Three-dimensional volume rendering ultrasound for assessing placenta accreta spectrum severity and discriminating it from simple scar dehiscence

BACKGROUND

Prenatal ultrasound discrimination between placenta accreta spectrum and scar dehiscence with underlying nonadherent placenta is challenging both prenatally and intraoperatively, which often leads to overtreatment. In addition, accurate prenatal prediction of surgical difficulty and morbidity in placenta accreta spectrum is difficult, which precludes appropriate multidisciplinary planning. The advent of advanced 3-dimensional volume rendering and contrast enhancement techniques in modern ultrasound systems provides a comprehensive prenatal assessment, revealing details that are not discernible in traditional 2-dimensional imaging.

OBJECTIVE

This study aimed to evaluate the use of 3-dimensional volume rendering ultrasound techniques in determining the severity of placenta accreta spectrum and distinguishing between placenta accreta spectrum and scar dehiscence with underlying nonadherent placenta.

STUDY DESIGN

A prospective, cohort study was conducted between July 2022 and July 2023 in the fetal medicine unit of Dr Soetomo Academic General Hospital, Surabaya, Indonesia. All pregnant individuals with anterior low-lying placenta or placenta previa with a previous caesarean section who were referred with suspicion of placenta accreta spectrum were consented and screened using the standardised 2-dimensional and Doppler ultrasound imaging. Additional 3-dimensional volumes were obtained from the sagittal section of the uterus with a filled urinary bladder. These were analyzed by rotating the region of interest to be perpendicular to the uterovesical interface. The primary outcomes were the clinical and histologic severity in the cases of placenta accreta spectrum and correct diagnosis of dehiscence with nonadherent placenta underneath. The strength of association between ultrasound and clinical outcomes was determined. Multivariate logistic regression analyses and diagnostic testing of accuracy were used to analyze the data.

RESULTS

A total of 70 patients (56 with placenta accreta spectrum and 14 with scar dehiscence) were included in the analysis. Multivariate logistic regression of all 2-dimensional and 3-dimensional signs revealed the 3-dimensional loss of clear zone (P<.001) and the presence of bridging vessels on 2-dimensional Doppler ultrasound (P=.027) as excellent predictors in differentiating scar dehiscence and placenta accreta spectrum. The 3-dimensional loss of clear zone demonstrated a high diagnostic accuracy with an area under the curve of 0.911 (95% confidence interval, 0.819-1.002), with a sensitivity of 89.3% (95% confidence interval, 78.1-95.97%) and specificity of 92.9% (95% confidence interval, 66.1-99.8%). The presence of bridging vessels on 2-dimensional Doppler demonstrated an area under the curve of 0.848 (95% confidence interval, 0.714-0.982) with a sensitivity of 91.1% (95% confidence interval, 80.4-97.0%) and specificity of 78.6% (95% confidence interval, 49.2-95.3%). A subgroup analysis among the placenta accreta spectrum group revealed that the presence of a 3-dimensional disrupted bladder serosa with obliteration of the vesicouterine space was associated with vesicouterine adherence (P<.001).

CONCLUSION

Three-dimensional volume rendering ultrasound is a promising tool for effective discrimination between scar dehiscence with underlying nonadherent placenta and placenta accreta spectrum. It also shows potential in predicting the clinical severity with urinary bladder involvement in cases of placenta accreta spectrum.

Absence of abnormal vascular changes on prenatal imaging aids in differentiating simple uterine scar dehiscence from placenta accreta spectrum: a case series

Accurate prenatal discrimination between a simple, non-adherent uterine scar dehiscence with an underlying placenta and the severe end of the placenta accreta spectrum is problematic as the two can appear similar on prenatal imaging. This may lead to the false diagnosis of placenta accreta spectrum resulting obstetric anxiety, overtreatment and potential iatrogenic morbidity. Despite potential similarities in the etiology, the manifestation and management of these two conditions is very different. The prenatal sonographic features of seven confirmed cases of simple uterine scar dehiscence with an underlying placenta previa were examined. The common sonographic features found for scar dehiscence was a thinned myometrium (<1 mm) overlying a generally homogenous placenta and a placental bulge. There was absence of lacunae and features of hypervascularity including bridging vessels. Our findings suggest accurate discrimination between a simple scar dehiscence with the placenta underlying it and placenta accreta spectrum can be made on prenatal ultrasound if the placenta is carefully examined for the vascular features unique to PAS.

