Optimizing cine MRI for uterine peristalsis: A comparison of three different single shot fast spin echo techniques

MRI of Adenomyosis: Where Are We Today?

Purpose of Review: The purpose of this review is to (i) summarize the current literature regarding the role of magnetic resonance imaging (MRI) in diagnosing adenomyosis, (ii) examine how to integrate MRI phenotypes with clinical symptomatology and histological findings, (iii) review recent advances including proposed MRI classifications, (iv) discuss challenges and pitfalls of diagnosing adenomyosis, and (v) outline the future role of MRI in promoting a better understanding of the pathogenesis, diagnosis, and treatment options for patients with uterine adenomyosis. Recent Findings: Recent advances and the widespread use of MRI have provided new insights into adenomyosis and the range of imaging phenotypes encountered in this disorder. Summary: Direct and indirect MRI features allow for accurate non-invasive diagnosis of adenomyosis. Adenomyosis is a complex and poorly understood disorder with variable MRI phenotypes that may be correlated with different pathogeneses, clinical presentations, and patient outcomes. MRI is useful for the assessment of the extent of findings, to evaluate for concomitant gynecological conditions, and potentially can help with the selection and implementation of therapeutic options. Nevertheless, important gaps in knowledge remain. This is in part due to the lack of standardized criteria for reporting resulting in heterogeneous and conflicting data in the literature. Thus, there is an urgent need for a unified MRI reporting system incorporating standardized terminology for diagnosing adenomyosis and defining the various phenotypes.

Automated measurement of endometrial peristalsis in cine transvaginal ultrasound images

Objectives: Endometrial peristalsis (EP) in non-pregnant uterine can be assessed by visual assessment of transvaginal ultrasound (TVUS). However, visual assessment is subjective, and the outcome depends on the sonographers and video analysts. This study aimed to create a newly developed automatic analysis algorithm for measuring the EP compared to visual assessment.

Methods: A retrospective analysis was performed using the datasets from in vitro fertilization and embryo transfer (IVF-ET), who underwent the evaluation of EP by TVUS within 5 days prior to transplantation. 158 cine TVUS images were used to develop the automated analysis algorithm, and 37 cine TVUS images were evaluated by both visual and automated analysis algorithms. The algorithm was developed by applying the optical flow technology and enabled objective analysis of the number, direction, and intensity of EP.

Results: The number of peristaltic waves counted by visual assessment was 4.2 ± 2.3 (mean ± standard deviation) and 4.1 ± 2.1 for doctors one and two, respectively. The number of waves counted with the algorithm was 3.6 ± 2.1 at first evaluation and 3.7 ± 2.0 at repeated evaluation. A significant difference was found between the algorithm count and visual assessment (p = 0.001, 0.002, 0.003, 0.008). The ICC values for algorithm versus manuals ranged from 0.84 to 0.96 and 0.87 to 0.96. The numbers of the cervix-to-fundus (CF), fundus-to-cervix (FC), and both cervix-to-fundal and fundus-to-cervix (CF + FC) directions of EP counted by the algorithm were 50, 52, and 32, respectively. The numbers counted by visual assessment were 43, 45, and 46, respectively. The number of EP was the same in 87% of the two algorithm counts. The number was lower between the algorithm and visual analysis (79% with complete agreement). The EP intensity assessed by the algorithm was 2.6 ± 1.1, and the peristalsis velocity was 0.147 (0.07) mm/s.

Conclusion: The fully automated analysis algorithm can be used to quantify uterine peristalsis comparable to visual assessment.

Effect of uterine position and intrapelvic motions on the image quality of 3D T2-weighted MRI of the uterus: Can short prescans predict the non-diagnostic image quality?

PURPOSE

To evaluate prescan findings of uterine position and intrapelvic motions that predict the non-diagnostic image quality of three-dimensional T2-weighted MRI (3D-T2WI) of the uterus.

