Jeon Hor Chen

Detection of choline signal in human breast lesions with chemical-shift imaging.

To investigate the application of MR spectroscopy using chemical‐shift imaging (CSI) for characterizing human breast lesions at 1.5T, and to evaluate the diagnostic performance using ROC (receiver operating characteristics) analysis.

Computer-aided diagnosis of mass-like lesion in breast MRI

This study aimed to evaluate the value of using 3-D breast MRI morphologic features to differentiate benign and malignant breast lesions. The 3-D morphological features extracted from breast MRI were used to analyze the malignant likelihood of tumor from ninety-five solid breast masses (44 benign and 51 malignant) of 82 patients. Each mass-like lesion was examined with regards to three categories of morphologic features, including texture-based gray-level co-occurrence matrix (GLCM) feature, shape, and ellipsoid fitting features. For obtaining a robust combination of features from different categories, the biserial correlation coefficient (|r(pb)|)≧0.4 was used as the feature selection criterion. Receiver operating characteristic (ROC) curve was used to evaluate performance and Students t-test to verify the classification accuracy. The combination of the selected 3-D morphological features, including conventional compactness, radius, spiculation, surface ratio, volume covering ratio, number of inside angular regions, sum of number of inside and outside angular regions, showed an accuracy of 88.42% (84/95), sensitivity of 88.24% (45/51), and specificity of 88.64% (39/44), respectively. The AZ value was 0.8926 for these seven combined morphological features. In conclusion, 3-D MR morphological features specified by GLCM, tumor shape and ellipsoid fitting were useful for differentiating benign and malignant breast masses.

Rapid Breast Density Analysis of Partial Volumes of Automated Breast Ultrasound Images

Rapid volume density analysis (RVDA) for automated breast ultrasound (ABUS) has been proposed as a more efficient method for estimating breast density. In the current experiment, ABUS images were obtained for 67 breasts from 40 patients. For each case, three rectangular volumes of interest (VOIs) were extracted, including the VOIs located at the 6 and 12 o’clock positions relative to the nipple in the anterior to posterior pass and the lateral position relative to the nipple in the lateral pass. The centers of these VOIs were defined to align with the center of nipple, and the depths reached the retromammary fat boundary. The fuzzy c-means classifier was applied to differentiate the fibroglandular and fat tissues to estimate the density. The classification results of the three VOIs were averaged to obtain the breast density. The density correlations between the RVDA and the ABUS methods were 0.98 and 0.96 using Pearson’s correlation and linear regression coefficients, respectively. The average computation times for RVDA and ABUS were 4.2 and 17.8 seconds, respectively, using an Intel® Core™2 2.66 GHz computer with 3.25 GB memory. In conclusion, the RVDA method offers a quantitative and efficient breast density estimation for ABUS.

Percutaneous Transthoracic Lung Biopsy: Comparison Between C-Arm Cone-Beam CT and Conventional CT Guidance.

BACKGROUND: C-arm cone-beam computed tomography (CBCT) is a comparatively novel modality for guiding percutaneous transthoracic lung biopsies (PTLBs), and despite its potential advantages over conventional computed tomography (CCT), a head-to-head comparison of the two techniques has yet to be reported in the literature. This study aims to evaluate the diagnostic value and safety of CBCT-guided PTLB compared to CCT-guided biopsy, with cases performed in a single hospital. METHODS: A total of 104 PTLB patients were retrospectively analyzed in this study. 35 PTLBs were performed under CBCT guidance, and 69 PTLBs were performed under CCT guidance. Diagnostic accuracy, sensitivity, and specificity for malignancy as well as procedure time, radiation dose of patients, and complication rate in the two groups were compared. RESULTS: Total procedure time was significantly lower in the CBCT group (32 ± 11 minutes) compared to the CCT group (38 ± 9.7 minutes; P = .009), especially among patients ≥ 70 years of age (CBCT: 33 ± 12 minutes, CCT: 42 ± 13, P = .022). For lesions in the lower lobes, the CBCT-guided group received significantly reduced effective radiation dose (2.9 ± 1.6 mSv) than CCT-guided patients (3.7 ± 0.80; P = .042). Diagnostic accuracy, sensitivity, and specificity for malignancy were comparable between the two groups, as were post-biopsy complication rates. CONCLUSION: CBCT guidance significantly reduces the procedure time and radiation exposure for PTLBs compared with CCT, and should be considered in clinical settings that may be difficult or time-consuming to perform under CCT.

