Multispectral MRI-based virtual cystoscopy

Bladder cancer is the fifth cause of cancer deaths in the United States. Virtual cystoscopy (VC) can be a screening means for early detection of the cancer using non-invasive imaging and computer graphics technologies. Previous researches have mainly focused on spiral CT (computed tomography), which invasively introduces air into bladder lumen for a contrast against bladder wall via a small catheter. However, the tissue contrast around bladder wall is still limited in CT-based VC. In addition, CT-based technique carries additional radiation. We have investigated a procedure to achieve the screening task by MRI (magnetic resonance imaging). It utilizes the unique features of MRI: (1) the urine has distinct T1 and T2 relaxation times as compared to its surrounding tissues, and (2) MRI has the potential to obtain good tissue contrast around bladder wall. The procedure is fully non-invasive and easy in implementation. In this paper, we proposed a MRI-based VC system for computer aided detection (CAD) of bladder tumors. The proposed VC system is an integration of partial volume-based segmentation containing texture information and fast marching-based CAD employing geometrical features for detecting of bladder tumors. The accuracy and efficiency of the integrated VC system are evaluated by testing the diagnoses against a database of patients.