MR findings of uterine PEComa in patients with tuberous sclerosis: report of two cases.

Tuberous sclerosis complex (TSC), a rare autosomal dominant neurocutaneous disorder, is characterized by the presence of benign congenital tumors in multiple organs. Neoplasms with perivascular epithelioid cell differentiation (PEComas), including angiomyolipoma (AML) and lymphangioleiomyomatosis (LAM), can occur in association with TSC. This report describes two cases of uterine PEComas presenting characteristic MR imaging features reflecting pathological findings. From MR images, both cases showed single or multiple large, irregularly shaped or lobulated hemorrhagic lesions within the myometrium. They differed from typical adenomyotic cysts in their large size and irregular margins. Histopathologic analysis revealed that the hemorrhage was caused by adenomyosis and tumor cells that proliferated in surrounding stroma of the hemorrhagic lesions, compatible with PEComas. Microscopic observation revealed an infiltrative growth pattern of PEComas, with small nodules formed. The tumor lesions, however, were difficult to detect on MR images. The myometrium showed normal appearance on both T1-weighted and T2-weighted images in both cases. We speculate that PEComas may infiltrate extensively into the myometrium even when the myometrium shows almost normal radiologic appearance.

Uterine peristalsis and junctional zone: correlation with age and postmenopausal status.

Background Although age-related change of junctional zone (JZ) of the uterus has been known, there has been no previous systematic study of age-related changes of uterine peristalsis that is observed as the wave conduction of the thickest or darkest area within the JZ. Purpose To examine the age-related changes of uterine peristalsis in pre and postmenopausal women using cine magnetic resonance imaging (MRI), and to determine the correlation between peristalsis and JZ on T2-weighted (T2W) imaging. Material and Methods Cine MRI analysis was performed in 64 premenopausal volunteers and in 43 postmenopausal women. The peristaltic frequency, JZ detectability, and JZ thickness were evaluated and compared between the two groups. In the premenopausal group, the correlations between age and each item was examined. In the postmenopausal group, the number of years after menopause was used instead of age. The correlation between peristaltic frequency and JZ detectability or thickness was also analyzed. Results Peristaltic frequency and JZ detectability significantly differed between the two groups, while JZ thickness did not. Peristaltic frequency did not vary significantly with age before menopause and no peristalsis was observed after menopause. JZ detectability did not change significantly with age or number of years after menopause, while JZ thickness significantly increased with age before menopause, but did not vary after menopause. A significant moderate correlation was observed between JZ detectability and peristaltic frequency, but not between JZ thickness and peristaltic frequency. Conclusion Uterine peristalsis frequency did not change significantly according to age, but observed peristalsis on MRI significantly decreased after menopause.

Feasibility of Computed Diffusion Weighted Imaging and Optimization of b-value in Cervical Cancer.

PURPOSE: To evaluate the feasibility of computed diffusion weighted imaging (DWI) in cervical cancer and investigate the optimal b-value using computed DWI. METHODS: The present retrospective study involved 85 patients with cervical cancer in the International Federation of Gynecology and Obstetrics (FIGO) stage IB, IIA or IIB. DWI was obtained with b-values of 0, 100, 500 and 1000 s/mm2. Computed DWI with b-values of 800, 1000, 1300, 1600 and 2000 s/mm2 (cDWI800, cDWI1000, cDWI1300, cDWI1600, cDWI2000) were generated from all measured DWI (mDWI) data. Qualitatively, computed DWI was evaluated in terms of tumor conspicuity, signal suppression of the fat in the imaged area and total image quality by two radiologists independently with reference to mDWI with b-value of 1000 s/mm2. The b-value at which the signal of the endocervical canal was suppressed was recorded. Quantitatively, the signal intensities of tumor, myometrium, endocervical canal, endometrium, and gluteal subcutaneous fat were measured and represented as contrast ratios (CR). RESULTS: Regarding tumor conspicuity and total image quality, significantly higher scores were obtained at cDWI1300 and cDWI1600 compared to the others (post-hoc comparison, P < 0.001), except for the total image quality between cDWI1000 and cDWI1600 in one reader. Signal suppression of the fat was the worst at cDWI2000. The signal intensity of the endocervical canal was suppressed in 24/27 cases on cDWI1600 and in 26/27 cases on cDWI2000. The CRs of tumor to myometrium, cervix, and endometrium increased with higher b-values, while the CRs of tumor to fat decreased and were statistically significant (post-hoc comparison, P < 0.001). CONCLUSION: Computed DWI with the b-values of 1300 and 1600 would be suitable for the evaluation of cervical cancer due to good tumor conspicuity.

Evaluation of Appropriate Readout Sequence for Renal MRI Perfusion Using ASTAR (ASL) Technique.

