Spleen stiffness measurement by shear wave elastography using acoustic radiation force impulse in predicting the etiology of splenomegaly

Evaluation of liver and spleen stiffness measurement with shear wave elastography in brucellosis

BACKGROUND

Human brucellosis, which is endemic in the eastern region of Turkey, infects the reticulo-endothelial system. Acute brucellosis may cause hepatomegaly or splenomegaly.

AIMS

The main purpose of this study was to investigate the effectiveness of the point shear wave elastography (pSWE) method in identifying and detecting liver and spleen stiffness in acute brucellosis.

METHODS

This case-control study included 40 patients with acute brusellosis and 60 healthy individuals as a control group. The demographic data, abdominal ultrasonography (USG) and pSWE results of the patient and control groups were evaluated. Statistical and ROC analyses were performed.

RESULTS

The liver pSWE value was 3.8395 ± 1.171 kPa in the patient group and 1.6619 ± 0.495 kPa in the control group. The spleen pSWE value was 3.2431 ± 1.803 kPa in the patient group and 1.3793 ± 0.622 kPa in the control group. The mean liver and spleen pSWE values were statistically significantly higher in the patient group than in the control group (p < 0.001). Cut-off values were determined as 2.524 for the liver pSWE and 1.62667 for the spleen pSWE. From the AUC values (0.959, 0.903), the diagnostic performance of liver and spleen pSWE values were seen to be excellent in distinguishing between patient and control groups.

CONCLUSIONS

The study results showed that liver and spleen stiffness were high in acute brucellosis patients and had predictive significance above certain cut-off values. It can be considered that pSWE, which evaluates liver and spleen stiffness in acute brucellosis, may provide diagnostic benefit as a reliable, non-invasive technique.

Shear Wave Ultrasonographic Elastography in Pediatric Spleens and Its Role in Differential Diagnosis

Shear wave elastography (SWE) has become popular in clinical practice for many diseases. However, there is not adequate research on spleen-related diseases. This study aimed to investigate the potential of quantitative values obtained through SWE in evaluating spleen pathologies in the pediatric population and to demonstrate its performance to differentiate splenomegaly-related diseases. The research group retrospectively included children with pathological diagnoses related to the spleen from November 2016 to April 2021, and they were categorized into three groups, including portal hypertension (PH), benign lymphoid hyperplasia (BLH), and malignant infiltration (MI). Spleen sizes and parenchymal stiffness were also calculated for each group. Subsequently, mean spleen stiffness in each group was compared with normal values within the same age group. In total, 2781 children (1379 children for the study group; 1402 children for the control group) were enrolled in the study. The highest stiffness was observed in the PH group, which is statistically higher than others (p < 0.05). Although the mean spleen stiffness in the group with BLH was higher than the control and MI group, the difference was not statistically significant (p = 0.08). The mean stiffness in the group with MI was significantly lower than both the control group (p = 0.005) and PH (p = 0.01). In conclusion, using SWE in the differential diagnosis of etiologies causing splenomegaly could make an important contribution.

Acoustic Radiation Force Impulse (ARFI) Elastography of Focal Splenic Lesions: Feasibility and Diagnostic Potential

PURPOSE

Nontraumatic focal splenic lesions (FSL) are rare, and the need for tissue diagnosis must be weighed against the very high risk of bleeding after a splenic biopsy. The aim of this study was to explore the feasibility and diagnostic potential of acoustic radiation force impulse (ARFI) elastography as a noninvasive method for different benign and malignant FSLs. No human studies on the elastographic characteristics of FSL exist.

METHODS

This was a retrospective analysis of 34 patients with FSLs, who underwent abdominal B-mode ultrasound (B-US), contrast-enhanced ultrasound (CEUS), and standardized ARFI examinations between October 2021 and December 2022 at our university hospital. The inclusion criteria were: (i) FSL size ≥ 1 cm; (ii) 10 valid ARFI measurements of the FSL, as well as of the normal splenic parenchyma (NSP) as an in vivo reference; and (iii) diagnostic confirmation of FSL etiology based on histological examination (8/34; 23.5%) or clinical evaluation, which included a clinical and sonographic follow-up (FU), CEUS morphology, and/or morphology on cross-sectional imaging (26/34; 76.5%). CEUS was performed on all patients and the FSLs were classified according to the current guidelines; cross-sectional imaging was available for 29/34 (85.3%). The mean FU duration was 25.8 ± 30.5 months. The mean ARFI velocity (MAV) of the FSL (MAVL), the NSP (MAVP), and the ratio of the MAVL to the MAVP (MAVL/P) were calculated and compared.

RESULTS

Of the 34 FSLs, 13 (38.2%) were malignant (mFSL) and 21 (61.8%) were benign (bFSL). The MAVL of all 34 FSLs (2.74 ± 0.71 m/s) was lower than the MAVP (3.20 ± 0.59 m/s), p = 0.009, with a mean MAVL/P ratio of 0.90 ± 0.34. No significant differences in the MAVL were observed between the mFSL (2.66 ± 0.67 m/s) and bFSL (2.79 ± 0.75 m/s). There were also no significant differences between the MAVP in patients with mFSL (3.24 ± 0.68 m/s) as compared to that in the patients with bFSL (3.18 ± 0.55 m/s). Likewise, the MAV L/P ratio did not differ between the mFSL (0.90 ± 0.41 m/s) and bFSL (0.90 ± 0.30 m/s) groups.

