Magnetic resonance angiography. I. Basic principles

The objective of this paper is to describe the basic physical principles important in magnetic resonance angiography (MRA). The data used were obtained from recent articles on MRA retrieved from Index Medicus 1985–92 and direct experience working with prototype MRA sequences. The information is presented in a manner suitable for those unfamiliar with the principles of MRA and magnetic resonance imaging (MRI). Magnetic resonance angiography is an important method that can be used to obtain angiograms without the injection of intravascular contrast medium. It is already proving to be of clinical use in the assessment of vascular disease.     

Angiographic Transcat heter Embolization in Gynaecological Practice

Summary: Intractable uterine haemorrhage, unresponsive to medical therapy or curettage, has been traditionally treated by hysterectomy and/or internal iliac artery ligation. Percutaneous angiographic localization of the bleeding vessel with subsequent embolization, may be a genuine alternative approach that enables preservation of reproductive potential with minimal morbidity. We present 3 such cases here, all subsequent to curettage in the first trimester of pregnancy, 2 after a therapeutic termination of pregnancy and the odier after an incomplete abortion.     

Bursitis in association with solitary osteochondromas presenting as mass lesions

Three patients with solitary osteochondromas which were increasing in size have been recently examined. Plain films were available on all patients; two patients had MR studies, and two had CT scans. In all three cases, malignant transformation of the osteochondroma was suspected from the cross-sectional imaging studies, but pathologic examination proved that these patients all had bursa formation without any evidence of malignancy. The incidence of this rare complication of solitary osteochondroma is discussed. Ultrasound is also recommended for the evaluation of enlarging solitary osteochondromas.     

Active Surveillance, Radiofrequency Ablation, or Cryoablation for the Nonsurgical Management of a Small Renal Mass: A Cost-Utility Analysis

Background

Patients with a cortical small (≤4 cm) renal mass often are not candidates for or choose not to undergo surgery. The optimal management strategy for such patients is unclear.

Methods

A decision-analytic Markov model was developed from the perspective of a third party payer to compare the quality-adjusted life expectancy and lifetime costs for 67-year-old patients with a small renal mass undergoing premanagement decision biopsy, immediate percutaneous radiofrequency ablation or percutaneous cryoablation (without premanagement biopsy), or active surveillance with serial imaging and subsequent ablation if needed.

Results

The dominant strategy (most effective and least costly) was active surveillance with subsequent cryoablation if needed. On a quality-adjusted and discounted basis, immediate cryoablation resulted in a similar life expectancy (3 days fewer) but cost $3,010 more. This result was sensitive to the relative rate of progression to metastatic disease. Strategies that employed radiofrequency ablation had decreased quality-adjusted life expectancies (82–87 days fewer than the dominant strategy) and higher costs ($3,231–$6,398 more).

Conclusions

Active surveillance with delayed percutaneous cryoablation, if needed, may be a safe and cost-effective alternative to immediate cryoablation. The uncertainty in the relative long-term rate of progression to metastatic disease in patients managed with active surveillance versus immediate cryoablation needs to be weighed against the higher cost of immediate cryoablation. A randomized trial is needed directly to evaluate the nonsurgical management of patients with a small renal mass, and could be limited to the most promising strategies identified in this analysis.     

Predicting Prolonged Dysphagia in Acute Stroke: The Royal Adelaide Prognostic Index for Dysphagic Stroke (RAPIDS)

Dysphagia is common after stroke and is associated with increased morbidity and mortality. Predicting those who are likely to have significant prolonged dysphagia is not possible at present. This study was undertaken to validate the Royal Adelaide Prognostic Index for Dysphagic Stroke (RAPIDS) in the prediction of prolonged dysphagia following acute stroke using clinical and radiographic features. A prospective study of unselected, consecutive admissions to the Royal Adelaide Hospital acute stroke unit was undertaken. Clinical and radiographic features applicable to the RAPIDS test were calculated and the sensitivity, specificity, and likelihood ratio for predicting prolonged dysphagia were calculated with 95% confidence intervals (CI). Of 104 subjects admitted with acute stroke, 55 (53%) had dysphagia and 20 (19%) had dysphagia requiring nonoral feeding/hydration for 14 days or more or died while dysphagic prior to 14 days. The RAPIDS test had sensitivity of 90% (95% CI = 70–97%) and specificity of 92% (95% CI - 84–96%) for predicting this latter group of patients. We conclude that the RAPIDS test can be used early to identify patients likely to have prolonged dysphagia. This test could form a basis for selection of patients for trials of nonoral feeding methods.