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.

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.

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.

Validation of combined use of DWI and percentage signal recovery-optimized protocol of DSC-MRI in differentiation of high-grade glioma, metastasis, and lymphoma.

PURPOSE: With conventional MRI, it is often difficult to effectively differentiate between contrast-enhancing brain tumors, including primary central nervous system lymphoma (PCNSL), high-grade glioma (HGG), and metastasis. This study aimed to assess the discrimination ability of the parameters obtained from DWI and the percentage signal recovery- (PSR-) optimized protocol of DSC-MRI between these three tumor types at an initial step. METHODS: DSC-MRI using a PSR-optimized protocol (TR/TE = 1500/30 ms, flip angle = 90°, no preload) and DWI of 99 solitary enhancing tumors (60 HGGs, 24 metastases, 15 PCNSLs) were retrospectively assessed before treatment. rCBV, PSR, ADC in the tumor core and rCBV, and ADC in peritumoral edema were measured. The differences were evaluated using one-way ANOVA, and the diagnostic performance was evaluated using ROC curve analysis. RESULTS: PSR in the tumor core showed the best discriminating performance in differentiating these three tumor types with AUC values of 0.979 for PCNSL vs. others and 0.947 for HGG vs. metastasis. The ADC was only helpful in the tumor core and distinguishing PCNSLs from others (AUC = 0.897). CONCLUSION: Different from CBV-optimized protocols (preload, intermediate FA), PSR derived from the PSR-optimized protocol seems to be the most important parameter in the differentiation of HGGs, metastases, and PCNSLs at initial diagnosis. This property makes PSR remarkable and carries the need for comprehensive DSC-MRI protocols, which provides PSR sensitivity and CBV accuracy together, such as the preload use of the PSR-optimized protocol before the CBV-optimized protocol.

Added Value of CT Pelvic Bone Unfolding Software to Radiologist Performance in Detecting Osteoblastic Pelvic Bone Lesions in Patients With Prostate Cancer.

PURPOSE: To evaluate the contribution of CT Bone Unfolding software to the diagnostic accuracy and efficiency for the detection of osteoblastic pelvic bone lesions in patients with prostate cancer. METHODS: A total of 102 consecutive (January 2016-September 2019) patients who underwent abdominopelvic CT with prostate cancer were retrospectively evaluated for osteoblastic pelvic bone lesions, using commercially available the post-processing-pelvic bone flattening-image software package "CT Bone Unfolding." Two radiologists with 3 and 15 years of experience in abdominal radiology evaluated CT image data sets independently in 2 separate reading sessions. At the first session, only MPR images and at the second session MPR images and additionally unfolded reconstructions were assessed. Reading time for each patient was noted. A radiologist with 25 years of experience, established the standard of reference. RESULTS: In the evaluations performed with the MPR-Unfold method, the diagnostic accuracy were found to be 2.067 times higher compared to the MPRs method (P < 0.001). The location of the lesions or the reader variabilities did not show any influence on accuracy (P > 0.05) For all readers the reading time for MPR was significantly longer than for MPR-Unfold (P < 0.05). For both methods substantial to almost-perfect inter-reader agreement was found (0.686-0.936). CONCLUSIONS: The use of unfolded pelvic bone reconstructions increases diagnostic accuracy while decreasing the reading times in the evaluation of pelvic bone lesions. Therefore, our findings suggest that utilizing unfolded reconstructions in addition to MPR images may be preferable in patients with prostate cancer for the screening of osteoblastic pelvic bone lesions.

Dynamic Volume Perfusion CT of the Foot in Critical Limb Ischemia: Response to Percutaneous Revascularization.

OBJECTIVE. The purpose of this study was to assess the reproducibility and validity of quantitative perfusion parameters derived from dynamic volume perfusion CT in patients with critical limb ischemia (CLI) and to evaluate perfusion parameter changes before and after endovascular revascularization. SUBJECTS AND METHODS. Patients with CLI referred for unilateral extremity endovascular arterial recanalization were enrolled in this study. CT examinations obtained 1-3 days before the procedure and then within 1 week after the treatment were evaluated at two reading sessions. Blood flow (BF), blood volume (BV), and time to peak (TTP) were measured on color-coded maps and compared statistically. Intraobserver agreement was assessed using intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS. Endovascular treatment was technically successful for all 16 patients. The posttreatment BF and BV showed a statistically significant increase in both dermal and muscle areas (p < 0.05). The posttreatment TTP shortened at a statistically significant level (p < 0.05). In the 3-month clinical follow-up period, the limb salvage rate was 81% and the percentage change in BF and BV of patients with poor response to treatment had no statistically significant increase after treatment, consistent with the clinical assessment. The percentage change in BF and BV correlated well with the improvement of the clinical condition (r = 0.673-0.901). ICC values showed excellent agreement in the range of 0.95-0.98. CONCLUSION. As a reproducible method, dynamic volume perfusion CT of the foot may enable quantitative evaluation of the perfusion of soft tissues and also provide a novel approach to assessing response to endovascular recanalization in CLI.

Determination of Normal Breast and Areolar Skin Elasticity Using Shear Wave Elastography.

