Role of MRI diffusion tensor imaging in assessment of normal appearing white matter in cases of multiple sclerosis

Background: Multiple sclerosis [MS] is an inflammatory demyelinating condition of the central nervous system [CNS] that is generally considered to be autoimmune in nature. White matter tracts are affected, including those of the cerebral hemispheres, infratentorium, and spinal cord. Several methods have been proposed, mainly using conventional MR modalities like T1, FLAIR or T2 images and enhanced MRI to delineate lesions. Conventional MR techniques cannot give detailed information about the integrity and location of WM tracts. Diffusion MRI is one of the non-conventional MRI techniques used for assessment of multiple sclerosis. The emergence of diffusion tensor imaging [DTI] is of great interest in MS. DTI probe the details of water diffusion within tissues, and could therefore reveal alterations in normal appearing white matter fibers before being visible in conventional MRI. Fractional anisotropy [FA], is the measure of the portion of the diffusion tensor that results from anisotropy [i.e, a measure of the directionality of the molecular motion of water]

Purpose: to evaluate the role of diffusion tensor imaging [DTI] in the examination of the brain white matter that shows normal appearance on conventional MRI sequences in patients with MS, thus assessing its ability to detect early abnormalities at diffusion level

Methods: the study included 50 patients; 38 females and 12 males having MS [between 20 and 40 years of age] referred from Neurologists to Radiodiagnosis Department with 10 ages' matched healthy control volunteers. Each patient included in the study was subjected to full history taking, reviewing medical sheet and MR examination including: Conventional MR examination and Diffusion Tensor imaging. Technique was performed using a standard 3 Tesla unit [Acheiva, Philips]

Results: the study showed that DTI can reveal normal appearing white matter affection in MS cases before visible sizable plaques can be detected by conventional MRI

Conclusion: the current application of diffusion MRI to patients with MS shows that it has enhanced our understanding of the disease pathophysiology. The study reviewed here provides evidence that DTI-derived measures are more specific to the disease pathological processes and sensitive to the diffuse microscopic injury in the NAWM

Role of diffusion weighted magnetic resonance imaging [dw-mri] in assessment of urinary bladder carcinoma

Background: bladder cancer is the fourth most common cancer in males and the tenth most common cancer in females. Urinary bladder cancer occurs three to four times more frequently in men than in women and has a high recurrence rate, necessitating long-term surveillance after initial therapy. Patients with bladder cancer survive longer than those with most other common cancers. For the radiological evaluation of the urinary bladder and prostate gland, magnetic resonance imaging [MRI] is a valuable imaging modality due to high tissue contrast, multiplanar imaging capabilities, and the possibility of tissue characterization. Diffusionweighted imaging [DWI] has emerged as a diagnostic technique in the evaluation of various abdominal lesions

Aim of the Work: to evaluate the role of diffusion weighted magnetic resonance imaging [MRI-DWI] in the diagnosis of urinary bladder carcinoma, with pathological diagnosis was taken as the reference

Patients and Methods: this is a retrospective study that included 20 patients in whom bladder cancer had been suspected either clinically or by U/S and confirmed by biopsy and 20 patients in whom bladder cancer had been not suspected and MRI was done because of other pelvic diseases as a control group. The study was conducted in El-Demerdash hospital. The patients will be referred to the radiology department from the urology department for further MRI evaluation with DWIs

Results: in this study, 20 patients suspected to have bladder cancer were scheduled for MR imaging. All patients were scheduled for different MR sequences including T2WIs, DWIs and post contrast T1WIs. Regarding the detection of urinary bladder carcinoma the sensitivity, specificity, and accuracy for differentiating superficial from invasive tumors using T2 images alone and combined use of T2 and DW images were 62.5%, 66.7%, 63.2% and 100%, 100%, 100% respectively. The sensitivity, specificity, and accuracy for differentiating superficial from invasive tumors using post contrast MR images alone and combined use of post contrast MR images and DW images were 92.3%, 100%, 93.3% and 100%, 100%, 100% respectively

Conclusion: we assume that DW-MRI is a safe and confident method in detection and local staging of urinary bladder carcinoma. In addition, DW images may predict the histological grade of the tumor. Hence DWI may be added to routine imaging protocols of urinary bladder tumors