Voxel‐wise quantification of myocardial perfusion by cardiac magnetic resonance. Feasibility and methods comparison

The purpose of this study is to enable high spatial resolution voxel‐wise quantitative analysis of myocardial perfusion in dynamic contrast‐enhanced cardiovascular MR, in particular by finding the most favorable quantification algorithm in this context. Four deconvolution algorithms—Fermi function modeling, deconvolution using B‐spline basis, deconvolution using exponential basis, and autoregressive moving average modeling —were tested to calculate voxel‐wise perfusion estimates. The algorithms were developed on synthetic data and validated against a true gold‐standard using a hardware perfusion phantom. The accuracy of each method was assessed for different levels of spatial averaging and perfusion rate. Finally, voxel‐wise analysis was used to generate high resolution perfusion maps on real data acquired from five patients with suspected coronary artery disease and two healthy volunteers. On both synthetic and perfusion phantom data, the B‐spline method had the highest error in estimation of myocardial blood flow. The autoregressive moving average modeling and exponential methods gave accurate estimates of myocardial blood flow. The Fermi model was the most robust method to noise. Both simulations and maps in the patients and hardware phantom showed that voxel‐wise quantification of myocardium perfusion is feasible and can be used to detect abnormal regions. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.     

Racial and ethnic differences in symptom severity of PTSD, GAD, and depression in trauma-exposed, urban, treatment-seeking adults

Urban, socially disadvantaged individuals are at high risk for traumatic event exposure and its subsequent psychiatric symptomatology. This study examined the association between race/ethnicity and symptom severity of posttraumatic stress disorder (PTSD), generalized anxiety disorder (GAD), and depression in an urban clinical sample of 170 trauma-exposed adults. In addition, this study investigated the role of socioeconomic position (SEP) and coping style in the relationship between race/ethnicity and posttrauma psychiatric symptom severity. Hierarchical regression analyses indicated that Blacks had lower depression symptom severity compared to Whites. No significant relationship was found between racial/ethnic group status and indices of SEP, PTSD, or GAD symptom severity. Adjustment for trauma exposure, gender, positive reframe coping, avoidance coping and negative coping accounted for 3%, 3%, 8%, 4%, and 3% of the variance in depression severity, respectively; however, Black race remained significantly associated with decreased depression symptom severity accounting for a statistically significant 5% of the variance in lower depression symptom severity. These preliminary findings and their clinical implications are discussed.     

Outcome of Invasive and Noninvasive Intraductal Papillary-Mucinous Neoplasms of the Pancreas (IPMN): A 10-year Experience

BACKGROUND: Intraductal papillary-mucinous neoplasms (IPMN) were officially introduced into the TNM classification in 1996. Based on a two-center database, we reevaluated histopathological findings, clinicopathological pattern, predictive markers for malignancy, and outcome. METHODS: Between 1996 and 2006, a total of 1424 pancreatic resections were performed in the University Hospitals Dresden and Mannheim. Pathologists of both institutions reviewed the IPMN diagnoses and other with cystic or solid tumor diagnoses. All possible markers, such as diabetes, jaundice, etc., were analyzed for prediction of malignancy. We performed a survival analysis based on the morphologic classification to determine the prognosis of IPMN. RESULTS: There were 43 patients of primarily diagnosed IPMN along with 1174 patients with diagnoses, such as ductal adenocarcinoma. In 207 patients, the diagnoses revealed other cystic or small solid tumors. A histopathological review of the latter patients revealed 54 IPMNs, resulting in a total of 97 IPMN patients (29 noninvasive, 68 invasive). All IPMN patients had a median survival of 36 months. Recurrence occurred more frequently in invasive IPMN. Predictive markers of malignancy were pain, preoperative weight loss, jaundice, and elevated CA 19.9. The strongest independent prognostic factor was invasive growth. The survival analysis revealed excellent prognosis for noninvasive IPMN. CONCLUSIONS: Since the introduction of IPMN in 1996, even specialized centers have had to deal with a learning curve. By reevaluating all cystic or small solid tumors, centers can improve and their patients' treatment can be optimized. Because the preoperative diagnostic methods are not sensitive enough to differentiate between benign and malignant lesions, surgery is advocated for all main duct IPMN, because they have a high malignant potential. For branch duct IPMN, surgery is advocated if the lesion is symptomatic, >3 cm, or has enlarged nodules.     

