI findings: The relatively homogeneous and cystic mass arising from the sella turcica and extending superiorly and posteriorly with compression of normal regional structures. Fluid-filled mass is consistent with a typical cranio-pharyngioma.
Q-34. A 40 years old female patient on long term steroid therapy presents with recent onset of severe pain in the right hip. Imaging modality of choice for the problem is
a) CT scan
b) Bone scan
c) MRI
d) Plain X-ray
Ans: MRI
Explanation:
MR imaging is the imaging modality of choice for early evaluation of bone marrow changes indicative of avascular necrosis of the femoral heads.
Radionuclide scintigraphy had a sensitivity of 81%, compared with 100% for MR imaging.
Q-35. Which of the following organs should always be imaged in a suspected case of bronchogenic carcinoma?
a) Adrenal
b) Kidney
c) Spleen
d) Pancreas
Answer: Adrenal
Explanation:
The adrenal gland is one of the common sites of metastasis from primary lung cancer.
Adrenal metastases are usually unilateral however bilateral adrenal metastases are seen in 10% of all lung cancer patients; of this 2–3% occurs at the initial presentation of non-small cell lung cancer.
Secondary tumors can disrupt the structure and function of the adrenal. This can lead to adrenal hemorrhage, which constitutes a life threatening hazard for the patient.
Q-36. Which of the following techniques use piezoelectric crystal?
a) USG
b) Xero-radiography
c) X-ray diffraction
d) MR imaging
Answer: USG
Explanation:
The transducer probe is the main part of the ultrasound machine.
The transducer probe generates and receives sound waves using a principle called the piezoelectric (pressure electricity) effect, which was discovered by Pierre and Jacques Curie in 1880.
In the probe, there are one or more quartz crystals called piezoelectric crystals. When an electric current is applied to these crystals, they change shape rapidly. The rapid shape changes, or vibrations, of the crystals produce sound waves that travel outward.
Ultrasound uses high frequency sounds that are higher than the human ear can hear. These frequencies generally range between 1-50 MHz.
The active element of most acoustic transducers used today is a piezoelectric ceramic, which can be cut in various ways to produce different wave modes. The first piezoceramic in general use was barium titanate, and that was followed during the 1960’s by lead zirconate titanate compositions, which are now the most commonly employed ceramic for making transducers. New materials such as piezo-polymers and composites are also being used in some applications.
Q-37. In computed tomography, the attenuation values are measured in Hounsfield Unit. An attenuation value of 0 HU correspond to
a) Water
b) Air
c) Very dense bone structure
d) Fat
Answer: Water
Explanation:
The Hounsfield unit (HU) scale is a linear transformation of the original linear attenuation coefficient measurement into one in which the radio-density of distilled water at standard pressure and temperature (STP) is defined as zero Hounsfield units (HU), while the radio-density of air at STP is defined as -1000 HU. It is the definition for CT scanners that are calibrated with reference to water.
Water is the reference material for CT numbers: value of zero. Attenuation (density) > water: positive CT numbers. Density < water: negative CT numbers. X-ray attenuation and CT number depends on the density. Q-38. Which one of the following is the earliest radiographic manifestation of childhood leukemia? a) Radiolucent transverse metaphyseal bands b) Diffuse demineralization of bones c) Osteoblastic lesions in skull d) Parenchymal pulmonary lesions on chest films Answer: Radiolucent transverse metaphyseal bands Explanation: Radiographic manifestation of childhood leukemia: Metaphyseal translucencies are earliest and most characteristic feature. Metaphyseal cortical erosion Osteolytic lesions Periosteal erosion Osteosclerosis of metaphysic Q-39. The EEG cabins should be completely shielded by a continuous sheet of wire mesh of copper to avoid the picking of noise from external electromagnetic disturbances. Such a shielding is called as a) Maxwell cage b) Faraday cage c) Edison’s cage d) Ohm’s cage Answer: Faraday cage Explanation: High performance faraday cages to shield medical rooms, a new mu-copper wall-paper system, has been developed. The system is easy to apply in new buildings and can be used for retrofitting existing sites. Applications of Faraday cage: MRI rooms Clinical Neurophysiologic (EEG, EMG, ECG) Physiotherapy Q-40. For the evaluation of blunt abdominal trauma, which of the following imaging modalities is ideal? a) USG b) CT c) MRI d) Nuclear Scintigraphy Answer: CT Explanation: Blunt abdominal trauma can cause multiple internal injuries. However, these injuries are often difficult to accurately evaluate, particularly in the presence of more obvious external injuries. Bedside ultra-sonography is a rapid, portable, noninvasive, and accurate examination that can be performed by emergency clinicians and trauma surgeons to detect hemo-peritoneum. Computed tomography is the standard for detecting solid organ injuries. Computed tomography (CT) imaging is currently used to assess clinically stable patients with blunt abdominal trauma. CT can provide a rapid and accurate appraisal of the abdominal viscera, retro-peritoneum and abdominal wall, as well as a limited assessment of the lower thoracic region and bony pelvis.