ABDOMINAL ULTRASONOGRAPHY

Sonographically Diagnosed Urothelial Thickening in Kidney Allografts: A Noninvasive and Clinically Highly Relevant Marker for the Detection of Acute Rejection

Fananapazir G, Navarro SM, Zhou C, et al. Sonographically Diagnosed Urothelial Thickening in Kidney Allografts: A Noninvasive and Clinically Highly Relevant Marker for the Detection of Acute Rejection. AJR Am J Roentgenol. 2020;215(1):148-152.
https://doi.org/10.2214/AJR.19.22128

Background: Early recognition of transplant rejection is important to potentially preserve the organ. Many of the studies investigating renal transplant rejection on ultrasound are dated.
Question: Can gray-scale and/or color doppler ultrasound (US) identify renal allograft rejection given recent advances in knowledge and technology?
Location: Single center; UC Davis Medical Center, Sacramento, California, USA
Participants and inclusion criteria: 107 renal transplant patients with acute rejection who had a biopsy within 2 weeks of an US.
Design: Retrospective study reviewing data from 2015-2018. US images were reviewed by 3 radiologists in the patients that pathologically had acute transplant rejection. Imaging findings recorded included echogenicity of the renal cortex, perfusion, uroepithelial thickening, and corticomedullary differentiation.
Results: Among the recorded imaging findings only uroepithelial thickening was significantly associated with acute renal transplant rejection (p<0.001). It had a sensitivity of 96% and a negative predictive value (NPV) of 98% for rejection.
Conclusions and remarks: Uroepithelial thickening on US is both highly sensitive and has a high negative predictive value for acute renal transplant rejection.

Diagnostic Value of Contrast-Enhanced Ultrasound Versus Computed Tomography for Hepatocellular Carcinoma: A Retrospective, Single-Center Evaluation of 234 Patients

Schwarze V, Marschner C, Völckers W, et al. Diagnostic value of contrast-enhanced ultrasound versus computed tomography for hepatocellular carcinoma: a retrospective, single-center evaluation of 234 patients. J Int Med Res. 2020;48(6):300060520930151.
https://doi.org/10.1177/0300060520930151

Background: Imaging in hepatocellular carcinoma (HCC) often involves a multimodality approach with ultrasound often being used in screening. Contrast enhanced US (CEUS) is a dynamic study which is able to assess the vascularization pattern of hepatic lesions, including HCC.
Question: How does CEUS compare to CT in the assessment of HCC lesions?
Location: Single center; Ludwig Maximilian University of Munich, Germany
Participants and inclusion criteria: 234 patients who had concerning hepatic lesions with a CT and CEUS.
Design: Retrospective study compiling data from 2004-2018. Studies were interpreted by a single experienced radiologist.
Results: Compared to the CT standard, CEUS had a sensitivity of 94% and specificity of 70% for analyzing HCC. Correspondingly the positive predictive value was 93% and the negative predictive value was 72%.
Conclusions and remarks: CEUS is highly accurate in HCC assessment compared to CT.

Characterization of Indeterminate Liver Lesions on CT and MRI With Contrast-Enhanced Ultrasound: What Is the Evidence?
Wang DC, Jang HJ, Kim TK. Characterization of Indeterminate Liver Lesions on CT and MRI With Contrast-Enhanced Ultrasound: What Is the Evidence?. AJR Am J Roentgenol. 2020;214(6):1295-1304. https://doi.org/10.2214/AJR.19.21498

Overview: The article aims to provide a review in the methodology, usefulness, and interpretation of CEUS in liver imaging. CEUS is unique because the contrast stays purely intravascular and it allows for real time evaluation. There is a focus on evaluating hepatic lesions that are indeterminate on CT and MRI. Some key areas US may help include evaluating between HCC or intrahepatic cholangiocarcinoma, assessment of bland vs. tumor thrombus, and hepatocellular adenoma from focal nodular hyperplasia.