Differentiation between Glioblastoma Multiforme and Primary Cerebral Lymphoma: Additional Benefits of Quantitative Diffusion-Weighted MR Imaging.

The differentiation between glioblastoma multiforme (GBM) and primary cerebral lymphoma (PCL) is important because the treatments are substantially different. The purpose of this article is to describe the MR imaging characteristics of GBM and PCL with emphasis on the quantitative ADC analysis in the tumor necrosis, the most strongly-enhanced tumor area, and the peritumoral edema. This retrospective cohort study collected 104 GBM (WHO grade IV) patients and 22 immune-competent PCL (diffuse large B cell lymphoma) patients. All these patients had pretreatment brain MR DWI and ADC imaging. Analysis of conventional MR imaging and quantitative ADC measurement including the tumor necrosis (ADCn), the most strongly-enhanced tumor area (ADCt), and the peritumoral edema (ADCe) were done. ROC analysis with optimal cut-off values and area-under-the ROC curve (AUC) was performed. For conventional MR imaging, there are statistical differences in tumor size, tumor location, tumor margin, and the presence of tumor necrosis between GBM and PCL. Quantitative ADC analysis shows that GBM tended to have significantly (P<0.05) higher ADC in the most strongly-enhanced area (ADCt) and lower ADC in the peritumoral edema (ADCe) as compared with PCL. Excellent AUC (0.94) with optimal sensitivity of 90% and specificity of 86% for differentiating between GBM and PCL was obtained by combination of ADC in the tumor necrosis (ADCn), the most strongly-enhanced tumor area (ADCt), and the peritumoral edema (ADCe). Besides, there are positive ADC gradients in the peritumoral edema in a subset of GBMs but not in the PCLs. Quantitative ADC analysis in these three areas can thus be implemented to improve diagnostic accuracy for these two brain tumor types. The histological correlation of the ADC difference deserves further investigation.

Primary Renal Rhabdomyosarcoma in an Adolescent With Tumor Thrombosis in the Inferior Vena Cava and Right Atrium: A Case Report and Review of the Literature.

AbstractAlthough the second peak of the age distribution of rhabdomyosarcoma (RMS) is at adolescence, renal RMS is extremely rare at this age group. This tumor is indistinguishable from other renal tumors based on clinical and imaging findings, and the diagnosis relies on histology and immunohistochemical staining. We report a unique case of adolescent renal RMS associated with tumor thrombus extending into the inferior vena cava (IVC) and right atrium.An 18-year-old female adolescent presented with shortness of breath and palpitations, associated with right flank discomfort, and hematuria. A pleomorphic-type renal RMS with Budd–Chiari syndrome and arrhythmia induced by IVC and RA thrombosis was diagnosed. Despite complete tumor resection, the patient developed multiple lung metastases a month after surgery. Chemotherapy was recommended, but the patient declined. She died within a year of the initial operation.Adolescent renal RMS is rare and associated with poor outcome. Early aggressive multimodal therapy seems to be appropriate, in particular, in the presence of tumor thrombosis.

Posteromedial olecranon impingement of the pitching elbow: Additional findings provided by CT.