Ultrasound discrimination between placenta accreta spectrum and urinary bladder varices

Distinguishing between urinary bladder varices and retroplacental neovascularization in placenta accreta spectrum in high-risk patients with placental previa is a diagnostic challenge since they have similar appearances on prenatal ultrasound. Placenta accreta spectrum is associated with massive obstetric haemorrhage while the presence of urinary bladder varices in pregnancy poses a lower surgical risk. Since the clinical implications and management approach for both conditions are entirely different, false positive diagnoses have iatrogenic consequences. In this article, we share our experiences in differentiating these two phenomena on prenatal ultrasound supported by ultrasound and intraoperative images.

A simple guide to ultrasound screening for placenta accreta spectrum for improving detection and optimizing management in resource limited settings

Placenta accreta spectrum is a pregnancy complication associated with severe morbidity and maternal mortality especially when not suspected antenatally and appropriate management instigated. Women in resource-limited settings are more likely to face adverse outcomes due to logistic, technical, and resource inadequacies. Accurate prenatal imaging is an important step in ensuring good outcomes because it allows adequate preparation and an appropriate management approach. This article provides a simple three-step approach aimed at guiding clinicians and sonographers with minimal experience in placental accreta spectrum through risk stratification and basic prenatal screening for this condition both with and without Doppler ultrasound.

The role of multimodality radiological imaging in extrauterine misplaced IUCD: A case report

Intrauterine contraceptive device (IUCD) is among the commonly used contraceptive methods in the world including sub-Saharan Africa but have been associated with a number of complications that although rare, can occur. Uterine perforation is the most serious complication of the IUCD. Surgical management is required in cases with complete uterine perforation, in which the IUCD is partially or completely within the peritoneal cavity. We present a case of a 27year old para 2 woman reporting with mild lower abdominal pains and the absence of IUCD string in the vagina after its insertion following evacuation of the uterus 2 years prior to this study. With the utilization of multiple imaging modalities, an exploratory laparotomy was done to remove the migrated IUCD and repair of the perforated bowel and urinary bladder.

Chest radiography patterns of COVID-19 pneumonia in Kumasi, Ghana

Objectives

To document the pattern of chest radiographic findings in coronavirus disease 2019 (COVID-19) patients with moderate to severe disease.

Design

Retrospective cross-sectional study.

Setting

The study site was Komfo Anokye Teaching Hospital (KATH) located at Bantama in Kumasi, the capital town of the Ashanti Region. It is the second largest hospital in the country and the major referral site for Ashanti region and the northern part of the country. The hospital hosts a highly infectious isolation unit (HIIU) for COVID-19 patients with moderate to severe infections and receives referred cases from the region and within the hospital.

Participants

The study involved 27 patients admitted to the HIIU at KATH with COVID-19 infection who underwent chest X-ray as part of their investigations.

Results

The study enrolled 12 males and 15 females. The common comorbidities were hypertension and diabetes. Chest x-ray findings in most of the patients (81.5%) revealed ground-glass opacities while a few of them (18.5%) had lung consolidations without ground-glass opacities. For those with ground-glass opacities, eight (29.6%) had superimposed consolidation. All the participants had positive chest x-ray findings.

Conclusion

The chest x-ray findings in the 27 COVID-19 positive patients with moderate to severe disease on admission at the KATH HIIU enrolled in this study showed significant pulmonary abnormalities. The predominant pulmonary abnormalities were bilateral peripheral ground-glass opacities with the lower lung zones being mostly affected.

Funding

Funding from the Radiology Directorate, Komfo Anokye Teaching Hospital, Kumasi, Ghana