Prospective Validation of Intra- and Interobserver Reproducibility of a New Point Shear Wave Elastographic Technique for Assessing Liver Stiffness in Patients with Chronic Liver Disease

Washout-parametric imaging with Sonazoid for enhanced differentiation of focal liver lesions

PURPOSE

The study aimed to compare the diagnostic performance of washout-parametric imaging (WOPI) with that of conventional contrast-enhanced ultrasound (cCEUS) in differentiating focal liver lesions (FLLs).

METHODS

A total of 181 FLLs were imaged with contrast-enhanced ultrasound using Sonazoid, and the recordings were captured for 10 minutes in a prospective setting. WOPI was constructed from three images, depicting the arterial phase (peak enhancement), the early portal venous phase (1-minute post-injection), and the vasculo-Kupffer phase (5 or 10 minutes post-injection). The intensity variations in these images were color-coded and superimposed to produce a single image representing the washout timing across the lesions. From the 181 FLLs, 30 hepatocellular carcinomas (HCCs), 30 non-HCC malignancies, and 30 benign lesions were randomly selected for an observer study. Both techniques (cCEUS and WOPI) were evaluated by four off-site readers. They classified each lesion as benign or malignant using a continuous rating scale, with the endpoints representing "definitely benign" and "definitely malignant." The diagnostic performance of cCEUS and WOPI was compared using the area under the receiver operating characteristic curve (AUC) with the DeLong test. Interobserver agreement was assessed using the intraclass correlation coefficient (ICC).

RESULTS

The difference in average AUC values between WOPI and cCEUS was 0.0062 (95% confidence interval, -0.0161 to 0.0285), indicating no significant difference between techniques. The interobserver agreement was higher for WOPI (ICC, 0.77) than cCEUS (ICC, 0.67).

CONCLUSION

The diagnostic performance of WOPI is comparable to that of cCEUS in differentiating FLLs, with superior interobserver agreement.

Comparison of Transient Elastography and Point Shear Wave Elastography for Analysis of Liver Stiffness: A Prospective Study

Liver stiffness measurement (LSM) by Fibroscan is the most used non-invasive method to assess liver fibrosis. Recently, point-shear wave elastography (pSWE) has been introduced as a simple alternative non-invasive test. Therefore, we aimed to compare the results of these two techniques. One hundred and eighty-four consecutive patients attending our outpatient ultrasound clinic were recruited. LSM was performed by both Fibroscan and pSWE. Statistical analysis was conducted by Spearman's test for correlation and linear regression. Bland-Altman graphs and ROC curves were drawn with area under the curve (AUC). Overall, the correlation of LS between Fibroscan and pSWE was substantial (r = 0.68, p < 0.001). Linear regression showed a coefficient b= 0.94 ± 0.02. The Bland-Altman plot found a bias of -0.10, with only 11 values exceeding the 95% confidence interval. When only considering patients with a LSM of > 10 kPa (n = 31), we found an excellent r = 0.79 (0.60-0.90, p < 0.001). A cutoff of 12.15 kPa for pSWE had sensitivity = 74.2% and specificity = 99.3% to detect relevant fibrosis, with an AUC = 0.98. The highest correlation was observed for hepatitis C (r = 0.91) and alcoholic liver disease (ALD)(r = 0.99). In conclusion, pSWE shows LSM estimation in agreement with Fibroscan in most cases, and the best concordance was observed for hepatitis C and ALD, and for higher ranges of LS.

Usefulness of New Shear Wave Elastography Technique for Noninvasive Assessment of Liver Fibrosis in Patients with Chronic Hepatitis B: A Prospective Multicenter Study

PURPOSE

 To explore the usefulness of liver stiffness measurements (LSMs) by sound touch elastography (STE) and sound touch quantification (STQ) in chronic hepatitis B (CHB) patients for staging fibrosis.

