Changing appearance of the normal uterus during the menstrual cycle: MR studies

Development of an Algorithm to Differentiate Uterine Sarcoma from Fibroids Using MRI and LDH Levels

BACKGROUND

This study aimed to establish an evaluation method for detecting uterine sarcoma with 100% sensitivity using MRI and serum LDH levels.

METHODS

One evaluator reviewed the MRI images and LDH values of a total of 1801 cases, including 36 cases of uterine sarcoma and 1765 cases of uterine fibroids. The reproducibility of the algorithm was also examined by four evaluators with different imaging experience and abilities, using a test set of 61 cases, including 14 cases of uterine sarcoma.

RESULTS

From the MRI images and LDH values of 1801 cases of uterine sarcoma and uterine fibroids, we found that all sarcomas were included in the group with a high T2WI and either a high T1WI, an unclear margin, or high LDH values. In addition, when cases with DWI were examined, all sarcomas had high DWI. Among the 36 sarcoma cases, the group with positive findings for T2WI, T1WI, margins, and serum LDH levels all had a poor prognosis (p = 0.015). The reproducibility of the algorithm was examined by four evaluators and the sensitivity of sarcoma detection ranged from 71% to 93%.

CONCLUSION

We established an algorithm to distinguish uterine sarcoma if tumors in the myometrium with low T2WI and DWI are present.

Cyclic changes in T2* relaxometry of human uterus during the menstrual cycle using BOLD MR imaging

PURPOSE

To evaluate dynamic changes of T2* values within the endometrium, junctional zone and myometrium during the menstrual cycle using blood oxygen level-dependent (BOLD) magnetic resonance imaging.

METHOD

Volunteers underwent MRI scans on menstrual phase, ovulatory phase and luteal phase, including T2-weighted imaging and BOLD MR imaging. Multi-gradient-recalled echo (MGRE) sequence was used to obtain BOLD MR images. T2* values of different uterine layers, including endometrium, junctional zone and myometrium, on sagittal images were analyzed quantitatively.

RESULTS

Twenty-four subjects calculated T2* values successfully. The T2* values of each zonal structure during menstruation were significantly lower than those during ovulatory phase (P < 0.05) and luteal phase (P < 0.001). The T2* value of junctional zone was significantly lower than that of the myometrium over all three menstrual phases (P = 0.000, menstrual; P = 0.000, ovulatory; P = 0.001, luteal). The mean T2* value in endometrium during the ovulatory phase was the highest of the uterine zones over menstrual cycle. During menstrual phase, there was no statistical difference between endometrium and junctional zone (P > 0.05). Conversely, the comparison of the T2* values between endometrium and myometrium, junctional zone and myometrium both showed significant difference (P = 0.000). The mean T2* values within endometrium during ovulatory phase and luteal phase were significantly higher than those within junctional zone and myometrium (P < 0.05).

CONCLUSIONS

Cyclic changes of T2* values in each zonal structure of the uterus were revealed during the menstrual cycle by means of BOLD technique, which may be potentially beneficial in investigating dysmenorrhea, guiding assisted reproductive technologies and monitoring hypoxia in gynecological tumors.

Influence of menstrual status and pathological type on the apparent diffusion coefficient in cervical cancer: a primary study

BACKGROUND

Apparent diffusion coefficient (ADC) value is an important quantitative parameter in the research of cervical cancer, affected by some factors.

PURPOSE

To investigate the effect of pathological type and menstrual status on the ADC value of cervical cancer.

MATERIAL AND METHODS

A total of 352 individuals with pathologically confirmed cervical cancer between January 2015 to December 2017 were retrospectively enrolled in this study, including 317 cases with squamous cell carcinomas (SCC) and 35 cases with adenocarcinomas (AC); 177 patients were non-menopausal and 175 were menopausal. All patients underwent a routine 3.0-T magnetic resonance imaging (MRI) scan and diffusion-weighted imaging (DWI) examination using b-values of 0, 800, and 1000 s/mm². Three parameters including mean ADC (ADC_mean), maximum ADC (ADC_max), and minimum ADC (ADC_min) of cervical cancer lesions were measured and retrospectively analyzed. Independent samples t-test was used to compare the difference of ADC values in different menstrual status and pathological types.

RESULTS

In all menopausal and non-menopausal patients, the ADC_mean and ADC_min values of SCC were lower than those of AC (P<0.05), the ADC_max of two pathological types showed no statistical difference (P > 0.05). In menopausal patients, the ADC_mean, ADC_max, and ADC_min values of SCC were not statistically different compared with those of AC (P > 0.05). The ADC_mean, ADC_max, and ADC_min values of different pathological types cervical cancers in non-menopausal patients were all higher than those in menopausal patients (P<0.05).

CONCLUSION

The ADC values of the cervical cancers were different in different pathological types and were also affected by menstrual status.

Significance of endometrial thickness change after human chorionic gonadotrophin triggering in modified natural cycles for frozen-thawed embryo transfer

Background

Peak endometrial thickness (EMT), measured on the end of follicular phase or early luteal phase, is the most widely used marker for endometrial receptivity during infertility treatment. However, the clinical significance of follicular-to-luteal EMT change remains unclear. We aimed to study whether the change of EMT between the day of human chorionic gonadotrophin (hCG) triggering and the day of frozen-thawed embryo transfer (FET) has any influence on pregnancy outcomes in modified natural cycles (mNCs).

Methods

This was a retrospective cohort study of 2,768 regular ovulatory women who underwent their first mNC-FET cycles from January 2011 to June 2015. Patients were divided into three groups according to the percentage change of EMT from the hCG triggering day to the FET day: >5% decrease (n=405), ±5% plateau (n=1,259) and >5% increase (n=1,104). The main outcome measure was live birth rate.

Results

Live birth rates were 41.9%, 39.8% [crude odds ratio (cOR) 0.91, 95% CI, 0.73–1.15) and 42.4% (cOR 1.02, 95% CI, 0.87–1.20) in the EMT plateau, decrease and increase groups, respectively (P=0.649). Multiple regression analysis did not alter the finding after controlling for a variety of confounders. Compared with the post-trigger EMT plateau group, the adjusted OR of live birth was 0.88 (95% CI, 0.69–1.12) in the decrease group and 1.05 (95% CI, 0.88–1.25) in the increase group. Similarly, no significant associations were observed before or after adjustment between EMT change and other pregnancy outcomes including positive hCG test, clinical pregnancy, early miscarriage and ongoing pregnancy.

Conclusions

EMT change from hCG triggering to embryo transfer was not associated with pregnancy chances in mNC-FET cycles. This reassuring finding should provide guidance for physicians and patients when confronted with EMT decrease on the transfer day.