METHODS

This retrospective study included 287 women who underwent pelvic MRI including 3D-T2WI and short prescans consisting of 2D-T2WI and cine imaging. One radiologist classified 3D-T2WI of the uterus as being of diagnostic or non-diagnostic image quality and evaluated the prescans regarding uterine position and intrapelvic motions. Multivariate logistic regression analysis was performed to identify predictors of non-diagnostic 3D-T2WI. The predictive ability of the prescans was verified by two independent MRI technologists.

RESULTS

Non-diagnostic 3D T2WI was found in 42 patients (14.6 %) and was significantly associated with severe motions of urinary flow in the bladder (p < 0.001), small bowel (p = 0.039), and respiration (p < 0.001). In the multivariate analysis of uterine position and intrapelvic motions, risk factors for the non-diagnostic image quality were prominent urinary flow when the uterus contacted the bladder (p < 0.001, adjusted odds ratio = 35.1) and severe respiratory and small bowel motions when the uterus was surrounded by the bowel (p < 0.001, adjusted odds ratio = 68.4). No risk factors were found for the uterus contacting the vertebrae. With these predictors, the prescans demonstrated a sensitivity of 82.9 and 68.3 %, and specificity of 88.2 and 93.9 % for the non-diagnostic 3D-T2WI by the two technologists, respectively.

CONCLUSION

Intrapelvic motions have a different effect on the image quality of 3D-T2WI depending on the uterine position, and short prescans may be useful in predicting time-consuming non-diagnostic 3D-T2WI of the uterus.

Uterine Peristalsis Before and After Ultrasound-Guided High-Intensify Focused Ultrasound (USgHIFU) Treatment for Symptomatic Uterine Fibroids

Background

This study investigated uterine peristalsis before and after ultrasound-guided high-intensify focused ultrasound (USgHIFU) treatment for symptomatic uterine fibroids by cine magnetic resonance imaging (cine MRI).

Material/Methods

A total of 30 patients with symptomatic uterine fibroids were treated by USgHIFU, who were subjected to cine MRI before and after USgHIFU treatment in the periovulatory phase. The images were analyzed for the existence, direction, and frequency of uterine peristalsis. The effects of uterine volume, the largest fibroid volume and location, and the fibroid number were examined before and after USgHIFU treatment.

Results

The incidence of uterine peristalsis was significantly increased after USgHIFU treatment. The main direction of uterine peristalsis before and after USgHIFU was cervix-to-fundus. In 12 cases, uterine peristalsis newly emerged after USgHIFU, and the largest fibroid volumes in these 12 cases were significantly smaller than in the remaining 18 cases before and after USgHIFU. The reduction rates of the largest fibroid volume in the 12 cases were significantly higher than in the remaining 18 cases. The largest fibroids were mainly located in the intramural area before and after USgHIFU.

Conclusions

USgHIFU treatment may contribute to the recovery of uterine peristalsis in patients with symptomatic fibroids, as detected by cine MRI. Uterine peristalsis recovery was related to the largest fibroid volume, especially for intramural fibroids.

Visual inspection of transvaginal ultrasound videos to characterize uterine peristalsis: an inter-observer agreement study

PURPOSE

Contractions in non-pregnant uterine can be assessed by visual inspection of transvaginal ultrasound (TVUS). Many authors have used this method to extract features like contraction frequency and direction. However, visual inspection is a subjective method and the outcome is dependent on the sonographers and video analysts. In this study, we wanted to see which uterine feature is reproducible enough, in terms of inter-observer agreement, to serve as a reliable control for future research.

METHODS

Six observers assessed 80 TVUS videos, and rated video quality, contraction frequency, direction and timing. One observer assessed operating time. A Fleiss' kappa (κ) or an intra-class correlation (ICC) was calculated to determine the inter-observer agreement of all features.

RESULTS

The inter-observer agreement in frequency was substantial (ICC = 0.68). Conversely, there was just slight to fair agreement in contraction timing and direction and in video quality: ICC = 0.26, κ = 0.17 and κ = 0.16, respectively. Overall, agreement among technical engineers was better than between medical professionals. The level of agreement was correlated with video quality, phase of the menstrual cycle and individual patient (all χ² with p < 0.00). The time to analyze one video ranged between 6 and 20 min.