METHODS

 This prospective multicenter study recruited normal volunteers and CHB patients between May 2018 and October 2019. The volunteers underwent LSM by STE and supersonic shear imaging (SSI) or by STQ and acoustic radiation force impulse imaging (ARFI). CHB patients underwent liver biopsy and LSM by both STE/STQ. The areas under the receiver operating characteristic curves (AUCs) for staging fibrosis were calculated.

RESULTS

 Overall, 97 volunteers and 524 CHB patients were finally eligible for the study. The successful STE and STQ measurement rates were both 100 % in volunteers and 99.4 % in CHB patients. The intraclass correlation coefficients (ICCs) for the intra-observer stability of STE and STQ (0.94; 0.90) were similar to those of SSI and ARFI (0.95; 0.87), respectively. STE and STQ showed better accuracy than the aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 index (FIB-4) (AUC: 0.87 vs 0.86 vs 0.73 vs 0.77) in staging cirrhosis. However, both STE and STQ were not superior to APRI and FIB-4 in staging significant fibrosis (AUC: 0.76 vs 0.73 vs 0.70 vs 0.71, all P-values > 0.05).

CONCLUSION

 STE and STQ are convenient techniques with a reliable LSM value. They have a similar diagnostic performance and are superior to serum biomarkers in staging cirrhosis in CHB patients.

Ovarian Stiffness Is Significantly Increased in Polycystic Ovary Syndrome and Related With Anti-Mullerian Hormone: A Point Shear Wave Elastography Study

OBJECTIVES

Parenchymal stiffness obtained by point shear-wave elastography (pSWE) in solid organs is used as a sign of damage in these organs. However, its clinical use and whether patients with polycystic ovary syndrome (PCOS) have increased ovarian tissue stiffness are still unclear. The aim of this study is to determine the parameters related to ovarian stiffness and whether there is an increase in ovarian stiffness in patients with PCOS compared with healthy controls.

METHODS

Forty-five women who were followed up regularly with the diagnosis of PCOS and 30 healthy controls similar to age and sex were included in this study. In addition to the routine follow-up parameters for PCOS, serum homeostatic model assessment of insulin resistance and anti-Mullerian hormone (AMH) levels were examined in all patients, and pSWE examination was performed with pelvic ultrasound (US) and ElastPQ technique.

RESULTS

Serum dehydroepiandrosterone sulfate, luteinizing hormone/follicle-stimulating hormone, testosterone, homeostatic model assessment of insulin resistance, and AMH were higher in PCOS compared with healthy controls (P < 0.001). Right, left, and mean ovary stiffness and volumes were significantly higher in PCOS group than healthy controls (P < 0.001). Correlation analysis was performed between mean ovary stiffness and dehydroepiandrosterone sulfate, luteinizing hormone/follicle-stimulating hormone, testosterone, homeostatic model assessment, and AMH and ovary volumes (P < 0.01 for each one). In linear regression analysis, only AMH was found to be related to mean ovary stiffness (P < 0.001 and β = 0.734).

CONCLUSIONS

Ovarian stiffness value obtained by ElastPQ technique and pSWE method increases in PCOS patients compared with healthy controls and is closely related to serum AMH levels. In patients with PCOS, in addition to the conventional US, ovarian stiffness measured by pSWE may be an auxiliary examination in the follow-up of the disease. However, it was concluded that the ovarian stiffness measurement obtained in our current study should be supported by studies involving more patients and the transvaginal US method.

Staging liver fibrosis after severe yellow fever with ultrasound elastography in Brazil: A six-month follow-up study

BACKGROUND

Yellow fever (YF) is a hemorrhagic disease caused by an arbovirus endemic in South America, with recent outbreaks in the last years. Severe cases exhibit fulminant hepatitis, but there are no studies regarding its late-term effects on liver parenchyma. Thus, the aim of this study was to determine the frequency and grade of liver fibrosis in patients who recovered from severe YF and to point out potential predictors of this outcome.