CONCLUSION

ARFI elastography is feasible in evaluating the stiffness of FSLs. The lesions' stiffness was lower than that of the NSP, regardless of the FSL etiology. However, differentiation between benign and malignant FSL with the help of this elastographic method does not appear possible. Larger prospective studies are needed to validate these findings.

Differential Diagnosis Value of Shear-Wave Elastography for Superficial Enlarged Lymph Nodes

Objectives

To evaluate the diagnostic efficiency and diagnostic threshold of conventional US and shear-wave elastography (SWE) in superficial enlarged lymph nodes (LNs).

Methods

A total of 204 patients with superficial enlarged LNs were enrolled in this retrospective study aged 46.0 ± 15.2 years from March 2020 to March 2021. LNs with a long axis larger than 0.7 cm were considered as superficial enlarged. Before the histological biopsy, LNs that were considered suspicious according to both conventional US and SWE were included, while LNs with no or unclear pathological results, or with no satisfactory SWE images, were excluded. The conventional and 2-D SWE examinations were performed with Aplio i800 and Acuson sequoia equipped with i18LX5 linear-array transducer (5-18 MHz) and 10L4 linear-array transducer (4-10 MHz), respectively. Both E Median and Vs Median parameters were investigated by two senior ultrasound physicians. The pathological results were performed as the gold standard.

Results

Variables including transverse axis size, lymphatic hilum, L/T ratio, echogenicity, and color Doppler pattern were considered significant. The mean E Median value in benign, metastatic LNs, and lymphoma were 28.26 ± 8.87 kPa, 77.46 ± 22.85 kPa, and 50.37 ± 5.41 kPa (p <0.001), while Vs Median values were 3.02 ± 0.50 m/s, 4.87 ± 0.90 m/s, and 4.09 ± 0.22 m/s, respectively (p < 0.001). The diagnostic performance indicated the high sensitivity, specificity, PPV, NPV, and overall accuracy of conventional US combined with SWE. The optimal cutoff values of E Median and Vs Median for predicting malignant LNs were 42.90 kPa and 3.73 m/s, respectively. As AUC value, sensitivity, specificity, accuracy, PPV, and NPV revealed, the indexes of E Median were 0.976, 0.927, 0.975, 0.946, 0.983, and 0.897, respectively, while Vs Median were 0.970, 0.927, 0.963, 0.941, 0.975, and 0.895, respectively (p <0.001). The ROC curves of both E Median (AUC=0.976) Vs Median (AUC=0.970) suggested the remarkable diagnostic efficiency in distinguishing benignity between suspected malignant LNs.

Conclusions

Above results indicated that conventional US together with 2-D SWE could elevate the diagnostic performance. Meanwhile, the parameters of 2-D SWE including E Median and Vs Median could effectively assess malignant LNs, which provide valuable differentiating information in superficial enlarged LNs.

Accuracy of B-mode ultrasound and ARFI elastography in predicting malignancy of canine splenic lesions

The objective was to evaluate the accuracy of B-mode ultrasonography and ARFI elastography in detecting malignancy in canine splenic lesions. Thirty-seven spleens with abnormalities (16 benign and 21 malignant) from dogs of different breeds and ages were evaluated. Echogenicity, echotexture, organ length and height were evaluated using B-mode. By ARFI elastography, tissue stiffness was evaluated qualitatively (elastogram) and quantitatively (measuring the shear wave velocity-SWV). Lesions were classified as diffuse, focal or multifocal (cranial, medial or caudal portion) and comparisons of the SWV between the injured and non-injured areas were performed. In the B-mode, no features were associated to malignancy (P > 0.05). In the elastogram, 35 spleens were non-deformable and 2 deformable, having no association with malignancy. The greater SWV was observed in malignant lesions (3.4 ± 0.6 m/s), followed by areas free from alterations (2.1 ± 0.3 m/s) and benign lesions (1.7 ± 0.5 m/s), with difference between groups (P < 0.0001). It was found that a SWV > 2.6 m/s indicates malignancy of canine splenic lesions (sensitivity of 95%, specificity of 100%, PPV of 100%, NPV of 94% and accuracy of 97%), concluding that ARFI elastography is a promising technique for differentiating malignancy in these lesions.

WFUMB Position Paper-Incidental Findings, How to Manage: Spleen

The World Federation for Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings (IFs) with a series of publications entitled "Incidental Imaging Findings-The Role of Medical Ultrasound." IFs are less commonly encountered in the spleen than in many other abdominal organs but remain a frequent dilemma in clinical practice. A histological diagnosis is rarely necessary for patient management. Many IFs, such as secondary spleens and splenic cysts, are harmless and do not require any further investigation. The diagnosis of many other focal splenic lesions is, however, often problematic. The following overview is intended to illustrate a variety of incidentally detected spleen pathologies such as size variants, shape variants, secondary spleens, focal splenic lesions and splenic calcifications. It should aid the examiner in establishing the diagnosis. Moreover, it should help the ultrasound practitioner decide which pathologies need no further investigation, those requiring interval imaging and cases in which immediate further diagnostic procedures are required.