Fat-containing liver lesions: a pictorial review

The aim of this pictorial essay is to review the spectrum of fat-containing liver lesions and their characterisation on magnetic resonance imaging with focus on the radiological features that aid in the differential diagnoses. Fat-containing liver lesions comprise a heterogeneous group of tumours with variable imaging findings. Magnetic resonance imaging clearly displays the micro- and macroscopic fat components of the lesions and other characteristic features that are helpful tools to make the differential diagnosis.

Tuboperitoneal fistula, ectopic pregnancy, and remnants of fallopian tube: a confocal microtomography analysis and 3D reconstruction of human fallopian tube pathologies

Objective: The aim of this study was to provide a three-dimensional (3D) microscopic reconstruction of morphological modifications of the fallopian tube (FT) following surgical sterilization (including tuboperitoneal fistula) and ectopic pregnancy (EP) using confocal microtomography (micro-CT). Methods: Six specimens of FT from elective and emergency surgeries were selected: three remnants of the FT (RFT) from surgical sterilization, including one presenting tuboperitoneal fistula, and three FTs with EP. The specimens were fixed in formalin and stained with Lugol solution. Micro-CT studies were conducted on the specimens using protocols adapted from biological studies. Results: Three RFTs from surgical sterilization and three FTs affected by EPs were successfully scanned using micro-CT. There was good contrast impregnation, allowing tissue segmentation and analysis of different sections of the FTs. Three FT specimens from EP exhibited considerable distortion of the tubal anatomy, mainly from the blood clot in the tubal abortion. Three RFT specimens exhibited some features observed in traditional microscopy, such as tubal distension and loss of normal anatomical characteristics of a normal FT, and indicated the presence of a tuboperitoneal fistula in one of the three specimens. Conclusion: Micro-CT can identify morphological characteristics of FT pathologies previously described in a microscopic scale, with tissue contrast and the possibility of 3D reconstruction. Micro-CT is also useful in guiding traditional sectioning of specimens for histopathological studies.

Detection of coronary artery calcification with nontriggered computed tomography of the chest

Objective

To evaluate the accuracy of visual analysis and of the coronary artery calcium (CAC) score in nontriggered computed tomography (CT), in comparison with that of the CAC score in electrocardiogram-triggered CT, in identifying coronary calcification.

Materials and Methods

A total of 174 patients for whom CT was indicated for CAC scoring underwent nontriggered and triggered CT in a 64-channel multislice scanner, in a single session without a change in position. The images were interpreted by a radiologist with seven years of experience in thoracic and cardiovascular radiology. The measurement of coronary calcium was carried out by three methods: CAC score with dedicated software in nontriggered CT, CAC score with dedicated software in triggered CT, and visual analysis without dedicated software in nontriggered CT.

Results

In nontriggered CT, the CAC score presented an accuracy of 95.98% (95% CI: 91.93-98.04). The visual analysis showed an accuracy of 97.13% (95% CI: 93.45-98.77).

Conclusion

Nontriggered CT showed excellent accuracy in the identification and exclusion of coronary calcification, either the CAC score was determined with dedicated software or through visual analysis.

Multiparametric Magnetic Resonance Imaging in the Assessment of Pulmonary Hypertension: Initial Experience of a One-Stop Study

INTRODUCTION

Our goal was to assess the diagnostic performance of magnetic resonance imaging (MRI) as a single method to diagnose pulmonary hypertension (PH) compared to right heart catheterization (RHC), computed tomography (CT), and ventilation/perfusion (V/Q) scintigraphy.

METHODS

We identified 35 patients diagnosed with PH by RHC in our institution who have also undergone a CT, a scintigraphy, and an MRI within a month. All cases were discussed in multidisciplinary meetings. We performed correlations between the MRI-derived hemodynamic parameters and those from RHC. The sensitivity and specificity of MRI were determined to identify its diagnostic performance to identify chronic thromboembolic pulmonary hypertension (CTEPH) and interstitial lung disease PH. The gold standard reference for the diagnosis of CTEPH and ILD was based on a review of multimodality imaging (V/Q scintigraphy and CT scan) and clinical findings.

RESULTS

Our results showed a good correlation between the hemodynamic parameters of cardiac MRI and RHC. Pulmonary vascular resistance had the best correlation between both methods (r = 0.923). The sensitivity and specificity of MRI to diagnose CTEPH was 100 and 96.8%, respectively. For the ILD-related PH, the MRI yielded a sensitivity of 60.0% and a specificity of 100%. Additionally, cardiac MRI was able to confirm all cases of PAH due to congenital heart disease initially detected by echocardiography.

CONCLUSIONS

MRI represents a promising imaging modality as an initial, single-shot study, for patients with suspected PH with the advantages of being non-invasive and having no radiation exposure.

Effects of blood glucose level on 18F fluorodeoxyglucose (18F-FDG) uptake for PET/CT in normal organs: an analysis on 5623 patients

Our purpose was to evaluate the effect of glycemia on ¹⁸F-FDG uptake in normal organs of interest. The influences of other confounding factors, such as body mass index (BMI), diabetes, age, and sex, on the relationships between glycemia and organ-specific standardized uptake values (SUVs) were also investigated. We retrospectively identified 5623 consecutive patients who had undergone clinical PET/CT for oncological indications. Patients were stratified into groups based on glucose levels, measured immediately before ¹⁸F-FDG injection. Differences in mean SUVmax values among glycemic ranges were clinically significant only when >10% variation was observed. The brain was the only organ that presented a significant inverse relationship between SUVmax and glycemia (p < 0.001), even after controlling for diabetic status. No such difference was observed for the liver or lung. After adjustment for sex, age, and BMI, the association of glycemia with SUVmax was significant for the brain and liver, but not for the lung. In conclusion, the brain was the only organ analyzed showing a clinically significant relationship to glycemia after adjustment for potentially confounding variables. The lung was least affected by the variables in our model, and may serve as an alternative background tissue to the liver.