Kidney R2* Mapping for Noninvasive Evaluation of Iron Overload in Paroxysmal Nocturnal Hemoglobinuria.

PURPOSE: The kidney iron deposition can cause kidney damage and renal insufficiency in paroxysmal nocturnal hemoglobinuria (PNH) patients. Assessment of iron deposition in the kidney is essential for the early diagnosis of renal damage in PNH patients. The purpose of this study was to evaluate kidney R2* (T2* reciprocals) values in PNH patients using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ). METHODS: Two radiologists measured the R2* values of the renal cortex in 14 PNH patients and 13 healthy volunteers using IDEAL-IQ. Lactate dehydrogenase (LDH), a reliable marker of intravascular hemolysis, was also measured in all participants. RESULTS: The kidney R2* values were significantly higher in PNH patients compared with those in healthy volunteers (P < 0.001). High inter-operator reproducibility of the measurements was also acquired using IDEAL-IQ. LDH levels were also significantly higher in PNH patients compared with those in healthy volunteers (P < 0.001). Kidney R2* values strongly correlated with LDH levels in PNH patients. CONCLUSION: IDEAL-IQ has a possibility of becoming a useful method for the noninvasive evaluation of renal iron overload in PNH patients.

Multiparametric magnetic resonance imaging of plasmacytoid urothelial carcinoma with histopathological correlation: A case report.

Plasmacytoid urothelial carcinomas of the bladder are rare, aggressive variants with a poor prognosis. Few reports have described the correlation of histopathological features with multiparametric magnetic resonance imaging findings in the local staging of plasmacytoid urothelial carcinoma. An 82-year-old woman with hematuria was referred to our hospital. Magnetic resonance imaging showed diffuse bladder wall thickening, with different signal intensities in the 2 layers-inner and outer. This case suggests that the presence of diffuse bladder wall thickening and varying signal intensities in the 2 layers could aid in the local staging of plasmacytoid urothelial carcinoma. A thickened bladder wall with restricted diffusion suggests tumor invasion, indicating that the tumor can invade the organ in contact with the thickened bladder wall.

Narrow pelvic inlet plane area and obesity as risk factors for anastomotic leakage after intersphincteric resection.

BACKGROUND: Intersphincteric resection (ISR) has been increasingly used as the ultimate sphincter-preserving procedure in extremely low rectal cancer. The most critical complication of this technique is anastomotic leakage. The incidence rate of anastomotic leakage after ISR has been reported to range from 5.1% to 20%. AIM: To investigate risk factors for anastomotic leakage after ISR based on clinicopathological variables and pelvimetry. METHODS: This study was conducted at Department of Colorectal Surgery, Japanese Red Cross Medical Center, Tokyo, Japan, with a total of 117 patients. We enrolled 117 patients with extremely low rectal cancer who underwent laparotomic and laparoscopic ISRs at our hospital. We conducted retrospective univariate and multivariate regression analyses on 33 items to elucidate the risk factors for anastomotic leakage after ISR. Pelvic dimensions were measured using three-dimensional reconstruction of computed tomography images. The optimal cutoff value of the pelvic inlet plane area that predicts anastomotic leakage was determined using a receiver operating characteristic (ROC) curve. RESULTS: We observed anastomotic leakage in 10 (8.5%) of the 117 patients. In the multivariate analysis, we identified high body mass index (odds ratio 1.674; 95% confidence interval: 1.087-2.58; P = 0.019) and smaller pelvic inlet plane area (odds ratio 0.998; 95% confidence interval: 0.997-0.999; P = 0.012) as statistically significant risk factors for anastomotic leakage. According to the receiver operating characteristic curves, the optimal cutoff value of the pelvic inlet plane area was 10074 mm2. Narrow pelvic inlet plane area (≤ 10074 mm2) predicted anastomotic leakage with a sensitivity of 90%, a specificity of 85.9%, and an accuracy of 86.3%. CONCLUSION: Narrow pelvic inlet and obesity were independent risk factors for anastomotic leakage after ISR. Anastomotic leakage after ISR may be predicted from a narrow pelvic inlet plane area (≤ 10074 mm2).

Internal Hernias in the Era of Multidetector CT: Correlation of Imaging and Surgical Findings.

