Hitomi Tani

Anemia and the risk of contrast-induced nephropathy in patients with renal insufficiency undergoing contrast-enhanced MDCT

PURPOSE The purpose of this study was to assess the effect of anemia on the incidence of contrast-induced nephropathy (CIN) in patients with renal impairment undergoing MDCT. MATERIALS AND METHODS Institutional review board approval was waived for this retrospective review of 843 patients with stable renal insufficiency (eGFR between 15 and 60 mL/min) who had undergone contrast-enhanced MDCT. Baseline hematocrit and hemoglobin values were measured. Serum creatinine (SCr) was assessed at the baseline and at 48-72 h after contrast administration. RESULTS The overall incidence of CIN in the patient population with renal insufficiency was 6.9%. CIN developed in 7.8% (54 of 695) of anemic patients, and in 2.8% (4 of 148) of non-anemic patients (P=.027). After adjustment for confounders, low hemoglobin and low hematocrit values remained independent predictors of CIN (odds ratio 4.6, 95% CI 1.0-20.5, P=.046). CONCLUSIONS Anemia is associated with a higher incidence of CIN in patients with renal insufficiency. Anemia is a potentially modifiable risk factor for CIN, and has an unfavorable impact on prognosis in patients with renal insufficiency undergoing contrast-enhanced MDCT.

Correlation of 18F-BPA and 18F-FDG uptake in head and neck cancers

BACKGROUND AND PURPOSE The aim of this study was to compare the accumulation of 4-borono-2-(18)F-fluoro-phenylalanine ((18)F-BPA) with that of (18)F-fluorodeoxyglucose ((18)F-FDG) in head and neck cancers, and to assess the usefulness of (18)F-FDG PET for screening candidates for boron neutron capture therapy (BNCT). MATERIAL AND METHODS Twenty patients with pathologically proven malignant tumors of the head and neck were recruited from March 2012 to January 2014. All patients underwent both whole-body (18)F-BPA PET/CT and (18)F-FDG PET/CT within 2weeks of each other. The uptakes of (18)F-BPA and (18)F-FDG at 1h after injection were evaluated using the maximum standardized uptake value (SUVmax). RESULTS The accumulation of (18)F-FDG was significantly correlated with that of (18)F-BPA. The SUVmax of (18)F-FDG ⩾5.0 is considered to be suggestive of high (18)F-BPA accumulation. CONCLUSIONS (18)F-FDG PET might be an effective screening method performed prior to (18)F-BPA for selecting patients with head and neck cancer for treatment with BNCT.

T2-Weighted Cardiac Magnetic Resonance Imaging of Edema in Myocardial Diseases

The purpose of this paper is to describe imaging techniques and findings of T2-weighted magnetic resonance imaging (MRI) of edema in myocardial diseases. T2-weighted cardiac MRI is acquired by combining acceleration techniques with motion and signal suppression techniques. The MRI findings should be interpreted based on coronary artery supply, intramural distribution, and comparison with delayed-enhancement MRI. In acute myocardial diseases, such as acute myocardial infarction and myocarditis, the edema is larger than myocardial scarring, whereas the edema can be smaller than the scarring in some types of nonischemic cardiomyopathy, including hypertrophic cardiomyopathy. T2-weighted MRI of edema identifies myocardial edema associated with ischemia, inflammation, vasculitis, or intervention in the myocardium and provides information complementary to delayed-enhancement MRI.

Molecular imaging using PET for breast cancer

Molecular imaging can visualize the biological processes at the molecular and cellular levels in vivo using certain tracers for specific molecular targets. Molecular imaging of breast cancer can be performed with various imaging modalities, however, positron emission tomography (PET) is a sensitive and non-invasive molecular imaging technology and this review will focus on PET molecular imaging of breast cancer, such as FDG-PET, FLT-PET, hormone receptor PET, and anti-HER2 PET.

Assessing Radiologist Performance and Microcalcifications Visualization Using Combined 3D Rotating Mammogram (RM) and Digital Breast Tomosynthesis (DBT)

We evaluated the diagnostic performance of a novel 3D visualization approach (rotating mammogram, RM) in combination with DBT compared with that of FFDM and DBT alone.. FFDM, DBT alone and DBT images plus reconstructed RM from 110 breasts (34 cases of breast cancer and 76 normal breasts) were evaluated and rated independently by 6 readers. DBT plus RM demonstrated superior diagnostic accuracy compared to FFDM (p<0.05) and a small improvement in performance compared to DBT alone. Visualization of microcalcifications was significantly better on RM than DBT (p<0.05) for all 14 microcalcification-dominant cancer lesions. Adjunction of RM to DBT will offer the benefit of increased diagnostic accuracy and contribute to more accurate assessment of DBT alone.

Clinical Efficacy of Novel Image Processing Techniques in the Framework of Filtered Back Projection (FBP) with Digital Breast Tomosynthesis (DBT)

Digital breast tomosynthesis (DBT) slices are reconstructed from projections acquired within a limited angular range. Out-of-plane artifacts are inevitable in reconstructed DBT images. In this study, we evaluated novel image processing techniques in the framework of filtered backprojection (FBP) and compared the results with reconstruction using a previously used FBP method. The novel FBP reconstruction has an adapted filter kernel, uses unbinned projections, performs an adaptive collapsing scheme and statistical artifact reduction, and applies iterative filtering in the image domain. Fifty-four image pairs were evaluated by three experienced radiologists. The images were compared on a 7-point scale (-3, -2, -1, 0, +1, +2, and +3) according to the following five categories: (1) visibility of noise, (2) diagnostic certainty regarding masses, (3) diagnostic certainty regarding microcalcifications, (4) visibility of structures in the pectoral muscle, and (5) overall image quality. The results showed a statistically significant superiority of the novel FBP reconstruction in comparison with standard FBP (p < 0.05). In particular, the improvement of the diagnostic certainty related to microcalcifications with the novel FBP is noteworthy.

Usefulness of a Combination DBT (Digital Breast Tomosynthesis) and Automated Volume Analysis of Dynamic Contrast-Enhanced Breast (DCEB) MRI in Evaluation of Response to Neoadjuvant Chemotherapy (NAC)

We evaluated the usefulness of DBT and automated volume analysis with DCEB MRI to assess its potential role in estimating viable tumor volume in pre-and pos-t NAC images in response to treatment in comparison with FFDM and US. Twenty women having 21 lesions, in total were recruited for this study.The diagnostic procedures were performed within one month prior to surgery. FFDM, DBT, US and DCEB MRI were performed on each of the patients before and after NAC. The imaging data was analyzed by a medical workstation dedicated to breast MRI imaging. Utilizing the dynamic contrast images from 1st to 4th phase, volume statistics with VOI (volume of interest) and the volume was automatically calculated and evaluated as to the efficacy of NAC. DBT has the advantage of providing macroscopic pathological fidings in total without utitiling contrast medium. On the other hand, DCEB MRI has the advantage of providing numerical and detailed vascularity details of viable areas. In accordance with the results, a combination of DBT and automated volume analysis of DCEB MRI will contribute to more accurate diagnosis in the assessment of pathological response to NAC.