Diffusion weighted magnetic resonance imaging in bladder cancer, is it time to replace biopsy?

INTRODUCTION: To assess if the apparent diffusion coefficient (ADC) value of magnetic resonance imaging (MRI) can discriminate between the cell type, histological grade and improve staging of urinary bladder cancer (BC). MATERIAL AND METHODS: 102 patients with urinary bladder masses underwent MRI using a 1.5 T machine. T2 weighted and diffusion weighted imaging (DWI) using b values of 0, 150, 500 and 1000 s/mm2 were done. The ADC values of bladder masses were measured. These values were correlated with the histopathologic results. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of T2WI, DWI and T2WI plus DWI for detecting bladder lesions were evaluated. RESULTS: The cut-off ADC value for diagnosing malignant bladder wall pathologies was ≤1 x 10-3 mm2/s with 94.5% sensitivity and 87.5% specificity. The mean ADC value of different malignant cell types was statistically insignificant. A significant difference in ADC values was found between G1 and G3 (P = 0.000), G2 and G3 (P = 0.045) but not between G1 and G2 (p = 0.066). Staging accuracy for differentiation between invasive and non-invasive lesions was nearly the same for all MRI data sets. For differentiation between organ confined (pT1-pT2) and non-organ confined lesions (pT3-pT4), staging accuracy was better in T2WI plus DWI (83%) as compared to DWI alone (77%) or T2WI alone (75%). CONCLUSIONS: Adding DWI and the ADC value to T2WI improve the accuracy of MRI in BC detection and staging. However, at this time point, MRI cannot replace transurethral resection (TUR) biopsy or distinguish sharply between all different histologic grades and cell types.

Evaluation of recently validated non- invasive formula using basic lung functions as new screening tool for pulmonary hypertension in idiopathic pulmonary fibrosis patients.

BACKGROUND: A prediction formula for mean pulmonary artery pressure (MPAP) using standard lung function measurement has been recently validated to screen for pulmonary hypertension (PH) in idiopathic pulmonary fibrosis (IPF) patients. OBJECTIVE: To test the usefulness of this formula as a new non invasive screening tool for PH in IPF patients. Also, to study its correlation with patients' clinical data, pulmonary function tests, arterial blood gases (ABGs) and other commonly used screening methods for PH including electrocardiogram (ECG), chest X ray (CXR), trans-thoracic echocardiography (TTE) and computerized tomography pulmonary angiography (CTPA). MATERIALS AND METHODS: Cross-sectional study of 37 IPF patients from tertiary hospital. The accuracy of MPAP estimation was assessed by examining the correlation between the predicted MPAP using the formula and PH diagnosed by other screening tools and patients' clinical signs of PH. RESULTS: There was no statistically significant difference in the prediction of PH using cut off point of 21 or 25 mm Hg (P = 0.24). The formula-predicted MPAP greater than 25 mm Hg strongly correlated in the expected direction with O2 saturation (r = -0.95, P < 0.000), partial arterial O2tension (r = -0.71, P < 0.000), right ventricular systolic pressure measured by TTE (r = 0.6, P < 0.000) and hilar width on CXR (r = 0.31, P = 0.03). Chest symptoms, ECG and CTPA signs of PH poorly correlated with the same formula (P > 0.05). CONCLUSIONS: The prediction formula for MPAP using standard lung function measurements is a simple non invasive tool that can be used as TTE to screen for PH in IPF patients and select those who need right heart catheterization.

The management of penile fracture based on clinical and magnetic resonance imaging findings.

OBJECTIVE: To present our experience with repairing penile fracture, based on clinical and magnetic resonance imaging (MRI) findings. PATIENTS AND METHODS: Between December 2002 and October 2004, 14 men (19-64 years old) presented to our centre with a penile fracture. Two patients had urethral bleeding. MRI was used before surgery in all patients, and the repair comprised a localized longitudinal penile incision in 13 men. This incision was designed according to the tunical tear site and size already depicted by MRI. One case was managed conservatively, as MRI confirmed an intercavernosal haematoma with no tunical tear. The follow-up was 4-21 months. RESULTS: The tear involved one corpus cavernosum in 11 patients; two were associated with urethral injury. The course after repair was uneventful in all men; the follow-up showed no erectile dysfunction in any. The patients reported neither pain nor penile curvature during erection. CONCLUSION: MRI is a simple and informative investigation for evaluating and documenting a penile fracture, and it improves the management plan.