ACCURACY OF MULTIPHASE HELICAL TOMOGRAPHY IN DETECTION AND CHARACTERISATION OF SUSPECTED RENAL MASSES USING HISTOPATHOLOGICAL FINDINGS AS GOLD STANDARD
AbstractBackground: The introduction of multiphase helical computed tomography has created manyimportant advances in the detection and characterisation of renal masses. Renal cell carcinoma (RCC)is the seventh most common cancer and makes up 80–85% of all primary renal cancer in adults. If it isfound and treated early, the chances of survival from kidney cancer are high. This cross-sectionalcomparative was carried out at department of CMH/MH Rawalpindi from 1st February 2007 to 25March 2008 to evaluate accuracy of multiphase helical tomography in detection and characterisation ofsuspected renal masses using histopathological findings as gold standard. Methods: Thirty patientswith suspicion of having renal masses were scanned with multiphase CT scanning and 5 mm thickcontiguous section were obtained from kidneys before and after injection of intravenous contrastmaterial. The corticomedullary phase images were obtained after a delay of 25 seconds andnephrographic phase images, after a delay of 120 seconds after initiation of contrast medium injection.The numbers of lesions detected in all three phases were determined. The mass was then characterisedby evaluation of its features and by its degree of contrast enhancement. Results of CT scan werecompared with histopathology. Results: At review of unenhanced, corticomedullary and nephrographicphase images, 26, 29 and 30 lesions, respectively, were identified. One malignant lesion was notidentified and 3 malignant lesions falsely appeared benign in the corticomedullary phase. All lesionswere detected in the nephrographic phase and only 1 malignant lesion falsely appeared benign. Thecorticomedullary phase had a sensitivity of 86.2% and nephrographic phase 96.6% in malignant lesiondetection. Conclusion: Enhancement of renal neoplasm is time dependent and is better innephrographic phase. Small, hypovascular tumours and those placed in medulla may be missed orinadequately characterised if nephrographic phase scanning is not done.Keywords: Computed tomography, renal masses, corticomedullary phase, nephrographic phase
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