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Schwannomas in and around the porta hepatis (porta hepatic schwannomas) are rare benign tumors easily misdiagnosed as other pathologies, including malignancies. We aimed to evaluate their imaging features on ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), andWe performed a multi-institutional retrospective study by reviewing the clinical and imaging findings of pathologically proven eight porta hepatic schwannomas (mean age, 55 years; range, 38-80 years; one male and seven females). Preoperative imaging included three ultrasonography, eight CT, eight MRI, and two FDG-PET/CT.All patients were asymptomatic. The mean tumor size was 61.9 mm (range, 30-180 mm), and all tumors demonstrated well-defined lesions on ultrasonography and their solid components showed soft tissue attenuation on non-contrast CT. MRI showed two distinct components in all cases: the component with T1-weighted hypointensities and T2-weighted hyperintensities with poor enhancement (suggestive of Antoni B histology); the component with T2-weighted hypointensities with gradually increasing enhancement (suggestive of Antoni A histology), resulting in a heterogeneous pattern on post-contrast CT or MRI (8/8, 100%). The separated deviation of surrounding bile ducts and vessels without obstruction allowed the recognition of extrahepatic localization and their benign nature. A ginger root-like morphology (2/8, 25%) seemed to be suggestive of extension along the Glisson's sheath, although this finding was not seen frequently.Recognizing imaging features such as extrahepatic location, benign nature with internal structures suggestive of Antoni A/B histology, and characteristic tumor extension may provide key diagnostic clues for porta hepatic schwannomas.

Gastroepiploic aneurysms are rare. We report the case of a 74-year-old man who presented with temporary loss of consciousness and abdominal pain. Computed tomography revealed a ruptured right gastroepiploic artery aneurysm. His vital signs improved after extracellular fluid infusion; hence, we performed transcatheter arterial embolization. There were no postoperative complications, and the patient was discharged on the 15th day of hospitalization. Ruptured abdominal aneurysms are often fatal and should be considered in patients with symptoms of anemia and abdominal pain. Currently, minimally invasive transcatheter arterial embolization had been designated as the preferred treatment option because of effectiveness in both diagnosis and treatment. Thus, we report a case of ruptured right gastroepiploic artery aneurysm treated by transcatheter arterial embolization, thereby preventing an emergency surgery.

Artificial intelligence algorithms utilizing deep learning are helpful tools for diagnostic imaging. A deep learning-based automatic detection algorithm was developed for rib fractures on computed tomography (CT) images of high-energy trauma patients. In this study, the clinical effectiveness of this algorithm was evaluated. A total of 56 cases were retrospectively examined, including 46 rib fractures and 10 control cases from our hospital, between January and June 2019. Two radiologists annotated the fracture lesions (complete or incomplete) for each CT image, which is considered the “ground truth.” Thereafter, the algorithm’s diagnostic results for all cases were compared with the ground truth, and the sensitivity and number of false positive (FP) results per case were assessed. The radiologists identified 199 images with a fracture. The sensitivity of the algorithm was 89.8%, and the number of FPs per case was 2.5. After additional learning, the sensitivity increased to 93.5%, and the number of FPs was 1.9 per case. FP results were found in the trabecular bone with the appearance of fracture, vascular grooves, and artifacts. The sensitivity of the algorithm used in this study was sufficient to aid the rapid detection of rib fractures within the evaluated validation set of CT images.

AIM The present study was designed to directly compare the diagnostic performance of preoperative magnetic resonance imaging (MRI) and intraoperative frozen section (FS) diagnoses in predicting deep myometrial invasion (MI) of endometrial cancer. METHODS Using MRI findings and FS diagnoses, 194 patients with surgically staged endometrial cancer were evaluated for deep MI between 2006 and 2018. Definitive histological diagnosis of paraffin sections of excised tissues was used as the gold standard approach. RESULTS Of 194 cases, 53 (27.3%) cases were finally diagnosed as having deep MI (≥50%). There was 82% total agreement between MRI and FS diagnoses in predicting deep MI, with a kappa value of 0.54 (95% confidence interval [CI] = 0.40-0.67, moderate agreement). The sensitivity of FS diagnosis (0.66, 95% CI = 0.52-0.78) for predicting deep MI was lower than that of MRI (0.77, 95% CI = 0.63-0.87; p = 0.21), while the specificity of FS (0.98, 95% CI = 0.93-0.99) was significantly higher than that of MRI (0.88, 95% CI = 0.81-0.93; p = 0.001). Overall, the accuracy of FS (0.89, 95% CI = 0.84-0.93) was higher than that of MRI (0.85, 95% CI = 0.79-0.90), although the difference did not reach statistical significance (p = 0.23). The accuracy (0.95, 95% CI = 0.90-0.97) was very high in cases with concordant MRI and FS results. CONCLUSIONS MRI and FS showed different diagnostic characteristics for predicting deep MI, with a higher specificity observed for FS and the greatest accuracy obtained in concordant cases. Thus, our findings recommend the addition of FS diagnosis, either alone or in conjunction with MRI, to MI evaluation.

