Diagnosing and staging of cystic echinococcosis: how do CT and MRI perform in comparison to ultrasound?

BACKGROUND: Imaging plays the key role in diagnosing and staging of CE. The description of CE-specific imaging features and the WHO CE cyst classification is based on ultrasound. The reproducibility of the ultrasound-defined features of CE cysts is variable in MR- and CT-imaging. This is of particular importance for cysts that are not accessible by US and because of the increasing availability and overuse of CT and MR imaging. METHODOLOGY/PRINCIPAL FINDINGS: Retrospective analysis of patients with abdominal CE cysts of an interdisciplinary CE clinic who had CT and/or MRI scans performed additionally to US imaging. All images were read and interpreted by the same senior radiologist experienced in the diagnosis of CE. US, CT and MR images were staged according to the WHO classification criteria. The agreement beyond chance was quantified by kappa coefficients (κ). 107 patients with 187 CE cysts met the inclusion criteria. All cysts were assessed by US, 138 by CT, and 125 by MRI. The level of agreement beyond chance of the individual CE stages 1-4 was clearly lower for CT, with κ ranging from 0.62 to 0.72, compared to MRI with values of κ between 0.83 and 1.0. For CE5 cysts CT (κ = 0.95) performed better than MRI (κ = 0.65). CONCLUSIONS: Ultrasound remains the corner stone of diagnosis, staging and follow up of CE cysts. MRI reproduces the ultrasound-defined features of CE better than CT. If US cannot be performed due to cyst location or patient-specific reasons MRI with heavily T2-weighted series is preferable to CT

Levels of agreement and kappa coefficients for US vs. CT, US vs. MRI and US vs. different MRI sequences.

1<p>FLASH: Fast Low Angle Shot,</p>2<p>TSE: Turbo-Spin-Echo,</p>3<p>TrueFisp: True Fast Imaging With Steady Precession,</p>4<p>HASTE: Half fourier-Acquired Single shot Turbo spin Echo (or corresponding sequences of other manufacturers than Siemens). Differences in number of cysts are due to varieties in MRI-protocols, especially of ex-domo-patients.</p

Levels of agreement and kappa coefficients for US vs. CT and for US vs. MRI stratified by WHO stages (defined by US).

<p>Cyst-stage specific kappa values: CT are more to the lower end of the category “good” (0.61–0.80), MRI at the upper end of the category “very good” (0.81–1.0).</p

“Best case” of CT/MR imaging.

<p>CE1: unilocular, simple cysts with liquid content and often with the CE1-specific “double line sign”, CE2: multivesicular, multiseptated cysts, CE3a: cysts with liquid content and the CE3a-specific detached endocyst, CE3b: unilocular cysts with daughter cysts inside a mucinous or solid cyst matrix, CE4: heterogenous solid cysts with degenerative, CE4-specific canalicular structure of the cyst content, and CE5: cysts with degenerative content and heavily calcified wall.</p

Scatter plots of the agreement beyond chance of US versus MRI.

<p>Scatter plots of the agreement beyond chance of US versus contrast enhanced T1w-FLASH, TrueFisp, HASTE and T2w-TSE MRI modes.</p

Number of cysts per WHO cyst stage (CE 1–5) as determined by US (N = 187).

<p>Number of cysts per WHO cyst stage (CE 1–5) as determined by US (N = 187).</p

Scatter plots of the agreement beyond chance of US vs. CT and US vs. MRI.

<p>Scatter plots of the agreement beyond chance of US vs. CT and US vs. MRI.</p

In-house MRI protocols with detailed sequence parameters.

1<p>TrueFisp: True Fast Imaging With Steady Precession,</p>2<p>TR: Repetition Time,</p>3<p>TE: Time to Echo.</p>4<p>FLASH: Fast Low Angle Shot,</p>5<p>TSE: Turbo-Spin-Echo,</p>6<p>HASTE: Half fourier-Acquired Single shot Turbo spin Echo, w: weighted.</p

Dietary Factors in Relation to Liver Fat Content: A Cross-sectional Study

Non-alcoholic fatty liver disease (NAFLD) can lead to functional liver impairment and severe comorbidities. Beyond energy balance, several dietary factors may increase NAFLD risk, but human studies are lacking. The aim of this cross-sectional study was to investigate the associations between food consumption (47 food groups, derived Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diet quality scores) and liver fat content (continuous scale and NAFLD, i.e., &gt;5% liver fat content). Liver fat content was measured by magnetic resonance imaging (MRI) in 136 individuals (BMI: 25&ndash;40 kg/m2, age: 35&ndash;65, 50.7% women) and food intake was recorded by food frequency questionnaires (FFQs). Associations between food items and liver fat were evaluated by multi-variable regression models. Intakes of cake and cookies as well legumes were inversely associated with liver fat content, while positive associations with intakes of high-fat dairy and cheese were observed. Only cake and cookie intake also showed an inverse association with NAFLD. This inverse association was unexpected, but not affected by adjustment for reporting bias. Both diet quality scores were inversely associated with liver fat content and NAFLD. Thus, as smaller previous intervention studies, our results suggest that higher diet quality is related to lower liver fat, but larger trials with iso-caloric interventions are needed to corroborate these findings