METHODOLOGY/PRINCIPAL FINDINGS

We followed-up 18 patients who survived severe YF during a recent outbreak (January-April 2018) in Brazil using ultrasound (US) with shear-wave elastography (SWE) at 6 months after symptoms onset. No patient had previous history of liver disease. Median liver stiffness (LS) was 5.3 (4.6-6.4) kPa. 2 (11.1%) patients were classified as Metavir F2, 1 (8.3%) as F3 and 1 (8.3%) as F4; these two last patients had features of cardiogenic liver congestion on Doppler analysis. Age and cardiac failure were associated with increased LS (p = 0.036 and p = 0.024, respectively). SAPS-3 at ICU admission showed a tendency of association with significant fibrosis (≥ F2; p = 0.053). 7 patients used sofosbuvir in a research protocol, of which none showed liver fibrosis (p = 0.119).

CONCLUSIONS/SIGNIFICANCE

We found a low frequency of liver fibrosis in severe YF survivors. US with SWE may have a role in the follow up of patients of age and / or with comorbidities after hospital discharge in severe YF, a rare but reemergent disease.

Interobserver and Intraobserver Reliability of Hepatic Shear Wave Elastography and the Influence of Fasted Versus Nonfasted States in Healthy Volunteers

OBJECTIVES

The primary objective of this study was to assess the effect of fasting versus ingestion of food and water on hepatic measurements by shear wave elastography (SWE) in healthy participants. The secondary objective was to assess inter- and intra-reader reliability of hepatic elastography in healthy participants.

METHODS

Twenty healthy participants were enrolled in this prospective study and underwent quantitative SWE under fasting conditions and after the ingestion of water and food and water. Two blinded sonographers each independently performed a total of 6 sessions of hepatic SWE in each participant. Sessions 1 to 3 were performed on day 0 and sessions 4 to 6 on day 7. Statistical tests used included the Wilcoxon signed ranks test, the intraclass correlation coefficient, and Bland-Altman plots.

RESULTS

There were no significant differences in hepatic SWE measurements after the ingestion of water versus the fasting state. Statistical significance was assessed as P < 0.05. The postprandial status had a statistically significant effect on hepatic SWE measurements at 1 hour (P = .04) but not at 3 hours (P = .08). By the intraclass correlation coefficient, there was poor-to-moderate inter-reader agreement and minimal-to-moderate intra-reader agreement. The median inter-reader difference in SWE measurements ranged from 0.66 to 0.96 kPa. The median intra-reader difference ranged from 0.43 to 0.55 kPa.

CONCLUSIONS

Our study shows that the ingestion of water has no effect on hepatic SWE measurements in healthy participants. The postprandial state had a significant effect on SWE measurements at 1 hour after ingestion but not at 3 hours. The inter-reader and intra-reader agreements were variable and moderate at best.

Texture Analysis of Gray-Scale Ultrasound Images for Staging of Hepatic Fibrosis

Purpose

Materials and Methods

Results

Conclusion

Liver Stiffness Is Increased in Polycystic Ovary Syndrome and Related With Complement C1q/Tumor Necrosis Factor-Related Protein 3 Levels: A Point Shear Wave Elastography Study