Noninvasive prediction of lymph node status for patients with early-stage cervical cancer based on radiomics features from ultrasound images

Jin X, Ai Y, Zhang J, et al. Noninvasive prediction of lymph node status for patients with early-stage cervical cancer based on radiomics features from ultrasound images. Eur Radiol. 2020;30(7):4117-4124. https://doi.org/10.1007/s00330-020-06692-1

Background: Lymph node metastasis in cervical cancer is the most important risk factor for recurrence and survival. Only a few reports of using ultrasound and radiomics, which uses machine learning to extract a large amount of detail from images, have previously been described in cervical cancer.
Question: Does the use of radiomics on ultrasound images aid in detection of lymph node metastasis in early-stage cervical cancer?
Location: Single center; 1st Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
Participants and inclusion criteria: 172 patients with confirmed lymph node metastasis and preoperative ultrasound images.
Design: Retrospective design evaluating exams performed across an approximately 4.5-year period. Senior radiologists identified the regions of interest in the ultrasound images which were then analyzed using the LIFEx software. Textural features were extracted, with training and validation groups used. Accuracy of the models were determined using receiver operating characteristic (ROC) curves.
Results: Using the radiomics software, 152 sonographic features were extracted and 6 of those were associated with lymph node metastasis (p <0.05). When selecting the best model, the training cohort achieved an area under the curve (AUC) in the ROC model of 0.75 and the validation cohort achieved an AUC of 0.77.
Conclusions and remarks: Preoperative ultrasound using radiomics models is potentially able to predict lymph node metastasis in cervical cancer. It may also be helpful to guide surgical approach, if validated.

Limited added value of contrast-enhanced ultrasound over B-mode for the subtyping of hepatocellular adenomas

Gregory J, Paisant A, Paulatto L, et al. Limited added value of contrast-enhanced ultrasound over B-mode for the subtyping of hepatocellular adenomas. Eur J Radiol. 2020.
https://doi.org/10.1016/j.ejrad.2020.109027

Background: Hepatocellular adenomas (HCA) are now understood to have multiple histopathologic subtypes which account for the variability in the clinical behavior and imaging appearances. Two common subtypes are inflammatory (I-HCA) and HNF1-α (H-ICA).
Question: Does the addition of contrast to US help different hepatocellular adenoma subtypes sonographically?
Location: Single center; Beaujon Hospital, Paris, France
Participants and inclusion criteria: 33 patients with 44 pathologically proven HCAs (29 I-HCA and 15 H-HCA) with a contrast enhanced US (CEUS).
Design: Study comparing features of pathologically proven I-HCAs and H-HCAs on B-mode US and CEUS. Data was collected retrospectively with prospective evaluation of imaging. Images were reviewed by two abdominal radiologists and 1 senior pathologist. The reviewing radiologists were blinded to the subtype of HCA.
Results: On B-mode US most I-HCAs were hypoechoic (79%) or isoechoic (14%), which was significantly different from H-HCAs, which were mostly hyperechoic (93%) (P=0.001). Homogenous and hyperechoic lesions were 100% specific for H-HCAs in the absence of hepatic steatosis. With CEUS, arterial hyperenhancement was common in both groups and seen in 93% of the I-HCA and H-HCA lesions (p=0.98). Washout between the two groups was also not statistically significant, seen in 21% of I-HCAs and 7% of H-HCAs (P=0.27). All (100%) H-HCAs and 79% of I-HCAs were homogenous on the portal and delayed contrast phases (p=0.04).
Conclusions and remarks: When hepatocellular adenoma is suspected or known, B-mode features may be helpful for differentiating these two subtypes. CEUS provides little additional benefit in this regard. 

Update to the Society of Radiologists in Ultrasound Liver Elastography Consensus Statement

Barr RG, Wilson SR, Rubens D, Garcia-Tsao G, Ferraioli G. Update to the Society of Radiologists in Ultrasound Liver Elastography Consensus Statement. Radiology. 2020. https://doi.org/10.1148/radiol.2020192437

Overview: The amount of data on liver shear-wave elastography (SWE) has grown significantly since the Society of Radiologists in Ultrasound published the consensus statement in 2015. Additionally, new technology has become available and been incorporated which has decreased the variability in measurements between systems. Therefore, the aim of this update is to address these changes, such as improved detection of compensated advanced chronic liver disease (cACLD). They also emphasize that in viral hepatitis, baseline values should be obtained after the virus has either been eradicated or adequately suppressed. Additionally, for all patients the change in liver stiffness over time should be used as opposed to absolute values.