CONCLUSIONS

This study shows that visual inspection of TVUS videos is a fairly reproducible method to assess contraction frequency. However, the operating time is too extensive to implement this method in daily practice. Automated methods could offer a solution for this problem in the future.

Uterine peristalsis and fertility: current knowledge and future perspectives: a review and meta-analysis

Although uterine contractions in the non-pregnant uterus have been studied extensively, the knowledge gained has not been used in general fertility treatment work-up. In this review paper, we provide an overview of the current knowledge on uterine peristalsis (UP), based on the available literature. This literature shows that UP influences pregnancy chances in both natural and artificial cycles. Although the physiological background of these contractions is not completely clear, we know that several factors can be of influence, like uterine pathologies and hormones. Several options to alter pregnancy outcome by interfering with uterine contractions have been studied. Our meta-analysis on therapeutic options shows positive results of progesterone at time of embryo transfer in IVF cycles or prostaglandins at time of intrauterine insemination, although the quality of evidence is low. These therapies are probably most beneficial in selected groups of patients with abnormal contraction patterns. The introduction of an objective and user-friendly UP measuring tool suitable for use in daily practice would make it possible to identify and monitor these patients. We suggest that future research should focus on the physiology of initiation of UP and on the development of an effective standard measuring tool.

Optimized approach to cine MRI of uterine peristalsis

PURPOSE

To determine the optimal slice thickness, playback rate, and scan time for uterine peristalsis with 3.0T magnetic resonance imaging (MRI).

MATERIALS AND METHODS

In all, 23 young female volunteers underwent a 3.0T MRI scan with different slice thicknesses of 3 mm (Cine_3mm ), 5 mm (Cine_5mm ), and 7 mm (Cine_7mm ) for 6 minutes. Subjective image quality score, signal-to-noise ratios (SNRs), and contrast-to-noise ratios (CNRs) of those MR images were evaluated by two radiologists independently. The number, intensity, and direction of uterine peristalsis with different thickness were compared at various playback rates. Also, the peristalsis frequency was counted and compared in different acquisition durations (1-6 minutes).

RESULTS

The subjective image quality score, peristalsis number, and intensity were significantly higher in Cine_7mm and Cine_5mm than Cine_3mm (P < 0.05), while the SNRs and CNRs of Cine_7mm were significantly higher than Cine_3mm (P < 0.05). Peristalsis numbers did not differ significantly at different playback rates with the same slice thickness (P = 0.548-0.962). However, peristalsis intensity at 12×, and 15× was significantly greater than that at 8× the actual speed for Cine_7mm and Cine_5mm (P < 0.05). The peristalsis frequency at 3, 4, 5, 6 minutes was significantly higher than that at 1 minute and 2 minutes (P < 0.05).

CONCLUSION

We recommend a slice thickness of 5 mm or 7 mm and a scan time of 3 minutes for uterine peristalsis with 3.0T MRI, and a playback rate of 12× or 15× the actual speed for peristalsis observation. J. Magn. Reson. Imaging 2016;44:1397-1404.

Uterine anatomy and function on cine magnetic resonance imaging

The female reproductive organ undergoes dynamic morphological changes under the influence of hormonal stimuli, and particularly those mediated by estrogen and progesterone. The uterus changes both its morphological appearance and its functional movements in function of these influences. Functionally, the uterus is known to exert two kinds of inherent contractility: sustained uterine contractions and uterine peristalsis. The former is focal and consists of the sporadic bulging of the myometrium, while the latter is rhythmic and manifests itself as the subtle stripping movement in the subendometrial myometrium. The mechanisms underlying these uterine movements, their relationship and their correlation to age, pharmaceutical administration, and a variety of gynecologic and obstetrical problems remain under discussion. Cine MR imaging may offer the potential to directly observe the changes undergone by the uterus in relation to important functions such as fertility and menstrual problems.