Value of endometrial thickness change after human chorionic gonadotrophin administration in predicting pregnancy outcome following fresh transfer in vitro fertilization cycles

PURPOSE

To study whether the change of endometrial thickness (EMT) between the day of human chorionic gonadotrophin (hCG) administration and the day of embryo transfer has any impact on pregnancy outcome in fresh in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles.

METHODS

This single-center retrospective cohort study included 2620 patients undergoing their first consecutive autologous IVF/ICSI cycles from January 2003 to December 2012. Patients were categorized into three groups based on the percentage change of post-hCG EMT: > 10% decrease, ± 10% plateau and > 10% increase. The primary outcome was live birth rate.

RESULTS

Live birth rates were similar in the EMT decrease, plateau and increase groups (27.4% [174/635], 29.7% [300/1010] and 27.6% [269/975]; P = 0.649). Compared with the plateau group, both EMT decrease (crude odds ratio [cOR] 0.89, 95% confidence interval [CI] 0.72-1.11) and increase (cOR 0.90, 95% CI 0.74-1.10) on the day of transfer did not affect the likelihood of live birth. The non-significant association was maintained after controlling for major confounding factors, with the adjusted OR being 0.92 (95% CI 0.73-1.16) and 0.92 (95% CI 0.75-1.13) for the decrease and increase groups, respectively.

CONCLUSION

EMT change after hCG administration did not provide significant prognostic information for pregnancy outcome in fresh IVF/ICSI cycles. This finding should offer reassuring information for patients with decreased EMT on the day of embryo transfer while questioning the necessity of EMT re-measurement prior to transfer as a routine practice.

Optimal timing of the loop electrosurgical excision procedure according to different phases of the menstrual cycle

OBJECTIVE

To determine whether treatment of cervical precancerous lesions in the follicular phase or luteal phase of the menstrual cycle affects perioperative and postoperative blood loss during the LEEP.

METHODS

In this randomized trial, 73 patients were assigned to either the follicular phase group (n = 37) or the luteal phase group (n = 36). Ultimately, the conditions of 36 patients in the follicular phase group and 34 patients in the luteal phase group were analyzed. The primary outcome measure was median early postoperative blood loss. Secondary outcomes were median intraoperative bleeding, the rate of late postoperative bleeding, and persistent vaginal bleeding.

RESULTS

Baseline demographic data were similar in the two groups. Median intraoperative blood loss was significantly lower in the follicular phase group than in the luteal phase group (32.7 [20.1-78.3] vs. 44.6 [30.4-104.2] mL, respectively; P < 0.001). Median early postoperative blood loss was also lower in the follicular phase group than in the luteal phase group (209.2 [67.7-468.6] vs. 289.0 [120.3-552.8] mL, respectively; P = 0.01). Moreover, the rate of late postoperative bleeding was higher in the luteal phase group than in the follicular phase group (20.6% vs. 2.8%, respectively; P = 0.02).

CONCLUSION

Performing LEEP during the follicular phase of the menstrual cycle significantly reduces median intraoperative blood loss, early postoperative blood loss, and the rate of late postoperative blood loss.

Interactions of circulating estradiol and progesterone on changes in endometrial area and pituitary responsiveness to GnRH†

Changes in circulating progesterone (P4) and estradiol (E2) during proestrus produce dynamic changes in endometrial function and pituitary release of gonadotropins. Independent and combined effects of P4 and E2 on endometrium and pituitary were evaluated. In a preliminary study, an exogenous hormone model of proestrus was created by removal of corpus luteum and follicles ≥5 mm followed by gradual removal of intravaginal P4 implants during 18 h and treatment with increasing doses of estradiol benzoate during 48 h to mimic proestrus using high E2 (n = 9) or low E2 (n = 9). Decreased P4, increased E2, and increased endometrial area (EA) simulated proestrus in high-E2 cows and this was used subsequently. The main experiment used a 2 × 2 factorial design with: high E2 and low P4 (n = 11); high E2 and high P4 (n = 11); low E2 and high P4 (n = 11); low E2 and low P4 (n = 10). At 48 h, gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone (LH) and follicle stimulating hormone (FSH) release was determined. Variables were analyzed using PROCMIXED of Statistical Analysis System. The EA increased dramatically during 48 h only in high-E2 and low-P4 cows. For FSH, high-E2 cows had greater area under the curve (AUC) and FSH peak after GnRH than low E2, with mild negative effects of high P4. For LH, concentration at peak and AUC were 2-fold greater in high E2 compared to low-E2 groups, with low P4 also 2-fold greater than high-P4 groups. Thus, maximal changes in uterus and pituitary during proestrus depend on both low P4 and high E2, but different physiologic responses are regulated differently by E2 and P4. Changes in endometrium depend on low P4 and high E2, whereas GnRH-induced FSH secretion primarily depends on high E2, and GnRH-induced LH secretion is independently increased by high E2 or reduced by high P4.

Investigating the diagnostic value of quantitative parameters based on T2-weighted and contrast-enhanced MRI with psoas muscle and outer myometrium as internal references for differentiating uterine sarcomas from leiomyomas at 3T MRI

Background

Post-hysterectomy histopathological examination is currently the main diagnostic tool for differentiating uterine sarcomas from leiomyomas. This study aimed to investigate the diagnostic accuracy of preoperative quantitative metrics based on T2-weighted sequences and contrast-enhanced MRI (CE-MRI) for distinguishing uterine sarcomas from leiomyomas.

Materials and methods

The institutional review board approved the study. Sixty-five women confirmed to have a total of 105 lesions participated. Routine pelvic MRI sequences, T2 map and CE-MRI images were performed preoperatively using a 3 T MR scanner. Six quantitative metrics—T2 mapping parameter, T2 scaled ratio, tumor myometrium contrast ratio on T2, tumor psoas contrast ratio on T2, tumor myometrium contrast-enhanced ratio, and tumor psoas contrast-enhanced ratio—were extracted from the acquired image sets. Chi-square test was used to compare the percentage of malignant lesions with the central necrosis to the corresponding percentage for the benign masses. Using the area under receiver operating characteristic (AUC) curve, the performance of different metrics for distinguishing uterine sarcomas from leiomyomas was measured. Moreover, for each metric, we extracted the optimal cut-off value. The values of sensitivity, specificity, negative predictive value, and positive predictive value were calculted for the classifiers based on different metrics.

Results

The average age, average lesion size, and proportion of premenopausal women in benign and malignant groups were comparable in our dataset. The signal intensity of uterine sarcomas at T2-weighted sequences was significantly higher than that of leiomyomas (p < 0.001), while intensity at T1-weighted sequences exhibited no significant difference between the two masses (p = 0.201). Our data also suggested that a central necrosis was ten times more common among malignant lesions compared to benign ones (p < 0.001). Among different metrics, T2 mapping parameter achieved the highest AUC value and accuracy in differentiating two groups. Three measures—T2 scaled ratio, tumor myometrium contrast ratio on T2, and tumor myometrium contrast-enhanced ratio—achieved a sensitivity of 100%, therefore none of the malignant lesions would have been missed if these metrics had been adopted in patient management.

