[A Case of renal Lymphangiectasia with a Follow-Up Duration of Twelve Years].

Renal lymphangiectasia is a rare disorder of renal lymphatics, which is not well-known in terms of its natural history. A 54-year-old woman without any symptoms was referred to our department for huge cystic lesions surrounding bilateral kidneys. Imaging examinations with ultrasonography, and computed tomography suggested renal lymphangiectasia of bilateral kidneys. These cystic lesions were increased in size 12 years later, compared with previous magnetic resonance imaging. This finding suggested the slow growing nature of renal lympahngioectasia.

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.

Magnetic resonance imaging manifestations of decidualized endometriotic cysts: comparative study with ovarian cancers associated with endometriotic cysts.

PURPOSE: The purpose of the study was to investigate the magnetic resonance imaging findings of decidualized endometriotic cysts in comparison with endometriotic cysts associated with ovarian cancers. METHODS: Eighteen decidualized endometriotic cysts and 24 ovarian cancers were retrospectively assessed on height, signal intensity of the solid component on T2- and diffusion-weighted imaging, apparent diffusion coefficient value of the solid component, size of the lesion, and signal intensity of the intracystic fluid on T1-weighted imaging. RESULTS: The heights of the solid components in the decidualized endometriotic cysts were inferior to 11.1 mm, significantly lower compared with the ovarian cancers. Similarly, decidualized tissues showed significantly higher signals on T2-weighted imaging and higher apparent diffusion coefficient values compared with ovarian cancers but not on diffusion-weighted imaging. The decidualized endometriotic cysts were also significantly smaller. Intracystic fluids showed higher signal in the decidualized endometriotic cysts compared with ovarian cancers on T1-weighted imaging. CONCLUSIONS: In pregnant subjects, the presence of endometriotic cysts with low-height solid component showing high signal intensities on T2-weighted imaging is highly indicative of decidualization.

The clinical utility of reduced-distortion readout-segmented echo-planar imaging in the head and neck region: initial experience.

OBJECTIVES: To evaluate whether readout-segmented echo-planar imaging (RS-EPI) diffusion weighted image (DWI) can diminish image distortion in the head and neck area, compared with single-shot (SS)-EPI DWI. METHODS: We conducted phantom and patient studies using 3 T magnetic resonance imaging (MRI) with a 16-channel coil. For the phantom study, we evaluated distortion and signal homogeneity in gel phantoms. For the patient study, 29 consecutive patients with clinically suspicious parotid lesions were prospectively enrolled. RS-EPI and SS-EPI DWI were evaluated by two independent readers for identification of organ/lesion and distortion, using semiquantitative scales and quantitative scores. Apparent diffusion coefficient (ADC) values and contrast-noise ratios of parotid tumours (if present; n = 15) were also compared. RESULTS: The phantom experiments showed that RS-EPI provided less distorted and more homogeneous ADC maps than SS-EPI. In the patient study, RS-EPI was found to provide significantly less distortion in almost all organs/lesions (p < 0.05), according to both semiquantitative scales and quantitative scores. There was no significant difference in ADC values and contrast-noise ratios between the two DWI techniques. CONCLUSIONS: The distortion in DWI was significantly reduced with RS-EPI in both phantom and patient studies. The RS-EPI technique provided more homogenous images than SS-EPI, and can potentially offer higher image quality in the head and neck area. KEY POINTS: The distortion in DWI is significantly reduced with RS-EPI compared with SS-EPI. Structures in the head and neck were identified more clearly using RS-EPI. No significant difference in ADC values was found between the techniques.

Changes of the normal ovary during menstrual cycle in reproductive age on the diffusion-weighted image.