ABSTRACT

Nonalcoholic fatty liver disease is very common in patients with polycystic ovary syndrome (PCOS). In patients with PCOS, the clinical use of liver stiffness (LS) and whether LS increases or decreases are still unclear. The purpose of this study was to determine the parameters related to LS and whether there is an increase in LS in patients with PCOS compared with healthy controls. Thirty-eight women diagnosed with PCOS according to Rotterdam criteria and 28 healthy age- and sex-matched controls were included in this study. In addition to routine follow-up parameters for all patients, serum homeostatic model assessment of insulin resistance (HOMA-IR) and complement C1q/tumor necrosis factor-related protein 3 (CTRP3) levels were measured, and point shear wave elastography was performed. Body mass index; waist circumference; systolic blood pressure; serum glucose, alanine aminotransferase, highly sensitive C-reactive protein, and dehydroepiandrosterone sulfate, testosterone, and HOMA-IR levels; and luteinizing hormone/follicle-stimulating hormone ratio were higher in PCOS group compared with healthy controls (P < 0.05). Serum CTRP3 levels were lower in patients with PCOS (P < 0.05). Liver stiffness value was significantly higher in PCOS group than healthy controls (P < 0.001). Positive correlation was found between LS and waist circumference as well as calcium, dehydroepiandrosterone sulfate, testosterone, and HOMA-IR levels (P < 0.05 for each one). Negative correlation was found between LS and CTRP (P < 0.01 for each one). In linear regression analysis, only CTRP3 level was found to be related to LS (P < 0.001 and β = 0.734). Liver stiffness value obtained by point shear wave elastography increases in patients with PCOS compared with healthy controls and is closely and negatively related to serum CTRP3 levels.

Ultrasound, shear-wave elastography, and magnetic resonance imaging in native liver survivor patients with biliary atresia after Kasai portoenterostomy: correlation with medical outcome after treatment

BACKGROUND

Biliary atresia (BA) is a rare obliterative cholangiopathy and Kasai portoenterostomy (KP) represents its first-line treatment; clinical and laboratory parameters together with abdominal ultrasound (US) are usually performed during the follow-up. Shear-wave elastography (SWE) is able to evaluate liver parenchyma stiffness; magnetic resonance imaging (MRI) has also been proposed to study these patients.

PURPOSE

To correlate US, SWE, and MRI imaging findings with medical outcome in patients with BA who are native liver survivors after KP.

MATERIAL AND METHODS

We retrospectively enrolled 24 patients. They were divided in two groups based on "ideal" (n = 15) or "non-ideal" (n = 9) medical outcome. US, SWE, and MRI exams were analyzed qualitatively and quantitatively for imaging signs suggestive of chronic liver disease (CLD).

RESULTS

Significant differences were found in terms of liver surface (P = 0.007) and morphology (P = 0.013), portal vein diameter (P = 0.012) and spleen size (P = 0.002) by US, liver signal intensity (P = 0.013), portal vein diameter (P = 0.010), presence of portosystemic collaterals (P = 0.042), and spleen size (P = 0.001) by MRI. The evaluation of portal vein diameter (moderate, κ = 0.44), of portosystemic collaterals (good, κ = 0.78), and spleen size (very good, κ = 0.92) showed the best agreement between US and MRI. A significant (P = 0.01) difference in liver parenchyma stiffness by SWE was also found between the two groups (cut-off = 9.6 kPa, sensitivity = 55.6%, specificity = 100%, area under the ROC curve = 0.82).

CONCLUSION

US, SWE, and MRI findings correlate with the medical outcome in native liver survivor patients with BA treated with KP.

Validation of a New Point Shear-Wave Elastography Method for Noninvasive Assessment of Liver Fibrosis: A Prospective Multicenter Study

Objective

To validate the diagnostic value of a new point shear-wave elastography method, S-shearwave elastography (S-SWE; Samsung Medison Co., Ltd.), in noninvasive assessment of liver fibrosis.

Materials and Methods

In this prospective multicenter study, liver stiffness (LS) measurements for 600 participants were obtained with both S-SWE and transient elastography (TE). The rates of unsuccessful LS measurements in S-SWE and TE were compared, and correlations between S-SWE and TE measurements were assessed. In 107 patients with histologic reference data, the optimal LS cut-off values for predicting severe fibrosis and cirrhosis on S-SWE were determined using receiver operating characteristic (ROC) curve analysis. The LS cut-off values in S-SWE were then validated in 463 patients without histologic reference data by using TE values as the reference standard, and the sensitivity and specificity of the cut-off values for predicting severe fibrosis and cirrhosis were calculated.

