Comparison of CT Urography and MRI in Bladder Cancer Detection

A final diagnosis of bladder cancer is made based on a pathological assessment using cystoscopy and biopsy. Recently, computed tomography (CT) and magnetic resonance imaging (MRI) have become widely used as screening tests for hematuria, and there are scattered reports of new imaging modalities such as CT urography (CTU) and diffusion-weighted MRI being useful in the detection of bladder cancer. However, there are no reports comparing CTU and MRI in this context. In the present study, we compared the bladder cancer detection abilities of CTU and MRI. We analyzed 58 cases of bladder cancer that had been examined by both CTU and bladder MRI. The objects of comparison were T2-weighted images and diffusion-weighted images for MRI and contrast CT images of the renal parenchyma and excretory phases for CTU. Bladder cancer was confirmed histopathologically via either biopsy or surgery for all cases. For patients with multiple bladder cancer, up to three lesions per case were included in the analysis. Two independent readers assessed all cases. Out of 91 lesions from 58 cases, Reader 1 detected 72 (79.1%) and 65 cases (71.4%), and Reader 2 detected 69 (75.8%) and 70 (76.9%), using MRI and CTU, respectively. The κ-values for Reader 1 versus Reader 2 were 0.780 for MRI and 0.857 for CT, showing high diagnostic consistency. MRI showed a higher lesion detection rate than CTU, but this difference was not statistically significant. This study showed no significant difference in bladder cancer detection rate between CTU and MRI, confirming the value of MRI in the clinical diagnosis of bladder cancer

Analysis of Factors Associated With Radiation-Induced Bronchiolitis Obliterans Organizing Pneumonia Syndrome After Breast-Conserving Therapy

Purpose: To evaluate factors associated with radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome after breast-conserving therapy. Methods and materials: A total of 702 women with breast cancer who received radiotherapy after breast-conserving surgery at seven institutions between July 1995 and December 2006 were analyzed. In all patients, the whole breast was irradiated with two tangential photon beams. The criteria used for the diagnosis of radiation-induced BOOP syndrome were as follows: (1) radiotherapy to the breast within 12 months, (2) general and/or respiratory symptoms lasting for >or=2 weeks, (3) radiographs showing lung infiltration outside the radiation port, and (4) no evidence of a specific cause. Results: Radiation-induced BOOP syndrome was seen in 16 patients (2.3%). Eleven patients (68.8%) were administered steroids. The duration of steroid administration ranged from 1 week to 3.7 years (median, 1.1 years). Multivariate analysis revealed that age (>or=50 years; odds ratio [OR] 8.88; 95% confidence interval [CI] 1.16-67.76; p = 0.04) and concurrent endocrine therapy (OR 3.05; 95% CI 1.09-8.54; p = 0.03) were significantly associated with BOOP syndrome. Of the 161 patients whose age was >or=50 years and who received concurrent endocrine therapy, 10 (6.2%) developed BOOP syndrome. Conclusions: Age (>or=50 years) and concurrent endocrine therapy can promote the development of radiation-induced BOOP syndrome after breast-conserving therapy. Physicians should carefully follow patients who received breast-conserving therapy, especially those who are older than 50 years and received concurrent endocrine therapy during radiotherapy

Clinical Significance of Reverse Redistribution Phenomenon for 201Tl Scintigraphy in Nonischemic Disease

The reverse redistribution phenomenon (RR) on 201Tl 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 201Tl 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 201Tl 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 201Tl SPECT could indicate the existence of myocardial damage ; however, it would not be a factor that determines the prognosis

Development of an artificial intelligence-assisted computed tomography diagnosis technology for rib fracture and evaluation of its clinical usefulness

AbstractArtificial 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.</jats:p

Dose-Volume Histogram Analysis in Point A-based Dose Prescription of High-dose-rate Brachytherapy for Cervical Carcinoma

Traditionally, cervical brachytherapy has been prescribed to point A. However, since the Groupe Europ?en de Curieth?rapie and European Society for Radiotherapy＆ Oncology guidelines were published, image-guided brachytherapy has become an emerging technique. The purpose of this study was to evaluate the high-risk clinical target volume （HR-CTV） coverage and analyze dose-volume histograms for organs at risk in point A prescription of high-dose-rate brachytherapy. A total of 68 patients with locally advanced cervical cancer were treated with three-dimensional conformal external beam radiation therapy and brachytherapy from December 2012 to March 2017. Fractions of 6Gy for a total of 12-24Gy were delivered at point A by brachytherapy to all patients. Following each brachytherapy application, a pelvic computed tomography scan was performed and imported into a three-dimensional brachytherapy treatment planning system. In this study, the HR-CTV, bladder, and rectum were re-delineated according to Report 89 of the International Commission on Radiation Units and Measurements using the magnetic resonance images at the time of diagnosis, and the dose-volume histogram of each structure was analyzed. The median age of patients at diagnosis was 67 years （range, 31-91 years）. Mean HR-CTV D90 for all patients was 558.3cGy （range, 228.7-1005.1cGy） and the mean HR-CTV D90 within each clinical T stage was: Ib, 646.4cGy; 2a, 579.3cGy; 2b, 545.2cGy; 3a, 556.6cGy; 3b, 451.3cGy; and 4, 497.9cGy. HR-CTVD90 was correlated with HR-CTV. The mean D2cm3 was 678.1cGy for the bladder and 511.9cGy for the rectum. Using point A-based dose prescription, HR-CTV coverage was insufficient, especially in cases with a large tumor volume or a high T stage. Image-guided brachytherapy is expected to improve HR-CTV coverage while keeping rectal and bladder doses within acceptable levels