Yumiko Oishi Tanaka

Smooth muscle tumors of uncertain malignant potential and leiomyosarcomas of the uterus: MR findings

To study the MR characteristics of nonbenign uterine smooth muscle tumors.

High incidence of silent venous thromboembolism before treatment in ovarian cancer

Venous thromboembolism (VTE) such as deep-vein thrombosis (DVT) and pulmonary thromboembolism (PTE) often occurs after surgery and rarely occurs even before surgery in patients with ovarian cancer. It is well known that levels of plasma D-dimer (DD) before treatment in most ovarian cancer patients are increased. This study therefore examined whether increased levels of DD are associated with presence of VTE before treatment of ovarian cancer. Between November 2004 and March 2007, DD levels prior to initial treatment were measured in 72 consecutive patients with presumed epithelial ovarian cancer (final diagnosis: epithelial ovarian cancer, n=60; and epithelial ovarian borderline malignancy, n=12). Venous ultrasound imaging (VUI) of the lower extremity was conducted for all patients except for two patients in whom DVT was detected by pelvic computed tomography (CT). When DVT was found, pulmonary scintigraphy was subsequently performed to ascertain presence of PTE. D-dimer levels were above the cut-off value (0.5 μg ml−1) in 65 of 72 patients (90.2%). Venous ultrasound imaging or CT revealed DVT in 18 of 72 patients (25.0%) and pulmonary scintigraphy found PTE in 8 patients (11.1%). All patients with VTE were asymptomatic when VTE was found. D-dimer levels were associated with incidence of VTE (0–1.4 μg ml−1; 0 of 26 (0%), 1.5–7.4 μg ml−1; 9 of 30 (30%) and ⩾7.5 μg ml−1; 9 of 16 (56.3%), P for trend=0.0003). However, even if 1.5 μg ml−1 was used as a cut-off value, this had low specificity and positive predictive value (47.2, 38.3%), though it had high sensitivity and negative predictive value (100, 100%). Therefore, ovarian cancer patients with DD level ⩾1.5 μg ml−1 should be examined using VUI to detect silent DVT. Patients with VTE underwent preventive managements including anticoagulant therapy before initial treatment, chemotherapy or surgery, and after surgery. There was no clinical onset of postoperative VTE in all 72 patients. Measurement of DD levels and subsequent ultrasonography revealed that silent or subclinical VTE frequently occurs before surgery in ovarian cancer. The usefulness of preoperative assessment of VTE needs further confirmation in randomised controlled trials.

High temporal resolution dynamic contrast MRI in a high risk group for placenta accreta

Antenatal diagnosis of placenta accreta with MR is not easy even now because T2-weighted images (T2WI) cannot differentiate chorionic villi from decidua basalis. We performed dynamic contrast MRI to study whether trophoblastic villi could be separately demonstrated from the decidua basalis, and whether the contrast resolution between the placenta and myometrium could improve compared to T2WI. Six pregnant women with prior cesarean section were examined at 34-38 gestational weeks. Sagittal T2-weighted images with fast spin echo sequences and dynamic contrast studies with fast field echo sequence every 10-14 s after contrast injection were performed. We analyzed the enhancing pattern of the placenta and compared the contrast between placenta and myometrium. We reviewed medical records to identify complications during the placental delivery and the complications of their newborns. In the early phase after contrast enhancement, multiple foci of the strong lobular enhancement were observed in all cases. Other parts of placenta were slowly but strongly enhanced following them. We speculated that the former corresponded to intervillous space and the latter decidua basalis. The contrast between placenta and myometrium tended to be distinct near the inner cervical os on both T2WI and dynamic contrast study. On the other hand, it was indistinct in the upper part of the uterine body on T2WI despite it was clearly demonstrated on dynamic contrast study. The placentae were delivered without any complication in all cases. Although two neonates showed fetal distress, none of the infant remained any sequelae at the time of the discharge. The other four were well although one of them complicated with meconium staining. As dynamic contrast MRI can differentiate chorionic villi and decidua basalis, and can provide excellent contrast between placenta and myometrium at anywhere within the uterus, it may be a promising technique for antepartum diagnosis of the placenta accreta.

Silent venous thromboembolism before treatment in endometrial cancer and the risk factors

Venous thromboembolism (VTE) often occurs after surgery and can even occur before surgery in patients with gynaecological malignancies. We investigated the incidence of VTE before treatment of endometrial cancer and associated risk factors. Plasma D-dimer (DD) levels before initial treatment were examined in 171 consecutive patients with endometrial cancer. Venous ultrasound imaging (VUI) of the lower extremities was performed in patients with DD ⩾1.5 μg ml−1, as the negative predictive value of DD for VTE is extremely high. For patients with deep vein thrombosis (DVT), pulmonary scintigraphy was performed to ascertain the presence of pulmonary thromboembolism (PTE). Risk factors for VTE were analysed using univariate and multivariate analyses for 171 patients. Of these, 37 patients (21.6%) showed DD ⩾1.5 μg ml−1, 17 (9.9%) displayed DVT by VUI and 8 (4.7%) showed PTE on pulmonary scintigraphy. All patients with VTE were asymptomatic. Univariate analysis for various risk factors revealed older age, non-endometrioid histology and several variables of advanced disease as significantly associated with VTE before treatment. Obesity, smoking and diabetes mellitus were not risk factors. Multivariate analysis confirmed extrauterine spread and non-endometrioid histology as independently and significantly associated with risk of VTE. These data suggest that silent or subclinical VTE occurs before treatment in at least around 10% of patients with endometrial cancer. Risk factors for VTE before treatment might not be identical to those after starting treatment.

