Diagnostic accuracy of venous system ultrasound for subtypes of acute kidney injury.

BACKGROUND: Management of acute kidney injury (AKI) in the ED can be difficult due to uncertainty regarding the aetiology. This study investigated the diagnostic value of venous system ultrasound for determining the aetiological subtypes of AKI in the ED. METHODS: This multidisciplinary prospective cohort study was conducted in a single academic ED over the course of a year. Adult patients with AKI were evaluated using the venous excess ultrasound (VExUS) score, which is a four-step ultrasound protocol. The protocol begins with the inferior vena cava (IVC) measurement and examines organ flow patterns, including portal, hepatic and renal veins in the presence of dilated IVC. The AKI subtypes (hypovolaemia, cardiorenal, systemic vasodilatation and renal) were adjudicated by nephrologists and emergency physicians, considering data that became available during the hospitalisation. We determined the diagnostic test characteristics of VExUS for identifying each of the four AKI aetiological subtypes. RESULTS: 150 patients with AKI were included in the study. Hypovolaemia was the most frequent finally adjudicated cause of AKI (66%), followed by cardiorenal (18%), systemic vasodilatation (8.7%) and renal (7.3%). In diagnosing the cardiorenal subtype, the area under the curve (AUC) for VExUS grade >0 was 0.819, with 77.8% sensitivity and 80.5% specificity, and the AUC for IVC maximum diameter >20.4 mm was 0.865, with 74.1% sensitivity and 86.2% specificity. For the hypovolaemia subtype, the AUC for VExUS grade ≤0 was 0.711, with 83.8% sensitivity and 56.9% specificity, and the AUC for IVC maximum diameter ≤16.8 mm was 0.736, with 73.7% sensitivity and 68.6% specificity. None of the parameters achieved adequate test characteristics for renal and systemic vasodilatation subtypes. CONCLUSION: The VExUS score has good diagnostic accuracy for cardiorenal AKI and fair accuracy for hypovolaemic AKI but cannot identify renal and systemic vasodilatation subtypes. It should not therefore be used in isolation to determine the cause of AKI in the ED. TRIAL REGISTRATION NUMBER: NCT04948710.

The value of venous system ultrasound in predicting the need for emergency haemodialysis in haemodialysis patients.

BACKGROUND: Emergency haemodialysis (HD) is a therapeutic procedure performed in serious clinical situations. This study investigated venous Doppler ultrasound parameters for predicting emergency HD in patients on routine HD treatment for end-stage renal disease in the emergency department (ED). METHOD: Adult patients on a routine HD program in a tertiary care ED between April and December 2022 were enrolled in the study. Inferior vena cava, hepatic, and portal vein flow parameters and the venous excess ultrasound (VExUS) score calculated from these parameters were noted in order to predict emergency HD indications. Hyperkalaemia, hypervolemia, missing more than one session, uremic findings, and metabolic acidosis were regarded as emergency HD indications. RESULTS: One hundred twenty-nine venous ultrasound examinations were performed on 43 patients with routine HD during the study period. The rate of emergency HD was 30.2%. The most common indication of it was hypervolemia (76.9%), followed by missing more than one session (23.1%). Only the portal vein had an AUC value of 0.714, with a sensitivity of 61.5% and specificity of 83.3% for predicting emergency HD. Other parameters including the IVC, hepatic vein, and VExUS score were of no diagnostic value. CONCLUSION: The findings of this study show that only the portal vein Doppler flow parameter has very limited diagnostic value for emergency HD in patients on a routine HD program in the ED. This study can serve as a guide to further research.

Assessment of forearm muscles with ultrasound shear wave elastography in patients with acromegaly.

