Diagnostic Accuracy of Diffusion Weighted Magnetic Resonance Imaging in Diagnosing Muscle Invasion in Urinary Bladder Cancer Taking Histopathology as Gold Standard

Nazish Hameed; Madeha Hussain; Nosheen Ahmad; Anum Ibrahim; Sadia Ali; Rabyea Rehman

Nazish Hameed Assistant Professor, Department of Radiology, Sargodha Medical College / UOS, DHQ Teaching Hospital Sargodha Pakistan
Madeha Hussain Assistant Professor, Department of Radiology, Islam Medical College, Sialkot Pakistan
Nosheen Ahmad Assistant Professor Radiology, Faisalabad Medical University / Allied Hospital, Faisalabad Pakistan
Anum Ibrahim Senior Registrar, Department of Radiology, DHQ Teaching hospital Sargodha Pakistan
Sadia Ali Assistant Professor, Department of Radiology, Avicenna Hospital and Medical College, Lahore Pakistan
Rabyea Rehman Associate Professor, Department of Pediatrics, Sargodha Medical College / UOS, DHQ Teaching Hospital Sargodha Pakistan

Keywords: Magnetic resonance imaging, Muscle invasion, Urinary bladder cancer

Abstract

Background: MRI is the most common investigation to diagnose bladder cancer. The efficacy of Diffusion weighted MRI in diagnosing muscle invasion in bladder cancer is questionable. Objective: To determine the diagnostic accuracy of diffusion weighted magnetic resonance imaging in diagnosing muscle invasion in urinary bladder cancer, taking histopathology as gold standard. Study Design: Cross-sectional validation study. Settings: Department of Radiology, DHQ Teaching Hospital, Sargodha Pakistan. Duration: August 01, 2018 to February 28, 2019. Methods: A total of 105 patients presented with hematuria >100 RBCs on high power micro field and irregular soft tissue structure projecting into bladder lumen from a fixed mural site on ultrasonography and age 25-65 years of either gender were included. Patients with h/o radiotherapy, CRF, recurrent tumor, biopsy proven muscle invasive urinary bladder cancer and any contraindication to MRI were excluded. All the patients were then underwent DW-MRI of the pelvis. DW-MRI findings were interpreted for presence or absence of muscle invasion in urinary bladder cancer and compared with DW-MRI findings. Results: In DW-MRI positive patients, 64 (True Positive) had muscle invasion and 03 (False Positive) had no muscle invasion on histopathology. Among 38, DW-MRI negative patients, 03 (False Negative) had muscle invasion on histopathology whereas 35 (True Negative) had no muscle invasion on histopathology (p=O.OOOI). Overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of diffusion weighted magnetic resonance imaging in diagnosing muscle invasion in urinary bladder cancer was 95.52%, 92.11%, 95.52%, 92.11% and 94.29% respectively. Conclusion: This study concluded that DW-MRI is a highly sensitive and accurate non-invasive modality for diagnosing muscle invasion in urinary bladder cancer.