Yuki Himoto

MR imaging findings of ovarian torsion correlate with pathological hemorrhagic infarction

The aim of this study was to clarify the magnetic resonance (MR) imaging findings, including diffusion‐weighted imaging (DWI), of hemorrhagic infarction of ovarian torsion.

Prenatal differential diagnosis of complete hydatidiform mole with a twin live fetus and placental mesenchymal dysplasia by magnetic resonance imaging

To assess the use of magnetic resonance imaging (MRI) for prenatal differentiation between complete hydatidiform mole with a twin live fetus (CHMTF) and placental mesenchymal dysplasia (PMD).

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.

Pretreatment Mean Apparent Diffusion Coefficient Is Significantly Correlated With Event-Free Survival in Patients With International Federation of Gynecology and Obstetrics Stage Ib to IIIb Cervical Cancer

Objectives To assess the prognostic impact of the pretreatment mean apparent diffusion coefficient (ADCmean) values of tumors obtained by diffusion-weighted magnetic resonance imaging. We evaluated the prognostic value of the ADCmean for event-free survival (EFS) and overall survival (OS) among patients with uterine cervical cancer. Methods/Materials We included 171 patients diagnosed as having International Federation of Gynecology and Obstetrics stage Ib to IIIb cervical cancer by pretreatment magnetic resonance imaging scans, regardless of therapeutic methods. In all patients and in patients with squamous cell carcinoma (SCC; n = 123), the optimal cutoff values of the tumor ADCmean for EFS and for OS were determined, respectively. The prognostic significance of the ADCmean was evaluated using univariate and multivariate Cox regression analyses. Results In the univariate analyses, the ADCmean values were significantly associated with negative effects on EFS both in all patients and in patients with SCC, while not being significantly associated with OS in both groups. In the multivariate analysis, ADCmean was an independent biomarker for EFS (P < 0.05) in patients with SCC along with lymph node metastasis and definitive surgery, whereas ADCmean was not independently significant in EFS in all patients. Conclusions The pretreatment ADCmean value of the tumor was an independent prognostic factor for EFS in International Federation of Gynecology and Obstetrics stage Ib to III SCC of the uterine cervix.

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.

Diagnostic performance of MR imaging findings and quantitative values in the differentiation of seromucinous borderline tumour from endometriosis-related malignant ovarian tumour

AbstractObjectivesTo evaluate the diagnostic performance of quantitative values and MRI findings for differentiating seromucinous borderline tumours (SMBTs) from endometriosis-related malignant ovarian tumours (MT).MethodsThis retrospective study examined 19 lesions from SMBT and 84 lesions from MT. The following quantitative values were evaluated using receiver-operating characteristic analysis: overall and solid portion sizes, fluid signal intensity (SI), degree of contrast-enhancement, and mean and minimum apparent diffusion coefficient (ADC) values of the solid portion. Two radiologists independently evaluated four MRI findings characteristic of SMBT, fluid SI on the T1-weighted image and SI of the solid portion on diffusion-weighted image. The diagnostic values of these findings and interobserver agreement were assessed.ResultsFor diagnosing SMBT, the mean ADC value of the solid portion showed the greatest area under the curve (0.860) (cut-off value: 1.31 × 10-3 mm2/s, sensitivity: 1.00, specificity: 0.61). The T2-weighted image (T2WI) high SI solid portion was the most useful finding, with high specificity and interobserver agreement (sensitivity, 0.58; specificity, 0.95–0.96, kappa = 0.96), followed by T2WI low SI core (sensitivity, 0.48–0.63; specificity, 0.98, kappa = 0.68).ConclusionMean ADC values of the solid portion, T2WI high SI solid portion, and T2WI low SI core were useful for differentiating SMBT from MT.Key Points• SMBT is a newly categorised ovarian tumour often associated with endometriosis. • Differentiation of SMBT from endometriosis-related malignant ovarian tumour is clinically important. • Diagnostic performances of quantitative values and MRI findings were evaluated. • Mean ADC value of the solid portion was the most useful value. • “T2WI high SI solid portion” was the most useful MRI finding.

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.

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.

Visualization of placental hypocirculation with typical patterns using conventional magnetic resonance imaging: Two case reports

We report two cases of clinically suspected placental hypocirculation, as per evidenced by specific half‐Fourier acquisition single‐shot turbo spin‐echo (HASTE) magnetic resonance findings of the whole placenta. Patient 1 was a case of fetal growth restriction caused by pregnancy‐induced hypertension, while patient 2 experienced a discordant dichorionic diamniotic twin pregnancy with fetal growth restriction complication with a velamentous insertion of the umbilical cord in the smaller twin. In both cases, HASTE images showed noticeably decreased signal intensity with high‐intensity signal spots present in the central region of the placenta. In the twin pregnancy case, the low‐intensity signal area in the placenta of the smaller twin was much lower compared to that of the larger twin. Pathological findings failed to support or explain these observations. HASTE images might reflect compensatory alternation of the distribution of maternal blood and villus caused by hypocirculation. In conclusion, our results suggest that HASTE imaging might be a useful approach for the visualization of placental hypocirculation.

Non-contrast-enhanced MR angiography of uterine arteries with balanced steady-state free precession and time-space labelling inversion pulse: Technical optimization and preliminary results

Magnetic resonance imaging (MRI) has been widely utilized for gynaecological disorders. Gadolinium-based contrast agents has been used in the evaluation of vessels, e.g., for the visualization of arteriovenous malformation (AVM) or in the planning of a uterine artery embolization (UAE). However, concerns about adverse side effects of gadolinium-based contrast agents, such as nephrogenic systemic fibrosis or hypersensitivity reactions, have stimulated investigations into the use of non-contrast-enhanced MR angiography (MRA).1,2 Recently, selective visualization of non-contrast MRA of renal or hepatic arteries have been