PURPOSE: The effects of acromegaly on soft tissues, bones and joints are well-documented, but information on its effects on muscle mass and quality remains limited. The primary goal of this study is to assess the sonoelastographic features of forearm muscles in patients with acromegaly. METHOD: Forty-five patients with acromegaly and 45 healthy controls similar in terms of gender, age, and body mass index (BMI) were included in a single-center, multidisciplinary, cross-sectional study. The body composition was analyzed using bioelectrical impedance analysis (BIA), and height-adjusted appendicular skeletal muscle index (hSMI) was calculated. The dominant hand's grip strength was also measured. Two radiologists specialized in the musculoskeletal system employed ultrasound shear wave elastography (SWE) to assess the thickness and stiffness of brachioradialis and biceps brachii muscles. RESULTS: The acromegaly group had significantly higher thickness of both the biceps brachii (p = 0.034) and brachioradialis muscle (p = 0.046) than the control group. However, the stiffness of the biceps brachii (p = 0.001) and brachioradialis muscle (p = 0.001) was lower in the acromegaly group than in the control group. Disease activity has not caused a significant difference in muscle thickness and stiffness in the acromegaly group (p > 0.05). The acromegaly group had a higher hSMI (p = 0.004) than the control group. The hand grip strength was similar between the acromegaly and control group (p = 0.594). CONCLUSION: The patients with acromegaly have an increased muscle thickness but decreased muscle stiffness in the forearm muscles responsible for elbow flexion. Acromegaly can lead to a permanent deterioration of the muscular structure regardless of the disease activity.

ChatGPT from radiologists' perspective.

ChatGPT is a newly developed technology created by the OpenAI company. It is an artificial-intelligence-based large language model (LLM) and able to generate human-like text. The potential roles of ChatGPT in clinical decision support and academic writing have led to intense criticism of this technology in the scientific community. Therefore, radiologists also need to be familiar with LLMs such as ChatGPT.

Elasticity of leg muscles and incidence of falls in older adults: a prospective cohort analysis.

PURPOSE: Aging impacts muscle strength and elasticity, which in turn influence dynamic balance, walking speed, and physical performance. We aimed to evaluate the relationship between the elasticity of leg muscles and incidence of falls in older adults. METHODS: We conducted a prospective cohort analysis with outpatients from a geriatric clinic. Any history of falls in the past year was recorded. Timed up and go test, muscle thickness, and handgrip strength tests were performed. Elasticities of the gastrocnemius medialis (GM) and rectus femoris (RF) muscles were evaluated using shear wave elastography. Patients self-recorded their falls, and additional phone calls were made to them each month for 6 months. RESULTS: The median age of the patients (n = 55) was 72 years (66-86); and 72% were women. The GM showed significantly lower elasticity in patients with history of falls in the past year than in those without it (8.08 kPa [3.90-16.17] vs. 9.70 kPa [4.99-20.95]; p = 0.028). A similar negative correlation between GM and fall incidence was noted among those with additional falls during the follow-up period (6.96 kPa [3.90-12.41] vs. 9.13 kPa [4.99-20.95]; p = 0.019). GM elasticity was significantly correlated with the timed up and go test score (r = - 0.612, p < 0.001), handgrip strength (r = 0.384, p = 0.015), and muscle thickness (r = 0.232, p = 0.049). No such associations were observed for the RF muscles. CONCLUSION: GM muscle elasticity is associated with alterations in muscle structure that may lead to falls in older adults. Therefore, muscle elasticity may be a fall predictor in older adults.

Do Ultrasound Based Quantitative Hepatic Fat Content Measurements Have Differences Between Respiratory Phases?

RATIONALE AND OBJECTIVES: The recently developed ultrasound based tools using attenuation coefficient (AC) and scatter distribution coefficient (SDC) values can be used to quantify hepatic fat content in patients with non-alcoholic fatty liver disease (NAFLD). However, currently the impact of respiratory phase on these measurements is not known. The purpose of this study is to compare AC and SDC measurements acquired at peak inspiration and end expiration phases. MATERIALS AND METHODS: AC and SDC measurements were obtained in 50 patients with NAFLD. Tissue Attenuation Imaging (TAI) and Tissue Scatter Distribution Imaging (TSI) tools were utilized to measure AC and SDC values, respectively. Five measurements were performed at respiratory phases using TAI and TSI tools and the median values were noted. Subgroup analyses were performed and Wilcoxon signed rank test was used for comparison of the measurements. RESULTS: The median values of the AC measurements at peak inspiration and end expiration phases were 0.87 dB/cm/MHz and 0.89 dB/cm/MHz, respectively. The median values of the SDC measurements at peak inspiration and end expiration phases were 97.91 and 96.62, respectively. There were no statistically significant differences in AC and SDC measurements between the respiratory phases except for AC measurements in BMI <30 kg/m2 subgroup. CONCLUSION: Our results revealed that respiratory phases have no impact on SDC measurements. However, while the AC measurements in BMI ≥30 kg/m2 subgroup showed no significant difference, there was a significant difference in AC measurements in BMI <30 kg/m2 subgroup between the respiratory phases.

