Usefulness of the twinkling artifact in identifying implanted mesh after inguinal hernia repair

Pore texture analysis in automated 3D breast ultrasound images for implanted lightweight hernia mesh identification: a preliminary study

Background

Precise visualization of meshes and their position would greatly aid in mesh shrinkage evaluation, hernia recurrence risk assessment, and the preoperative planning of salvage repair. Lightweight (LW) meshes are able to preserve abdominal wall compliance by generating less post-implantation fibrosis and rigidity. However, conventional 3D imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) cannot visualize the LW meshes. Patients sometimes have to undergo a second-look operation for visualizing the mesh implants. The goal of this work is to investigate the potential advantages of Automated 3D breast ultrasound (ABUS) pore texture analysis for implanted LW hernia mesh identification.

Methods

In vitro, the appearances of four different flat meshes in both ABUS and 2D hand-held ultrasound (HHUS) images were evaluated and compared. In vivo, pore texture patterns of 87 hernia regions were analyzed both in ABUS images and their corresponding HHUS images.

Results

In vitro studies, the imaging results of ABUS for implanted LW meshes are much more visualized and effective in comparison to HHUS. In vivo, the inter-class distance of 40 texture features was calculated. The texture features of 2D sectional plans (axial and sagittal plane) have no significant contribution to implanted LW mesh identification. Significant contribution was observed in coronal plane. However, since the mesh may have spatial variation such as shrinkage after implantation surgery, the inter-class distance of 3D coronal plane pore texture features are bigger than 2D coronal plane, so the contribution of 3D coronal plane pore texture features are more valuable than 2D coronal plane for implanted LW mesh identification. The use of 3D pore texture features significantly improved the robustness of the identification method in distinguishing between LW mesh and fascia.

Conclusions

An innovative new ABUS provides additional pore texture visualization, by separating the LW mesh from the fascia tissues. Therefore, ABUS has the potential to provides more accurate features to characterize pore texture patterns, and ultimately provide more accurate measures for implanted LW mesh identification.

Emerging Trends in Abdominal Wall Reinforcement: Bringing Bio-Functionality to Meshes

Abdominal wall hernia is a recurrent issue world-wide and requires the implantation of over 1 million meshes per year. Because permanent meshes such as polypropylene and polyester are not free of complications after implantation, many mesh modifications and new functionalities have been investigated over the last decade. Indeed, mesh optimization is the focus of intense development and the biomaterials utilized are now envisioned as being bioactive substrates that trigger various physiological processes in order to prevent complications and to promote tissue integration. In this context, it is of paramount interest to review the most relevant bio-functionalities being brought to new meshes and to open new avenues for the innovative development of the next generation of meshes with enhanced properties for functional abdominal wall hernia repair.

Identification of implanted mesh after incisional hernia repair using an automated breast volume scanner

OBJECTIVES

This study aimed to evaluate the utility of an automated breast volume scanner (ABVS) versus handheld ultrasound (US) for identifying implanted mesh after incisional hernia repair.

METHODS

In vitro, the appearances of 3 samples of different flat mesh and a mesh plug on both ABVS and handheld US examinations were evaluated. In vivo, 97 patients received both ABVS and handheld US examinations in the incisional region. The frequency used for handheld US was 11 MHz. The presence of the previously implanted mesh in the incisional region was evaluated and compared between the US modalities. The identified results were confirmed by surgical findings.

RESULTS

In the in vitro study, the ABVS had more visualized and efficient imaging results for implanted mesh than handheld US. In the in vivo study, among 97 cases, 39 and 32 were identified as regions with mesh by the ABVS and handheld US, respectively. The ABVS had better identification performance than handheld US in terms of accuracy (94.8% versus 83.5%), sensitivity (90.5% versus 69.0%), and specificity (98.2% versus 94.5%). The κ values showed that handheld US had substantial agreement with surgical findings (κ = 0.78; 95% confidence interval, 0.66-0.90), whereas the ABVS had almost perfect agreement with surgical findings (κ = 0.93; 95% confidence interval, 0.86-1.00). More importantly, the ABVS could display the texture of lightweight mesh in the coronal plane. The specificity and sensitivity for mesh texture were 100.0% (55 of 55) and 94.4% (17 of 18), respectively.

CONCLUSIONS

The use of an ABVS may help identify the presence of implanted mesh after incisional hernia repair in some cases in which the implant is difficult to appreciate on handheld US imaging with an 11-MHz transducer.

