Purpose:To evaluate morphological and signal intensity (SI) changes of placental insufficiency on magnetic resonance imaging (MRI) and to assess morphological changes and decreased flow voids (FVs) on T2-weighted rapid acquisition with relaxation enhancement (RARE) images for diagnosing placental insufficiency.Methods:Fifty singleton fetuses underwent MRI using a 1.5-T MR scanner. Placental thickness, area, volume, SI, amniotic fluid SI, and size of FVs between the uterus and the placenta were measured on MR images. Two radiologists reviewed T2-weighted RARE images for globular appearance of the placenta and FVs between the uterus and the placenta. Data were analyzed using t-tests, McNemar’s tests, and areas under the receiver operating characteristic curve (AUCs) at 5% level of significance.Results:Twenty-five of the 50 pregnancies were categorized as having an insufficient placenta. Significant differences were observed between insufficient and normal placentas in mean placental thickness, area, volume, placenta to amniotic fluid SI ratio, and size of FVs (49.0 mm vs. 36.9 mm, 1.62 × 104 mm2 vs. 2.67 × 104 mm2, 5.13 × 105 mm3 vs. 6.56 × 105 mm3, 0.549 vs. 0.685, and 3.4 mm vs. 4.3 mm, respectively). The sensitivity and accuracy using globular appearance plus decreased FVs were greater than those using decreased FVs (P < 0.01). There was no significant difference among AUCs using globular appearance and decreased FVs, and globular appearance plus decreased FVs.Conclusions:Placental insufficiency was associated with placental thickness, area, volume, placenta to amniotic fluid SI ratio, and size of FVs. Evaluating FVs on T2-weighted RARE images can be useful for detecting placental insufficiency, particularly in placentas without globular appearance on MR images.
Intracystic papillary neoplasm (ICPN) of gallbladder is a comparatively new concept and is described as pre-malignant lesions in Nakanuma et al. (In: Bosman et al. (eds) WHO Classification of Tumours of the Digestive System, World Health Organization of Tumours, IARC, Lyon, 2010). ICPN with high-grade intraepithelial neoplasia is understood to include intraepithelial carcinoma or noninvasive carcinoma. And lesions with invasive cancer components are classified as ICPN with an associated invasive carcinoma [1]. According to Adsay et al., more than half of patients diagnosed with ICPN have invasive cancer components (Adsay et al., Am J Surg Pathol 36:1279-1301, 2012).Polypoid masses in the gallbladder including benign, malignant, and non-neoplastic lesions have been called gallbladder polyps, and ICPN is also a polypoid lesion in the gallbladder. However, it is difficult to differentiate between them. In the literature, it is said that the possibility of malignancy is high in lesions exceeding 1 cm (Terzi et al., Surgery 127:622-627, 2000). And there are few reports on characteristic imaging findings of ICPN.We have experienced three cases (two females and one male) of ICPN and report our imaging findings. Contrast-enhanced computed tomography revealed large papillary polypoid lesions approximately 2-4 cm in size in the gallbladder. Findings suggestive of deformation of the gallbladder wall and extrinsic progression were absent in all cases. T2-weighted magnetic resonance imaging revealed intense signals and diffusion-weighted imaging showed high intensity. Expanding of the gallbladder was seen in case 1, and a tumor stalk-like appearance was seen in the papillary mass in cases 2 and 3. Surgery was performed in all three cases and ICPN was diagnosed pathologically. The cancer was localized to the mucosa, with no infiltration of surrounding tissue in all three cases.
: We investigated whether the Lipiodol-derived signal accumulated in hepatocellular carcinoma HCC after transcatheter arterial chemoembolization TACE using Lipiodol oil-based contrast agent mixed with an anticancer agent, known as Lp-TACE, could be evaluated with chemical-shift magnetic resonance imaging MRI . The subjects were 25 HCC patients n 45 tumors who had undergone Lp-TACE and chemical-shift MRI of the abdominal region from April 1, 2000 to March 31, 2012. The regions of interest ROIs were set as large as possible to include the Lipiodol accumulation region on computed tomography CT images and the hyperintense signal region in double-echo fast low-angle shot FLASH , automatic-subtracted images on MRI. We then used both modalities to measure the CT value and signal intensity for each specimen. The MRI signal intensity was calculated by subtracting the background signal intensity from the measured value. The mean CT value for the 45 tumors in the 25 patients of 710 Houns eld units HU ; range, 139-3,062 HU was positively correlated with the mean MRI signal intensity of 43.5 0-212 . Tumors with a diameter ≥ 2 cm exhibited a stronger correlation between CT values and MRI signal intensity in areas of Lipiodol accumulation than tumors smaller than 2 cm. A weaker correlation was observed between the CT values and MRI signal intensity in areas of Lipiodol accumulation when the period from Lp-TACE to MRI was shorter than a week compared to one week or over. Our ndings suggest that chemical-shift MRI can detect Lipiodol accumulation in HCCs and could therefore be useful in evaluating such types of accumulation.
: The reverse redistribution phenomenon RR on 201 Tl SPECT has been focused mainly on ischemic improvement regions after reperfusion therapy or vasospastic angina pectoris. However, RR analysis has not been used in the context of non-ischemic disease. The aim of this study was to evaluate the clinical role of RR on 201 Tl SPECT in patients without a history of myocardial ischemia. We retrospectively enrolled 86 patients showing RR by myocardial perfusion SPECT and studied 75 other patients as a control group. For quantitative analysis, each 201 Tl SPECT polar map was divided into 13 segments. Differences between the RR and control group were assessed with respect to patient characteristics and cardiac event-free survival using the Kaplan-Meier method. RR was detected frequently in the inferoposterior wall, septal portion of the anterior wall, and septum. The two groups showed signi cant differences in rates of heart failure P 0.01 , hypertrophic cardiomyopathy P 0.05 , and wall motion abnormality P 0.05 , but not in the rate of event occurrence. The study demonstrated that RR on 201 Tl SPECT could indicate the existence of myocardial damage ; however, it would not be a factor that determines the prognosis.
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