The aim of this study was to compare true-steady state free precession (True-SSFP) with fast field echo (FFE) as readout imaging sequences for renal arterial spin labeling (ASL), and to optimize the imaging condition. Renal ASL perfusion images were acquired using signal targeting with alternated radio frequency using asymmetric inversion slab (ASTAR) technique with respiratory triggering at 3T MRI system, using either 3D True-SSFP or FFE as the readout sequence. Inversion time (TI) varied from 800 to 2400 ms. Appropriate flip angles were estimated for each sequence by simulating signal intensity (SI). The SI of the renal cortex, vertebral body, and intestinal tract were measured, and the contrast ratio of the cortex (CRcortex) or intestine (CRintestine) related to vertebra was calculated. The image quality of the kidneys, background signal suppression, and misregistration were evaluated by four-point scales. As a result, in quantitative evaluation, the average of CRcortex of each TI (800, 1200, 1600, 2000, and 2400 msec) were 0.49, 0.57, 0.63, 0.63, and 0.56 in FFE, and 0.59, 0.71, 0.73, 0.73, and 0.68 in True-SSFP, respectively. IN qualitative evaluation, ASL images with True-SSFP readout were significantly better than those with FFE readout. In conclusion, True-SSFP sequences will be recommended as read out imaging sequence for obtaining ASL image compared with FFE image.

Placental function assessed visually using half-Fourier acquisition single-shot turbo spin-echo (HASTE) magnetic resonance imaging.

INTRODUCTION: To investigate a simple visual assessment method of placental function using half-Fourier acquisition single-shot turbo spin-echo (HASTE) magnetic resonance imaging (MRI). METHODS: The institutional review board approved this retrospective study of fetal MRI in 48 singleton pregnant women for whom placentas had undergone clinical pathological examinations. Two readers independently assessed the placentas using the HASTE scoring system, particularly emphasizing the visualization of the regular two-tone pattern inside and signal intensity (SI) of placental parenchyma referring to SI of the fetal kidney and liver. After categorization using the HASTE scoring system, the associations between the scores and the presence of pathologically proven placental insufficiency or of low birth weight less than the tenth percentile were examined using chi-square tests. The associations between the HASTE scores and the MRI findings previously reported to suggest placental insufficiency, such as placental thickness and placenta to amniotic fluid SI ratio, were also examined using Student t-tests. RESULTS: The HASTE scores were associated significantly with the presence of pathologically proven placental insufficiency (P = .003 for reader 1; P = .04 reader 2) and birth weight less than the tenth percentile (P = .005 for reader 1; P = .003 for reader 2). The HASTE scores were associated significantly with the placenta thickness (P < .0001 for both readers) and the placenta to the amniotic fluid SI ratio (P < .0001 for both readers). DISCUSSION: The HASTE scoring system is feasible for use in clinical assessment of placental function and for diagnosing placental insufficiency.

Optimization of non-contrast-enhanced MR angiography of the renal artery with three-dimensional balanced steady-state free-precession and time-spatial labeling inversion pulse (time-SLIP) at 3T MRI, in relation to age and blood velocity.

PURPOSE: To determine the optimal inversion time (TI) value of three-dimensional (3D) balanced steady-state free-precession time-spatial labeling inversion pulse (time-SLIP) technique for visualization of the renal artery at 3T MRI, and to assess whether the optimal TI is affected by the subject's age and blood velocity. MATERIALS AND METHODS: Forty-two healthy volunteers (range 20-67 years) were enrolled in the study and subjected to non-contrast-enhanced renal MR angiography. Five different TI values (1200, 1400, 1600, 1800, and 2000 ms) were selected for evaluation. For quantitative evaluation, the relative signal intensity (SI) of the main renal artery was compared with that of the renal medulla (Vessel-to-Kidney ratio; VKR). Blood velocity of the abdominal aorta was measured using 2D phase contrast technique. For qualitative evaluation, two radiologists scored the depiction of the renal pelvis and the quality of visualization of the renal artery. RESULTS: VKR is the highest at TI = 1600 ms. A strong negative correlation between age and blood velocity was demonstrated. Regarding the qualitative evaluation, the overall image scores of renal arteries were the highest at a TI = 1800 ms for both readers. The optimal TI values in subjects below 50 years of age were 1600 and 1800 ms, whereas in subjects above 50 years of age, the optimal TI value was 1800 ms. CONCLUSION: The optimal TI value for the visualization of renal arteries using time-SLIP technique at 3T MRI was 1800 ms. Subjects' age affected optimal TI and this is likely due to differences in the blood velocity of the abdominal aorta.

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.

Evaluation of uterine peristalsis using cine MRI on the coronal plane in comparison with the sagittal plane.