The role of the acoustic radiation force in color Doppler twinkling artifacts

PURPOSE

The aim of this experimental study was to evaluate whether the acoustic radiation force (ARF) is a potential source of twinkling artifacts in color Doppler images.

METHODS

Color Doppler images were obtained using a clinical ultrasonic scanner (Voluson e, GE Healthcare) for a high contrast (+15 dB) circular scattering phantom at pulse repetition frequencies (PRFs) ranging from 0.1 to 13 kHz. Ultrasound transmissions resulting in ARF were measured using a hydrophone at the various PRFs considered. The influence of ARF on the appearance of twinkling colors was examined via the common parameter PRF. This methodology is based on the fact that alternating positive and negative Doppler shifts induced by the ARF are centered at a PRF twice the maximum Doppler frequency on the color scale bar, whereas the twinkling color aliasing is expected to remain similar regardless of PRF.

RESULTS

Color twinkling artifacts were observed to be most conspicuous at the lowest PRF of 0.1 kHz. The extent of twinkling rapidly decreased as the PRF increased, eventually disappearing when the PRF ≥0.6 kHz. The measured ultrasound transmissions, however, were found to be insensitive to the PRF, and therefore it can be inferred that the PRF was insensitive to the ARF.

CONCLUSION

Based on our experimental observations, the ARF may not be a source of color Doppler twinkling artifacts.

A novel approach for quantification and analysis of the color Doppler twinkling artifact with application in noninvasive surface roughness characterization: an in vitro phantom study

OBJECTIVES

The twinkling artifact is an undesired phenomenon within color Doppler sonograms that usually appears at the site of internal calcifications. Since the appearance of the twinkling artifact is correlated with the roughness of the calculi, noninvasive roughness estimation of the internal stones may be considered as a potential twinkling artifact application. This article proposes a novel quantitative approach for measurement and analysis of twinkling artifact data for roughness estimation.

METHODS

A phantom was developed with 7 quantified levels of roughness. The Doppler system was initially calibrated by the proposed procedure to facilitate the analysis. A total of 1050 twinkling artifact images were acquired from the phantom, and 32 novel numerical measures were introduced and computed for each image. The measures were then ranked on the basis of roughness quantification ability using different methods. The performance of the proposed twinkling artifact-based surface roughness quantification method was finally investigated for different combinations of features and classifiers.

RESULTS

Eleven features were shown to be the most efficient numerical twinkling artifact measures in roughness characterization. The linear classifier outperformed other methods for twinkling artifact classification. The pixel count measures produced better results among the other categories. The sequential selection method showed higher accuracy than other individual rankings. The best roughness recognition average accuracy of 98.33% was obtained by the first 5 principle components and the linear classifier.

CONCLUSIONS

The proposed twinkling artifact analysis method could recognize the phantom surface roughness with average accuracy of 98.33%. This method may also be applicable for noninvasive calculi characterization in treatment management.

Two-/three-dimensional transperineal sonography of complicated tape and mesh implants

Transperineal sonography (TPS) affords dynamic evaluation of suburethral slings using tensionless vaginal tape and mesh implants used to treat complications associated with surgical procedures of the pelvic floor. This review describes and illustrates the TPS findings in postoperative complications such as recurrent prolapse, cystocele, enterocele, and rectocele. The potential use of live 3-dimensional TPS to delineate the dynamics aspects of pelvic floor disorder is also mentioned.

Correlation between twinkling artifact and color Doppler carrier frequency: preliminary observations in renal calculi

Color Doppler twinkling is a well-defined but not well-understood phenomenon that may assist in the detection of renal calculi. However, the relationship between the appearance of color Doppler twinkling and color Doppler carrier frequency has not been described systematically. To evaluate this relationship, a retrospective review was performed on 20 cases of renal calculi detected by twinkling on renal color Doppler sonography and confirmed with unenhanced computed tomography. The variable strength of twinkling at and behind renal calculi was observed with color Doppler carrier frequencies ranging from 1.75-4.0 MHz. All 20 calculi (100%) demonstrated twinkling when a low color Doppler carrier frequency, 1.75 or 2 MHz, was applied, whereas 12 of 20 cases (60%) were absent of twinkling when the highest carrier frequencies tested-3.5 or 4 MHz-were used. Quantitatively, there was a significant correlation between the amount of twinkling and carrier frequency (p = 0.002102). Hence, we conclude that the strength of the twinkling is color Doppler carrier frequency-dependent. The strength of the twinkling significantly increased when the color carrier frequency used for imaging decreased. Therefore, to improve renal calculi detection by enhancing the strength of the twinkling, the use of a lower color Doppler carrier frequency is recommended.