To retrospectively evaluate the utility of fusion images of pre- and post-ablation hepatobiliary phase (HBP) series to assess the ablation margins after radiofrequency ablation (RFA) of hepatocellular carcinomas (HCCs). Additionally, to identify factors indicative of an adequate ablation margin and predictors of local tumor progression (LTP). Fifty-nine HCCs in 29 patients were treated by RFA and followed-up for > 1 year (mean 37.9 months). Fusion images of pre- and post-ablation HBP series were created using a non-rigid registration and manual correlation. The ablation margin appearance was classified as ablation margin + (ablation margin completely surrounding the tumor), ablation margin-zero (a partially discontinuous ablation margin without protrusion of HCC), ablation margin—(a partially discontinuous ablation margin with protrusion of HCC), and indeterminate (index tumor was not visible). The minimal ablation margin was measured, and clinical factors were examined to identify other risk factors for LTP. LTP was observed at follow-up in 12 tumors. The mean minimal ablation margin was 3.6 mm. Multivariate analysis revealed that the ablation margin status was the only significant factor (p = 0.028). The cumulative LTP rates (3.3%, 3.3%, and 3.3% at 1, 2, and 3 years, respectively) in 30 ablation margin + nodules were significantly lower (p = 0.006) than those (20.0%, 28.0%, and 32.2% at 1, 2, and 3 years, respectively) in 25 ablation margin-zero nodules. Fusion images enable an early assessment of the ablation efficacy in the majority of HCCs. The ablation margin status is a significant factor for LTP.

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.

In April 2018, the national health insurance coverage of MRI-guided vacuum-assisted breast biopsy (VAB) was instituted with the application of the Japan Breast Cancer Society. Although MRI-guided VAB has been considered as a special procedure for a long time, having an access to this procedure should be recommended for facilities performing breast MRI as in Western countries. From now on, relevant societies should make efforts in data collection and quality control of MRI-guided VAB in Japan. We must avoid the following. To delay the early diagnosis of breast cancer in the judgment of an inaccurate indication, perform unnecessary biopsy due to overestimation of diagnosis, and reduce the success rate of MRI-guided VAB with immature techniques. This review explains the current status of MRI-guided VAB in Japan and shares procedure and biopsy data as a future reference from an experienced facility.

Background There is no consensus on the appropriate surveillance for high-risk women with breast cancer in Japan. We investigated their imaging features and pathological characteristics to build a proper surveillance system for asymptomatic high-risk individuals in the future. Methods We retrospectively reviewed 93 female (median age 43 years) BRCA1 and BRCA2 mutation carriers from our institutional clinical database from 2011 to 2017. The study population was composed of 112 breast cancers. Mammography and MRI were reviewed by examiners blinded to patients’ clinical history. Final surgical or biopsy histopathology served as the reference standard in all the patients. Results Fifty-nine breast cancers met selection criteria; of these, 30 were BRCA1-associated tumors, and 29 were BRCA2-associated tumors. Invasive ductal carcinoma was the most prevalent type in both BRCA1 and BRCA2. There were statistically significant differences in phenotype, nuclear grade, and Ki-67 labeling index between BRCA1 and BRCA2 mutation carriers. Additionally, imaging findings on mammography and MRI were statistically different. Tumors in BRCA2 carriers demonstrated mammographic calcifications more frequently, while those in BRCA1 carriers demonstrated a mass or architectural distortion (P

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 × 10(4) mm(2) vs. 2.67 × 10(4) mm(2), 5.13 × 10(5) mm(3) vs. 6.56 × 10(5) mm(3), 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.