Results

The frequency of unsuccessful LS measurements on TE (4.5%, 27/600) was significantly higher than that (0.7%, 4/600) on S-SWE (p < 0.001). LS measurements on S-SWE showed a significant correlation with TE values (r = 0.880, p < 0.001). In 107 patients with histological reference data, the areas under the ROC curves on S-SWE were 0.845 and 0.850, with optimal cut-offs of 7.0 kilopascals (kPa) and 9.7 kPa, for the diagnosis of severe fibrosis and cirrhosis, respectively. Using these cut-off values, S-SWE showed sensitivities of 92.9% and 97.4% and specificities of 89.5% and 83.1% in TE-based evaluations of severe fibrosis and cirrhosis, respectively.

Conclusion

LS measurements on S-SWE were well correlated with those on TE. In addition, S-SWE provided good diagnostic performance for staging of hepatic fibrosis, with a lower rate of unsuccessful LS measurements compared with TE.

Comparison of point and 2-dimensional shear wave elastography for the evaluation of liver fibrosis

PURPOSE

This study aimed to assess the technical performance of ElastQ Imaging compared with ElastPQ and to investigate the correlation between liver stiffness (LS) values obtained using these two techniques.

METHODS

This retrospective study included 249 patients who underwent LS measurements using both ElastPQ and ElastQ Imaging equipped on the same machine. The applicability, repeatability (coefficient of variation [CV]), acquisition time, and LS values were compared using the chi-square or Wilcoxon signed-rank tests. In the development group, the correlation between the LS values obtained by the two techniques was assessed with Spearman correlation coefficients and linear regression analysis. In the validation group, the agreement between the estimated and real LS values was evaluated using a Bland-Altman plot.

RESULTS

ElastQ Imaging had higher applicability (94.0% vs. 78.3%, P<0.001) and higher repeatability, with a lower median CV (0.127 vs. 0.164, P<0.001) than did ElastPQ. The median acquisition time of ElastQ Imaging was significantly shorter than that of ElastPQ (45.5 seconds vs. 96.5 seconds, P<0.001). The median LS value obtained using ElastQ Imaging was significantly higher than that obtained using ElastPQ (5.60 kPa vs. 5.23 kPa, P<0.001). The LS values between the two techniques exhibited a strong positive correlation (r=0.851, P<0.001) in the development group. The mean difference and 95% limits of agreement were 0.0 kPa (-3.9 to 3.9 kPa) in the validation group.

CONCLUSION

ElastQ Imaging may be more reliable and faster than ElastPQ, with strongly correlated LS measurements.

Interobserver agreement and diagnostic accuracy of shearwave elastography for the staging of hepatitis C virus-associated liver fibrosis

PURPOSE

Our study aimed to evaluate the technical success rate, interobserver reproducibility, and accuracy of shearwave elastography (SWE) in the staging of hepatitis C virus (HCV)-associated liver fibrosis.

METHODS

A total of 10 healthy controls and 49 patients with chronic liver disease were enrolled prospectively. Two examiners performed point shearwave elastography (pSWE) and two-dimensional shearwave elastography (2D-SWE) measurements with an RS85A ultrasound scanner using the S-Shearwave application (Samsung Medison, Hongcheon, Korea). The performance of S-Shearwave in the staging (METAVIR F0-F4) of liver fibrosis was compared with prior transient elastography (TE) with receiver operating characteristic (ROC) curve analysis.

RESULTS

The interobserver reproducibility was excellent with pSWE (ICC = 0.92, 95% CI: 0.86-0.95, P < .001). A very good agreement was found between pSWE and TE measurements (ICC =0.85, 95% CI: 0.78-0.89, P < .001). The ROC analysis determined the optimal cut-off values of pSWE for the staging of chronic hepatitis C-associated fibrosis (F2, 1.46 m/s; F3, 1.63 m/s; F4, 1.95 m/s). Both observers achieved excellent diagnostic accuracy (AUROC: 94% vs 97%) in the detection of significant (≥F2) liver fibrosis.