Conclusions

The findings suggested that the evaluated metrics could be useful in the preoperative assessment of myometrial masses to differentiate uterine sarcomas from leiomyomas. The proposed framework has major implications for improving current practice in the management of myometrial masses.

Assessment of Myometrial Invasion in Premenopausal Grade 1 Endometrial Carcinoma: Is Magnetic Resonance Imaging a Reliable Tool in Selecting Patients for Fertility-Preserving Therapy?

OBJECTIVES

The aim of this study was to evaluate the diagnostic ability of magnetic resonance imaging (MRI) in premenopausal women with G1 endometrial carcinoma.

METHODS

Twenty-six patients underwent T2W, diffusion weighted, and dynamic contrast-enhanced 3-T MRI. The degree of myometrial invasion was pathologically classified into no invasion, shallow (3 mm or less), and more. Two radiologists assessed myometrial invasion on MRI. Diagnostic accuracy, sensitivity, specificity, positive and negative predictive values, AUC, and interobserver agreement were analyzed.

RESULTS

For assessing myometrial invasion, mean accuracy, sensitivity, specificity, positive predictive values, negative predictive values, and AUC, respectively, were as follows: 63%, 42%, 85%, 79%, 47%, and 0.75. Mean interobserver agreement was fair (k = 0.36). Shallow invasions were underestimated as no invasion on MRI in all 6 cases.

CONCLUSIONS

Magnetic resonance imaging produced false-negative result on half of patients. The misjudgments tended to happen in patients with shallow invasion.

MR appearance of normal uterine endometrium considering menstrual cycle: differentiation with benign and malignant endometrial lesions

Background The thickness and signal intensity (SI) of normal uterine endometrium on T2-weighted (T2W) imaging changes depend on the menstrual cycle phase. Cases of normal endometrium that appear similar to endometrial lesions sometimes occur, and may result in misdiagnosis. Purpose To investigate normal endometrial appearance in luteal phase (LP) compared to that in follicular phase (FP), and to differentiate these appearances with those of endometrial lesions. Material and Methods Thirty-two normal volunteers prospectively underwent magnetic resonance (MR) examinations during LP and FP. Patients with pathologically confirmed endometrial polyps ( n = 9), hyperplasia ( n = 7), and cancer ( n = 15), who underwent MR examinations, were evaluated for comparison. Endometrial appearance was categorized into the following five types on sagittal T2W imaging and compared between LP, FP, and endometrial lesions: type 1, homogeneous higher SI; type 2, homogeneous iso SI; type 3, a bright midline and a peripheral iso SI layer; type 4, a lower/iso SI central line; and type 5, heterogeneous lower/iso SI. Endometrial thickness and SI were measured and also compared. Results Endometrial lesions were more frequently categorized as type 5 than normal endometrium ( P < 0.05). Endometrial thickness in LP (mean, 1.0 cm) was significantly greater than that in FP (0.6 cm), but not significantly different from polyps (1.1 cm), hyperplasia (1.0 cm), and cancer (0.9 cm). SI in FP was significantly higher than that in LP and that of all endometrial lesions. Conclusion Differentiation between normal endometrium in LP and endometrial lesions may be difficult based on thickness alone. Heterogeneous low SI may help to differentiate normal endometrium from endometrial lesions. Performing MR imaging during FP may also help due to higher SI of normal endometrium.

Diffusion Tensor Imaging of the Uterine Zones Related to the Menstrual Cycle and Menopausal Status at 3 Tesla MRI

BACKGROUND

Diffusion and diffusion tensor imaging techniques (DTI) are widely available and used both in central nervous system and body imaging, including gynecological diseases.

AIMS

The aims of this study were to assess the capability of DTI of uterine zones in relation to the menstrual cycle and ascertain the normal apparent diffusion coefficient and fractional anisotropy values at 3T magnetic resonance imaging (MRI).

STUDY DESIGN

Prospective clinical study.

METHODS

A total of 13 young reproductive and 12 postmenopausal healthy volunteers were included in the study. MRI examination included sagittal T2-weighted and single-shot echo planar imaging DTI obtained under free breathing. Fractional anisotropy (FA) values of the endometrium, junctional zone, and myometrium were determined.

RESULTS

The median (minimum-maximum) FA of the endometrium, myometrium, and junctional zone of the reproductive group were 0.31 (0.260-0.465), 0.42 (0.302-0.664), and 0.58 (0.420-0.745), respectively, in the proliferative phase and 0.26 (0.180-0.413), 0.48 (0.357-0.656), and 0.59 (0.490-0.675)], respectively, in the secretory phase. In the postmenopausal group, the FA values of the endometrium, myometrium, and junctional zone were 0.275 (0.136-0.425), 0.255 (0.191-0.553), and 0.27 (0.129-0.397), respectively. Apparent diffusion coefficient (ADC) values of the endometrium, myometrium, and junctional zone of the reproductive group were 1.25±0.254 (0.970-1.463), 1.67 (1.213-1.854), and 1.23 (0.853-1.301), respectively, in the proliferative phase and 1.32±0.283 (1.165-1.706), 1.55 (1.360-1.791), and 1.17 (1.163-1.705), respectively, in the secretory phase. In the postmenopausal group, the ADC values of the endometrium, myometrium, and junctional zone were measured as 1.100±0.192 (0.850-1.302), 1.14 (0.864-1.283), and 1.09 (0.912-1.291). The FA values of the endometrium and myometrium were lower in the secretory phase of the reproductive group, while ADC values were higher. However, both the FA and ADC values were lower in the postmenopausal group.

CONCLUSION

The present study showed that uterine DTI is feasible when used quantitatively. While FA values tend to decrease, ADC values increase significantly in all zones in the secretory phase except the junctional zone. Zonal FA and ADC values of postmenopausal women are lower in comparison to those in young women.

Uterine junctional zone thickness in infertile women evaluated by MRI

PURPOSE

To prospectively evaluate and compare the junctional zone (JZ) and outer myometrial thickness in infertile and healthy nulliparous women at different locations in the uterine wall during the menstrual cycle by magnetic resonance imaging (MRI).

MATERIALS AND METHODS

We performed pelvic 1.5T MRI (T₂ -weighted turbo spin echo sequences) on 28 infertile women: 5 with infertility of unknown origin, 12 anovulating, and 11 on ovarian stimulation therapy (mean age 28.5, 30.8, and 29.3 years, respectively); and a control group consisting of 18 healthy nulliparous volunteers (mean age 26.4 years). The women with unknown infertility origin and the control group underwent MRI investigations during their follicular, ovulatory, and luteal phase. The JZ and outer myometrial thicknesses were measured at six locations in the uterine wall: anterior and posterior wall of the isthmus, midcorpus, and fundus.