The diagnostic performances of the International Ovarian Tumor Analysis (IOTA) ultrasound-based logistic regression model (LR2) and magnetic resonance imaging (MRI) in discriminating between benign and malignant adnexal masses have not been directly compared in a single study. Using the IOTA LR2 model and subjective interpretation of MRI findings by experienced radiologists, 265 consecutive patients with adnexal masses were preoperatively evaluated in two hospitals between February 2014 and December 2015. Definitive histological diagnosis of excised tissues was used as a gold standard. From the 265 study subjects, 54 (20.4%) tumors were histologically diagnosed as malignant (including 11 borderline and 3 metastatic tumors). Preoperative diagnoses of malignant tumors showed 91.7% total agreement between IOTA LR2 and MRI, with a kappa value of 0.77 [95% confidence interval (CI), 0.68–0.86]. Sensitivity of IOTA LR2 (0.94, 95% CI, 0.85–0.98) for predicting malignant tumors was similar to that of MRI (0.96, 95% CI, 0.87–0.99; P = 0.99), whereas specificity of IOTA LR2 (0.98, 95% CI, 0.95–0.99) was significantly higher than that of MRI (0.91, 95% CI, 0.87–0.95; P = 0.002). Combined IOTA LR2 and MRI results gave the greatest sensitivity (1.00, 95% CI, 0.93–1.00) and had similar specificity (0.91, 95% CI, 0.86–0.94) to MRI. The IOTA LR2 model had a similar sensitivity to MRI for discriminating between benign and malignant tumors and a higher specificity compared with MRI. Our findings suggest that the IOTA LR2 model, either alone or in conjunction with MRI, should be included in preoperative evaluation of adnexal masses.

To evaluate the usefulness of computed tomographic (CT) features for identifying acute torsion of uterine subserosal leiomyoma (USL). We analyzed contrast-enhanced CT examinations of 7 USLs with torsion and 44 USLs without torsion. Two radiologists evaluated the CT features, which consisted of poor contrast enhancement inside the USL, thin rim enhancement around the USL, calcification within the USL, a beak sign between the uterus and USL, fan-shaped poor contrast enhancement in the uterus area adjacent to the USL (dark fan sign), and ascites. We analyzed the frequencies of these CT features in the USLs with versus without torsion using Fisher’s exact test. The respective frequencies of CT features in USLs with and without torsion were as follows: poor contrast enhancement, 86 and 5% (P = 0.001); thin rim enhancement, 71 and 9% (P = 0.001); calcification, 29 and 18% (P = 0.61); beak sign, 57 and 86% (P = 0.10); dark fan sign, 57 and 0% (P = 0.001); and ascites, 100 and 20% (P = 0.01). The CT features of poor contrast enhancement, thin rim enhancement, and dark fan sign are valuable for identifying acute torsion of USL.

PURPOSE We evaluated the ability of diffusion-weighted imaging (DWI) at 3 tesla for diagnosing T stage and detecting stalks in bladder cancer. METHODS In total, 39 consecutive patients with bladder tumors underwent magnetic resonance (MR) imaging that included T2-weighted imaging (T2WI) and DWI using a 3T MR scanner. Two radiologists interpreted T2WI plus DWI and T2WI for diagnosis of T stage and for detection of stalks. We used McNemar's test to examine differences in diagnostic performance and Fisher's exact test to evaluate differences in stalk detection frequency. RESULTS Specificity and accuracy in differentiating T1 tumors from T2 to T4 tumors were significantly better with T2WI plus DWI (83% [20/24] and 85% [33/39]) than T2WI (50% [12/24] and 67% [26/39]; P = 0.02), and accuracy for diagnosing tumor stage was significantly better with T2WI plus DWI (82% [32/39]) than T2WI alone (59% [23/39]; P = 0.03). The observers identified stalks in 11 tumors by T2WI (48% [11/23]) and 17 by DWI (74% [17/23]) (P < 0.03). CONCLUSION DWI at 3T was superior to T2WI for evaluating the T stage of bladder cancer, particularly in differentiating T1 tumors from those T2 or higher, and in detecting stalks of papillary bladder tumors.

