Mohamed E. Abou-El-Ghar

Bladder tumour staging: comparison of diffusion- and T2-weighted MR imaging

The aim of this work was to evaluate the clinical feasibility of diffusion-weighted (DW) MRI in detection and staging of urinary bladder tumour and to compare DW MRI with the T2-weighted technique. One hundred and six patients with bladder tumour were prospectively included in our study. All patients were evaluated with MR imaging. We started with axial T2-weighted high resolution MR of the urinary bladder, then DW MRI. Two radiologists independently interpreted the MR images, and discrepancies were resolved by consensus. The accuracy of DW MRI in staging of bladder tumour was evaluated using the final histopathological findings. In DW imaging (DWI) staging accuracy was 63.6% and 69.6% in differentiating superficial from invasive tumours and organ-confined from non-organ-confined tumours, respectively. On a stage by a stage basis, DWI accuracy was 63.6% (21/33), 75.7% (25/33), 93.7% (30/32) and 87.5% (7/8) for stages T1, T2, T3 and T4, respectively. In the T2-weighted technique, the overall staging accuracy was only 39.6% and accuracy for differentiating superficial from invasive tumours and organ-confined from non-organ-confined tumours was 6.1% and 15.1%, respectively. DW is superior to T2-weighted MRI in staging of organ-confined tumours (≤T2) and both techniques are comparable in the evaluation of higher-stage tumours.

Bladder Cancer : Diagnosis with Diffusion-weighted MR Imaging in Patients with Gross Hematuria

PURPOSE To prospectively evaluate the usefulness of diffusion-weighted (DW) magnetic resonance (MR) imaging for the detection of bladder neoplasms in patients with gross hematuria of lower urinary tract origin. MATERIALS AND METHODS The study protocol received institutional ethical committee approval, and informed consent was obtained. Between April 2007 and March 2008, 130 consecutive patients with gross hematuria whose upper urinary tract had a normal appearance at ultrasonographic examination were prospectively enrolled. Mean age was 59.4 years (range, 45-75 years). All patients were evaluated by using T2-weighted high-spatial-resolution MR imaging of the urinary bladder, followed by DW MR imaging. Two radiologists independently interpreted the T2-weighted and DW images, and discrepancies were resolved by consensus. Agreement was evaluated by using the kappa statistic. All patients underwent conventional cystoscopy. With cystoscopy and the final histopathologic findings as the reference standards, a comparison with imaging findings was performed by using the McNemar test. RESULTS The consensus diagnostic performance of DW MR imaging for identification of bladder tumors was: sensitivity, 98.1% (104 of 106); specificity, 92.3% (24 of 26); PPV, 100% (104 of 104); negative predictive value, 92.3% (24 of 26); and accuracy, 97.0% (128 of 132). Two cases were falsely negative on T2-weighted MR images but were correctly diagnosed by using DW MR images. The agreement between DW MR imaging results and cystoscopic findings was excellent (kappa = 0.94) for identification of bladder neoplasm. DW MR imaging had a sensitivity and PPV of 98.5% (128 of 130) and 100% (128 of 128), respectively, for determining the cause of hematuria. CONCLUSION DW MR imaging is a highly reliable imaging approach for identification of bladder tumors in patients with gross hematuria.

Diffusion-Weighted MR Imaging in Diagnosis of Superficial and Invasive Urinary Bladder Carcinoma: A Preliminary Prospective Study

We conducted a prospective study to demonstrate the feasibility of using diffusionweighted (DW) magnetic resonance imaging (MRI) for the detection of urinary bladder carcinomas. Between January to June 2007, 43 patients with single bladder tumor were included in our study. Before taking a biopsy, DW MRI was obtained in the axial plane under free breathing scanning with a multisection, spin-echo type, single-shot echo planar sequence with a body coil. Moreover, the apparent diffusion coefficient (ADC) value was measured in a circular region of interest within the carcinoma, urine, normal bladder wall, prostate, and seminal vesicle. All carcinomas in the 43 patients were clearly shown as high signal intensity relative to the surrounding structure. The sensitivity and positive predictive values of DW MRI were 100% in terms of correctly detecting the carcinomas. The ADC value in the carcinoma (1.40 ± 0.51) was significantly lower compared with that of urine (3.50 ± 0.43) (p < 0.001), normal bladder wall (2.29 ± 0.78) (p < 0.001), peripheral zone of prostate (1.77 ± 0.44) (p < 0.05), transition zone of prostate (1.88 ± 0.54) (p < 0.05), and the seminal vesicle (2.12 ± 0.43) (p < 0.001). There was no statistical difference in ADC values between different histological subtypes. There was no overlap between the ADC values of the tumors and the urine, but there was no clear cutoff between the tumor and bladder wall, prostate, or seminal vesicles. Bladder carcinomas have significantly lower ADC when compared to surroundings. Clinical experience with this method is still preliminary and further studies are required.

