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BackgroundThe 2010 Revisions to the McDonald Criteria have established that dissemination in time (DIT) of multiple sclerosis (MS) can be demonstrated by simultaneous presence of asymptomatic gadolinium-enhancing and nonenhancing lesions on a single magnetic resonance imaging (MRI). However, gadolinium-based contrast agents (GBCAs) have contraindications. Diffusion-weighted imaging (DWI) can detect diffusion alterations in active inflammatory lesions. The purpose of this study was to investigate if DWI can be an alternative to contrast-enhanced T1-weighted imaging (CE T1WI) for demonstrating DIT in MS.MethodsWe selected patients with clinically definite MS and evaluated their baseline brain MRI. Asymptomatic lesions were identified as either hyperintense or nonhyperintense on DWI and enhancing or nonenhancing on CE T1WI. Fisher’s exact test was performed to determine whether the hyperintensity on DWI was related to the enhancement on CE T1WI (P < 0.05). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the DWI to predict lesion enhancement were calculated.ResultsTwenty-two patients with 384 demyelinating lesions that were hyperintense on T2-weighted imaging and more than 3 mm in size were recruited. The diffusion hyperintensity and lesion enhancement were significantly correlated (P <0.001). The sensitivity, specificity, PPV, NPV and accuracy were 100%, 67.9%, 32.3%, 100% and 72.1%, respectively.ConclusionsA hyperintense DWI finding does not necessarily overlap with contrast enhancement. There are many false positives, possibly representing other stages of lesion development. Although DWI may not replace CE T1WI imaging to demonstrate DIT due to the low PPV, it may serve as a screening MRI sequence where the use of GBCAs is a concern.

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Breast magnetic resonance imaging (MRI) is currently a widely used clinical examination tool. Recently, MR diffusion-related technologies, such as intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI), have been extensively studied by breast cancer researchers and gradually adopted in clinical practice. In this study, we explored automatic tumor detection by IVIM-DWI. We considered the acquired IVIM-DWI data as a hyperspectral image cube and used a well-known hyperspectral subpixel target detection technique: constrained energy minimization (CEM). Two extended CEM methods—kernel CEM (K-CEM) and iterative CEM (I-CEM)—were employed to detect breast tumors. The K-means and fuzzy C-means clustering algorithms were also evaluated. The quantitative measurement results were compared to dynamic contrast-enhanced T1-MR imaging as ground truth. All four methods were successful in detecting tumors for all the patients studied. The clustering methods were found to be faster, but the CEM methods demonstrated better performance according to both the Dice and Jaccard metrics. These unsupervised tumor detection methods have the advantage of potentially eliminating operator variability. The quantitative results can be measured by using ADC, signal attenuation slope, D*, D, and PF parameters to classify tumors of mass, non-mass, cyst, and fibroadenoma types.

Modifications to the McDonald MRI dissemination in space criteria (by using fewer T2 lesions, removal of the restriction on the spinal cord lesion and reduction of the cutoff of MRI criteria) are more appropriate for use in the Taiwanese population for the diagnosis of classic multiple sclerosis.

The study aimed to characterize the association of gastric acid suppressants (GAS) with the development of spontaneous bacterial peritonitis (SBP) in cirrhotic patients with ascites. A retrospective case controlled study from January 2013 to December 2017 at Cheng‐Ching General Hospital was conducted. We included patients with a diagnosis of liver cirrhosis with ascites, divided into those with and without SBP. SBP was defined by ascitic fluid polymorphonuclear cell level. GAS users were patients who received GAS daily for more than 7 days in the 90 days before admission. Of 229 cirrhotic patients enrolled, 60 had SBP and 169 did not. The groups differed significantly in albumin (P = .045) and total bilirubin (P = .016) levels; in international normalized ratio (P = .007) and proton pump inhibitor (PPI) use (P = .021); but not in histamine‐2 receptor antagonist (H2RA) use. Multivariate analysis identified PPI use as the only independent risk factor for SBP development (odds ratio 2.101, 95% confidence interval 1.122‐3.935, P = .02). PPIs but not H2RAs may increase the incidence of SBP in cirrhotic patients with ascites. Prescribing PPIs in cirrhotic patients should be done carefully, for the minimal effective treatment duration.

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