OBJECTIVES: In this study, we aimed to determine reference values for normal breast and areolar skin elasticity using shear wave elastography. METHODS: The right breasts of 200 female participants were evaluated. The age, weight, body mass index, menopausal status, and parity number of all participants were noted. The elasticity values and thickness of the areolar skin and 4 quadrants of the breast skin of all participants were measured. To assess the reproducibility of shear wave elastography, a randomly selected subgroup of 35 participants was reevaluated by a second observer. RESULTS: The mean age of the participants ± SD was 48.79 ± 10.74 years (range, 18-79 years). The mean elasticity measurements for the superior, inferior, lateral, and medial regions of the breast and areolar skin were 33.54, 29.84, 30.16, 29.20, and 31.35 kPa, respectively. The mean of the 4-quadrant measurements of breast skin elasticity was 30.68 ± 9.11 kPa. Age had a moderate negative correlation with breast skin elasticity (r = -0.353; P < .001) and a weak negative correlation with areolar skin elasticity (r = -0.237; P = .001). The parity number had weak negative correlations with breast (r = -0.150; P = .034) and areolar (r = -0.207; P < .001) skin elasticity. The interobserver agreement varied from good to excellent (intraclass correlation coefficients, 0.67-0.91) for the breast and areolar skin elasticity measurements. CONCLUSIONS: Shear wave elastography is a reproducible imaging modality for evaluations of breast and areolar skin elasticity, and our results may provide important pilot data for evaluations of clinical entities that affect the breast and areolar skin structures.

Interobserver variability and stiffness measurements of normal common extensor tendon in healthy volunteers using shear wave elastography.

OBJECTIVES: The purposes of our study are to determine the quantitative elasticity values of normal common extensor tendon (CET) and to assess the interobserver variability of stiffness measurements using shear wave elastography (SWE). MATERIALS AND METHODS: A total of 60 CETs of 30 (15 female, 15 male, mean age 30.2 years) healthy volunteers without any symptoms of lateral epicondylitis were examined by two radiologists. Age, sex, height, weight, body mass index (BMI), and dominant hand of all participants were noted. The first observer performed B-mode and SWE imaging, and the second observer performed only SWE imaging. Tendon thickness and stiffness values in kPa were measured. RESULTS: The mean thickness of CETs was 3.57 ± 0.36 mm. The mean stiffness values of CETs for two observers were 45.28 ± 9.82 kPa and 45.80 ± 9.72 kPa respectively. Tendon thickness had a weak correlation with weight (r = 0.281, p = 0.03), and moderate correlation with stiffness values (r = 0.429, p < 0.001). The mean interobserver difference of CET stiffness measurements was -0.5% of the mean CET stiffness values. Range of measurement error, defined as 95% limits of agreement, was ±23.5%. There was no significant difference between absolute values of interobserver measurements (p = 0.741). CONCLUSION: Shear wave elastography is a reproducible imaging technique for the evaluation of CET elasticity and the standard stiffness values of normal CET can be used as reference data to differentiate normal from pathological tissues.

Treatment-related alterations of imaging findings in osteoid osteoma after percutaneous radiofrequency ablation.

OBJECTIVES: We aimed to report the long-term outcomes of osteoid osteoma patients and to determine CT and dynamic contrast-enhanced MR imaging characteristics of radiofrequency ablation (RFA) treatment related changes of osteoid osteoma between follow-up periods. MATERIALS AND METHODS: Thirty patients (seven female, 23 male) who underwent CT-guided RFA of osteoid osteoma were included. Follow-up imaging examinations were divided into two subgroups; first (1-3 months) and second (> 6 months) periods. Nidus size, calcification, cortical thickening, maximum signal intensity (SImax), time of SImax (Tmax), slope of signal intensity-time (SIT) curves were noted. CT and dynamic MR imaging findings were compared between follow-up periods. RESULTS: Clinical success rate was 100%. The mean of OO nidi size was 5.85 ± 1.98 mm before treatment. There was a significant difference for OO nidi sizes between pretreatment and second follow-up period examinations (p = 0.002). SImax and slope of SIT curves of all patients (100%) showed decrease on follow-up MRIs. There was a significant decrease for SImax values between pretreatment and second follow-up period. There was a significant decrease for slope of SIT curves between pretreatment and both follow-up periods. CONCLUSIONS: RFA is an effective and safe treatment choice for osteoid osteomas. On follow-up imaging, slope of SIT curve and Tmax have the most important positive predictive value for long-term outcomes and single dynamic contrast-enhanced MRI within first 3 months after treatment may be sufficient for symptom-free patients.

The Utility of Diffusion-Weighted Imaging and Perfusion Magnetic Resonance Imaging Parameters for Detecting Clinically Significant Prostate Cancer.

INTRODUCTION: To establish the diagnostic performance of the parameters obtained from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging at 3T in discriminating between non-clinically significant prostate cancers (ncsPCa, Gleason score [GS] < 7) and clinically significant prostate cancers (csPCa, GS ≥ 7) in the peripheral zone. MATERIALS AND METHODS: Twenty-six male patients with peripheral zone prostate cancer (PCa) who had undergone 3T multiparametric magnetic resonance imaging (MRI) scan prior to biopsy were included in the study and evaluated retrospectively. The GS was obtained by both standard 12-core transrectal ultrasound guided biopsy and targeted MRI-US fusion biopsy and then confirmed by prostatectomy, if available. For each confirmed tumour focus, DCE-derived quantitative perfusion metrics (Ktrans, Kep, Ve, initial area under the curve [AUC]), the apparent diffusion coefficient (ADC) value, and normalized versions of quantitative metrics were measured and correlated with the GS. RESULTS: Ktrans had the highest diagnostic accuracy value of 82% among the DCE-MRI parameters (AUC 0.90), and ADC had the strongest diagnostic accuracy value of 87% among the overall parameters (AUC 0.92). The combination of ADC and Ktrans have higher diagnostic performance with the area under the receiver operating characteristic curve being 0.98 (sensitivity 0.94; specificity 0.89; accuracy 0.92) compared to the individual evaluation of each parameter alone.The GS showed strong negative correlations with ADC (r = -0.72) and normalized ADC (r = -0.69) as well as a significant positive correlation with Ktrans (r = 0.69). CONCLUSION: The combination of Ktrans and ADC and their normalized versions may help differentiate between ncsPCa from csPCa in the peripheral zone.

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.

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.