Faculty Bibliography

OBJECTIVES: To determine the utility of hematuria testing in a large series of patients with suspected renal colic using unenhanced helical computed tomography (CT) as the reference standard. METHODS: A retrospective review of the CT reports of all patients who underwent unenhanced helical CT for suspected renal colic at one institution during a 3.5-year period and who also underwent a formal microscopic urinalysis within 24 hours of the CT study was conducted. The sensitivity, specificity, positive predictive value, and negative predictive value of the presence of any blood on the urinalysis for renal colic were calculated. RESULTS: Urolithiasis was present in 587 (62%) of the 950 patients, and 363 patients had negative examinations for renal colic, including 69 with significant alternative diagnoses in the latter group. Of the urinalyses, 492 were true-positive, 174 were true-negative, 189 were false-positive, and 95 were false-negative, yielding a sensitivity, specificity, positive predictive value, and negative predictive value of 84%, 48%, 72%, and 65%, respectively. Forty-six percent of the urinalysis results were negative for blood in the subset of patients with significant alternative diagnoses. CONCLUSIONS: The sensitivity of hematuria on microscopic urinalysis for renal colic using unenhanced CT as the reference standard was 84%, and the specificity and negative predictive value was low. The presence or absence of blood on urinalysis cannot be used to reliably determine which patients actually have ureteral stones

The CT findings of a congenital portacaval shunt are presented, and the literature on this unusual anomaly is reviewed.

OBJECTIVE:The purpose of this study was to evaluate the clinical significance of the "flat cava" sign on abdominal CT scans in hospitalized patients without trauma. MATERIALS AND METHODS/METHODS:CT scans of the abdomen of 500 inpatients imaged for a wide variety of nontraumatic indications were retrospectively reviewed for a flat cava sign. Two radiologists measured the maximal anteroposterior and transverse diameters of the inferior vena cava at four predetermined levels. The medical records of the subset of patients with a flat cava sign--defined as a maximal transverse-to-anteroposterior ratio of 3:1 or greater at one or more of the four levels--were reviewed for evidence of hypovolemia or hypotension. RESULTS:Seventy patients (14%; 48 women, 22 men) had a flat inferior vena cava present on at least one of the four levels. Of these 70 patients, 21 had definite and three had possible clinical evidence of hypotension or hypovolemia. A flat cava sign isolated to only one level was seen in 22 of the 70 patients, most commonly at the level just below the renal veins, and only four of these 22 patients had evidence of hypotension or hypovolemia. CONCLUSION/CONCLUSIONS:Of the 500 inpatients, 14% had a flat cava sign on at least one of the four levels examined on abdominal CT scans. The majority of these patients with a flat cava sign did not have hypotension or evidence of hypovolemia, but a minority (30%) did.