T-cell alloimmunity and chronic allograft dysfunction

Solid organ transplantation is the standard treatment to improve both the quality of life and survival in patients with various end-stage organ diseases. The primary barrier against successful transplantation is recipient alloimmunity and the need to be maintained on immunosuppressive therapies with associated side effects. Despite such treatments in renal transplantation, after death with a functioning graft, chronic allograft dysfunction (CAD) is the most common cause of late allograft loss. Recipient recognition of donor histocompatibility antigens, via direct, indirect, and semidirect pathways, is critically dependent on the antigen-presenting cell (APC) and elicits effector responses dominated by recipient T cells. In allograft rejection, the engagement of recipient and donor cells results in recruitment of T-helper (Th) cells of the Th1 and Th17 lineage to the graft. In cases in which the alloresponse is dominated by regulatory T cells (Tregs), rejection can be prevented and the allograft tolerated with minimum or no immunosuppression. Here, we review the pathways of allorecognition that underlie CAD and the T-cell effector phenotypes elicited as part of the alloresponse. Future therapies including depletion of donor-reactive lymphocytes, costimulation blockade, negative vaccination using dendritic cell subtypes, and Treg therapy are inferred from an understanding of these mechanisms of allograft rejection.     

Risk-Adapted Anastomosis for Partial Pancreaticoduodenectomy Reduces the Risk of Pancreatic Fistula: A Pilot Study

Background

Pancreatic fistula (PF) is the main cause of postoperative morbidity and mortality after pancreatectomy. Two reasons for PF are a “soft” pancreatic texture and a narrow pancreatic duct (high-risk gland). Pancreaticojejunostomy (PJ) may lead to a higher fistula rate in such glands. In the literature there are no data available on risk-adapted assignment of pancreatogastrostomy (PG) in a high-risk gland. Therefore, an observational pilot study was conducted to address this issue.

Methods

Since January 2007 the concept of a “risk-adapted pancreatic anastomosis” (RAP) was introduced (PG for high-risk glands). The PF rate, morbidity, and mortality during this period (January 2007 to December 2008, n = 74) were compared to those between January 2004 and December 2006 (n = 119, only PJ). PF was defined according to the International Study Group on Pancreatic Surgery.

Results

Through RAP the PF rate was reduced from 22 to 11% (P = 0.0503). Grade C PF rate was reduced from 6.7 to 1.4% (P = 0.1569) and grade A PF from 6 to 1.4% (P = 0.2537). The PF-associated mortality was reduced from 3.4 to 1.4%. PG revealed a PF rate of 7% and PJ accounted for 19% of PFs (P = 0.1765). There was no incidence of grade C PF following PG. The incidence of intraluminal hemorrhage (P = 0.0422) and delayed gastric emptying (P = 0.0572) was higher following PG.

Conclusions

The rate of PF could be significantly reduced with the use of RAP. One should be cautious about the indication for PG, since it is associated with a higher rate of intraluminal hemorrhage and delayed gastric emptying. There are no long-term results on PG with respect to its durability and function. A general recommendation for its use cannot currently be made.     

Cytotoxic lesions of the corpus callosum (CLOCCs) associated with SARS-CoV-2 infection

Journal of Neurology -     

Factors Predicting Long-Term Survival Following Pancreatic Resection for Ductal Adenocarcinoma of the Pancreas: 40 Years of Experience

Background

Long-term survival after resection for pancreas carcinoma has rarely been reported. Factors influencing long-term survival are still under debate. The aim of this study was to define predictors for long-term survival.

Methods

Between 1972 and 2004, a total of 415 patients underwent resection. Data were collected in a prospective data base. Data of 360 patients were available for further analysis in 2011. All specimens of long-term survivors were histologically reviewed.

Results

Long-term survivors (n?=?69) had a median survival of 91 months. Pathological re-evaluation of all specimens re-confirmed the diagnosis. Predictive factors for long-term survival in univariate analysis were no preoperative biliary stent, low CA 19-9 level, lack of blood transfusion, R0 resection, tumour diameter, and -grading, absence of lymph node or distant metastases, lymphangiosis, and perineural infiltration. Adjuvant chemotherapy showed a significant influence on overall survival but not on long-term survival. In multivariate analysis, lymph node ratio and volume of blood transfusion were predictors of long-term survival.

Conclusion

Nearly 20 % of patients with pancreas carcinoma who undergo surgical resection have a chance of long-term survival. Survival beyond 5 years is predicted by clinical and tumour-specific factors. Adjuvant chemotherapy might prolong overall survival but is, according to these results, unable to contribute to long-term survival. There is still a risk of recurrence after a 5- or even a 12-year mark. Survival beyond 5 or even 12 years, therefore, does not assure cure.