OBJECTIVE: The objective of this study was to investigate changes in magnetic resonance findings of the normal ovary during menstrual cycle on diffusion-weighted image (DWI). METHODS: Magnetic resonance imaging was performed in 9 healthy females at the menstrual, periovulatory, and luteal phases using a 1.5-T unit. Signal intensity (SI) of the ovary on DWI with a b value of 1000 s/mm was visually scored. The ovary-to-muscle contrast ratios on DWI and apparent diffusion coefficient (ADC) values were also evaluated. RESULTS: All the ovaries were identified, and higher SI than the nerve root was identified in 70% (38/54) of the ovaries, although visual scores did not show significant difference among menstrual phases. The mean ADC values (10 mm/s) were 1.71 (SD, 0.27), 1.71 (SD, 0.22), and 1.67 (SD, 0.19) in menstrual, periovulatory, and luteal phases, respectively. No phase-dependent change was observed in contrast ratios and ADC values. CONCLUSION: The normal ovary in fertile period shows high SI enough to be identified on DWI, and observed values are independent of the menstrual cycle.

BLADE acquisition method improves T2-weighted MR images of the female pelvis compared with a standard fast spin-echo sequence.

PURPOSE: To investigate feasibility of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER or BLADE) T2-weighted imaging (T2WI) of the female pelvis by comparing it with standard fast spin-echo T2WI (STD-T2WI). MATERIALS AND METHODS: Sagittal STD-T2WI and BLADE-T2WI of the female pelvis were performed with (36 patients) or without (15 patients) administration of butylscopolamine on a 1.5 T MR unit. Two radiologists independently rated depiction of the uterus, ovary, intestines, bladder, gynecological lesions, overall quality, and artifacts using a four-point scale. Results were compared between STD-T2WI vs. BLADE-T2WI either with (B+) or without (B-) administration of butylscopolamine, BLADE-T2WI (B-) vs. BLADE-T2WI (B+), and STD-T2WI (B+) vs. BLADE-T2WI (B-). RESULTS: When butylscopolamine was administrated, depiction of the uterus, ovary, intestines, gynecological lesions, and overall image quality was rated higher and artifacts were rated fewer for BLADE-T2WI with significance compared with STD-T2WI. When the drug was not administrated, significant difference was observed in depiction of the lesion, overall quality, and artifacts. Depiction of the uterus, gynecological lesion, and overall quality was rated significantly higher and artifacts were fewer in BLADE-T2WI (B+) than in BLADE-T2WI (B-). CONCLUSION: BLADE method was feasible for female pelvic MRI, with best image quality in BLADE-T2WI (B+).

Diffusion tensor MRI of the kidney at 3.0 and 1.5 Tesla.

BACKGROUND: Diffusion tensor imaging (DTI) at 3 T provides information on the microstructure and pathophysiology of tissues that is not available from conventional imaging with an advantage of high signal to noise ratio (SNR). PURPOSE: To evaluate the feasibility of DTI of the normal kidney at 3.0 T compared to results obtained at 1.5 T. MATERIAL AND METHODS: DTI of the normal kidney of 15 healthy volunteers obtained with 3.0 and 1.5 T scanners using respiration-triggered acquisition was examined. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of both the renal cortex and the medulla and SNRs were measured (b-values 0 and 400 s/mm², diffusion direction of 6). The image quality of FA and ADC maps was also compared subjectively. RESULTS: The FA values of the renal cortex were 0.15 ± 0.03 at 3.0 T and 0.14± 0.03 at 1.5 T on average. This difference was not significant. The FA values of the renal medulla were 0.49 ±0.04 at 3.0 T and 0.42 ± 0.05 at 1.5 T. ADC values of the renal cortex were 2.46 x 10⁻³± 0.09 mm<²/s at 3.0 T and 2.20 x 10⁻³±0.11 mm²/s at 1.5 T. The ADC values of the renal medulla were 2.08 x 10⁻³ ± 0.08 mm²/s at 3.0 T and 1.90 x 10⁻³± 0.11 mm²/s at 1.5 T. These FA and ADC values were consistent with previous publications. The difference was significant for the FA value of the medulla (P< 0.01) and ADC values in both cortex and medulla (P < 0.01). The subjective image quality of the FA map with the 3.0 T scanner was significantly superior to that with the 1.5 T scanner (P< 0.01), but not significant for the ADC map (P = 0.18). There was a significant difference in SNR between 3.0 T (48.8 ± 6.6) and 1.5 T images (32.8 ± 5.0). CONCLUSION: The feasibility of renal DTI with a 3.0 T magnet resulting in improved SNR was demonstrated.

