Contrast-enhanced ultrasound of the liver: Vascular pathologies and interventions

Over the past two decades, contrast-enhanced ultrasound (CEUS) has been established as a method complementary to B-mode ultrasound and color Doppler sonography for diagnosing vascular liver pathologies and interventions.The objective of this review is to elucidate the application of CEUS in diagnosing vascular pathologies and interventional procedures.Considering the limitations of ultrasound, CEUS presents a similar alternative to other imaging modalities, such as computed tomography and magnetic resonance imaging, for evaluating vascular pathologies, guiding interventions, identifying complications, and assessing outcomes post intervention. Due to its widespread availability and the absence of radiation exposure, CEUS should be employed as a primary modality. · CEUS plays an important role in the detection of vascular liver pathologies.. · CEUS is helpful in characterizing vascular pathologies.. · CEUS is helpful in guiding interventions and identifying complications..

The value of contrast-enhanced ultrasound in percutaneous biopsy of retroperitoneal masses

PURPOSE

To evaluate the diagnostic yield of contrast-enhanced ultrasound (CEUS)-guided biopsy of retroperitoneal masses (RMs).

MATERIALS AND METHODS

Between 2006 and 2023, 87 patients presented at our US center for biopsy of an RM. In all biopsies, CEUS was performed prior to the intervention. The technical success rate of biopsy, the presence of diagnostic tissue in solid tumor biopsy samples, the accuracy of the biopsy and the occurrence of post-interventional complications were evaluated.

RESULTS

A US-guided biopsy could be conducted in 84/87 cases (96.6%). In 3/87 cases (3.4%), US-guided biopsy was impossible because the planned needle path was obstructed by vital structures. Of 84 lesions, 80 (95.2%) were solid lesions, and 4 (4.8%) were lesions containing fluid. In all solid tumors, 80/80 (100%), diagnostic vital tissue was successfully obtained. CEUS-guided biopsy showed a sensitivity of 93.2%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 72.2%, and a diagnostic accuracy of 94.2% for the differentiation between malignant and benign RMs. In one of the 84 cases (1.2%), there was a complication of postinterventional abdominal pain.

CONCLUSION

Percutaneous CEUS-guided biopsy is a safe procedure with a high diagnostic yield and a low complication rate.

Imaging in pulmonary infections of immunocompetent adult patients

Pneumonia is a clinical syndrome characterised by fever, cough and alveolar infiltration of purulent fluid, caused by infection with a microbial pathogen. It can be caused by infections with bacteria, viruses or fungi, but a causative organism is identified in less than half of cases. The most common type of pneumonia is community-acquired pneumonia, which is caused by infections acquired outside the hospital. Current guidelines for pneumonia diagnosis require imaging to confirm the clinical suspicion of pneumonia. Thus, imaging plays an important role in both the diagnosis and management of pneumonia, with each modality having specific advantages and limitations. Chest radiographs are commonly used but have limitations in terms of sensitivity and specificity. Lung ultrasound shows high sensitivity and specificity. Computed tomography scans offer higher diagnostic accuracy but involve higher radiation doses. Radiological patterns, including lobar, lobular and interstitial pneumonia, provide valuable insights into causative pathogens and treatment decisions. Understanding these radiological patterns is crucial for accurate diagnosis. In this review, we will summarise the most important aspects pertaining to the role of imaging in pneumonia and will highlight the imaging characteristics of the most common causative organisms.

Hughes-Stovin syndrome-An important differential diagnosis in patients with suspected chronic thromboembolic pulmonary hypertension : A case report

Hughes-Stovin syndrome (HSS) is a rare vasculitis of unknown etiology. The disease is characterized by pronounced inflammation and damage to the vessel walls, with subsequent widespread vascular thrombosis and the formation of pulmonary artery aneurysms that can lead to fatal hemoptysis. This disorder can be mistaken for other conditions, such as chronic thromboembolic pulmonary disease (CTEPD) without or with pulmonary hypertension at rest (CTEPH).We report the case of a 20-year-old female with HSS, which was misdiagnosed as CTEPH and subsequently treated with anticoagulants, which led to severe hemoptysis and eventually death of the patient. This case highlights the challenges of diagnosing HSS at early stages of the disease.HSS should be considered in young patients with signs of large vessel vasculitis in combination with thrombotic occlusions of pulmonary arteries, with or without aneurysms of the pulmonary arteries, and particularly, if there are no risk factors for thromboembolic disease.

