IgG4-related intracranial disease.

IgG4-related disease (IgG4-RD) is a multi-organ chronic inflammatory process caused by infiltration of IgG4-positive plasma cells in one or more organs. Intracranial involvement has only recently become better recognized. Our case series adds to the growing literature on the varying presentations of intracranial IgG4 by describing the clinical and imaging findings of three patients who presented to our institution with intracranial involvement. Our first patient presented with a mass-forming IgG4 pachymeningitis mimicking a sphenoid wing meningioma, which is to our knowledge the largest mass-forming pachymeningitis published in the literature. Our second case depicts another presentation of extensive IgG4 pachymeningitis involving both cavernous sinuses and surrounding Meckel's caves. The third case describes a patient with presumed lymphocytic hypophysitis, which was later determined to be IgG4-related hypophysitis with concomitant pachymeningitis and perineural spread along the optic nerves. The delayed diagnoses in our cases illustrates the diagnostic challenge that clinicians face in differentiating intracranial IgG4-RD from other infiltrative diseases such as sarcoidosis, granulomatous disease, tuberculosis and lymphoma. Earlier consideration of IgG4-related hypophysitis and hypertrophic pachymeningitis in the differential diagnosis can prevent significant morbidity including unnecessary surgical intervention and organ failure secondary to extensive fibrosis.

Peer Review in Radiology: A Resident and Fellow Perspective.

PURPOSE: The purpose of this study was to explore Canadian radiology residents' and fellows' understanding, attitudes, opinions, and preferences toward peer review. METHODS: An Internet-based anonymous questionnaire designed to understand one's familiarity, attitudes, opinions, and preferences toward peer review was distributed to radiology residents and fellows across Canada. Data were analyzed using descriptive statistics, and answers were stratified by level of training. RESULTS: A total of 136 trainees responded to the survey with 92 completed survey responses available for descriptive statistics. Approximately half of respondents are familiar with peer review (49%), and 39% of trainees are involved in peer review. Most respondents (92%) expressed an interest in learning more about peer review; believe that it should be incorporated into the residency training curriculum (86%), be mandatory (72%), and that current participation will increase odds of future participation (91%). Most trainees (80%) are comfortable advising one another about errors, but less comfortable advising staff (21%). CONCLUSIONS: Residents and fellows welcome the opportunity to learn more about peer review and believe it should be incorporated into the residency training curriculum. Understanding the attitudes and perceptions held by trainees regarding peer review is important, as a means to optimize education and maximize current and future participation in peer review.

Endovascular first strategy for de novo TransAtlantic Inter-Society Consensus C and D femoro-popliteal disease: mid-term outcomes from a single tertiary referral center.

PURPOSE: Describe outcomes after endovascular intervention of TransAtlantic Inter-Society Consensus C and D femoro-popliteal disease. MATERIALS AND METHODS: Retrospective cohort study. Patient demographics, ankle-brachial indices, and lesion details were analyzed from a prospectively maintained database. In all, 980 limbs treated with percutaneous transluminal angioplasty±stenting of the femoro-popliteal segment between 2005 and 2012 were reviewed. Seventy-six patients representing 83 limbs with de novo TransAtlantic Inter-Society Consensus C and D lesions measuring ≥15 cm continuously were identified (mean age 71.3±12.1 years, 62% male). RESULTS: Twenty-five (30.1%) limbs were treated for severe claudication and 58 (69.9%) for critical limb ischemia. The mean pre-procedural ankle-brachial index was 0.47±0.19. The mean lesion length was 22.9±4.82 cm. Seventy patients representing 77 limbs were available for a mean follow-up length of 19.5 months (range 0-79). The mean post-procedural ankle-brachial index was 0.71±0.28. Primary, assisted-primary, and secondary patency rates were 68.1%, 72.7%, and 83.3% at 6 months, 55.3%, 63.6%, and 58.3% at 12 months, and 38.2%, unavailable, and 10.4% at 24 months, respectively. CONCLUSIONS: Angioplasty-first strategy for TransAtlantic Inter-Society Consensus C and D lesions of the femoro-popliteal artery can be safely performed. However, patency drastically decreases after 12 months suggesting further improvements are required to achieve longer-term clinical benefit.

