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Updated: Aug 22, 2025
3D Ultrasound Imaging: Fast and Cost-effective Morphometry of Musculoskeletal Tissue
Published on: November 27, 2017
Tissue Characterization of Puborectalis Muscle From 3-D Ultrasound
Catalin Cernat1, Shreya Das1, Gijs A G M Hendriks1
1Medical Ultrasound Imaging Center (MUSIC), Radboud University Medical Center, Nijmegen, The Netherlands.
Insights
Quantitative ultrasound tissue characterization can detect microdamage in the puborectalis muscle (PRM) after childbirth. This method reveals distinct echogenicity and entropy changes in damaged PRMs, aiding in diagnosing subtle muscle trauma.
Area of Science:
- Biomedical Engineering
- Medical Imaging
- Musculoskeletal Ultrasound
Background:
- Pelvic floor (PF) muscles, including the puborectalis muscle (PRM), are crucial for preventing pelvic organ descent.
- Childbirth can cause trauma and avulsion (disconnection from the pubic bone) in the PRM, leading to irreversible damage.
- Current ultrasound imaging can diagnose severe avulsion but struggles to detect microdamage within the muscle tissue.
Purpose of the Study:
- To develop a quantitative ultrasound tissue characterization method for assessing PRM tissue state and microdamage.
- To differentiate between healthy and unilaterally avulsed PRMs using quantitative ultrasound parameters.
Main Methods:
- Ultrasound imaging was used to analyze the PRM, segmented into regions of interest (ROIs) and sub-ROIs.
- Quantitative analysis of mean echogenicity, entropy, and shape parameters was performed on sub-ROIs near the pubic bone.
- Analysis included both resting and contracted muscle states, comparing healthy and avulsed PRMs.
Main Results:
- Unilaterally avulsed PRMs showed significantly higher mean echogenicity (p=0.02) and shape parameters (p<0.01) compared to undamaged PRMs.
- Avulsed PRMs exhibited significantly lower entropy (p<0.01) than undamaged PRMs.
- These quantitative differences were observed in the sub-ROIs nearest to the bone, indicative of damage.
Conclusions:
- Quantitative ultrasound tissue characterization provides objective measures of PRM microdamage.
- This method can potentially quantify PRM damage, including subtle microdamage not visible on standard ultrasound inspection.
- The findings suggest applicability for diagnosing and monitoring PRM trauma post-childbirth.
Abstract:
Pelvic floor (PF) muscles have the role of preventing pelvic organ descent. The puborectalis muscle (PRM), which is one of the female PF muscles, can be damaged during child delivery. This damage can potentially cause irreversible muscle trauma and even lead to an avulsion, which is disconnection of the muscle from its insertion point, the pubic bone. Ultrasound imaging allows diagnosis of such trauma based on comparison of geometric features of a damaged muscle with the geometric features of a healthy muscle. Although avulsion, which is considered severe damage, can be diagnosed, microdamage within the muscle itself leading to structural changes cannot be diagnosed by visual inspection through imaging only. Therefore, we developed a quantitative ultrasound tissue characterization method to obtain information on the state of the tissue of the PRM and the presence of microdamage in avulsed PRMs. The muscle was segmented as the region of interest (ROI) and further subdivided into six regions of interest (sub-ROIs). Mean echogenicity, entropy and shape parameter of the statistical distribution of gray values were analyzed on two of these sub-ROIs nearest to the bone. The regions nearest to the bones are also the most likely regions to exhibit damage in case of disconnection or avulsion. This analysis was performed for both the muscle at rest and the muscle in contraction. We found that, for PRMs with unilateral avulsion compared with undamaged PRMs, the mean echogenicity (p = 0.02) and shape parameter (p < 0.01) were higher, whereas the entropy was lower (p < 0.01). This method might be applicable to quantification of PRM damage within the muscle.
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