Comparison of Supersonic Shear Wave Imaging–Derived Renal Parenchyma Stiffness Between Diabetes Mellitus Patients With and Without Diabetic Kidney Disease

Shi LQ, Sun JW, Miao HH, Zhou XL. Comparison of Supersonic Shear Wave Imaging-Derived Renal Parenchyma Stiffness Between Diabetes Mellitus Patients With and Without Diabetic Kidney Disease. Ultrasound Med Biol. 2020;46(7):1630-1640.
https://doi.org/10.1016/j.ultrasmedbio.2020.03.026

Background: Diabetic kidney disease can be difficult to detect and diagnose, especially early in the disease course. Pathologic alterations, such as tubulointerstitial fibrosis from diabetic kidney disease may result in changes in renal stiffness. Shear wave elastography (SWE) has been shown to be reliable for estimating stiffness in other organs, such as the liver.
Question: Is there a difference in renal stiffness between patients with type 2 diabetes mellitus (DM) with diabetic kidney disease and those without?
Location: Single center; Second Affiliated Hospital of Harbin Medical University, Harbin, China
Participants and inclusion criteria: 124 total patients who were healthy (n=31), had type 2 DM without kidney disease (n=38), or had diabetic kidney disease (n=55)
Design: Prospective design with measurements of renal size, thickness, interlobar arterial resistive index (RI), and stiffness obtained. Stiffness was measured by Young’s Modulus (YM) with SWE and mean, minimum, and maximum recorded. Patients with diabetic kidney disease were subcategorized by stage of chronic kidney disease (CKD) from 1-5.
Results: The mean YM in healthy patients (26.45 ± 4.32 kPa) was significantly lower than in patients with type 2 DM but without kidney disease (31.44 ± 3.83 kPa) and the group with diabetic kidney disease (37.60 ± 6.56 kPa)(all P<0.05). The mean stiffness in diabetic patients without and those with CKD stage 1-2 was lower than in patients with CKD stage 5. In the diabetic kidney disease group, there was a positive correlation between YM and creatinine (r = 0.690) levels as well as a negative correlation with glomerular filtration rate (GFR) (r= -0657).
Conclusions and remarks: SWE may be an effective, non-invasive method to detect diabetic kidney disease and is superior to conventional ultrasound. It may also be beneficial for monitoring of renal damage in patients with type 2 DM.

Sonography of the penis/erectile dysfunction

Bertolotto M, Campo I, Sachs C, et al. Sonography of the penis/erectile dysfunction. Abdom Radiol. 2020;45(7):1973-1989.
https://doi.org/10.1007/s00261-020-02529-z

Overview: This review article goes through the spectrum of erectile dysfunction, particularly how it relates to imaging. The anatomy, indications for US, and scanning techniques are discussed in detail. Several disease processes are detailed including several subtypes of priapism, Peyronie’s disease, and postramatic erectile dysfunction as well as their imaging findings on sonography. Attention is also given to the role that elastrography can play in diagnosis and recent publications on the subject.

THORACIC ULTRASONOGRAPHY

Lung Ultrasonography as an Accurate Diagnostic Method for the Diagnosis of Community-Acquired Pneumonia in the Elderly Population

Buda N, Hajduk A, Jaworska J, Zdrojewski Z. Lung Ultrasonography as an Accurate Diagnostic Method for the Diagnosis of Community-Acquired Pneumonia in the Elderly Population. Ultrasound Q. 2020;36(2):111-117.
https://doi.org/10.1097/RUQ.0000000000000499