Purpose To investigate the diagnostic accuracy of 3.0-T diffusion-weighted imaging (DWI) for detection of prostate cancer by using different b -values. Methods Seventy-three patients underwent magnetic resonance imaging (MRI) at 3.0 T. Three MRI sets were reviewed by two radiologists: MRI and DWI ( b =500s/mm 2 ) (protocol A), MRI and DWI ( b =1000s/mm 2 ) (protocol B), and MRI and DWI ( b =2000s/mm 2 ) (protocol C). Areas under the receiver operating characteristic curve (AUCs) were calculated. Results The mean of the AUCs in protocol C was larger than those in protocol A and in protocol B ( P Conclusion DWI ( b =2000s/mm 2 ) at 3.0 T can improve the diagnostic accuracy for detection of prostate cancer.

Magnetic resonance imaging with phased-array coils was performed in patients with prostate carcinoma before and after hormonal therapy, radiation therapy or radical prostatectomy to evaluate therapeutic effect and recurrence. After hormonal therapy, the prostate gland, seminal vesicle and primary site of tumor usually decrease in size with variable T2 hypointensity. Recurrent or residual tumors after hormonal therapy usually represent T2 hyperintense lesions compared to the hypointensity of the surrounding tissues. Changes of metastatic sites after therapy were also demonstrated.

Computed tomography (CT) plays an important role in diagnosis of acute intestinal obstruction and planning of surgical treatment. Although internal hernias are uncommon, they may be included in the differential diagnosis in cases of intestinal obstruction, especially in the absence of a history of abdominal surgery or trauma. CT findings of internal hernias include evidence of small bowel obstruction (SBO); the most common manifestation of internal hernias is strangulating SBO, which occurs after closed-loop obstruction. Therefore, in patients suspected to have internal hernias, early surgical intervention may be indicated to reduce the high morbidity and mortality rates. In a study of 13 cases of internal hernias, nine different types of internal hernias were found and the surgical and radiologic findings were correlated. The following factors may be helpful in preoperative diagnosis of internal hernias with CT: (a) knowledge of the normal anatomy of the peritoneal cavity and the characteristic anatomic location of each type of internal hernia; (b) observation of a saclike mass or cluster of dilated small bowel loops at an abnormal anatomic location in the presence of SBO; and (c) observation of an engorged, stretched, and displaced mesenteric vascular pedicle and of converging vessels at the hernial orifice.

The objective of our study was to evaluate the clinical usefulness of MRI findings, including diffusion-weighted imaging, in relation to the clinical signs and symptoms of Creutzfeldt-Jakob disease (CJD).We reviewed nine cases of CJD in which MRI was performed from the early to terminal phase of the disease. MRI findings were correlated before (early phase) and after (intermediate phase) the onset of the characteristic clinical findings of myoclonus and periodic synchronous discharges on electroencephalograms. The chronologic changes in imaging findings were followed from the akinetic mutism to the terminal phase of the disease (terminal phase). T2-weighted images had been obtained in all the patients, and diffusion-weighted images and FLAIR images had been obtained in six patients. We evaluated the images for the presence and location of abnormal signal intensities.During the early phase, the T2-weighted images showed no abnormal findings. The diffusion-weighted images, however, revealed abnormal high signal intensities in the cortex in all patients and in the basal ganglia in five patients. In two cases, there were abnormal signals on FLAIR images that corresponded to diffusion-weighted imaging abnormalities. During the intermediate phase, the area of the high signal intensities on the diffusion-weighted images had expanded and progressive cerebral atrophy had become apparent. During the terminal phase, abnormal high signal intensities in the cerebral cortex and basal ganglia on the diffusion-weighted images in one patient disappeared.Diffusion-weighted imaging is extremely useful in detecting CJD during the very early phase-even before the onset of characteristic clinical findings.

PURPOSE We assessed the usefulness of apparent diffusion coefficients (ADCs) for solid renal tumor imaging using diffusion-weighted magnetic resonance imaging (DWI) at 3T. METHODS This retrospective study assessed ADCs of 31 patients with renal tumors that were imaged using preoperative DWI. DWI was performed with the b values of 50, 500, and 1000 s/mm(2), using a 3T magnetic resonance imaging (MRI) system (MAGNETOM Trio, 3T, Siemens Healthcare, Erlangen, Germany). The ADC map was calculated using the b values of 50 and 1000 s/mm(2). ADCs of the different tumors were compared according to the Tukey-Kramer test. RESULTS The tumors were diagnosed as clear cell renal cell carcinoma (RCC; n = 20), papillary RCC (n = 1), infiltrating urothelial carcinoma (UC) of the kidney (n = 4), cystic RCC (n = 1), poorly differentiated carcinoma (n = 1), and angiomyolipoma (AML; n = 4). The mean ADC of clear cell RCC was significantly higher than that of infiltrating UC of the kidney (1.423 vs. 0.931 × 10(-3) mm(2)/s; P < 0.05), and the mean ADC of AML was significantly lower than that of clear cell RCC (0.674 vs. 1.423 × 10(-3) mm(2)/s; P < 0.01). CONCLUSION ADCs used in DWI at 3T may be useful for differentiation of different types of solid renal tumors.