PURPOSE Posteromedial olecranon impingement (PMOI) is the most common diagnosis in baseball players with throwing-induced elbow injuries. CT imaging manifestations of PMOI have seldom been previously reported. Our purpose is to investigate the additional value of CT imaging in the evaluation of PMOI. MATERIALS AND METHODS From July 2010 to December 2013, 47 baseball players with throwing-induced elbow pain received imaging studies (CT and/or MRI) of the elbow at our institution. After retrospectively reviewing the clinical records and imaging studies, 31 of the 47 players were diagnosed with PMOI by the criteria of posteromedial elbow pain with clinical consistency for PMOI and characteristic osteoarthrosis at the posteromedial ulnotrochlear articulation (posteromedial olecranon space, PMOS) detected by CT and/or MRI. The imaging modalities of these 31 players including radiography, CT, and MRI were reviewed by 2 experienced musculoskeletal radiologists. RESULTS The most common imaging manifestations of PMOI by CT or MRI include joint space narrowing, subchondral sclerosis, and osteophytes at the PMOS. CT was superior to MRI with a statistically significant (P<0.05) difference in detecting joint space narrowing, medial olecranon subluxation, as well as the number of loose bodies. In contrast, bone marrow edema and associated soft tissue injuries in PMOI are more readily observed on MRI. CONCLUSIONS CT is superior in identifying some imaging features of PMOI. Whenever PMOI is diagnosed in the pitching elbow of a baseball player, CT should be considered prior to surgical intervention as it will often provide additional information to the surgeon that may alter surgical management.

Added value of delayed computed tomography angiography in primary intracranial hemorrhage and hematoma size for predicting spot sign

Background The computed tomography angiography (CTA) spot sign represents active contrast extravasation within acute primary intracerebral hemorrhage (ICH) and is an independent predictor of hematoma expansion (HE) and poor clinical outcomes. The spot sign could be detected on first-pass CTA (fpCTA) or delayed CTA (dCTA). Purpose To investigate the additional benefits of dCTA spot sign in primary ICH and hematoma size for predicting spot sign. Material and Methods This is a retrospective study of 100 patients who underwent non-contrast CT (NCCT) and CTA within 24 h of onset of primary ICH. The presence of spot sign on fpCTA or dCTA, and hematoma size on NCCT were recorded. The spot sign on fpCTA or dCTA for predicting significant HE, in-hospital mortality, and poor clinical outcomes (mRS ≥ 4) are calculated. The hematoma size for prediction of CTA spot sign was also analyzed. Results Only the spot sign on dCTA could predict high risk of significant HE and poor clinical outcomes as on fpCTA (P < 0.05). With dCTA, there is increased sensitivity and negative predictive value (NPV) for predicting significant HE, in-hospital mortality, and poor clinical outcomes. The XY value (product of the two maximum perpendicular axial dimensions) is the best predictor (area under the curve [AUC] = 0.82) for predicting spot sign on fpCTA or dCTA in the absence of intraventricular and subarachnoid hemorrhage. Conclusion This study clarifies that dCTA imaging could improve predictive performance of CTA in primary ICH. Furthermore, the XY value is the best predictor for CTA spot sign.

The role of CT in predicting the need for surgery in patients diagnosed with mesenteric phlebosclerosis

Abstract To determine if imaging findings on computed tomography (CT) can predict the need of surgery in patients with idiopathic mesenteric phlebosclerosis (IMP). This retrospective study included 28 patients with IMP. Abdominal CT images were reviewed to determine the extent and severity of mesenteric calcifications and the presence of findings related to colitides. We compared the number of colonic segments with mesenteric venous calcification, a total calcification score, and the rate of colonic wall thickening, pericolic fat stranding, and bowel loop dilatation between patients undergoing surgery (surgery group) and patients without surgery (nonsurgery group). Comparisons were made using the Mann–Whitney U test and Fisher exact test. Receiver operating characteristic analysis was also performed. Inter-reader agreement for the calcification scores was analyzed using kappa statistics. The number of colonic segments with mesenteric venous calcification and the total calcification scores were both significantly higher in the surgery group than the nonsurgery group (4.33 vs 2.96, P = 0.003; and 15.00 vs 8.96, P <0.001). The areas under the receiver operating characteristics to identify patients who need surgery were 0.96 and 0.92, respectively. The prevalence of bowel loop dilatation in the surgery group was also significantly higher than that in the nonsurgery group (16% vs 100%, P = 0.011). Evaluation of the severity and extent of IMP based on the total mesenteric venous calcification score, number of involved colonic segments, and the presence bowel loop dilatation on CT may be useful to indicate the outcomes of conservative treatment and need for surgery.