Brain MRI in Type 2 Diabetes

In recent years is has become clear that type 2 diabetes affects the central nervous system. These long-term complications manifest as structural changes on brain imaging, cognitive decrements and a 1.5-2 fold increased risk for the development of dementia, in particular in the elderly. The pathogenesis of diabetes-induced brain damage is not completely understood. Both vascular and metabolic disturbances may play an important role in the impact of diabetes on the brain. The course of development of cerebral changes in diabetes is also uncertain and may already have an onset in the preclinical stages of diabetes, like the metabolic syndrome. In this thesis, brain MR imaging, MR angiography and MR spectroscopy were performed to study structural brain changes as well as functional alterations of the cerebral vasculature and cerebral metabolism in patients with type 2 diabetes or metabolic syndrome. The relation of MR findings with clinical features and cognitive functioning was also addressed. With the results of these studies, we are able to identify patients with type 2 diabetes who have an increased risk for cognitive decline. This may direct the development of effective preventive strategies and help to decide at what stage these interventions should be initiated

Metabolic Syndrome, Prediabetes, and Brain Abnormalities on MRI in Patients With Manifest Arterial Disease: The SMART-MR Study

Pathophysiology, epidemiology and therapy of agein

Metabolic Syndrome, Prediabetes, and Brain Abnormalities on MRI in Patients With Manifest Arterial Disease: The SMART-MR Study

Pathophysiology, epidemiology and therapy of agein

Computer-aided detection improves detection of pulmonary nodules in chest radiographs beyond the support by bone-suppressed images

Item does not contain fulltextTo evaluate the added value of computer-aided detection (CAD) for lung nodules on chest radiographs when radiologists have bone-suppressed images (BSIs) available.Written informed consent was waived by the institutional review board. Selection of study images and study setup was reviewed and approved by the institutional review boards. Three hundred posteroanterior (PA) and lateral chest radiographs (189 radiographs with negative findings and 111 radiographs with a solitary nodule) in 300 subjects were selected from image archives at four institutions. PA images were processed by using a commercially available CAD, and PA BSIs were generated. Five radiologists and three residents evaluated the radiographs with BSIs available, first, without CAD and, second, after inspection of the CAD marks. Readers marked locations suspicious for a nodule and provided a confidence score for that location to be a nodule. Location-based receiver operating characteristic analysis was performed by using jackknife alternative free-response receiver operating characteristic analysis. Area under the curve (AUC) functioned as figure of merit, and P values were computed with the Dorfman-Berbaum-Metz method.Average nodule size was 16.2 mm. Stand-alone CAD reached a sensitivity of 74\% at 1.0 false-positive mark per image. Without CAD, average AUC for observers was 0.812. With CAD, performance significantly improved to an AUC of 0.841 (P = .0001). CAD detected 127 of 239 nodules that were missed after evaluation of the radiographs together with BSIs pooled over all observers. Only 57 of these detections were eventually marked by the observers after review of CAD candidates.CAD improved radiologists' performance for the detection of lung nodules on chest radiographs, even when baseline performance was optimized by providing lateral radiographs and BSIs. Still, most of the true-positive CAD candidates are dismissed by observers

Bone suppressed images improve radiologists' detection performance for pulmonary nodules in chest radiographs

To assess the effect of bone suppression imaging on observer performance in detecting lung nodules in chest radiographs.Posteroanterior (PA) and lateral digital chest radiographs of 111 (average age 65) patients with a CT proven solitary nodule (median diameter 15mm), and 189 (average age 63) controls were read by 5 radiologists and 3 residents. Conspicuity of nodules on the radiographs was classified in obvious (n=32), moderate (n=32), subtle (n=29) and very subtle (n=18). Observers read the PA and lateral chest radiographs without and with an additional PA bone suppressed image (BSI) (ClearRead Bone Suppression 2.4, Riverain Technologies, Ohio) within one reading session. Multi reader multi case (MRMC) receiver operating characteristics (ROC) were used for statistical analysis.ROC analysis showed improved detection with use of BSI compared to chest radiographs alone (AUC=0.883 versus 0.855; p=0.004). Performance also increased at high specificities exceeding 80\% (pAUC=0.136 versus 0.124; p=0.0007). Operating at a specificity of 90\%, sensitivity increased with BSI from 66\% to 71\% (p=0.0004). Increase of detection performance was highest for nodules with moderate and subtle conspicuity (p=0.02; p=0.03).Bone suppressed images improve radiologists' detection performance for pulmonary nodules, especially for those of moderate and subtle conspicuity