Diffusion tensor imaging of kidneys with respiratory triggering: optimization of parameters to demonstrate anisotropic structures on fraction anisotropy maps.

PURPOSE: To demonstrate the feasibility of diffusion tensor imaging (DTI) of kidneys with respiratory triggering, and determine the optimal imaging parameters for fraction anisotropy (FA) maps. MATERIALS AND METHODS: DTI of kidneys from 16 healthy volunteers was performed using a 1.5T scanner. Five different sequences with different parameters including respiration-triggered acquisition or multiple breath-holding, slice thicknesses of 3 or 5 mm, and different numbers of signal averaging and b values were compared. FA and apparent diffusion coefficients (ADCs) of the cortex and medulla were measured. Measurement error within the same and repeated examination was examined using within-individual standard deviation (Sw). RESULTS: FAs of the renal cortex were lower than the medulla (mean value of a sequence ranging 0.148-0.224, 0.433-0.476) and the ADCs of the cortex were higher than the medulla (2.26-2.69x10(-3) mm2/s, 1.77-2.19x10(-3) mm2/s) in all sequences (P<0.001). The renal cortex-medulla difference was the largest, with respiratory trigger- ing including a 3-mm slice thickness, three signal averages,and a b-value=0, 200, or 400 s/mm2 (P<0.001). Sw tended to be smaller in the sequence with a b-value of 400 s/mm2. CONCLUSION: DTI of kidneys with respiratory triggering is feasible with excellent cortex-medulla differentiation.

A case of Sertoli-Leydig cell tumour of the ovary with a multilocular cystic appearance on CT and MR imaging.

We present a case of Sertoli-Leydig cell tumour of the ovary in a 14-year-old girl who presented with abdominal distension. Ultrasonography showed a multilocular cystic lesion filled with finely echogenic fluid. Contrast-enhanced CT demonstrated a huge multilocular cystic mass with thickened septa. At MR imaging, the capsule of the cyst was focally thickened, showing intermediate signal intensity on T2-W images. Although extensive cyst formation of Sertoli-Leydig cell tumour is rare, this tumour should be considered in the differential diagnosis of a multilocular cystic ovarian tumour in a young female.

The utility of diffusion-weighted MR imaging for differentiating uterine sarcomas from benign leiomyomas.

The usefulness of diffusion-weighted (DW) magnetic resonance (MR) imaging for the diagnosis of uterine sarcomas was investigated, as well as whether DW images and quantitative measurement of apparent diffusion coefficient (ADC) values can facilitate differentiating uterine sarcomas from benign leiomyomas. MR images including DW images were obtained in 43 surgically treated patients with 58 myometrial tumors, including seven uterine sarcomas (five leiomyosarcomas and two endometrial stromal sarcomas) and 51 benign leiomyomas (43 ordinary leiomyomas, two cellular leiomyomas and six degenerated leiomyomas). Qualitative analysis of non-enhanced and postcontrast MR images and DW images and quantitative measurement of ADC values were performed for each myometrial tumor. Both uterine sarcomas and cellular leiomyomas exhibited high signal intensity on DW images, whereas ordinary leiomyomas and most degenerated leiomyomas showed low signal intensity. The mean ADC value (10(-3) mm(2)/s) of sarcomas was 1.17 +/- 0.15, which was lower than those of the normal myometrium (1.62 +/- 0.11) and degenerated leiomyomas (1.70 +/- 0.11) without any overlap; however, they were overlapped with those of ordinary leiomyomas and cellular leiomyomas. In addition to morphological features on nonenhanced and postcontrast MR sequences, DW imaging and ADC measurement may have a potential ability to differentiate uterine sarcomas from benign leiomyomas.

MR imaging of the female pelvis at 3 Tesla: evaluation of image homogeneity using different dielectric pads.