RESULTS

The JZ in the anovulating women at the posterior wall of the isthmus (4.2 mm) was significantly thicker compared to the control group (3.2, 3.0, and 2.9 mm, in respectively the three menstrual phases) (P = 0.027). The outer myometrium in the anovulating women was significantly thicker at all measured locations (average 11.5 mm) in comparison to the control group (8.1, 8.0, and 8.5 mm, in respectively the three menstrual phases) (P < 0.050). The infertile women on ovarian stimulation therapy showed a significantly thicker outer myometrium at the anterior wall (isthmus, midcorpus, and fundus) (P < 0.050).

CONCLUSION

The results indicate that a thickened JZ, and especially a thickened outer myometrium, might be associated with infertility.

LEVEL OF EVIDENCE

1 J. Magn. Reson. Imaging 2017;45:926-936.

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.

[An Examination for Uterine Dynamic Study with Phase-sensitive Inversion-recovery]

The depth of myometrial invasion in patients with endometrial carcinoma is recognized as an important factor that closely correlates with prognosis. Preoperative assessment of myometrial invasion is essential for planning surgery. To enhance the contrast between myometrium and endometrium including myometrial invasion with endometrial carcinoma, we optimized the sequence parameter with phase-sensitive inversion-recovery (PSIR) in gadolinium dynamic study of uterine corpus. On a 1.5-T magnetic resonance imaging (MRI), images were acquired by three-dimensional (3D) T1 -turbo field echo (TFE) with PSIR sequence and gadolinium-diethylenetriamine pentaacetic acid( Gd-DTPA) diluted phantom (0-5 mmol/L) and myometrium model (manganese chloride tetrahydrate+agar). We calculated the null point and the contrast-to-noise ratio (CNR) at multiple TFE inversion delay times, 200 ms-maximum in each combination; flip angles (FAs), 5-35 degrees; TFE factor, 20-40; and shot interval (SI), 500-1000 ms. We assumed that dynamic scanning time was 30 seconds when the sensitivity encoding factor was 2, namely, in this study, the scanning time was 1 minute with no sensitivity encoding. In addition, we compared CNR between optimized PSIR sequence ande-Thrive. We recognized a successful CNR of the 3D PSIR parameter was TFE inversion delay times, 335 ms; FA, 25 degrees; TFE factor, 20; and SI, 500 ms. In each gadolinium-DTPA diluted phantom, the average CNR of the optimized PSIR sequence was approximately 1.7 times (maximum: 3 times) higher than e-Thrive. Optimizing sequence parameter of PSIR is applicable in gadolinium dynamic study of uterine corpus.

Magnetic resonance imaging relaxation times of female reproductive organs

BACKGROUND

Relaxation time of female reproductive organs affects the tissue contrast of magnetic resonance image (MRI), and is used for quantitative analysis.

PURPOSE

To evaluate the relaxation times of normal female reproductive organs in the luteal phase of the menstrual cycle.

MATERIAL AND METHODS

On a 1.5-T MRI, relaxation times were measured in pelvic tissues (endometrium, junctional zone, myometrium, follicle, and stroma) of 32 female healthy volunteers (33.5 ± 6.8 years). The Look-Locker sequence was used to measure T1 relaxation times. Furthermore, a multiple spin-echo method with 32 different echo times was used to measure T2 relaxation times. The images were obtained in the luteal phase of each volunteer's menstrual cycle.

RESULTS

The measured relaxation times (means ± standard deviations) were as follows: endometrium (T1, 1703 ± 147 ms; T2, 214 ± 35 ms), junctional zone (T1, 1168 ± 63 ms; T2, 72 ± 12 ms), myometrium (T1, 1314 ± 103 ms; T2, 138 ± 20 ms), follicle (T1, 2267 ± 49 ms; T2, 603 ± 68 ms), and stroma (T1, 1481 ± 129 ms; T2, 126 ± 29 ms).

CONCLUSION

Reliable MRI measurements of T1 and T2 relaxation times of normal female reproductive organs in the luteal phase of the menstrual cycle are useful as references to recognize the normal value.

3-T diffusion tensor imaging (DTI) of normal uterus in young and middle-aged females during the menstrual cycle: evaluation of the cyclic changes of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values

OBJECTIVE

To evaluate cyclic changes of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of normal uterus in different age groups during the menstrual cycle, and the correlation with serum female hormone levels.

METHODS

29 normal volunteers accepted diffusion tensor imaging of the uterus on menstrual phase (MP), follicular phase (FP), ovulatory phase (OP) and luteal phase. FA and ADC values of different uterine layers on midsagittal images were measured. Differences between two age groups during the menstrual cycle were evaluated using liner mixed models and one-way analysis of variance. Pearson correlation analysis compared variation of FA and ADC values with serum female hormone levels measured in MP.

RESULTS

During menstrual cycle, endometrial FA values declined, whereas ADC values increased with significant differences (p < 0.05). Serum oestradiol (E) levels correlated moderately with variations of FA values between MP-FP (p = 0.045; r = 0.389) and MP-OP (p = 0.008; r = 0.511). FA and ADC values of junctional zones showed no significant difference (p > 0.05) as well as FA values of myometrium (p = 0.0961), while ADC values of myometrium showed significant increase from menstrual phase to luteal phase (p < 0.05). FA and ADC values of uterine three zonal structures showed significant differences (p < 0.05) at each phase during the menstrual cycle. No significant difference of FA and ADC values was found between age groups (p > 0.05).

CONCLUSION

Dynamic changes of uterine FA and ADC values were observed during menstrual cycle. Variation of FA values between MP-FP, MP-OP correlated moderately with serum E levels.

ADVANCES IN KNOWLEDGE

No publications on the relationship between FA and ADC values and the female hormone levels were found; our study prospectively investigated the cyclic changes of FA and ADC values of the normal uterus and the correlation with the basic serum female hormone levels in MP.

T2* relaxometry mapping of the uterine zones

BACKGROUND

Previous literature demonstrated that the T2* value of the uterine junctional zone was lower than that of peripheral myometrium by using BOLD MR imaging. We expect T2* mapping image may add more information to T2-weighted images of the uterine myometrium.

PURPOSE

To evaluate whether T2* mapping software would reproduce the result of previous report, and to apply the software to benign uterine diseases.

MATERIAL AND METHODS

Five healthy volunteers and 19 patients clinically suspected of having benign pelvic disease were imaged using a 1.5T MR system. All women were of reproductive age, and all provided informed consent. Sagittal T2* images using a multishot EPI sequence were obtained. T2* values were calculated and color T2* maps reconstructed using a T2* fitting tool.