This article describes the fast MRI of fetal abnormalities and placental anomalies in evaluation of the usefulness of fast MRI in obstetric diagnoses. Fast MRI provides excellent resolution for imaging fetal and maternal anatomies without the need for sedation. Fast MRI is therefore useful to clarify diagnoses suggested by equivocal ultrasonographic findings and to obtain additional information for prenatal counseling and management.

Background Although CT urography (CTU) is widely used for the evaluation of the entire urinary tract, the most important drawback is the radiation exposure. Purpose To evaluate the effect of a noise reduction filter (NRF) using a phantom and to quantitatively and qualitatively compare excretory phase (EP) images using a low noise index (NI) with those using a high NI and postprocessing NRF (pNRF). Material and Methods Each NI value was defined for a slice thickness of 5 mm, and reconstructed images with a slice thickness of 1.25 mm were assessed. Sixty patients who were at high risk of developing bladder tumors (BT) were divided into two groups according to whether their EP images were obtained using an NI of 9.88 (29 patients; group A) or an NI of 20 and pNRF (31 patients; group B). The CT dose index volume (CTDIvol) and the contrast-to-noise ratio (CNR) of the bladder with respect to the anterior pelvic fat were compared in both groups. Qualitative assessment of the urinary bladder for image noise, sharpness, streak artifacts, homogeneity, and the conspicuity of polypoid or sessile-shaped BTs with a short-axis diameter greater than 10 mm was performed using a 3-point scale. Results The phantom study showed noise reduction of approximately 40% and 76% dose reduction between group A and group B. CTDIvol demonstrated a 73% reduction in group B (4.6 ± 1.1 mGy) compared with group A (16.9 ± 3.4 mGy). The CNR value was not significantly different ( P = 0.60) between group A (16.1 ± 5.1) and group B (16.6 ± 7.6). Although group A was superior ( P < 0.01) to group B with regard to image noise, other qualitative analyses did not show significant differences. Conclusion EP images using a high NI and pNRF were quantitatively and qualitatively comparable to those using a low NI, except with regard to image noise.

The aim of this study was to examine attenuation values in the central vein and perivenous artefacts at the subclavian vein in cervical CT angiography (CTA) when using 40 ml contrast material (CM) followed by different volumes (25 ml vs 40 ml) of saline flush (SF).61 patients underwent CTA between the aortic arch (AA) and distal to the circle of Willis (cW). After calculating test-bolus time to peak enhancement at the cW (Tc), scanning delay was represented as [(Tc + 4) - scan duration between AA and cW] s. 28 patients (Group A) received 40 ml of 370 mg iodine (I) ml(-1) CM followed by 25 ml of SF, and 33 patients (Group B) received the same CM followed by 40 ml of SF, both administered through the right antecubital vein. Arterial attenuation was measured at seven points in the aorto-carotid artery and at three points in the vertebrobasilar artery. Venous attenuation in the central vein was measured at four points. Mean attenuation values were analysed quantitatively. Axial and post-processing three-dimensional images were assessed qualitatively.When Groups A and B were compared, there were no differences in the mean attenuation values in either the aorto-carotid artery (p=0.78) or the vertebrobasilar artery (p=0.82). Mean venous attenuation values were lower (p=0.002) in Group B than in Group A. Although the qualitative assessment of arterial images showed no differences between the two groups overall, perivenous artefacts at the subclavian vein were assessed as less prominent (p0.01) in Group B.When compared with CTA followed by 25 ml of SF, CTA followed by 40 ml of SF can reduce venous attenuation values and perivenous artefacts at the subclavian vein.

