Magnetic resonance urography (MRU) versus intravenous urography (IVU) in obstructive uropathy: a prospective study of 30 cases.

AIM: Intravenous Urography (IVU) as a diagnostic modality has limitations in patients of obstructive uropathy with impaired renal function. Our aim was to study the technique and diagnostic accuracy of Magnetic Resonance Urography (MRU) in obstructive uropathy and to correlate the findings with IVU. METHODOLOGY: Forty-eight patients, selected over a six-month period, based on mild to severe pelvicalyceal dilatation on screening ultrasonography, underwent an IVU; those having non-obstructive dilatation were excluded (18 patients). Thirty patients (age range 10 to 75 years) with definite obstructive dilatation underwent MRU. These were obtained using an open MRI unit (Siemens Magnetom Open Viva) with low-dose gadolinium-DTPA (0.01 mmol/kg body weight) using various MRI sequences. MRU studies were classified as 'excellent' or 'diagnostic' and data generated was compared with that of IVU. RESULTS: MRU studies were 'excellent' in twelve and 'diagnostic' in eighteen patients. Of the sixty pelvicalyceal systems (PCS) evaluated in thirty patients, there were thirty-seven calculi, nine pelvi-ureteric junction (PUJ) obstructions, six with impaired renal function, four malrotated kidneys and one each of horseshoe kidney, pancake kidney, pelvic mass (endometriomas), duplex moieties, ureterocele and vesico-ureteric reflux. MRU better depicted moderate-severe PCS dilatation, staghorn and urethral calculi, impaired renal function, extrinsic ureteric and PUJ obstruction. IVU better depicted small calculi and mild PCS dilatation. CONCLUSIONS: In these thirty patients of obstructive uropathy, low magnetic field, open MRI units and low-dose Gd-DTPA provided cost-effective MRU studies with excellent diagnostic utility. MRU scored over IVU in patients with moderate-severe dilatation, staghorn and urethral calculi, impaired renal function, extrinsic ureteric and PUJ obstruction.

Evaluation of the knee pathology by ultrasonography.

Fourteen patients undergoing total knee replacement for the arthritic conditions of the knee were evaluated by ultrasonography (USG) prior to surgery. USG findings (synovium, fluid, femoral cartilage, cyst and loose bodies) were compared with surgical findings. USG and surgical findings matched for synovial pathology in 57%, for presence fluid in 71% and for cartilage damage in 45%. Loose bodies and cyst present in one patient was not picked up by USG. Baker's cyst was detected in one patient.

Comparison of MR angiography with contrast angiography for the diagnosis of carotid artery stenosis.

To assess the accuracy of MR angiography for screening vascular stenosis of the extracranial carotid arteries, 20 consecutive patients with suspected extracranial carotid atherosclerotic disease were evaluated with time-of-flight MR angiography and intra-arterial contrast angiography. Both studies were independently reviewed by three observers in a blinded manner. The internal carotid arteries were graded as either normal or mildly stenotic (0%-29%), moderately stenotic (30%-69%), severely stenotic (70%-99%) or occluded. Results of the study indicate that time-of-flight MR angiography has a high rate of agreement with contrast angiography and is an accurate screening technique of the common carotid bifurcation in patients with suspected carotid stenosis.