Biomedical subjects

Mohan U Sivananthan

Publications and source records attributed to Mohan U Sivananthan.

21 records · Page 2Linked to original sources

PubMed2002

Coronary artery disease: assessment with a comprehensive MR imaging protocol--initial results.

A comprehensive magnetic resonance (MR) imaging protocol for assessment of coronary artery disease (CAD) is presented. The protocol includes multiphase gradient-echo cine MR imaging for assessment of cardiac function, first-pass myocardial perfusion imaging at rest and during adenosine stress, MR imaging with delayed contrast enhancement for assessment of myocardial viability, and coronary MR angiography with a three-dimensional respiratory navigator-gated technique. In 10 patients, the protocol was completed in 61.5 minutes +/- 5.5 and yielded high image quality and diagnostic accuracy. This protocol may provide an integrated noninvasive screening tool for patients with CAD.

Adenosine↗

PubMedDate not supplied

Diagnosis of arrhythmogenic right ventricular dysplasia: a review.

Arrhythmogenic right ventricular dysplasia (ARVD) is a myocardial disorder of primarily the right ventricle, with unknown cause and prevalence and with a frequent familial occurrence. The typical clinical manifestation consists of ventricular arrhythmias with a left bundle branch block (LBBB) pattern that occur predominantly in young adults. ARVD may result in sudden death. Other manifestations are electrocardiographic repolarization and depolarization changes, structural abnormalities that range from subtle wall aneurysms within the so-called "triangle of dysplasia" to biventricular regional or global dysfunction, and localized or widespread fibrofatty infiltration of the right ventricular myocardium. The diagnosis of ARVD is based on the presence of major and minor criteria encompassing genetic, electrocardiographic, pathophysiologic, and histopathologic factors. The imaging modalities used to evaluate right ventricular abnormalities include conventional angiography, echocardiography, radionuclide angiography, ultrafast computed tomography, and magnetic resonance (MR) imaging. Among these techniques, MR imaging allows the clearest visualization of the heart. Because MR imaging depicts both functional and structural abnormalities, positive MR imaging findings should be used as important additional criteria in the clinical diagnosis of ARVD. MR imaging appears to be the optimal technique for detection and follow-up of clinically suspected ARVD.

Adult↗

PubMedDate not supplied

MR imaging of cardiac tumors.

Magnetic resonance (MR) imaging is an important tool in the evaluation of cardiac neoplasms. T1-weighted, T2-weighted, and gadolinium-enhanced sequences are used for anatomic definition and tissue characterization, whereas cine gradient-echo imaging is used to assess functional effects. Recent improvements in pulse sequences for cardiac MR imaging have led to superior image quality, with reduced motion artifact and improved signal-to-noise ratio and tissue contrast. Although there is some overlap in the MR imaging appearances of cardiac tumors, particularly of primary malignancies, differences in characteristic locations and features should allow confident differentiation between benign and malignant tumors. Indicators of malignancy at MR imaging are invasive behavior, involvement of the right side of the heart or the pericardium, tissue inhomogeneity, diameter greater than 5 cm, and enhancement after administration of gadolinium contrast material (as a result of higher tissue vascularity). Concomitant pericardial or pleural effusions are rare in benign processes but occur in about 50% of cases of malignant tumors. MR imaging offers improved resolution, a larger field of view, and superior soft-tissue contrast compared with those of echocardiography, suggesting that knowledge of the MR imaging features of cardiac neoplasms is important for accurate diagnosis and management.

Adult↗