Imaging Modalities - Identification MCQs

Ans. Ultrasonography Ultrasonography is based on piezoelectric effect. MRI is based on gyeromagnetic property of proton (IP).

The picture archiving and communications system (PACS) is an image management system for improving the efficiency and workflow of radiology practices. Reference: PACS and Imaging Informatics: Basic Principles and Applications Radiology 2005 235:3, 740-740

MRI was the first imaging technique to permit the visualization of the uterine junctional zone and remains the imaging method of choice to evaluate it and its associated pathology. Junctional zone is a region representing the inner myometrium and is a very important imaging feature in pelvic MR imaging for interpretation of various pathologies. In its intact state, it is usually visualized on MRI as a low T2 signal layer beneath the endometrium. Reference: AIIMS-MAMC-PGI’s Comprehensive textbook of diagnostic radiology page number 224

For detecting metastasis of colorectal carcinomas, CECT is helpful as it covers the whole abdomen in it's field and hepatic metastasis can be seen. MRI is used for local staging of disease and in evaluation of local extension into mesorectal fascia. Reference: AIIMS-MAMC-PGI’s Comprehensive textbook of diagnostic radiology page number 1760

Answer is B (Urinary Catecholamines): Pheochromocytomas synthesize and store catecholamines which include norepinephrine, epinephrine and dopamine. The investigation of choice for diagnosis of Pheochromocytomas is determination of elevated levels of catecholamines and their methylated metabolites (metanephrines) in the plasma and urine. CT scan, MRI and MBIG Scintography are all useful diagnostic modalities for localization of pheochromocytoma once the diagnosis is established.

Magnetic resonance imaging, MRI has more advantages than ultrasound, computed tomography, CT, positron emission tomography, PET, or any other imaging modality in diagnosing focal hepatic masses. With a combination of basic T1 and T2 weighted sequences, diffusion weighted imaging, DWI, and hepatobiliary gadolinium contrast agents, that is gadobenate dimeglumine (Gd-BOPTA) and gadoxetic acid (Gd-EOB), most liver lesions can be adequately diagnosed and differentiated into benign and malignant lesions. Reference: AIIMS-MAMC-PGI's Comprehensive textbook of diagnostic radiology page number 1656

Hysterosalpingography (HSG) has been the traditional imaging modality of choice to evaluate tube patency, newer techniques involving agitated saline and ultrasound contrast agents injected during sono hysterography (SIS) have shown promise as an alternate imaging technique. Although the injection of saline agitated with air bubbles when performing SIS can confirm tube patency Ultrasound contrast "microbubbles" last longer and can be imaged with real-time cine clips and reconstructed two-dimensional and three-dimensional images to confirm tube patency Reference: Callen's Ultrasonography in Obstetrics and Gynecology, sixth edition page number 949

MRI is the modality of choice for rectal cancer staging. The high soft-tissue contrast of MRI accurately assesses the extramural tumor spread and relation to mesorectal fascia and the sphincter complex. MRI is the modality of choice for staging rectal cancer to assist surgeons in obtaining negative surgical margins. MRI facilitates the accurate assessment of mesorectal fascia and the sphincter complex for surgical planning. Reference: AIIMS-MAMC-PGI’s Comprehensive textbook of diagnostic radiology page number 1766