Diffusion‐weighted magnetic resonance imaging in follow‐up of superficial urinary bladder carcinoma after transurethral resection: initial experience

Study Type – Diagnostic (exploratory cohort)

Multidetector Computed Tomography: Role in Determination of Urinary Stones Composition and Disintegration With Extracorporeal Shock Wave Lithotripsy—an in Vitro Study

OBJECTIVES To evaluate the ability of noncontrast computed tomography (NCCT) to predict stone composition and fragility for treatment with extracorporeal shock wave lithotripsy (SWL). METHODS A total of 103 stones from patients who had undergone different open surgical procedures were scanned with a 64 detector row helical computed tomography (CT) scanner using 1-mm collimation at 2 energy levels of 80 and 120 kV. The chemical compositions of the urinary stones were assessed on the basis of the differences in the densities measured in Hounsfield units (HU). Stones were then broken in an electromagnetic lithotripter until complete fragmentation, and number of shock waves was counted. RESULTS After exclusion of the groups with few calculi, 46 pure stones (18 uric acid, 22 calcium oxalate monohydrate, 6 struvite) and 48 mixed stones were included in the statistical analysis. For measurements at 120-kV, 80-kV, and dual-energy CT values, the overall difference between the densities of the stones was statistically significant; however there was a cross-over in densities between all stone groups. There were significant positive correlations at 120-kV, 80-kV, and dual-energy CT values between stone density and number of shock waves required for complete fragmentation. Stones with HU >1000 required statistically significant higher number of shock waves. CONCLUSIONS Multidetector CT is not an accurate method for detection of human stone compositions; however a high stone CT attenuation value is s significant predictor of failure to fragment renal stones by SWL.

Role of multiphasic helical computed tomography in planning surgical treatment for pelvi-ureteric junction obstruction

To evaluate the role of multiphasic helical computed tomography (CT) in planning surgical treatment for pelvi‐ureteric junction obstruction (PUJO).

False Penile Fracture: Value of Different Diagnostic Approaches and Long-term Outcome of Conservative and Surgical Management

OBJECTIVES We determined the value of clinical and radiological findings in diagnosis of false penile fracture. Also, the long-term outcome of conservative and surgical treatment of such patients was evaluated. METHODS Seventeen patients with false penile fracture were treated conservatively (3 patients) and surgically (14 patients) at our center. Medical records were retrospectively reviewed for etiology, symptoms, signs of physical examination, and information on findings of surgical exploration. Data on erectile function and penile sequelae were obtained during follow-up using the Sexual Health Inventory for Men (SHIM) questionnaire and local examination. RESULTS The most common cause of false penile fracture is sexual intercourse (76.5%). False fracture was suspected in 3 patients who presented with small hematoma and slow post-trauma detumescence; intact tunicas were diagnosed by magnetic resonance imaging (MRI) in all of them and were managed conservatively. Surgical penile exploration was performed in 14 cases, in whom preoperative ultrasound was done in 6, and it was false positive for presence of tunical tear in 50%. Exploration revealed nonspecific dartos bleeding in 9 cases and avulsed superficial dorsal vein in 5. Long-term follow-up (mean=93 months) was available for 16 patients, among whom there was no complications. CONCLUSIONS In most cases, false penile fracture is indistinguishable from true penile fracture either clinically or radiologically. In atypical cases, MRI seems to be a promising modality for diagnosis of such patients. The long-term outcome of conservative and surgical treatment is excellent.

Radiological diagnosis of vesicouterine fistula: Role of magnetic resonance imaging

To retrospectively assess the value of magnetic resonance imaging (MRI) in the diagnosis of vesicouterine fistula (VUF).

Use of Magnetic Resonance Angiography in Diagnosis and Decision Making of Post-Traumatic, High-Flow Priapism

The ideal imaging modality should demonstrate the presence or absence of a clinically significant, causative vascular lesion that, in high-flow arterial priapism, may need intervention. We report a 22-year-old male with post-traumatic arterial priapism. Color Doppler ultrasound could not reliably identify a significant vascular lesion. Magnetic resonance angiography (MRA) demonstrated the presence of a cavernous artery pseudoaneurysm. Based on this finding, embolization was decided, with a successful outcome. Contrast-enhanced MRA appears to be a useful, noninvasive diagnostic tool for decision making in cases of high-flow priapism.

Giant seminal vesicle cyst causing ipsilateral hydronephrosis with contralateral renal agenesis.

Seminal vesicles cyst (SVC) associated with ipsilateral renal agenesis is a rare condition. Until now, contralateral renal agenesis has been found together with SVC in only 3 cases. We report the first case in the literature where contralateral renal agenesis was seen together with giant SVC, causing ipsilateral ureteral obstruction with rising of serum creatinine.