Background: Community acquired pneumonia (CAP) is a large cause of morbidity and mortality in elderly patients. Chest radiography sensitivity is fairly low for suspected pneumonia.
Question: Can lung US be used to identify CAP in geriatric populations with improved accuracy over chest xrays?
Location: Single center; Medical University of Gdansk, Poland
Participants and inclusion criteria: 191 elderly patients who were hospitalized for pneumonia
Design: Prospective study design with both chest xrays and lung US being obtained within a few hours of hospital admission. US was performed by an experienced clinician and findings indicative of pneumonia included subpleural consolidation, B-line pattern, and/or focal “white lung.”
Results: Only 65 patients had findings of pneumonia on chest xray, while 114 (60% of study group and 99% of patients with confirmed pneumonia at discharge) had pneumonia by US findings. This resulted in a 99% sensitivity and specificity of lung US, with chest xray only 57% and 100%, respectively.
Conclusions and remarks: Lung US was superior to chest xrays for identification of pneumonia in elderly populations. Utilization could result in rapid and cheaper diagnosis of pneumonia in the elderly populations.

INTERVENTIONAL RADIOLOGY

Feasibility of Shear Wave Sonoelastography to Detect Endoleak and Evaluate Thrombus Organization After Endovascular Repair of Abdominal Aortic Aneurysm

Voizard N, Bertrand-Grenier A, Alturkistani H, et al. Feasibility of shear wave sonoelastography to detect endoleak and evaluate thrombus organization after endovascular repair of abdominal aortic aneurysm. Eur Radiol. 2020;30(7):3879-3889.
https://doi.org/10.1007/s00330-020-06739-3

Background: Endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA) can rarely be complicated by endoleak, which increases the risk of rupture if not treated. CTA is often used for evaluation of complications, which is more sensitive but also more invasive than color doppler ultrasound.
Question: Can shear wave elastography (SWE) be used to identify endoleak after EVAR and how does it compare to CTA and ultrasound?
Location: Single center; Montreal, Canada
Participants and inclusion criteria: 28 patients who had a prior EVAR for AAA and pre-procedure CTA.
Design: Prospective design with patients being recruited and followed post EVAR with SWE, CTA, and color doppler US. Follow up at 3 years was obtained to ensure endoleak or other complications was not missed. 2 radiologists, who were blinded to the CTA and ultrasound images, evaluated the SWE results to detect endoleak.
Results: 7 (25%) of patients developed endoleak as determined by the two radiologists with elastrography demonstrating a 100% specificity and 67% sensitivity. The sensitivity of color doppler alone was estimated at 43%. Aneurysmal sac thrombi were also able to be differentiated from endoleak (P<0.001).
Conclusions and remarks: Shear wave elastography shows promise to detect endoleak after EVAR, especially if combined with other sonographic features. 

MUSCULOSKELETAL ULTRASONOGRAPHY

Evaluation of effects of aging on skeletal muscle elasticity using shear wave elastography

Şendur HN, Cindil E, Cerit MN, Kılıç P, Gültekin Iİ, Oktar SÖ. Evaluation of effects of aging on skeletal muscle elasticity using shear wave elastography. Eur J Radiol. 2020;128:109038.
https://doi.org/10.1016/j.ejrad.2020.109038

Background: Aging leads to alterations in skeletal muscle which may limit function and mobility. Results have been mixed on whether skeletal muscle stiffness increases or decreases with age.
Question: How does skeletal muscle stiffness change with aging when measured with shear wave elastography (SWE)?
Location: Single center; Gazi University, Ankara, Turkey
Participants and inclusion criteria: 57 healthy volunteers aged 18-74 (mean 41).
Design: Prospective design with 1 radiologist experienced in SWE measuring the gastrocnemius muscle at the medial head with stiffness in relaxed and contracted states. Muscle thickness was also measured and a stiffness increase rate (SIR) was calculated [(Scontracted-Srelaxed)/Srelaxed]. They were separated into 3 age groups for analysis.
Results: The stiffness values in relaxed (mean 12.51) and contracted (mean 81.74) state inversely correlated with age (r range: -0.703 to -0.590). There were also significant differences in thickness and stiffness values between the age groups. SIR mean value was 5.62 but was not significantly different between the age groups.
Conclusions and remarks: Skeletal muscle stiffness decreased with age, but SIR remained the same.

Common abbreviations:

*US: Ultrasound
*CEUS: Contrast Enhanced Ultrasound
*SWE: Shear-Wave Elastography
*HCC: Hepatocellular Carcinoma
*HCA: Hepatocellular Adenoma