BACKGROUND: Uterine peristalsis is supposed to be closely related to the early stages of reproduction. Sperms are preferentially transported from the uterine cervix to the side of the tube with the dominant follicle. However, with respect to magnetic resonance imaging (MRI), uterine peristalsis has only been evaluated at the sagittal plane of cine MRI. PURPOSE: To evaluate and compare uterine peristalsis both on sagittal and coronal planes using cine MRI. MATERIAL AND METHODS: Internal ethics committee approval was obtained, and subjects provided informed written consent. Thirty-one women underwent MRI scans in the periovulatory phase of the menstrual cycle. Cine MR images obtained by fast advanced spin echo sequence at 3-T field strength magnet (Toshiba Medical Systems) were visually evaluated by two independent radiologists. The frequency and the direction of peristalsis, and the presence of outer myometrium conduction of signal intensities (OMC), were evaluated. The laterality of the dominant follicle was determined on axial images and compared with the peristaltic direction in fundus. RESULTS: The subjects in which peristaltic directions were more clearly recognized were significantly frequent in coronal planes than in sagittal planes (P < 0.05). There was no significant difference in the peristaltic frequency between the sagittal and the coronal plane. However, the OMC was more recognized in the coronal plane than in the sagittal plane (P < 0.05). Peristaltic waves conducted toward the possible ovulation side were observed in only three of the 10 subjects. CONCLUSION: OMC of uterine peristalsis was better demonstrated in the coronal plane compared to the sagittal plane.

MR imaging-based evaluation of morphological changes in the uterus and ovaries of patients following neoadjuvant chemotherapy for cervical cancer.

OBJECTIVE: We used magnetic resonance (MR) imaging and hormonal levels to evaluate the influence of chemotherapy for cervical cancer on female pelvic reproductive organs. MATERIALS AND METHODS: We retrospectively evaluated 16 pre- and 11 postmenopausal patients with cervical cancer who underwent neoadjuvant chemotherapy (NACT) and radical surgery. We evaluated morphological changes in the uterus and ovaries by MR imaging both quantitatively and qualitatively, measuring the volume of the uterine body and bilateral ovaries, endometrial thickness, and signal intensity of the myometrium and bilateral ovaries and assessing visibility of the junctional zone and bilateral ovarian follicles. We compared both quantitative and qualitative factors between pre- and post-NACT. Pre- and post-NACT hormonal values of estradiol, progesterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) of 8 patients in the premenopausal group were obtained and analyzed statistically. RESULTS: In the premenopausal group, we observed a statistically significant decrease in all quantitative parameters as well as in the visibility of the left ovarian follicle. In the postmenopausal group, only endometrial thickness changed significantly. Premenopausal patients showed a statistically significant decrease in levels of progesterone, FSH, and LH after chemotherapy. CONCLUSIONS: MR demonstrated changes in the uterus and ovaries in premenopausal subjects who underwent chemotherapy that resembled those changes classically reported in physiological postmenopausal subjects. These changes are likely due to ovarian toxicity and secondary hormonal changes. MR imaging might be a valuable tool for obtaining information regarding chemotherapy-induced infertility.

Assessment of the early predictive power of quantitative magnetic resonance imaging parameters during neoadjuvant chemotherapy for uterine cervical cancer.

OBJECTIVES: The purpose of this study was to quantitatively evaluate 3 types of magnetic resonance imaging (MRI) parameters in parallel for the early prediction of neoadjuvant chemotherapy (NACT) effectiveness in cervical cancer-tumor volume parameters, diffusion parameters, and perfusion parameters. MATERIALS AND METHODS: We prospectively evaluated 13 patients with International Federation of Gynecology and Obstetrics stage IB to IIB cervical squamous cell carcinoma who underwent 3 serial MRI studies, that is, pretreatment, post-first course NACT, and post-second course NACT followed by radical hysterectomy. We obtained tumor volume parameters, diffusion parameters, and dynamic contrast material-enhanced perfusion parameters quantitatively from pretreatment MRI and post-first course MRI. The correlation of these parameters and the eventual tumor volume regression rate (TVRR) obtained from pretreatment MRI and post-second course MRI before surgery were investigated, statistically based on the Pearson correlation coefficient. RESULTS: Thirteen patients had a total of 39 scans. Early TVRR (r = 0.844; P < 0.001), the fractional volume of the tissue extracellular extravascular space (Ve, r = 0.648; P < 0.05), and the change of Ve during the first course of NACT (r = -0.638; P < 0.05) correlated with eventual TVRR. CONCLUSIONS: Early TVRR, Ve, and the change of Ve could be useful predictors for the treatment effectiveness of NACT. These parameters could help to modify strategy in the early stage of NACT and to choose individualized treatment to avoid the delay of radical treatment, even when NACT is ineffective.

Decidualized adenomyosis during pregnancy and post delivery: three cases of magnetic resonance imaging findings.

Adenomyosis is a common gynecologic disease. Pregnancy with adenomyosis is on the increase due to a tendency of delay with first pregnancies and various infertility treatments involved in the process. We encountered decidualized adenomyosis in three patients during pregnancy, who were suspected by magnetic resonance (MR) imaging and were followed monitored post delivery. The MR imaging findings of adenomyosis during pregnancy showed low signal intensity areas with embedded bright foci that expanded to a few mm in diameter on half Fourier single-shot turbo spin-echo images. This finding may reflect decidual change of the stroma within the ectopic endometrium caused during pregnancy. The MR imaging findings of adenomyosis after childbirth showed hemorrhage inside the lesion, which were assumed to be led by rapid decrease in a blood flow to adenomyosis post childbirth.