Correlation of histologic, imaging, and artificial intelligence features in NAFLD patients, derived from Gd-EOB-DTPA-enhanced MRI: a proof-of-concept study

OBJECTIVE

To compare unsupervised deep clustering (UDC) to fat fraction (FF) and relative liver enhancement (RLE) on Gd-EOB-DTPA-enhanced MRI to distinguish simple steatosis from non-alcoholic steatohepatitis (NASH), using histology as the gold standard.

MATERIALS AND METHODS

A derivation group of 46 non-alcoholic fatty liver disease (NAFLD) patients underwent 3-T MRI. Histology assessed steatosis, inflammation, ballooning, and fibrosis. UDC was trained to group different texture patterns from MR data into 10 distinct clusters per sequence on unenhanced T1- and Gd-EOB-DTPA-enhanced T1-weighted hepatobiliary phase (T1-Gd-EOB-DTPA-HBP), then on T1 in- and opposed-phase images. RLE and FF were quantified on identical sequences. Differences of these parameters between NASH and simple steatosis were evaluated with χ2- and t-tests, respectively. Linear regression and Random Forest classifier were performed to identify associations between histological NAFLD features, RLE, FF, and UDC patterns, and then determine predictors able to distinguish simple steatosis from NASH. ROC curves assessed diagnostic performance of UDC, RLE, and FF. Finally, we tested these parameters on 30 validation cohorts.

RESULTS

For the derivation group, UDC-derived features from unenhanced and T1-Gd-EOB-DTPA-HBP, plus from T1 in- and opposed-phase, distinguished NASH from simple steatosis (p ≤ 0.001 and p = 0.02, respectively) with 85% and 80% accuracy, respectively, while RLE and FF distinguished NASH from simple steatosis (p ≤ 0.001 and p = 0.004, respectively), with 83% and 78% accuracy, respectively. On multivariate regression analysis, RLE and FF correlated only with fibrosis (p = 0.040) and steatosis (p ≤ 0.001), respectively. Conversely, UDC features, using Random Forest classifier predictors, correlated with all histologic NAFLD components. The validation group confirmed these results for both approaches.

CONCLUSION

UDC, RLE, and FF could independently separate NASH from simple steatosis. UDC may predict all histologic NAFLD components.

CLINICAL RELEVANCE STATEMENT

Using gadoxetic acid-enhanced MR, fat fraction (FF > 5%) can diagnose NAFLD, and relative liver enhancement can distinguish NASH from simple steatosis. Adding AI may let us non-invasively estimate the histologic components, i.e., fat, ballooning, inflammation, and fibrosis, the latter the main prognosticator.

KEY POINTS

• Unsupervised deep clustering (UDC) and MR-based parameters (FF and RLE) could independently distinguish simple steatosis from NASH in the derivation group. • On multivariate analysis, RLE could predict only fibrosis, and FF could predict only steatosis; however, UDC could predict all histologic NAFLD components in the derivation group. • The validation cohort confirmed the findings for the derivation group.

Imaging in patients with acute dyspnea when cardiac or pulmonary origin is suspected

A wide spectrum of conditions, from life-threatening to non-urgent, can manifest with acute dyspnea, thus presenting major challenges for the treating physician when establishing the diagnosis and severity of the underlying disease. Imaging plays a decisive role in the assessment of acute dyspnea of cardiac and/or pulmonary origin. This article presents an overview of the current imaging modalities used to narrow the differential diagnosis in the assessment of acute dyspnea of cardiac or pulmonary origin. The current indications, findings, accuracy, and limits of each imaging modality are reported.

Chest radiography is usually the primary imaging modality applied. There is a low radiation dose associated with this method, and it can assess the presence of fluid in the lung or pleura, consolidations, hyperinflation, pneumothorax, as well as heart enlargement. However, its low sensitivity limits the ability of the chest radiograph to accurately identify the causes of acute dyspnea.

Computer tomography provides more detailed imaging of the cardiorespiratory system, and therefore, better sensitivity and specificity results, but it is accompanied by higher radiation exposure. Ultrasonography has the advantage of using no radiation, and is fast and feasible as a bedside test and appropriate for the assessment of unstable patients. However, patient-specific factors, such as body habitus, may limit its image quality and interpretability.

Advances in knowledge: this review provides guidance to the appropriate choice of imaging modalities in the diagnosis of patients with dyspnea of cardiac or pulmonary origin.