Purpose: To evaluate motion artifacts, tissue contrasts, and lesion detectability in the neck with the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) (BLADE) technique. Materials and Methods: A total of 46 patients referred for MRI of the neck were included in a comparison of T2-weighted BLADE (T2W-BLADE) sequence and T2W fast spin-echo (T2W-FSE) sequence. All examinations were performed at 3T using the same parameters. Two observers evaluated unlabelled images for motion artifacts, the preferred image quality, and lesion detectability. Region of interest (ROI)-based quantitative measurements were performed to assess tissue contrasts. The frequency of occurrence of the different assessed artifacts and the lesion detectability was tested using McNemar's test. Tissue contrasts were compared using the Wilcoxon paired test. Reader agreement was assessed using kappa test. Results: T2W-BLADE showed less ghosting and pulsation artifacts than T2W-FSE (P < 0.01). T2W-BLADE images were rated as better than or equal to T2W-FSE images in majority cases (93.5%; kappa = 0.64). There was not significant difference in tissue contrasts between T2W-BLADE and T2W-FSE. A total of 32 lesions were present in 32 patients and equally well seen on T2W-BLADE and T2W-FSE. Conclusion: T2W-BLADE can reduce motion artifacts and provide tissue contrasts and lesion detectability equivalent to T2W-FSE. J. Magn. Reson. Imaging 2010;32:1061–1067. © 2010 Wiley-Liss, Inc.

Background: Although fast acquisition of multidetector-row computed tomography (MDCT) can make it possible to acquire sufficient early vascular enhancement using small volumes and high concentrations of contrast material (CM), there are still some problems with nephrotoxicity and costs related to CM. Purpose: To compare the qualitative and quantitative performance in cervicocranial CT angiography (CTA) using two different iodine volumes and concentrations of CM. Material and Methods: CTA ranging from the aortic arch (AA) to distal to the circle of Willis (cW) was performed on a 32-MDCT system. Fifty-eight patients were randomly divided into two groups: group A (29 patients) received 60 ml of 300 mg I/ml CM, and group B (the other 29 patients) received 40 ml of 370 mg I/ml CM. Time to peak arterial enhancement at cW (Tc) was calculated. As scan speed was 96.9 mm/s and injection rate was 4.0 ml/s, scanning delay was individually decided according to Tc and scan duration between AA and cW. Arterial attenuation along the z-axis at eight points in the carotid-cerebral artery and venous attenuation of the internal jugular vein (IJV) at carotid bifurcation were measured. Mean attenuation values were then quantitatively analyzed. Postprocessing images were qualitatively assessed. Results: Arterial attenuation profiles revealed maximum attenuation at the distal common carotid artery in both groups. Although there were no significant differences in mean arterial attenuation in group A versus group B (402±70 HU vs. 407±67 HU; P=0.78), venous attenuation of the IJV was lower in group B than in group A (114±57 HU vs. 224±81 HU; P Conclusion: Although a different amount of CM was administered in both groups, quantitative and qualitative arterial images did not show significant differences between the two groups.

Our purpose was to evaluate the ability of diffusion tensor imaging (DTI) to characterize cervical spinal cord white matter (WM) in patients with multiple sclerosis (MS). DTI were obtained in 21 MS patients and 21 control subjects (CS). Regions of interest (ROIs) were placed at C2/3, C3/4, and C4/5 within the right, left, and dorsal (WM) to calculate fractional anisotropy (FA) and the apparent diffusion coefficient (ADC). Measurements in plaques and normal-appearing white matter (NAWM) of MS patients were compared with mean FA and ADC of WM in CS. FA was significantly lower in all regions in MS patients than in CS. ADC was significantly higher in all regions in MS patients than in CS except for in the dorsal WM at C2/3 and the bilateral WM at C4/5. The mean FA was 0.441 for plaques and 0.542 for NAWM, as compared with 0.739 in CS. The mean ADC was 0.810 x 10(-3) mm(2)/s for plaques and 0.722 x 10(-3) mm(2)/s for NAWM, as compared with 0.640 x 10(-3) mm(2)/s for CS. FA and ADC showed significant differences between plaques, NAWM and control WM(P0.01).