CONCLUSION

The interobserver agreement is excellent with S-Shearwave pSWE, and observers can diagnose significant liver fibrosis with a comparable accuracy to TE.

Inter-platform reproducibility of liver stiffness measured with two different point shear wave elastography techniques and 2-dimensional shear wave elastography using the comb-push technique

PURPOSE

The purpose of this study was to compare the technical success rate and reliability of measurements made using three shear wave elastography (SWE) techniques and to assess the inter-platform reproducibility of the resultant liver stiffness measurements.

METHODS

This prospective study included 54 patients with liver disease. Liver stiffness (LS) measurements were obtained using 2-point SWE techniques (Virtual Touch Quantification and S-Shearwave) and 2-dimensional (2D) SWE, with transient elastography (TE) serving as the reference standard. The technical success rates and measurement reliability of the three techniques were compared. LS values measured using the three SWE techniques and TE were compared using Spearman correlation coefficients and 95% Bland-Altman limits of agreement. Intra-class correlation coefficients (ICC) were used to analyze the inter-platform reproducibility of LS measurements.

RESULTS

The three SWE techniques and TE showed similar technical success rates (P=0.682) but demonstrated significant differences in the reliability of LS measurements (P=0.006) and mean LS measurements (P<0.001). Despite strong correlations (r=0.73-0.94) between SWE systems, various degrees of inter-platform reproducibility (ICC, 0.58-0.92) were observed for the three SWE techniques. The best agreement was observed between S-Shearwave and TE (ICC, 0.92), and the worst agreement was observed between 2D-SWE and TE (ICC, 0.58). In the BlandAltman analysis, a tendency toward lower LS values with the three SWE techniques than with TE in patients with F3 and F4 disease was observed.

CONCLUSION

Significant inter-system variability was observed in LS measurements made using the three SWE techniques. Therefore, LS values measured using different SWE techniques should not be used interchangeably for longitudinal follow-up.

Addition of Reliability Measurement Index to Point Shear Wave Elastography: Prospective Validation via Diagnostic Performance and Reproducibility

The clinical value of the reliability measurement index (RMI), newly added to point shear wave elastography (pSWE), was investigated. Forty-nine patients underwent both pSWE providing RMI (range: 0.0-1.0) and transient elastography (TE) before hepatic surgery. Interclass correlation coefficients (ICCs) between the median of the first two to nine measurements (as categorized by RMI values ≥0.0 (liver stiffness-reliability measurement index [LS-RMI] 0.0), ≥0.4 (LS-RMI 0.4) and ≥0.7 (LS-RMI 0.7) and the median of 10 consecutive measurements (LS-REF) were obtained. Compared with LS-REF, minimums of 7 LS-RMI 0.0, 5 LS-RMI 0.4 and 3 LS-RMI 0.7 measurements were required to obtain an ICC ≥0.95 with high inter-observer agreement (ICC ≥0.90). Diagnostic performance did not differ (p values >0.05) using these reduced numbers of LS measurements. Significant correlations were found between the reduced number of LS measurements and TE or METAVIR (p values <0.001). Therefore, RMI helped to improve reliability and reduce the number of LS measurements while maintaining the diagnostic performance of pSWE.

Intra- and inter-operator reproducibility of US point shear-wave elastography in various organs: evaluation in phantoms and healthy volunteers

PURPOSE

This study was conducted in order to assess the intra- and interoperator reproducibility of shear-wave speed (SWS) measurement on elasticity phantoms and healthy volunteers using ultrasound-based point shear-wave elastography.

MATERIALS AND METHODS

This study was approved by the institutional review board. Two operators measured the SWS of five elasticity phantoms and seven organs (thyroid, lymph node, muscle, spleen, kidney, pancreas, and liver) of 30 healthy volunteers with 1.0-4.5 MHz convex (4C1) and 4.0-9.0 MHz linear (9L4) transducers. The phantom measurements were repeated ten times, while the volunteer measurements were performed five times each. Intra- and interoperator reproducibility was assessed. Interoperator reproducibility was also evaluated with the 95% Bland-Altman limits of agreement (LOA).