RESULTS

The uterine zones could be identified in all 24 examinations on the T2* maps. In addition, a thin "4th zone" was seen between the endometrium and the JZ (junctional zone) in 19 of 24 examinations. The T2* value of JZ was significantly lower than that of peripheral myometrium (PM) (P < 0.001). No significant difference in the T2* value of the JZ or of PM was noted between normal uterus and uterus with leiomyomas and/or adenomyosis.

CONCLUSION

A quantitative T2* map can easily be obtained using the PRIDE software T2* fitting tool, and the software reproduces the result from previous report. T2* value of the junctional zone was lower than that of peripheral myometrium regardless of having benign myometrial diseases.

Apparent diffusion coefficients of normal uterus in premenopausal women with 3.0-T magnetic resonance imaging

PURPOSE

To investigate the apparent diffusion coefficients (ADCs) of the normal uterine zonal structures (myometrium, endometrium, and junctional zone) during different phases of the menstrual cycle among premenopausal women with different age groups.

MATERIALS AND METHODS

Magnetic resonance (MR) images of 67 healthy women were obtained during the midproliferative and midsecretory phases. They were further divided into 3 age groups: group A (age range, 20-29 years); group B (age range, 30-39 years), and group C (mean age, 44.62 years; age range, 40-49 years). All the women underwent 3.0-T MR scanning twice. The ADC values were compared among each uterine zonal structure and 3 age groups and were calculated between the midproliferative and midsecretory phase.

RESULTS

The ADC values among each uterine zonal structures were significantly different from one another (P < 0.001). The ADC values for endometrium in women in their 30s were higher than those in their 20s and in their 30s during the midproliferative and midsecretory phases (P < 0.05), and the ADC values for endometrium in each age groups were lower during the midproliferative phase than those during the midsecretory phase (P < 0.05), but there were no statistical differences in the myometrium and the junctional zone between the 2 phases or among age groups (P > 0.05).

CONCLUSION

These preliminary results suggested that the zone, age, and phase of the menstrual cycle in premenopausal women should be considered when interpreting the ADC values of uterine structures (especially for endometrium).

Apparent diffusion coefficient values of the normal uterus: Interindividual variations during menstrual cycle

OBJECTIVES

To assess the apparent diffusion coefficient (ADC) changes of the normal uterine zones among reproductive women during the menstrual cycle.

METHODS

The study included 101 women of reproductive age, each with regular cycle and normal endometrium/myometrium, as proved on histopathology or MR imaging examination. Diffusion-weighted (DW) imaging was performed along the axial plane, using a single shot, multi-slice spin-echo planar diffusion pulse sequence and b-values of 0 and 800s/mm(2). The mean and standard deviation of the ADC values of normal endometrium/myometrium were calculated for menstrual, proliferative and secretory phase. Analysis of variance followed by the least significant difference test was used for statistical analysis.

RESULTS

The ADC values of the endometrium were different in the three phases of the menstrual cycle (menstrual phase: 1.25±0.27; proliferative phase: 1.39±0.20; secretory phase: 1.50±0.18) (F: 9.64, p: 0.00). Statistical significant difference was observed among all groups (p<0.05). The ADC values of the normal myometrium were different in the three phases of the menstrual cycle (menstrual phase: 1.91±0.35; proliferative phase: 1.72±0.27; secretory phase: 1.87±0.28) (F: 3.60, p: 0.03). Statistical significant difference was observed between menstrual and proliferative phase and between proliferative and secretory phase (p<0.05). No significant difference was noted between menstrual and secretory phase (p>0.05).

CONCLUSIONS

A wide variation of ADC values of normal endometrium and myometrium is observed during different phases of the menstrual cycle.

Changes in apparent diffusion coefficients in the normal uterus during different phases of the menstrual cycle

This study investigated the apparent diffusion coefficients (ADCs) of the uterine zonal structures (myometrium, endometrium and junctional zone) among reproductive women, and their changes during the menstrual cycle. Magnetic resonance (MR) images of seven healthy females (aged 24-31 years) were obtained during the periovulatory, luteal and menstrual phases. Diffusion-weighted imaging (DWI) was performed with a single-shot echo-planar imaging (EPI) sequence in the midsagittal plane of the uterus using three b-values (b = 0, 500 or 1000 s mm(-2)). The ADC values of the three uterine zonal structures were measured on an ADC map by placing two regions of interest (ROI) on the corresponding zonal structures. The average changes of ADC values (intra-individual ADC value variation) over three menstrual phases were 0.41 x 10(-3) mm(2) s(-1) (range, 0.08-0.91) for myometrium, 0.55 x 10(-3) mm(2) s(-1) (0.35-0.84) for endometrium, and 0.40 x 10(-3) mm(2) s(-1) (0.18-0.59) for the junctional zone. The ADC values for myometrium and endometrium were lower in the menstrual phase, although there was some overlap of individual values. Interindividual variation in ADC value for a given zone or phase ranged from 0.48 x 10(-3) mm(2) s(-1) to 0.85 x 10(-3) mm(2) s(-1). Intermeasurement variation between the two ROIs ranged from 0 to 0.48 x 10(-3) mm(2) s(-1) per measurement. The magnitude of these variations was comparable to reported differences between malignant and non-malignant tissues. These preliminary results, from a small number of subjects, suggest that the menstrual cycle and individual variation in pre-menopausal women should be considered when interpreting the ADC values of uterine structures.

Issues in imaging malignant neoplasms of the female reproductive system

Radiological evaluation of malignant neoplasms of the female reproductive system is invaluable in the initial diagnosis, staging, treatment planning, and follow-up management. Radiologists serving as consultants for the general primary care internist, gynecologists, and specialists in gynecologic oncology should be familiar with the strengths and limitations of various modalities used to evaluate gynecologic cancer patients. This article discusses the most common female reproductive tract neoplasms (ie, cervical, endometrial, and ovarian cancers) and the role of ultrasound, computed tomography, magnetic resonance imaging, and positron emission tomography in their diagnosis and management. Imaging features that impact on clinical diagnostic or treatment algorithms are highlighted and illustrated. Finally, recent technical advances that demonstrate promise are described.