The purpose of our study was to assess the usefulness of dynamic MRI in distinguishing high-flow vascular malformations from low-flow vascular malformations, which do not need angiography for treatment.Between September 2001 and January 2003, 16 patients who underwent conventional and dynamic MRI had peripheral vascular malformations (six high- and 10 low-flow). The temporal resolution of dynamic MRI was 5 sec. Time intervals between beginning of enhancement of an arterial branch in the vicinity of a lesion in the same slice and the onset of enhancement in the lesion were calculated. We defined these time intervals as "artery-lesion enhancement time." Time intervals between the onset of enhancement in the lesion and the time of the maximal percentage of enhancement above baseline of the lesion within 120 sec were measured. We defined these time intervals as "contrast rise time" of the lesion. Diagnosis of the peripheral vascular malformations was based on angiographic or venographic findings.The mean artery-lesion enhancement time of the high-flow vascular malformations (3.3 sec [range, 0-5 sec]) was significantly shorter than that of the low-flow vascular malformations (8.8 sec [range, 0-20 sec]) (Mann-Whitney test, p0.05). The mean maximal lesion enhancement time of the high-flow vascular malformations (5.8 sec [range, 5-10 sec]) was significantly shorter than that of the low-flow vascular malformations (88.4 sec [range, 50-100 sec]) (Mann-Whitney test, p0.01).Dynamic MRI is useful for distinguishing high-flow from low-flow vascular malformations, especially when the contrast rise time of the lesion is measured.

To determine whether interlobar pleural invasion into the adjacent lobe (interlobar P3) should be assessed as T3 according to the tumor-node metastasis classification.Surgically treated patients with primary lung cancer (n = 322) were analyzed.Tumors with interlobar P3 had a significantly lower incidence of mass screening detection, a higher occurrence rate of squamous cell carcinoma, and a larger tumor diameter than tumors without interlobar P3. The lymph node metastatic rate did not differ between the patients with and without interlobar P3. The 5-year survival rate of patients with interlobar P3 was 63% and the rates of other patients were 56% with T1 disease, 57% with T2, 31% with T3, and 19% with T4. The survival rate for patients with interlobar P3 was higher than for those with T3 without interlobar P3 (P0.05). The 5-year survival rate of the patients with interlobar P3 was lower in adenocarcinoma (39%) than in squamous cell carcinoma (69%, P0.01). The results were similar when the analysis was restricted to patients without lymph node metastasis. In adenocarcinoma, the survival rate for interlobar P3 was between the rates for T2 (53%) and T3 (13%) without interlobar P3, whereas in squamous cell carcinoma, the survival rate for interlobar P3 was between the rates for T1 (88%) and T2 (54%) without interlobar P3.Tumors with interlobar P3 should be classified as T2 only in squamous cell carcinoma.

To evaluate the effect of Joint Photographic Experts Group (JPEG) compression ratios of 10:1 and 20:1 on detection of acute cerebral infarction at computed tomography (CT).CT images obtained in 25 patients with acute cerebral infarction and 25 patients with no lesions were compressed by means of a JPEG algorithm at ratios of 10:1 and 20:1. Normal and abnormal sections (on original and compressed images) were reviewed by using a color soft-copy computed monochrome cathode ray tube monitor. Five observers rated the presence or absence of a lesion with a 50-point scale (0, definitely absent; 25, equivocal; and 50, definitely present). Diagnostic accuracy was evaluated with receiver operating characteristic (ROC) curve analysis. Significant difference was defined as a P value less than.05 for the area tested with a two-tailed paired Student t test.At ROC analysis, no statistically significant difference was detected for all cases considered together (Az [area under the ROC curve] = 0.887 +/- 0.038 [mean +/- SD] on noncompressed images, Az = 0.897 +/- 0.038 on 10:1 compressed images, and Az = 0.842 +/- 0.073 on 20:1 compressed images; P.05).JPEG compression at ratios of 10:1 and 20:1 was tolerated in the detection of acute cerebral infarction at CT.

RATIONALE AND OBJECTIVES To assess the demonstration of aberrant hepatic and gastric arteries with routine axial biphasic helical CT. METHODS The arterial-phase images of biphasic helical CT were reviewed to evaluate aberrant hepatic and gastric arteries in 166 patients with hepatocellular carcinomas. Biphasic (30 and 70 seconds) helical CT was performed with 10 mm of collimation. The results were compared with angiography performed within 2 weeks after this CT. RESULTS Aberrant hepatic arteries were identified by CT in 38 patients and by angiography in 43 patients (38/43, 88%). Aberrant left gastric arteries were identified in three patients by angiography and by CT (3/3). Careful observation of the fissure for the ligamentum venosum and portacaval space was useful for the detection of these arteries. CONCLUSIONS Aberrant hepatic and gastric arteries were well demonstrated with routine axial biphasic helical CT. This may be useful for the surgical and transcatheter management of hepatic tumors.