Interobserver Variability in Ultrasound-Based Liver Fat Quantification.

OBJECTIVES: To assess interobserver variability in ultrasound-based quantitative liver fat content measurements and to determine how much time these quantitative ultrasound (QUS) techniques require. METHODS: One hundred patients with known or suspected of having nonalcoholic fatty liver disease were included in this prospective study. Two observers who were blinded to each other measurements performed tissue attenuation imaging (TAI) and tissue scatter distribution imaging (TSI) techniques independently. Both observers assessed hepatic steatosis visually and obtained 5 measurements for each QUS technique and the median values of the measurements were recorded. Spearman's correlation test was used to assess the correlation between QUS measurements and visual hepatic stetaosis grades. Intraclass correlation coefficient (ICC) test was used to assess interobserver variability in QUS measurements. RESULTS: The median values of TAI measurements for the observers 1 and 2 were 0.75 and 0.74 dB/cm/MHz, respectively. The median values of TSI measurements for the observers 1 and 2 were 93.53 and 92.58, respectively. The interobserver agreement in TAI (ICC: 0.970) and TSI (ICC: 0.938) measurements were excellent. The mean of the required time period for TAI technique were 55.1 ± 7.8 and 59.9 ± 6.6 seconds for the observers 1 and 2, respectively. The mean of the required time period for TSI technique were 49.1 ± 5.8 and 54.1 ± 5.4 seconds for the observers 1 and 2, respectively. CONCLUSION: The current study revealed that both TAI and TSI techniques are highly reproducible and can be implemented into daily practice with little additional time requirement.

Hepatic Fat Quantification With Novel Ultrasound Based Techniques: A Diagnostic Performance Study Using Magnetic Resonance Imaging Proton Density Fat Fraction as Reference Standard.

Purpose: To assess the diagnostic performances of novel Tissue attenuation imaging (TAI) and Tissue scatter distribution imaging (TSI) tools in quantification of liver fat content using magnetic resonance imaging proton density fat fraction (MRI PDFF) as reference standard. Methods: Eighty consecutive patients with known or suspected non-alcoholic fatty liver disease (NAFLD) who volunteered to participate in the study comprised the study cohort. All patients underwent MRI PDFF scan and quantitative ultrasound (QUS) imaging using TAI and TSI tools. The cutoff values of ≥5%, ≥16.3% and ≥21.7% on MRI PDFF were used for mild, moderate and severe steatosis, respectively. Area under the Receiver operating characteristic (AUROC) curves were used to assess the diagnostic performance of TAI and TSI in detecting different grades of hepatic steatosis. Results: The AUROCs of TAI and TSI tools in detecting hepatosteatosis (MRI PDFF ≥5%), were 0.95 [95% Confidence Interval (CI): 0.91-0.99] (P < 0.001) and 0.96 (95% CI: 0.93-0.99) (P < 0.001), respectively. In distinguishing between different grades of steatosis, the values of 0.75, 0.86 and 0.96 dB/cm/MHz have 88%, 88% and 100% sensitivity, respectively, for TAI tool; and the values of 92.44, 96.64 and 99.45 have 90%, 92% and 91.7% sensitivity, respectively, for TSI tool. Conclusion: TAI and TSI tools accurately quantify liver fat content and can be used for the assessment and grading of hepatosteatosis in patients with known or suspected NAFLD.

A Standardized Approach for MRI-PDFF is Necessary in the Assessment of Diagnostic Performances of the Ultrasound-Based Hepatic Fat Quantification Tools.

