Pheochromocytoma and Adrenocortical Carcinoma: Morphological Characteristics in Endoscopic Ultrasound Imaging

Purpose Pheochromocytoma (PCC) and adrenocortical carcinoma (ACC) are two rare endocrine diseases. Early diagnosis is crucial to significantly reduce morbidity and mortality. In this study, we used endoscopic ultrasound (EUS) for high-resolution imaging to investigate the endosonographic morphology pattern of PCC and ACC. Materials and Methods This retrospective cohort study included 58 PCC/ACC lesions diagnosed by EUS imaging at two tertiary care centers between 1997 and 2015. The following groups were defined by histology or by the presence of a pheochromocytoma-associated syndrome without histological proof: bPCC (benign PCC), mPCC (malignant PCC), and ACC. Results In our cohort, mPCC tended to be larger at the time of diagnosis (n=5; 39.9±41.9 mm) than bPCC (n=46; 27.3 ±20.8 mm, P=0.548). ACC lesions were significantly larger (n=7; 50.6±14.8 mm) than bPCC and mPCC (n=51; 28.5±23.3 mm, P=0.002). In EUS, bPCC and ACC lesions frequently appeared to have a round shape and nodular structure. bPCC and ACC tended to be more hyperechoic (P=0.112 and P=0.558, respectively) and heterogeneous (P=0.501 and P=0.098, respectively) than mPCC. Compared to PCC, ACC did not show high hyperperfusion (P=0.022). In contrast to adenoma, all tumor entities showed hypo-/anechoic areas within the tumor (P<0.05). Conclusion No significant differences in EUS morphology were found to reliably distinguish benign from malignant PCC and ACC lesions. However, EUS may be a reasonable alternative or complementary method to conventional imaging techniques for the early detection of these tumor entities.

Transthoracic Vector Flow Imaging in Pediatric Patients with Valvular Stenosis – A Proof of Concept Study

Purpose Continuous wave Doppler ultrasound is routinely used to detect cardiac valve stenoses. Vector flow imaging (VFI) is an angle-independent real-time ultrasound method that can quantify flow complexity. We aimed to evaluate if quantification of flow complexity could reliably assess valvular stenosis in pediatric patients. Materials and Methods Nine pediatric patients with echocardiographically confirmed valvular stenosis were included in the study. VFI and Doppler measurements were compared with transvalvular peak-to-peak pressure differences derived from invasive endovascular catheterization. Results Vector concentration correlated with the catheter measurements before intervention after exclusion of one outlier (r=−0.83, p=0.01), whereas the Doppler method did not (r=0.49, p=0.22). The change in vector concentration after intervention correlated strongly with the change in the measured catheter pressure difference (r=−0.86, p=0.003), while Doppler showed a tendency for a moderate correlation (r=0.63, p=0.07). Conclusion Transthoracic flow complexity quantification calculated from VFI data is feasible and may be useful for assessing valvular stenosis severity in pediatric patients.

Development of a Standardized Semantic Feature-Based Reporting Proforma for Intraoperative Ultrasound Findings in Brain Tumors and Application in High-Grade Gliomas – A Preliminary Study

Purpose A semantic feature-based reporting proforma for intraoperative ultrasound findings in brain tumors was devised to standardize reporting. It was applied as a pilot study on a cohort of histologically confirmed high-grade supratentorial gliomas (Grade 3 and 4) for internal validation. Materials and Methods This intraoperative semantic ultrasound proforma was used to evaluate 3D ultrasound volumes using Radiant DICOM software by 3 surgeons. The ultrasound semantic features were correlated with histological features like tumor grade, IDH status, and MIB index. Results 68 patients were analyzed using the semantic proforma. Irregular crenated was the most common margin (63.2%) and lesions were heterogeneously hyperechoic (95.6%). Necrosis was commonly seen and noted as single (67.6%) or multiple (13.2%) in over 80% cases. A separate perilesional zone, which was predominantly hyperechoic in 41.8% and both hypo and hyperechoic in 12.7%, could be identified in 54.5% of cases. Grade 4 tumors were more likely to have an irregular crenated margin (71.2%) with a single large area of necrosis, while Grade 3 tumors were likely to have smooth (31.3%) or non-characterizable margins (31.2%) with no or multiple areas of necrosis. IDH-negative tumors were more likely to have a single large focus of necrosis. Among the GBMs (52 cases), MIB labelling index of>15% was associated with poorly delineated, uncharacterizable margins, when compared with MIB labelling index<15% (23.5 vs. 0%), (p=0.046). Conclusion A detailed semantic proforma was developed for brain tumors and was internally validated. A few ultrasound sematic features were identified correlating with histological features in high-grade gliomas. It will require further external validation for refinement and acceptability.