RESULTS

In phantoms, all intraclass correlation coefficients (ICCs) were above 0.90 and the 95% LOA between the two operators were less than ± 18%. In volunteers, intraoperator ICCs were > 0.75 for all regions except the pancreas. Interoperator ICC was above 0.75 for the right lobe of the liver (depth 4 cm) and the kidney, but the 95% LOA was less than ± 25% only for the liver.

CONCLUSION

Although excellent in phantoms, interoperator reproducibility was insufficient for all regions in the volunteers other than the right hepatic lobe at a depth of 4 cm. Clinicians should be aware of the 95% LOA when using SWS in patients.

KEY POINTS

• Our phantom study indicated a high reproducibility for shear-wave speed (SWS) measurements with point shear-wave elastography (pSWE). • In volunteers, intraoperator reproducibility was generally high, but the interoperator reproducibility was not high enough except for the right hepatic lobe at 4 cm depth. • To evaluate interoperator reproducibility, the 95% limits of agreement (LOA) between operators should be considered in addition to the intraclass correlation coefficient (ICC).

Multifactor Analysis of Thyroid Stiffness in Graves Disease: A Preliminary Study

OBJECTIVE. The aim of this study was to evaluate the value of shear wave elastography (SWE) in Graves disease (GD) and to identify the potential factors influencing thyroid stiffness. MATERIALS AND METHODS. A total of 207 subjects were enrolled and underwent SWE examination in the study, including 162 patients with GD and 45 healthy volunteers with normal thyroids, matched for age and sex. For all subjects, five measurements of elastic modulus values (SWE mean, SWE minimum, and SWE maximum of a 9-mm ROI) were performed on each thyroid lobe, and a mean value was calculated. The indicators including free three-triiodothyronine (FT₃), free thyroxine (FT₄), thyroid-stimulating hormone (TSH), thyroid size, isthmus thickness, anti-thyroid peroxidase (TPO) antibodies (Abs), and antithyroglobulin (TG) Abs were detected in the 162 patients with GD, among whom 88 patients underwent initial TSH receptor (TR) Ab examination. RESULTS. The elastic modulus values for patient with GD were significantly higher than those for healthy control subjects. The ROC AUC values for GD by SWE mean was 0.656, and the cutoff value was 15.45 kPa. The sensitivity and specificity were 56.8% and 71.1%, respectively. The duration of disease, thyroid size, isthmus thickness, and levels of TPO Ab, TG Ab, and TR Ab were positively correlated with SWE mean in GD. However, there was no correlation between age, FT₃, FT₄, TSH, and SWE mean. CONCLUSION. Quantitative SWE helps in the diagnosis of GD. The duration of disease, thyroid size, isthmus thickness, and levels of thyroid autoantibodies (TPO Ab, TG Ab, and TR Ab) could influence thyroid stiffness of GD.

Reproducibility of liver stiffness measurements made with two different 2-dimensional shear wave elastography systems using the comb-push technique

Purpose

The purpose of this study was to retrospectively compare the technical success and reliability of the measurements made using two 2-dimensional (2D) shear wave elastography (SWE) systems using the comb-push technique from the same manufacturer and to assess the intersystem reproducibility of the resultant liver stiffness (LS) measurements.

Methods

Ninety-four patients with suspected chronic liver diseases were included in this retrospective study. LS measurements were obtained using two 2D-SWE systems (LOGIQ E9 and LOGIQ S8) from the same manufacturer, with transient elastography (TE) serving as the reference standard, on the same day. The technical success rates and reliability of the measurements of the two 2D-SWE systems were compared. LS values measured using the two 2D-SWE systems and TE were correlated using Spearman correlation coefficients and 95% Bland-Altman limits of agreement. Thereafter, Bland-Altman limits of agreement and intraclass correlation coefficients (ICCs) were used to analyze the intersystem reproducibility of LS measurements.