The recently developed ultrasound-based hepatic fat quantification tools have the potential to be implemented in daily practice with wide acceptance due to inherited advantages of ultrasound technology. Researchers intensively focused on this topic and the accumulated evidences that support clinical usefulness of these tools. However, differences in the researcher-dependent factors of the utilized MRI-PDFF technique, the recommended reference standard, may hinder the better understanding of the diagnostic performances of these tools. Therefore, a standardized approach for MRI-PDFF technique, which is established with international consensus may be considered as important.

Evaluation of Diaphragm Thickness and Stiffness Using Ultrasound and Shear-Wave Elastography.

ABSTRACT: The purposes of this study are to measure the thickness and stiffness of diaphragm in association with the respiratory cyclus and to assess the reproducibility of these measurements. Forty individuals who are volunteered for participating diaphragm evaluation were included in the study. Two radiologists with 14 and 15 years of experiences in abdominal ultrasound performed all examinations independently. Furthermore, 8 chronic obstructive pulmonary disease (COPD) patients were examined by only the first radiologist. Gray scale and shear-wave elastography imaging of only the right hemidiaphragm of all participants were performed. Thickness and stiffness of diaphragm were measured at the peak inspiration and end expiration phases. Intraclass correlation coefficients test was used to assess the interobserver agreement. The thickness and stiffness of diaphragm significantly increased with inspiration (P < 0.001). The mean ± SD stiffness of diaphragm in peak inspiration and end expiration phases was 51.84 ± 16.83 kPa and 38.49 ± 9.42 kPa, respectively, for the first radiologist and 49.61 ± 13.83 kPa and 37.52 ± 10.71 kPa, respectively, for the second radiologist. Intraclass correlation coefficient values for diaphragm stiffness were 0.667 and 0.736 in peak inspiration and end expiration phases, respectively. In COPD patients, there was no significant difference between stiffness measurements of respiratory phases. In conclusion, the current study revealed that diaphragm thickness and stiffness increase at inspiration, and these measurements are slightly more reproducible at the end of expiration. However, diaphragm stiffness changes between respiratory phases may not be valid for COPD patients, and this may be related to loss of force-generating capacity of diaphragm in COPD patients.

Comparison of diagnostic performances in the evaluation of breast microcalcifications: synthetic mammography versus full-field digital mammography.

BACKGROUND: Although several studies proved that SM could substitute for FFDM, the efficacy of SM in microcalcification evaluation remains controversial. AIMS: To investigate the diagnostic performance of synthetic mammography (SM) in the evaluation of microcalcifications in comparison with full-field digital mammography (FFDM). METHODS: In this retrospective study, 76 mammograms of 76 patients who underwent FFDM and digital breast tomosynthesis (DBT) acquisitions concomitantly between 2018 and 2019 and whose final mammography interpretation revealed microcalcifications (28 malignant microcalcifications and 48 benign microcalcifications) were included. All mammograms were reviewed independently by three radiologists with different levels of breast imaging experience. Readers were blinded to patient outcomes and interpreted each case in two separate reading sessions (first FFDM, second SM + DBT), according to the BI-RADS lexicon. The area under the receiver operating characteristic (ROC) curve (AUC) was calculated using ROC analysis in all cases for FFDM and SM + DBT sessions. The readers also assigned conspicuity scores to mammograms. The interobserver agreement was calculated using intraclass correlation coefficients (ICC). RESULTS: The overall AUCs for malignant microcalcifications were 0.80 (95% CI: 0.75-0.85) in FFDM and 0.85 (95% CI: 0.80-0.89) in SM, and no significant difference was found between the groups (p = 0.0603). The sensitivity of the readers increased slightly with experience. The ICC values of BI-RADS categorization between readers were 0.93 (95% CI: 0.90-0.95) and 0.94 (95% CI: 0.91-0.96) for FFDM and SM, respectively. CONCLUSIONS: SM had similar diagnostic performance in the evaluation of breast microcalcifications in comparison with FFDM, regardless of reader experience levels.