Evaluation of Cystic and Solid Renal Lesions with Contrast-Enhanced Ultrasound: A Retrospective Study

Purpose Renal lesions are frequent random findings on CT, MRI, and conventional ultrasound. Since they are usually found accidentally, the respective examinations have not been performed optimally to provide a conclusive diagnosis, making additional multiphase contrast-enhanced examinations necessary. The aim of the study is to correlate CEUS findings with the final diagnosis and to determine whether it is a suitable method for the conclusive characterization of undetermined renal lesions. Materials and Methods All CEUS examinations of focal renal lesions performed at our institute between 2007 and 2014 were retrospectively examined. 437 patients with a total of 491 lesions and 543 examinations were included. 54 patients had bilateral lesions. One patient had three lesions in one kidney. Histology was available in 49 cases and follow-ups in 124 cases. The sensitivity, specificity, positive and negative predictive value as well as positive and negative likelihood ratios were calculated. Results There were 54 malignant and 437 benign lesions. The sensitivity and specificity were 0.981/0.954 overall, 1.000/0.956 for cystic lesions, 0.977/0.906 for solid lesions, and 0.971/0.071 for the histologically confirmed lesions. Bosniak classification was consistent in 289 of 301 lesions (96%). Only 12 lesions (3.9%) were falsely assessed as malignant. Conclusion CEUS is an appropriate method for the clarification of undetermined renal lesions. The characterization of cystic lesions according to Bosniak is adequately possible, especially for potentially malignant lesions (types III and IV).

Editorial

Dear Colleagues,It is a special pleasure to introduce the first issue of Ultrasound International Open in a still difficult year – a year, in which many of us had concerns and clinical tasks reaching far beyond basic or clinical science on ultrasonography (US). Thus, I am delighted to draw your attention to some interesting and important new papers teaching us on various aspects of our every dayʼs US practice.

Diagnostic Accuracy of Transabdominal Ultrasound and Computed Tomography in Chronic Pancreatitis: A Head-to-Head Comparison

Purpose Computed tomography (CT) is the most used imaging modality for diagnosing chronic pancreatitis (CP), but advances in transabdominal ultrasound (US) technology have given US a position as a viable alternative. We aimed to evaluate the diagnostic accuracy of abdominal CT and pancreatic US compared to the reference standard, a modified Mayo score. Materials and Methods CT, US, and endoscopic ultrasound (EUS) were performed in patients referred due to suspected CP. The modified Mayo score included EUS results, clinical presentation, and results from exocrine and endocrine pancreatic function tests. We scored CT findings according to the modified Cambridge classification and US findings according to the Rosemont classification. Results In total, 73 patients were included. 53 patients (73%) were categorized as CP and 20 (27%) as non-CP. CT and US yielded similar sensitivities (68% and 64%, respectively) and specificities (75 and 85%, respectively) and similar areas under the receiver operating characteristic curves for diagnosing CP. We found no significant differences between the areas under the receiver operating characteristic curves (AUROCs) for CT (AUROC 0.75, 95% CI 0.63–0.87) and US (AUROC 0.81, 95% CI 0.71–0.91). Conclusion We conclude that CT and US had comparable, moderate accuracy in diagnosing CP. Neither modality had high enough sensitivity to exclude the diagnosis as a standalone method.

Gastrointestinal Ultrasound in Functional Disorders of the Gastrointestinal Tract - EFSUMB Consensus Statement

Abdominal ultrasonography and intestinal ultrasonography are widely used as first diagnostic tools for investigating patients with abdominal symptoms, mainly for excluding organic diseases. However, gastrointestinal ultrasound (GIUS), as a real-time diagnostic imaging method, can also provide information on motility, flow, perfusion, peristalsis, and organ filling and emptying, with high temporal and spatial resolution. Thanks to its noninvasiveness and high repeatability, GIUS can investigate functional gastrointestinal processes and functional gastrointestinal diseases (FGID) by studying their behavior over time and their response to therapy and providing insight into their pathophysiologic mechanisms. The European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) has established a Task Force Group consisting of GIUS experts, which developed clinical recommendations and guidelines on the role of GIUS in several acute and chronic gastrointestinal diseases. This review is dedicated to the role of GIUS in assisting the diagnosis of FGID and particularly in investigating patients with symptoms of functional disorders, such as dysphagia, reflux disorders, dyspepsia, abdominal pain, bloating, and altered bowel habits. The available scientific evidence of GIUS in detecting, assessing, and investigating FGID are reported here, while highlighting sonographic findings and its usefulness in a clinical setting, defining the actual and potential role of GIUS in the management of patients, and providing information regarding future applications and research.

Klebsiella Pneumoniae Liver Abscess Syndrome – A Challenge for Contrast-Enhanced Ultrasound

IntroductionInvasive liver abscess syndrome (ILAS) is caused by strains of hypervirulent Klebsiella pneumoniae (hvKp) and has emerged as the leading cause of liver abscesses in immuno-competent patients (L.K. Siu et al. Lancet Infect Dis 2012; 12: 881–87). ILAS is frequently associated with metastatic spread including the eyes, lungs, and the central nervous system. The morbidity and mortality of affected patients are increased compared to liver abscesses of other origin, especially in cases with concomitant diabetes mellitus (J. E. Choby et al. J Intern Med 2020; 287(3): 283–300). Immediate diagnosis and early intervention are essential for an optimal outcome. Therefore, ultrasound plays a crucial role if hvKp is suspected. However, experience with the characteristics of such abscesses on contrast-enhanced ultrasound (CEUS) is very limited.