Renal vasculature in potential renal transplant donors: comparison of MR imaging and digital subtraction angiography.

PURPOSE: To compare magnetic resonance (MR) angiography with a selective inversion-recovery sequence and digital subtraction angiography (DSA) in renal transplant donors. MATERIALS AND METHODS: Thirteen potential donors underwent MR imaging at 1.5 T and conventional angiography. Blinded evaluation of imaging findings was performed. A selective inversion-recovery sequence was used to obtain MR arteriograms. RESULTS: Eight accessory vessels were present; MR angiography showed 100% sensitivity in accessory vessel detection. Both studies depicted early arterial branching in two vessels, mild fibromuscular dysplasia in one patient, normal renal size in all patients, and prominent fetal lobulation in two kidneys. A small cyst was detected with MR imaging only. Minor venous anomalies were noted in three patients, though these were not surgically confirmed owing to contralateral surgery. CONCLUSION: Despite the small study population, MR angiography with this sequence appears to have potential value in pretransplantation evaluation of the kidney. Advantages include short examination time, noninvasiveness, avoidance of iodinated contrast media, no radiation, and lower cost than DSA.

Dynamic contrast-enhanced subtraction MR angiography of the lower extremities: initial evaluation with a multisection two-dimensional time-of-flight sequence.

PURPOSE: To determine the clinical feasibility of a contrast material--enhanced two-dimensional (2D) magnetic resonance (MR) angiographic sequence in lower extremity arteries. MATERIALS AND METHODS: Four healthy volunteers and 12 patients underwent dynamic contrast-enhanced MR angiography; all patients also underwent conventional angiography. A 2D multisection gradient-echo sequence with image subtraction was used for all MR imaging examinations. RESULTS: Oblique-coronal contrast-enhanced MR angiography was completed in less than 4 minutes, with a 256 x 512 matrix. The arterial contrast enhancement ratio was 2.0 +/- 0.8 (standard deviation), and the pre- and post-contrast contrast-to-noise ratios were 2.1 +/- 13.8 and 46.2 +/- 18.7, respectively. The sensitivity for MR angiography was 100% and specificity was 69% for distinction of vessels with greater than 50% stenoses from normal or mildly stenotic vessels. CONCLUSION: Dynamic contrast-enhanced 2D MR angiography is capable of increasing intraarterial signal intensity and depicting small vessel anatomy of the lower extremities over a large field of view in a short imaging time.

A complementary role for thallium-201 scintigraphy with mammography in the diagnosis of breast cancer.

Physical examination and mammography are currently the only proven and reliable methods of early detection of breast cancer. Although both procedures are highly sensitive, their limited specificity often requires surgical biopsy in order to differentiate between malignant and benign lesions. The purpose of this prospective study is to investigate the diagnostic specificity of thallium imaging for breast cancer and to determine its efficacy as a complement to mammography. Two groups were studied: Group A: Patients found to have breast abnormalities and scheduled for biopsy or surgery and Group B: Patients who were suspected to have a recurrence of cancer after mastectomies or lumpectomies. In Group A, thallium scans of 32 breasts in 30 patients were performed prior to biopsy or surgery, yielding pathological diagnoses of 31 breasts in 29 patients. Results for Group A included seven true-positive thallium scans, twenty-two true-negative scans, two false-negative scans, and one false-positive scan. In Group B, seven patients were scanned to evaluate subcutaneous nodules for breast cancer following mastectomy or lumpectomy. Results for Group B included five true-positive scans, one true-negative scan, one false-negative scan and no false-positive scans. Thallium breast scanning was shown to have high specificity for cancer (specificity 96% and sensitivity 80%), suggesting that this technique should be evaluated in additional patient studies to determine its role in clinical situations.