Results

The two 2D-SWE systems showed similar technical success rates (98.9% for both) and reliability of LS measurements (92.3% for the LOGIQ E9, 91.2% for the LOGIQ S8; P=0.185). Despite the excellent correlation (ICC=0.92), the mean LS measurements obtained by the two 2D-SWE systems were significantly different (LOGIQ E9, 6.57±2.33 kPa; LOGIQ S8, 6.90±6.64 kPa; P=0.018).

Conclusion

Significant intersystem variability was observed in the LS measurements made using the two 2D-SWE systems. Therefore, even 2D-SWE systems from the same manufacturer should not be used interchangeably in longitudinal follow-up.

Age of Data in Contemporary Research Articles Published in Representative General Radiology Journals

Objective

To analyze and compare the age of data in contemporary research articles published in representative general radiology journals.

Materials and Methods

We searched for articles reporting original research studies analyzing patient data that were published in the print issues of the Korean Journal of Radiology (KJR), European Radiology (ER), and Radiology in 2017. Eligible articles were reviewed to extract data collection period (time from first patient recruitment to last patient follow-up) and age of data (time between data collection end and publication). The journals were compared in terms of the proportion of articles reporting the data collection period to the level of calendar month and regarding the age of data.

Results

There were 50, 492, and 254 eligible articles in KJR, ER, and Radiology, respectively. Of these, 44 (88%; 95% confidence interval [CI]: 75.8-94.8%), 359 (73%; 95% CI: 68.9-76.7%), and 211 (83.1%; 95% CI: 78-87.2%) articles, respectively, provided enough details of data collection period, revealing a significant difference between ER and Radiology (p = 0.002). The age of data was significantly greater in KJR (median age: 826 days; range: 299-2843 days) than in ER (median age: 570 days; range: 56-4742 days; p < 0.001) and Radiology (median age: 618; range: 75-4271 days; p < 0.001).

Conclusion

Korean Journal of Radiology did not fall behind ER or Radiology in reporting of data collection period, but showed a significantly greater age of data than ER and Radiology, suggesting that KJR should take measures to improve the timeliness of its data.

Histogram Analysis of Diffusion Kurtosis Magnetic Resonance Imaging for Diagnosis of Hepatic Fibrosis

Objective

To investigate the diagnostic value of diffusion kurtosis imaging (DKI) histogram analysis in hepatic fibrosis staging.

Materials and Methods

Thirty-six rats were divided into carbon tetrachloride-induced fibrosis groups (6 rats per group for 2, 4, 6, and 8 weeks) and a control group (n = 12). MRI was performed using a 3T scanner. Histograms of DKI were obtained for corrected apparent diffusion (D), kurtosis (K) and apparent diffusion coefficient (ADC). Mean, median, skewness, kurtosis and 25th and 75th percentiles were generated and compared according to the fibrosis stage and inflammatory activity.

Results

A total of 35 rats were included, and 12, 5, 5, 6, and 7 rats were diagnosed as F0–F4. The mean, median, 25th and 75th percentiles, kurtosis of D map, median, 25th percentile, skewness of K map, and 75th percentile of ADC map demonstrated significant correlation with fibrosis stage (r = −0.767 to 0.339, p < 0.001 to p = 0.039). The fibrosis score was the independent variable associated with histogram parameters compared with inflammatory activity grade (p < 0.001 to p = 0.041), except the median of K map (p = 0.185). Areas under the receiver operating characteristic curve of D were larger than K and ADC maps in fibrosis staging, although no significant differences existed in pairwise comparisons (p = 0.0512 to p = 0.847).

Conclusion

Corrected apparent diffusion of DKI histogram analysis provides added value and better diagnostic performance to detect various liver fibrosis stages compared with ADC.