Endovascular model of ischemic stroke in swine guided by real-time MRI

Modeling stroke in animals is essential for testing efficacy of new treatments; however, previous neuroprotective therapies, based on systemic delivery in rodents failed, exposing the need for model with improved clinical relevance. The purpose of this study was to develop endovascular approach for inducing ischemia in swine. To achieve that goal, we used intra-arterial administration of thrombin mixed with gadolinium and visualized the occlusion with real-time MRI. Placement of the microcatheter proximally to rete allowed trans-catheter perfusion of the ipsilateral hemisphere as visualized by contrast-enhanced perfusion MR scans. Dynamic T2*w MRI facilitated visualization of thrombin + Gd solution transiting through cerebral vasculature and persistent hyperintensities indicated occlusion. Area of trans-catheter perfusion dynamically quantified on representative slice before and after thrombin administration (22.20 ± 6.31 cm2 vs. 13.28 ± 4.71 cm2 respectively) indicated significantly reduced perfusion. ADC mapping showed evidence of ischemia as early as 27 min and follow-up T2w scans confirmed ischemic lesion (3.14 ± 1.41 cm2). Animals developed contralateral neurological deficits but were ambulatory. Our study has overcome long lasting challenge of inducing endovascular stroke model in pig. We were able to induce stroke using minimally invasive endovascular approach and observe in real-time formation of the thrombus, blockage of cerebral perfusion and eventually stroke lesion.

TO SEPARATELY ASSESS THE DIAGNOSTIC POTENTIAL OF TVS & MRI IN THE TERMS OF SENSITIVITY AND SPECIFICITY BY CORRELATING THE IMAGING FINDINGS WITH HISTOPATHOLOGY

This prospective study was done in the Department of Radio diagnosis Govt. Medical College, Kozhikode. A total of 65 patients who were referred to our department with clinical suspicion of endometrial lesions and incidentally detected endometrial lesions on ultrasonography underwent transvaginal ultrasound and subsequent Imaging evaluation of pelvis MRI has very high sensitivity (95%) and specificity (98%) and is almost as accurate (97%) as histopathology in differentiating benign from malignant lesions. Addition of DWI with ADC mapping to conventional MRI increases its accuracy even more. However there is inherent limitation to MRI in detecting carcinoma in situ and micrometastasis. Keywords: TVS, MRI, Sensitivity, Specificity, Histopathology.

Added value of diffusion weighted mri to conventional mri in the assessment of uterine cervix cancer post therapy

Purpose of this study is: Assessing the role of Diffusion weighted imaging with ADC mapping in the evaluation of uterine cervical cancer post therapy regarding tumor residual, recurrence or post treatment benign changes/ complications after tumor resection and/or chemotherapy/radiotherapy. Methods The study included 48 female underwent cervical cancer treatment, referred to Radio diagnosis Department of National Cancer Institute for post therapy assessment. Each patient included in the study was subjected to full history taking, reviewing medical sheet and MR examination including: Conventional MR examination and Diffusion Weighted imaging. Results The study showed that the use of quantitative DW imaging with ADC mapping provide added value in the detection of post-treatment malignant masses and differentiating it from post-treatment benign changes. Conclusion The current application of diffusion Weighted MRI as a routine with conventional MRI sequences increased the accuracy of detection of post therapy benign and malignant masses , Our results suggested also that the use of ADC can be helpful in differentiating post-treatment malignant masses from benign post-treatment changes.

Are We Heading to the Future of Musculoskeletal Tumor Imaging with Ultra-High Field 7T MRI?

Background and objectives: Sarcoma preoperative planning critically depends on MRI, sometimes uninformative when compartments barriers or critical structures are involved. objective: to prospectively assess the feasibility and the potential of 7T MRI in sarcoma. Methods: Two patients with femoral chondrosarcoma were CT and MRI (1.5 and 7T) scanned with T1W, T2W, GRE and DTI sequences. Image quality and characteristics of the tumors were compared between these modalities. Results: In-plane resolution was higher at 7T as compared to 1.5T MRI, tumor delineation was more reliable and soft tissue involvement was clearer. DT imaging and corresponding ADC mapping allowed a clear distinction between edema and tumor and identified tumor involvement of collateral ligament allowing healthy structures sparing with histopathology confirmation. 7T MRI was also able to define cortical reaction as precisely as CT imaging. Conclusion: Musculoskeletal tumours UHF-MRI is promising. Higher resolution and enhanced signal to noise ratio improved tumoral assessment, infiltration and cortex changes. One could expect this nonradiating technique to replace CT investigation for bone tumours assessment and open new perspectives in the fields of vascular or nerve salvage and response to chemo/radiotherapy. Healthy tissue sparing might be facilitated with impacts on function, complication or reconstruction type.