Age-Related Structural and Metabolic Changes in the Pelvic Reproductive End Organs

In this work, we provide preliminary data and a review of the literature regarding normal structural and functional changes that occur in the aging uterus, ovary, testicle, and prostate gland. It is expected that such knowledge will help physicians to distinguish physiologic changes from pathologic changes at an early stage. We retrospectively reviewed pelvic magnetic resonance imaging (MRI) scans of 131 female and 79 male subjects ages 13 to 86 years to determine changes in volume of the uterus, ovary, and prostate gland with age. Scrotal ultrasound examinations of 150 male subjects ages 0 to 96 years also were analyzed retrospectively to determine changes in testicular volume with age. In addition, (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) scans of 145 male subjects ages 11 to 90 years were analyzed retrospectively to assess for changes in maximum standardized uptake value (SUV(max)) of the testicles with age. The uterus had a mean volume of 38.55 +/- 3.68 cm(3) at 17 to 19 years of age, increased to a peak volume of 71.76 +/- 19.81 cm(3) between 35 to 40 years, and then declined to 24.02 +/- 8.11 cm(3) by the eighth decade of life. The maximal ovarian volume per subject maintained a relatively stable size in early life, measuring 9.46 +/- 3.25 cm(3) during the second decade of life, 8.46 +/- 3.32 cm(3) in the mid-fourth decade of life, and 7.46 +/- 3.33 cm(3) at 45 years of age, after which it declined to 4.44 +/- 2.02 cm(3) by the late fifth decade of life. The ovaries were not identifiable on MRI in subjects beyond the sixth decade of life. The volume of the prostate increased from 23.45 +/- 6.20 cm(3) during the second decade of life to 47.5 +/- 41.59 cm(3) by the late eighth decade of life; the central gland of the prostate increased from 9.96 +/- 3.99 cm(3) to 29.49 +/- 28.88 cm(3) during the same age range. Mean testicular volume was 11.2 +/- 5.9 cm(3). Testicular volume increased with age from birth to 25 years. After age 25, there was a significant decline in the testicular volume. The mean SUV(max) for the testicles was 1.9 +/- 0.5. Testicular metabolic activity demonstrated an increasing trend until the age of 35 years. A plateau in SUV(max) was observed after the age of 35 years until the age of 65 years. A slight decrease in SUV(max) was observed after the age of 65 years. The pelvic structures of men and women change both structurally and functionally over the lifespan, and such changes can be quantified using ultrasound, MRI, and (18)F-FDG-PET.

Physiological changes of the human uterine myometrium during menstrual cycle: Preliminary evaluation using BOLD MR imaging

PURPOSE

To investigate the T2* values within the junctional zone and outer uterine myometrium and their changes during the menstrual cycle, and thus to evaluate their physiologic changes on blood oxygenation level-dependent (BOLD) magnetic resonance (MR) imaging.

MATERIALS AND METHODS

Single-shot echo-planar imaging (EPI) was used to acquire T2*-weighted images (TR/TE = 1000 msec/23-150 msec) from 15 healthy females with a 1.5-T magnet. T2* values of both junctional zone and outer uterine myometrium were measured within a single breathhold and during three menstrual cycle phases (menstrual, periovulatory, and luteal phase). Signal intensities of uterine myometrium on T2-weighted images were also evaluated.

RESULTS

T2* could successfully be calculated in 13 subjects. T2* values for the junctional zone were significantly lower than those of the outer myometrium at every phase(P < 0.001), and T2* values of both junctional zone (P < 0.05) and outer (P < 0.01). Myometrium in the menstrual phase was significantly lower than those in the other phases. On T2-weighted images, the signal intensity of the junctional zone was significantly lower than outer myometrium in every phase (P < 0.01), but there was no significant difference among menstrual cycle phases in both layers (P > 0.05).

CONCLUSION

This preliminary study suggested that menstrual cycle changes of the uterine myometrium were shown by BOLD imaging. BOLD MR imaging may be an potential modality to investigate physiologic changes of the uterine myometrium during the menstrual cycle.

MR imaging of the uterus and cervix in healthy women: Determination of normal values

The purpose of this study was to establish normal values for the volume of the uterus and cervix in MRI based on age and the menstrual cycle phase. We performed MRI of the pelvis in 100 healthy women. For the uterus, they were further divided into two groups: one with myomas and/or adenomyosis and one without either. The volume of the uterus and cervix and thickness of the uterine wall layers were analysed by age and the menstrual cycle phase. The mean volume of the uterus in both groups and the cervix significantly increased with age to reach its peak at 41-50 years, and then dropped. Likewise, the thickness of the endometrium and the junctional zone, but not the myometrium, significantly increased until 41-50 years, and then decreased. When we compared the volume of the uterus and cervix and the thickness of the uterine wall layers between the two phases of the menstrual cycle, we found no significant differences. The volume of the uterus and cervix and the thickness of the endometrium and junctional zone differ significantly with age, but not between the two phases of the menstrual cycle. Knowledge of MRI-related normal values can be expected to aid the early identification of uterine pathologies.

Functioning ovarian tumors: direct and indirect findings at MR imaging

There are many kinds of ovarian tumors and tumorlike conditions that produce estrogen or androgen. Magnetic resonance imaging can demonstrate not only ovarian tumors but also an enlarged uterus with a thick endometrium, even in cases of a clinically latent excess of estrogen. These clinical and indirect imaging findings can aid in the differential diagnosis of ovarian tumors. Granulosa cell tumor and thecoma are well-known estrogen-producing tumors. In pediatric or postmenopausal patients, they manifest as precocious pseudopuberty or postmenopausal bleeding, respectively. Conversely, Sertoli-Leydig cell tumor is representative of hormone-producing tumors that cause virilization. However, there are other functioning ovarian tumors besides the sex cord-stromal tumors. It is well known that metastatic ovarian tumors often have androgen-producing stroma and that mucinous cystadenoma sometimes produces estrogens. Most other ovarian tumors can produce sexual hormones in their stroma. In addition, some endocrinologic abnormalities (eg, polycystic ovary syndrome) also cause virilization.

Uterine tissue development in healthy women during the normal menstrual cycle and investigations with magnetic resonance imaging

OBJECTIVE

High-resolution magnetic resonance imaging (MRI) was used to monitor both uterine endometrial and junctional zone morphometry during the normal menstrual cycle.

STUDY DESIGN

Twenty-four healthy, ovulating women were studied during a single menstrual cycle. Three scans were performed to prospectively coincide with the follicular, periovulatory, and luteal phases of the cycle.

RESULTS

MRI data showed a significant increase in endometrial and junctional zone volume, between the follicular and periovulatory phases, with a significant decrease in endometrial volume observed from the periovulatory to luteal phases. The regularity index, which is a novel subjective assessment of junctional zone structure, varied significantly and demonstrated a less regular junctional zone in the luteal phase.

CONCLUSION

This study has quantified the normal developmental changes of uterine tissue during the menstrual cycle with MRI. Junctional zone data from MRI may play a major role in future studies that investigate menstrual disorders, subfertility, and pathologic changes.

A semiautomated technique for evaluation of uterine peristalsis

PURPOSE

To evaluate the capability of a newly developed semiautomatic analysis technique for evaluation of uterine peristalsis in comparison with visual assessment.

