Effect of a dedicated PI-QUAL curriculum on the assessment of prostate MRI quality.

PURPOSE: The Prostate Imaging Quality (PI-QUAL) score is a metric to evaluate the diagnostic quality of multiparametric magnetic resonance imaging (MRI) of the prostate. This study evaluated the impact of a prostate MRI quality training lecture on the participant's ability to assess prostate MRI image quality. METHODS: Eighteen in-training-radiologists of varying experience in reviewing diagnostic prostate MRI assessed the image quality of ten examinations. Then, they attended a dedicated lecture on MRI quality assessment using the PI-QUAL score. After the lecture, the same participants evaluated the image quality of a new set of ten scans applying the PI-QUAL score. Results were assessed using receiver operating characteristic (ROC) analysis. The reference standard was the PI-QUAL score assessed by a fellowship trained abdominal radiologist with experience in reading prostate MRI. RESULTS: There was a significant improvement in the average area under the curve (AUC) for assessment of prostate MRI image quality from baseline (0.82; [0.576 - 0.888]) to post teaching (1.0; [0.954-1]), with an improvement of 0.18 (p < 0.03). When ROC curves were computed for different cohorts stratified based on year of training, difference ranged from 0.48 for second year residents to 0.32 for fourth year residents (p < 0.001-0.01). For abdominal imaging fellows, the pre-teaching AUC was 0.9 [0.557-1] and post teaching AUC was 1 [0.957-1], a difference of 0.1 (p = 0.20). CONCLUSIONS: A dedicated lecture on PI-QUAL improved the ability of radiologists-in-training to assess prostate MRI image quality, with variable impact depending on year of training.

Liquid Nitrogen-Based Cryoablation in In Vivo Porcine Tissue: A Pilot Study.

INTRODUCTION: Liquid nitrogen-based cryoablation induces freezing evenly throughout the probe tip surface, resulting in larger ablation volumes and faster treatment times. The purpose of this preliminary investigation is to determine the efficacy of the liquid nitrogen-based Visica2 Cryoablation System (Sanarus Technologies, Pleasanton, CA) in in vivo porcine kidney, liver, and fibro-fatty tissue. METHODS: Ablations were performed under ultrasound guidance in 4 Yorkshire pigs. The target lesion cross-section width (W) and depth (D) were 1 cm for liver (n=8), kidney (n=4), and head-neck (n=5) and 2 cm for kidney (n=4).  Expected axial length (L) of the resulting lesion is approximately 4 cm.  After three-day survival, the ablated tissue was harvested and histologically analysed. The mean width and depth were compared with the target diameter using a one-sample t-test. RESULTS: All animals survived the procedure. For the 1 cm target, mean dimensions (L x W x D) were 3.8±1.5 x 1.7±0.3 x 1.7±0.7 for liver, 3.0±0.5 x 2.0±0.4 x 1.7±0.6 for kidney, and 3.3±0.8 x 1.8±0.4 x 1.8±0.4 for head-neck.  Mean width and depth were significantly greater than desired dimension.  For the 2 cm target, mean dimensions were 3.2±0.5 x 3.1±0.8 x 1.9±0.7.  Mean width and depth were not significantly different to desired target. CONCLUSION: Our preliminary results show that the Visica2 liquid nitrogen-based cryoablation system can efficiently and reproducibly create ablation volumes in liver, kidney, and fibro-fatty tissue within 4 minutes and 12 minutes for 1cm and 2cm targeted diameters, respectively. Further investigation is necessary to determine the optimal freeze-thaw-freeze protocol for larger ablation volumes.
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Infrapopliteal Artery Occlusive Disease: An Overview of Vessel Preparation and Treatment Options.

Critical limb ischemia (CLI) is defined as chronic rest pain and/or the presence of tissue loss (ulcers or gangrene) in the lower extremities secondary to ischemia. CLI is a limb and potentially life-threatening disease associated with a poor prognosis with only 50% of patients being able to preserve both limbs within 12 months of diagnosis. CLI related to diabetes is often more extensive with multi-level long segmental arterial disease resulting in a 5-30-fold increased rate of amputation. As the incidence and prevalence of diabetes mellitus increases within our aging society, the rate of infrapopliteal artery occlusive disease (IPOD) and the need for intervention rises with it. The aim of this manuscript is to provide the reader with an overview of the various devices available for vessel preparation (VP) and treatment of IPOD in order to optimize patency rates, symptom resolution, healing of wounds, and minimize complications.

Simulation-based Training for Interventional Radiology and Opportunities for Improving the Educational Paradigm.

The current model for medical education is based on the Master-Apprentice model which was adopted into practice over a century ago. Since then, there have been many changes in healthcare and the environment in which trainees learn, practice and become proficient in procedural and critical thinking skills. The current model for medical education has however, not changed considerably in this time frame, resulting in significant limitations to trainee education. Simulator-based training is a technique which can minimize the limitations of the apprenticeship model by mitigating the effect of time constraints, increased emphasis on patient safety and satisfaction and nonstandardization of Interventional Radiology (IR) curricula. Currently, simulators are utilized in some IR programs, however robust research into simulators must be performed to prove the educational validity of simulators and support formalization and widespread integration of simulation based training into a new, improved and standardized IR curriculum.

High-Fidelity Endovascular Simulation.

With the ongoing changes in graduate medical education, emphasis has been placed on simulation models to increase clinical exposure and optimize learning. In specific, high-fidelity simulation presents as a potential option for procedural-skill development in interventional radiology. With improved haptic, visual, and tactile dynamics, high-fidelity endovascular simulators have gained increasing support from trainees and certified interventionalists alike. The 2 most common high-fidelity endovascular simulators utilized today are the Procedicus VIST and ANGIO Mentor, which contain notable differences in technical features, case availability, and cost. From the perspective of a trainee, high-fidelity simulation allows for the ability to perform a greater volume of cases. Additionally, without the risk of potential harm to the patient, trainees can focus on repetition and improved performance in a stress-free environment. When errors are made, high-fidelity simulator metrics will generate instantaneous feedback and error notification, erasing ambiguity and thus facilitating learning. Furthermore, in an environment devoid of time and cost stressors, the supervising physician is afforded the opportunity to properly mentor and instruct the trainee throughout the case. For the experienced interventionalists, high-fidelity simulation allows for a decreased learning curve for new procedures or techniques, as well as the opportunity for procedure rehearsal for unusual or high-risk cases. Despite the limitations created by cost, high-fidelity endovascular simulation should continue to be increasingly utilized in the development of the interventional radiology curriculum.

A Venous Malformation in the Vastus Lateralis: Our Experience with Cryotherapy.

The present report describes a case of cryotherapy ablation in a 35-year-old woman with a 1.5 cm painful venous malformation (VM) in the right vastus lateralis muscle. After the patient had failed sclerotherapy, a single session of cryotherapy was performed that resulted in both technical and clinical success. At 8-month follow-up, there was no residual pain. The use of cryotherapy ablation for the treatment of an intramuscular VM has only been previously described on 1 occasion. Based on our results, cryotherapy is a promising therapy for fast and safe treatment for patients with venous vascular malformations.