Ovarian dysgerminoma. MR and CT appearance

Objective We determined the MR and CT appearance of ovarian dysgerminoma and correlated our findings with the pathologic features. Materials and Methods CT and MR findings of three patients with ovarian dysgerminoma were retrospectively reviewed and compared with the pathologic findings. Results The tumors were divided into lobules by septa that were hypointense or isointense on T2-weighted imaging and showed marked enhancement on Gd-diethylene triamine pentaacetic acid enhanced T1 -weighted imaging and contrast-enhanced CT. These septa corresponded to fibrovascular bundles at histologic examination. Conclusion CT and MR findings characteristic of fibrovascular septa within solid ovarian masses should raise the possibility of dysgerminomas.

Assessment of cervical cancer radioresponse by serum squamous cell carcinoma antigen and magnetic resonance imaging

OBJECTIVE To investigate the possibility of objective clinical assessment of the radioresponse of cervical cancer via determination of serum squamous cell carcinoma antigen levels and magnetic resonance imaging (MRI)‐based estimation of tumor shrinkage. METHODS The cases of 60 patients undergoing definitive radiotherapy for cervical squamous cell carcinoma (stage I–II: n = 20; stage III–IV: n = 40) were reviewed. Measurements of serum squamous cell carcinoma antigen levels (n = 60), estimated tumor volume on preradiotherapy MRIs (n = 60), and evaluated tumor shrinkage on postradiotherapy MRIs available (n = 30) were taken. The relation between postradiotherapy squamous cell carcinoma antigen level 2 months after the start of radiotherapy and disease recurrence was investigated. Regression analysis of tumor volume measured on MRIs was used to estimate the extent of tumor shrinkage 2 months after the start of radiotherapy. RESULTS Preradiotherapy squamous cell carcinoma antigen levels correlated significantly with preradiotherapy tumor volumes. Recurrence was identified in 27 patients as distant (n = 19), distant and local (n = 1), local (n = 5), or regional (n = 2). Of 51 patients with elevated preradiotherapy squamous cell carcinoma antigen levels, 33 achieved normalized levels after radiotherapy. Squamous cell carcinoma antigen normalization was associated with a higher recurrence‐free survival rate at 2 years (74.3%) than that associated with nonnormalization of squamous cell carcinoma antigen (5.6%, P < .001). The extent of shrinkage ranged from 61% to 100%, and there was no local recurrence. CONCLUSION Postradiotherapy squamous cell carcinoma antigen status is a useful indicator of clinical outcome, particularly about tumor recurrence. It is not, however, useful for assessing response to radiotherapy. Magnetic resonance imaging is useful for obtaining an objective assessment of radioresponse.

Carcinosarcoma of the uterus: MR findings.

To clarify the imaging characteristics of carcinosarcomas, which are the most common malignant mixed epithelial and mesenchymal tumors (MEMTs) of the uterus.

Malignant or borderline mucinous cystic neoplasms have a larger number of loculi than mucinous cystadenoma: A retrospective study with MR

To determine whether there is any correlation between the number of loculi and the pathological grade of malignancy in mucinous cystic tumors of the ovary.

The functional hepatic volume assessed by99mTc-GSA hepatic scintigraphy

The accuracy of measurement of the functional hepatic volume by single photon emission computed tomography (SPECT) with99mTc-galactosyl serum albumin (99mTc-GSA) was evaluated.99mTc-GSA planar scintigraphic images were obtained dynamically and the hepatic SPECT imaging was then performed in 25 patients with hepatobiliary tumors. The patients were divided into 4 groups with normal hepatic function, and mild, moderate and severe hepatic dysfunction. The functional hepatic volume determined by SPECT was compared with the morphological hepatic volume determined by computed tomography. The ratio of the hepatic volumes obtained by the two methods was calculated. The mean hepatic volume ratio was 96.6 ± 2.3% in the normal hepatic function group and 95.9 ± 2.2% in the mild dysfunction group (n.s.). In both the moderate and severe hepatic dysfunction groups, the hepatic volume ratio was smaller than that in the normal group (87.9 ±5.2%, p < 0.001, and 71.9 ± 7.6%, p < 0.0001, respectively). There was a linear correlation between the hepatic volume ratio and various indices of reserve hepatic function, such as LHL15 (r = 0.83, p < 0.0001), HH15 (r = 0.74, p < 0.0001), and ICG15 (r = 0.75, p < 0.0005). These results indicate that the hepatic volume ratio is proportional to the severity of hepatic dysfunction, and suggest that the functional hepatic volume measured with99mTc-GSA faithfully reflects the functioning hepatocyte mass.99mTc-GSA scintigraphy and hepatic SPECT therefore provide information regarding global and regional reserve hepatic function.

Improved CT fat detection in small kidney angiomyolipomas using thin sections and single voxel measurements.

Objective and Methods Seven echogenic renal masses < 1.0 cm in size were studied by CT to make the diagnosis of angiomyolipoma by identifying the presence of fat. Results In four of six lesions, initial 5 mm section CT failed to detect fat, although repeat 3 and/or 1.5 mm section CT was successful in demonstrating fat. In one patient who underwent 3 and 1.5 mm section CT, attenuation values of four voxels were low enough to indicate the presence of fat only on the 1.5 mm sections. Conclusion Measuring single voxel values in the hypoattenuating areas on nonenhanced thin (3 or 1.5 mm) sections is essential for CT diagnosis of small (< 1.0 cm) renal angiomyolipomas.