MATERIALS AND METHODS

Cine magnetic resonance (MR) images were obtained from 16 normal volunteers in periovulatory phase. Sixty-eight studies were evaluated by both visual evaluation and by a semiautomated computer assisted software. The software was developed by applying an automated contour tracking method and enables objective analysis of frequency, amplitude, velocity, and direction. Assessments were based on: 1) the recognition of peristalsis, 2) peristaltic direction and frequency, and 3) the way of recognizing peristaltic direction. The data obtained by both modalities were compared with those of previously reported ultrasound (US) findings.

RESULTS

Uterine peristalsis was identified in all studies by both objective and visual analyses. There was no significant difference in the identification of peristalsis, recognition of peristaltic directions, or peristaltic frequency (P > 0.05). Data were well in accordance with those in US literature. Peristaltic direction was recognized either by configuration change in the endometrium or by conduction of low signal intensity in the subendometrial myometrium and there was statistically no difference.

CONCLUSION

Evaluation of uterine peristalsis by the semiautomatic analysis accorded well with the results obtained visual assessments and previous US findings.

Defining endometrial growth during the menstrual cycle with three-dimensional ultrasound

OBJECTIVE

To define the changes in endometrial morphometry that occur during the normal menstrual cycle and to examine the discriminatory power of volumetric analysis over conventional two-dimensional measurements in quantifying the effect of compounding factors on endometrial growth.

DESIGN

The design was that of a longitudinal observational study. Subjects were seen on an alternate-day basis until ovulation and then every four days until the next menstrual period.

SETTING

A University teaching hospital.

POPULATION

Thirty women with regular cycles and acceptable "normal", menstrual patterns.

METHODS

Three-dimensional ultrasound data were acquired and subsequently analysed by a single observer.

MAIN OUTCOME MEASURES

Endometrial thickness and volume.

RESULTS

Both endometrial volume and thickness increased significantly during the follicular phase (P < 0.001), reaching a plateau around the time of ovulation and remaining relatively stable throughout the luteal phase. These changes in endometrial thickness and volume were highly correlated (R(2)= 0.767; P < 0.001). Parity was associated with a significantly greater endometrial volume than nulliparity (4.159 vs 2.234 cm(3); P < 0.05).

CONCLUSIONS

This study has defined the relative and absolute changes in endometrial growth, both in terms of thickness and volume, throughout the normal menstrual cycle. These data provide a reference for future three-dimensional studies investigating menstrual disorders, pathophysiological change and subfertility.

Uterine peristalsis shown on cine MR imaging using ultrafast sequence

PURPOSE

To demonstrate and evaluate uterine peristalsis on cine magnetic resonance imaging (MRI) using ultrafast imaging.

MATERIALS AND METHODS

Serial MR uterine images (300) were obtained from 15 normal volunteers over four menstrual phases using true fast imaging with steady-state precession (true FISP) technique over 117 seconds and videotaped. Three radiologists independently evaluated videotapes of 59 studies. Uterine peristalsis was defined as wavy movements of subendometrial myometrium or endometrium. Interobserver reliability was evaluated using a Kappa coefficient. Fifty-four studies obtained in appropriate phases were analyzed.

RESULTS

Cine MRI displayed uterine peristalsis in 30 of 59 studies; consensus reading showed direction in 23 studies. Reliability between the final consensus of the recognition of uterine peristalsis and those of the three readers was extremely concordant, with a Kappa coefficient of 0.908. Wave direction was cervico-fundal in follicular and periovulatory phases, with frequency of contraction waves being 1.2-2.3 per minute in positive studies.

CONCLUSION

Uterine peristalsis was demonstrated on cine MR using ultrafast MRI. Direction and frequency of peristaltic waves are closely related to menstrual cycle phases. Supplementary material for this article can be found on the JMRI website at http://www.interscience.wiley.com/jpages/1053-1807/suppmat/index.html.

Anatomy and physiology of the female pelvis: MR imaging revisited

This article reviews the normal anatomy of the female pelvis and focuses on uterine physiology, presenting the kinematics of the uterus that can be identified on ultra-fast MR imaging. It also discusses the many facets of the junctional zone on MR imaging. Ultra-fast MR imaging seems to be a powerful tool for evaluating normal anatomy, physiology, and pathology of the uterus. J. Magn. Reson. Imaging 2001;13:842-849.

Abnormal uterine cavity: differential diagnosis with MR imaging

The objective of the study was to assess the usefulness of magnetic resonance (MR) imaging in distinguishing malignant from benign conditions in patients with an abnormal uterine cavity. Fifty-four patients that were suspected of having abnormal uterine cavities were retrospectively evaluated by using MR imaging. The diagnosis of an abnormal uterine cavity included a thickened endometrium, and/or a endometrial mass, and/or a submucosal mass. Threshold values to classify the uterine cavity as abnormal on sagittal T2-weighted images were >10 mm for premenopausal women and >5 mm for postmenopausal women. Malignancy was diagnosed when lesions invaded the myometrial/junctional zone, and/or lesion enhancement was lower than that of the adjacent myometrium. The results found that histology confirmed 18 malignant and 37 benign lesions. Twelve of 15 endometrial carcinomas and 3 malignant mixed mesodermal tumors (MMMT) were correctly characterized as malignant on enhanced T1-weighted images; whereas 6 of 15 endometrial carcinomas and 3 MMMT were correctly characterized on T2-weighted images. Thirty-four of 37 benign cases were correctly characterized as not malignant on enhanced T1-weighted images. One of 14 submucosal leiomyomas, one endometrial stromal metaplasia, and one of ten pathologically normal endometria were misdiagnosed on enhanced T1-weighted images but were correctly diagnosed on T2-weighted images. The overall sensitivity, specificity, and accuracy for distinguishing malignant from benign central uterine masses were 83%, 92%, and 89% for enhanced T1-weighted image, and 50%, 97%, and 82% for T2-weighted image, respectively. We came to the conclusion that in diagnosing patients with abnormal uterine cavity, MR imaging may help differentiate malignant from benign disorders.

Tissue characterization in the female pelvis by means of MR imaging

Pelvic imaging techniques such as computed tomography and ultrasonography provide a limited capability for tissue characterization. Fat, fluid, and calcification, for example, can be identified on the basis of parameters such as x-ray attenuation, echogenicity, and sound attenuation. Because of the many tissue parameters, such as T1, T2, magnetic susceptibility, and chemical shift, that contribute to signal intensity, magnetic resonance (MR) imaging may afford an ability to identify a wider array of specific tissues. The purpose of this article is to review the ability of MR imaging to help identify various types of soft tissue and to provide an approach to interpretation of MR images of the female pelvis through tissue characterization. Lipid, fluid, hemorrhage, smooth muscle, fibrosis, solid malignant tissue, and hydrated soft tissue (including edema, mucin, and myxomatous tissue) have typical MR imaging properties, and their presence in a mass can often be established on MR images. Consideration of the tissue composition of various pathologic processes in the pelvis can result in more systematic approaches to image interpretation and thus narrow the differential diagnosis.

