Improved detection of renal pathologic features on multiphasic helical CT compared with IVU in patients presenting with microscopic hematuria.

OBJECTIVES: To examine the virtues of multiphasic helical computed tomography (CT) in the diagnosis of upper urinary tract lesions refractory to identification by intravenous urography (IVU). METHODS: A total of 86 patients (59 men and 27 women), 27 to 88 years old, with microscopic hematuria and negative IVU findings were examined with multiphasic helical CT consisting of a pre-enhancement, late arterial-early cortical-medullary, nephrographic, and excretory phase helical CT of the kidneys, using 3 to 5-mm collimation and 7.5-mm/s table feed. RESULTS: The multiphasic helical CT was conclusive in 84 lesions. Twenty-five cases of early papillary and medullary necrosis, 7 of 8 inflammatory lesions, 3 caliceal diverticula, 1 lupus nephritis, 26 small calculi, 2 medullary sponge kidney, 5 vascular anomalies, and 3 infarcts presented with characteristic manifestations on CT but lacked findings on IVU. Similarly 8 of 9 small malignant neoplasms, 2 small benign neoplasms, and 2 small cysts produced no detectable findings on IVU but were readily diagnosed on helical CT. CONCLUSIONS: Characteristic findings, particularly on late arterial, early corticomedullary, parenchymal, and excretory phase helical CT make possible the diagnosis of early inflammatory disease, small masses and neoplastic lesions, and vascular abnormalities. Limited resolution (needed to identify small calculi) and the lack of ability to capture phases significantly reduce the diagnostic ability of IVU.

CT-guided biopsy of indeterminate renal cystic masses (Bosniak 3 and 2F): accuracy and impact on clinical management.

The purpose of this study was to determine ability of cyst aspiration and core biopsy to differentiate malignancies, and benign lesions needing intervention from benign complex cysts in the group of Bosniak 2F and 3 renal cysts. One hundred ninety-nine indeterminate complex renal cysts were biopsied under CT or US guidance using a coaxial system (19-G sheath, 20- or 21-G Chiba or Franseen or 18-G spring biopsy needle). Cytology, amylase, lipase, LDH, fat, protein, urea nitrogen, creatine, and culture and sensitivity were assessed in all patients, histopathology in 116, and flow cytometry in 32. In 179 patients (87.9%) a definitive diagnosis was made; in 20 the specimen was inadequate. Twenty of 28 malignancies were correctly diagnosed (sensitivity 0.71); 27 of 31 benign lesions needing intervention (sensitivity 0.87) and 128 of 140 benign complex cysts (sensitivity 0.91). All inconclusive biopsies were explored revealing six malignancies. There were four CT biopsy misdiagnoses: two renal cell carcinomas; one angiomyolipoma; and one abscess. Guided cyst puncture aspiration and core biopsy significantly altered management of Bosniak 3 and 2F renal cysts obviating surgery or invasive procedures in 70% of the patients with an affirmed diagnosis of benign complex cyst and rendering timely surgical and other interventions in the remaining patients. Long-term follow-up (mean 5.6 years) revealed no further misdiagnosis.

Computerized tomography tailored for the assessment of microscopic hematuria.

PURPOSE: We report the results of a multicenter study of arterial, corticomedullary, nephrographic and excretory phase helical computerized tomography (CT) for detecting and characterizing abnormalities causing asymptomatic microscopic hematuria. MATERIALS AND METHODS: We evaluated 350 consecutive patients, including 216 men and 134 women 23 to 88 years old, with asymptomatic microscopic hematuria of undetermined cause at 4 medical centers. Patients with known urological pathology were excluded from study. We performed 4 helical CT sequences, including pre-enhancement phase imaging from kidney to symphysis pubis, arterial phase imaging of the kidney and lower pelvis, corticomedullary nephrographic phase imaging of the kidney and lower pelvis, and excretory phase imaging from kidney to symphysis pubis with 2 to 5 mm. collimation and 1 to 1.5 pitch. RESULTS: Of 171 proved lesions 158 were correctly diagnosed. There were 10 false-positive and 13 false-negative diagnoses, indicating 0.9239 sensitivity, 0.9441 specificity, 0.9404 positive and 0.9285 negative predictive values, (p <0.001). All cases of congenital renal lesions, calculous disease, ureteral lesion and neoplastic lesion of the bladder were correctly diagnosed, as were 40 of 41 inflammatory renal, 21 of 23 renal masses and 13 of 16 inflammatory bladder lesions. In 27 patients with renal calculi the study was limited to pre-enhancement spiral CT. CONCLUSIONS: A positive diagnosis rate of 45.1% (158 of 350 cases) for the causes of heretofore refractory cases of hematuria with high sensitivity and specificity attest to the effectiveness of our hematuria CT protocol and support its use.