Clinical diagnosis of internal hernias is challenging because of their nonspecific signs and symptoms. Many types of internal hernias have been defined: paraduodenal, small bowel mesentery-related, greater omentum-related, lesser sac, transverse mesocolon-related, pericecal, sigmoid mesocolon-related, falciform ligament, pelvic internal, and Roux-en-Y anastomosis-related. An internal hernia is a surgical emergency that can develop into intestinal strangulation and ischemia. Accurate preoperative diagnosis is crucial for appropriate management. Multidetector computed tomography (CT), with its thin-section axial images, high-quality multiplanar reformations, and three-dimensional images, currently plays an essential role in preoperative diagnosis of internal hernias. The diagnostic approach to internal hernias at multidetector CT includes detecting an intestinal closed loop, identifying the hernia orifice, and analyzing abnormal displacement of surrounding structures and key vessels around the hernia orifice and hernia sac. At each step, multidetector CT can depict pathognomonic findings. A saclike appearance suggests an intestinal closed loop in several types of internal hernias. Convergence, engorgement, and twisting of mesenteric vessels in the hernia orifice can be seen clearly at multidetector CT, especially with use of multiplanar reformations. For definitive diagnosis of an internal hernia, analysis of displacement of anatomic landmarks around the hernia orifice is particularly important, and thin-section images provide the required information. Detailed knowledge of the anatomy, etiology, and imaging landmarks of the various hernia types is also necessary. Familiarity with the appearances of internal hernias at multidetector CT allows accurate and specific preoperative diagnosis. (©)RSNA, 2015.

Computer-Aided Diagnosis Scheme for Distinguishing Between Benign and Malignant Masses in Breast DCE-MRI.

Our purpose in this study was to develop a computer-aided diagnosis (CAD) scheme for distinguishing between benign and malignant breast masses in dynamic contrast material-enhanced magnetic resonance imaging (DCE-MRI). Our database consisted 90 DCE-MRI examinations, each of which contained four sequential phase images; this database included 28 benign masses and 62 malignant masses. In our CAD scheme, we first determined 11 objective features of masses by taking into account the image features and the dynamic changes in signal intensity that experienced radiologists commonly use for describing masses in DCE-MRI. Quadratic discriminant analysis (QDA) was employed to distinguish between benign and malignant masses. As the input of the QDA, a combination of four objective features was determined among the 11 objective features according to a stepwise method. These objective features were as follows: (i) the change in signal intensity from 2 to 5 min; (ii) the change in signal intensity from 0 to 2 min; (iii) the irregularity of the shape; and (iv) the smoothness of the margin. Using this approach, the classification accuracy, sensitivity, and specificity were shown to be 85.6 % (77 of 90), 87.1 % (54 of 62), and 82.1 % (23 of 28), respectively. Furthermore, the positive and negative predictive values were 91.5 % (54 of 59) and 74.2 % (23 of 31), respectively. Our CAD scheme therefore exhibits high classification accuracy and is useful in the differential diagnosis of masses in DCE-MRI images.

[Breast multidetector-row CT with histopathologic correlation].

PURPOSE: To evaluate the correlation between multidetector-row CT (MDCT) and histopathologic findings using the same MDCT image as the histopathologic cross-section. MATERIALS AND METHODS: MDCT with contrast enhancement was performed in 10 patients with breast cancers (8 invasive ductal carcinomas, one invasive lobular carcinoma, and one non-invasive ductal carcinoma). We tried to reconstruct multiplanar reconstructions (MPR) in the same plane as the histopathologic cross-section, and we evaluated the histopathologic findings of the false-positive lesions. RESULTS: In all cases, we obtained the same MDCT image as the histopathologic cross-section. There were 10 main lesions and 18 other lesions. In the other lesions, we found no false-negative lesions and 11 false-positive lesions. False-positive lesions included periductal fibrosis, cystic change, duct papillomatosis, sclerosing adenosis, fibroadenoma, and others. CONCLUSION: Using MDCT of the breast, it is possible to obtain good correlation between CT images and histopathologic findings. MDCT is thought to be useful in the evaluation CT findings on the basis of histopathologic evidence.