Uterine contractions: possible diagnostic pitfall at MR imaging

A total of 206 nongravid patients with various gynecologic problems underwent pelvic magnetic resonance (MR) examinations that included both sagittal T2-weighted and contrast agent-enhanced T1-weighted images. MR images were retrospectively reviewed to identify changes in endometrial configuration on serial images obtained during the same MR examination. In 20 MR examinations (all in women of reproductive age), endometrial distortion due to myometrial bulging was noted on T2-weighted or contrast-enhanced T1-weighted images. It was absent on other MR images obtained at different times. Myometrial bulging exhibited low signal intensity in 18 examinations. The finding resembled adenomyosis or leiomyoma on T2-weighted or contrast-enhanced T1-weighted images. These results evidence the presence of transient myometrial bulging and transient low-intensity myometrium in the nongravid uterus. This phenomenon is thought to represent uterine contraction. Clinicians should be aware of the potential presence of transient low-signal-intensity myometrial bulging that could present diagnostic problems in the normal uterus.

Relaxation time changes of the uterus during the menstrual cycle: correlation with hormonal status

Six women volunteers underwent pelvic MR imaging at 0.02 T four times during their menstrual cycle. The T1 and T2 relaxation times of the myometrium and endometrium were measured and correlated with the serum estradiol and progesterone levels. The magnitude of the relaxation times were highly individual but the pattern of their variation during the menstrual cycle was similar. The relaxation times were shortest at the beginning and end of the cycle. The most rapid increase occurred during the proliferative phase, followed by little or no increase through to the middle of the secretory phase. The T1 and T2 times of the endometrium correlated directly with the serum estradiol levels during the entire menstrual cycle (r = 0.5, P = 0.02) and the T2 times of the endometrium with the serum progesterone levels during the secretory phase (r = 0.6, P = 0.05). The correlation between the relaxation times of the myometrium and the serum hormonal levels was poor. The results indicate that the relaxation times of the myometrium and endometrium vary during the menstrual cycle reflecting the serum hormonal status. MR imaging of the uterus with relaxation time measurements may be clinically useful to examine the menstrual cycle and its pathology.

Sonohysterography for endometrial abnormalities: preliminary results

In examinations where the etiology of an abnormal endometrial sonographic image is not clear, saline infusion through a fine flexible catheter during transvaginal sonography provides visual contrast and uterine expansion. In 39 women, polyps, myomata, synechiae, endometrial hyperplasia, and cancer were correctly described as verified at surgery. Hyperplasia and neoplasia are not distinguishable, but the approach for biopsy and therapy is established by this simple and well-tolerated technique, which is here called sonohysterography.

Quantitative MRI of the prostate and uterus in monkeys

Quantitative MRI has been carried out in the prostate, seminal vesicles, uterus, and ovaries in the pig-tailed monkey, Macaca nemestrina. T2-weighted, fat-suppressed, multislice experiments were performed at 2.35 T. Eight males, 14 ovariectomized females, and 20 intact females were studied. In the prostate, the caudal and cranial lobe were readily distinguished since the latter had a longer T2 value. For all tissues and organs, interanimal variations were large (up to 12-fold variation in volume), but reproducibility was excellent in the prostate and in the ovariectomized monkey uterus with coefficients of variation (CV) of 3 and 5%, respectively. In the intact monkey uterus, cycle-cycle reproducibility was good with CVs of 6-10% in the myometrium and 14-18% in the endometrium. In the follicular phase, endometrial growth (+3.8% day-1, P < 0.001) was accompanied by myometrial shrinkage (-1.6% day-1, P < 0.001), while in the luteal phase, growth was seen in both tissues (+4.3% day-1, P < 0.001 and +1.4% day-1, P < 0.001, respectively). The great value of these MRI techniques in obtaining data in pharmacological efficacy studies of endocrine drugs, and in limiting the number of animals used, is discussed.

Gynecologic magnetic resonance imaging

Magnetic resonance imaging (MRI) is an excellent modality with which to delineate normal anatomic structures and a variety of pathologic conditions in the female pelvis. It excels at demonstrating the extent of local tumor involvement in cases of endometrial and cervical cancer. It can help to elucidate the origin and nature of a variety of benign pelvic masses in cases where ultrasound findings are equivocal, and it is an accurate tool in demonstrating congenital abnormalities of the female reproductive tract. As technology continues to evolve, MRI will likely assume an even greater role in evaluating the female pelvis.

The normal uterus on magnetic resonance imaging and variations associated with the hormonal state

Magnetic Resonance Imaging of the pelvis has lead to a new radioanatomical description of the uterus. Variations in the anatomical zones of the uterus were noted with different sequences used in MRI. There was also structural and signal variation depending on hormonal impregnation. Twenty seven MRIs of pelvices were carried out on 16 female volunteers. Eight of them were on oestroprogesterone as the method of contraception (Group I) and had a single MRI. Six were not taking contraceptives (Group II) and had different MRI's during the same cycle. Two women already had already gone through the menopause (Group III). Results showed differences in the size of the uterus (uterine height, length of the uterine body and cervix, diameter of the cervix) between groups I and II but no cyclic changes were observed within group II. The myometrium was found to be thicker in group I and in the luteal phase of group II females in comparison to the follicular phase in the same group. The endometrial cavity was seen in 40% of cases on T1 weighted sequences; on T2 weighted sequences it was seen in all the cases. It was thicker during the second phase in group II than in group I and III. The myometrial signal compared to that of the bladder content (urine) showed a significant increase between early and late echoes on T2 weighted sequences in group I and during the second phase of the menstrual cycle in group II. No variations, or at times a decrease in signal, were observed during the first phase of the cycle in group II.(ABSTRACT TRUNCATED AT 250 WORDS)

Oblique NMR imaging of the uterus in macaques: uterine response to estrogen stimulation

We report methods for quantitative NMR imaging of the primate uterus and the application of these methods of measuring the response of the monkey (Macaca nemestrina) uterus (endometrial volume, myometrial volume, T2 values, myometrial junction zone) to estrogen stimulation. High-field (2.35 T), fat-suppressed, T2-weighted (TE50) oblique methods were used. Slice thickness, location, and angle were varied on each examination to obtain six contiguous slices between the cervix and fundus, regardless of size or orientation of the uterus. Basal endometrial and myometrial volumes were 0.05 +/- 0.01 cm3 and 1.31 +/- 0.23 cm3 in chronically ovariectomized animals. These increased by 15.7 +/- 3.6-fold and 3.1 +/- 0.4-fold, respectively, during 7 days of estrogen stimulation (estradiol benzoate, 5 micrograms/kg sc daily) while myometrial T2 increased from 52 +/- 1 to 67 +/- 4 ms. These changes reversed following menstrual bleeding.