PURPOSE: To evaluate improvements in image homogeneity in pelvic MR imaging at 3 Tesla (T) using two different dielectric pads. MATERIALS AND METHODS: A total of eight healthy females were scanned using a 3T MR scanner equipped with a body-array coil. Axial and sagittal fast spin-echo T2-weighted images (T2WI) (TR/TE = 3200 msec/94 msec), axial fast spin-echo T1-weighted images (T1WI) (TR/TE = 700 msec/11 msec), and sagittal half-Fourier acquisition single-shot turbo spin-echo (HASTE) images (TR/TE = 3000 msec/100 msec) were performed for pelvic imaging. Sequences were repeated with dielectric pads (consisting of either ultrasound [US] gel or water), and without pads. Three or four regions of interest (ROIs) were placed on fatty tissues and the ratio of minimum to maximum signal intensity (RSI) was calculated as a marker of image homogeneity. RESULTS: RSI was significantly higher on T2WI and T1WI when using dielectric pads than when no pad was used. A similar tendency was observed in RSI on HASTE. No significant difference was found between images with US gel pads and those with water pads. CONCLUSION: Dielectric pads consisting of either US gel or water are effective in improving image homogeneity of the pelvis on 3T MRI.

MRI of the female pelvis at 3T compared to 1.5T: evaluation on high-resolution T2-weighted and HASTE images.

PURPOSE: To evaluate the feasibility of MRI of the female pelvis using high-resolution T2-weighted imaging (T2WI) and the half-Fourier acquisition single-shot turbo spin-echo (HASTE) technique at 3 Tesla (T) compared to 1.5T, while focusing on the uterine body and cervical anatomy. MATERIALS AND METHODS: A total of 19 healthy women underwent pelvic MR scans on 3T and 1.5T scanners. Axial and sagittal T2W (voxel size of 0.6 x 0.8 x 2 mm) and sagittal HASTE images were obtained. The images were evaluated qualitatively for overall image quality, contrast in the uterine zonal appearance and cervical structure, image inhomogeneity, and artifacts. A quantitative evaluation was performed regarding zonal contrast and image inhomogeneity. RESULTS: On T2WI, the image contrast in the uterine cervix and vagina were significantly higher at 3T than at 1.5T, although there was no significant difference in the overall image quality or contrast in the uterine zonal appearance. Image inhomogeneity was more prominent at 3T, and motion artifact was more severe at 1.5T. CONCLUSION: Our results suggest that MRI of the female pelvis at 3T may potentially provide excellent images of the uterine cervix on high-resolution T2WI. New techniques to reduce inhomogeneity are thus called for.

MR imaging findings of adenomyosis: correlation with histopathologic features and diagnostic pitfalls.

Adenomyosis is a nonneoplastic condition, characterized by benign invasion of ectopic endometrium into the myometrium with hyperplasia of adjacent smooth muscle. The common symptoms include dysmenorrhea, menorrhagia, and abnormal uterine bleeding, but these do not allow diagnosis. Therefore, imaging plays an important role because establishment of the correct preoperative diagnosis is critical to avoid unnecessary intervention. Magnetic resonance (MR) imaging is a highly accurate noninvasive modality for diagnosis of adenomyosis, differentiation of adenomyosis from other gynecologic disorders, and planning of appropriate treatment. Although the typical MR imaging findings are well established, adenomyosis actually varies widely in terms of histopathologic features (adenomyosis with sparse glands), growth patterns (polypoid adenomyoma, adenomyotic cyst, and miniature uterus), responses to hormonal activity (tamoxifen, decidual changes), and responses to treatment (gonadotropin-releasing hormone agonist). The MR imaging findings of adenomyosis occasionally mimic those of uterine malignancy or ovarian cancer. Furthermore, malignancy occasionally develops in otherwise benign adenomyosis. Pitfalls in diagnosis of adenomyosis include myometrial contractions, leiomyoma, adenomatoid tumor, metastases, endometrial carcinoma, and endometrial stromal sarcoma. Knowledge of the various appearances of adenomyosis and the possible pitfalls in differential diagnosis help guide the determination of appropriate treatment options.