Bridging stent-graft pullout force analysis.

PURPOSE: To assess the pullout force (POF) of bridging stent-grafts used in thoracoabdominal stent-grafts and iliac bifurcated grafts. METHODS: In an experimental setup, the POFs of Viabahn or Fluency with or without a Zilver stent were measured when deployed into the renal and celiac branches of a Zenith thoracoabdominal cuff-bearing branched stent-graft. The POFs of the Atrium i-Cast, Viabahn, Fluency, and Fluency+Zilver were measured when deployed into an iliac bifurcated graft with a short side-branch for the internal iliac artery. At least 10 trials were performed for each stent in air at room temperature. RESULTS: The median POF (IQR; absolute range) required to dislodge each bridging stent-graft from the 6-mm renal branch was 1.89 N (0.47 N; 1.65-2.5) for the 7-mm Viabahn, 1.17 N (0.39 N; 0.68-1.57 N) for the 7-mm Fluency, and 2.08 N (0.49 N; 1.59-2.62 N) for the 7-mm Fluency with a supporting 8-mm Zilver stent (p<0.001). For the 8-mm celiac branch, the POFs were 2.79 N (0.82 N; 2.31-4.16 N), 1.74 N (0.18 N; 1.51-1.91 N), and 2.73 N (0.94 N; 1.9-3.61 N) for the 9-mm Viabahn, 9-mm Fluency, and 9-mm Fluency with a 10-mm Zilver stent, respectively (p<0.001). For the 8-mm internal iliac branch, the POFs were 3.53 N (0.85 N; 2.55-4.72 N) for the 9-mm i-Cast, 3.82 N (0.41 N; 3.29-4.45 N) for the 9-mm Viabahn, 2.32 N (0.23 N; 1.63-2.64 N) for the 9-mm Fluency, and 2.61 N (0.71 N; 1.65-3.63 N) for the 9-mm Fluency with a 10-mm Zilver stent (p<0.001). CONCLUSION: There is a small but significant difference in pullout forces among various bridging stent-grafts. As pullout forces may be one factor contributing to type III endoleaks in complex endovascular repairs involving fenestrated and branched stent-grafts, further study is warranted to compare these grafts clinically to determine if they perform differently. According to this study, the theoretical advantages associated with the Viabahn stent-graft make it a strong choice for minimizing branch dislocations.

The E646D-ATP13A4 mutation associated with autism reveals a defect in calcium regulation.

ATP13A4 is a member of the subfamily of P5-type ATPases. P5-type ATPases are the least studied of the P-type ATPase subfamilies with no ion specificities assigned to them. In order to elucidate ATP13A4 function, we studied the protein's subcellular localization and tested whether it is involved in calcium regulation. The intracellular calcium concentration was measured in COS-7 cells over-expressing mouse ATP13A4 using ratiometric calcium imaging with fura-2 AM as a calcium indicator. The results of this study show that ATP13A4 is localized to the endoplasmic reticulum (ER). Furthermore, we demonstrate that over-expression of ATP13A4 in COS-7 cells caused a significant increase in the intracellular calcium level. Interestingly, over-expression of the sequence variant containing a substitution of aspartic acid for a glutamic acid (E646D), previously found in patients with autism spectrum disorder (ASD), did not increase the free cellular calcium likely due to the mutation. In this study, we also describe the expression of ATP13A4 during mouse embryonic development. Quantitative real-time PCR revealed that ATP13A4 was highly expressed at embryonic days 15-17, when neurogenesis takes place. The present study is the first to provide further insights into the biological role of a P5-type ATPase. Our results demonstrate that ATP13A4 may be involved in calcium regulation and that its expression is developmentally regulated. Overall, this study provides support for the hypothesis that ATP13A4 may play a vital role in the developing nervous system and its impairment can contribute to the symptoms seen in ASD.