Chihiro Tani

Iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) magnetic resonance imaging as a biomarker for symptomatic multiple myeloma.

Introduction To evaluate the effectiveness of iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) magnetic resonance imaging (MRI) to discriminate between symptomatic and asymptomatic myeloma in lumbar bone marrow without visible focal lesions. Materials and Methods The lumbar spine was examined with 3-T MRI in 11 patients with asymptomatic myeloma and 24 patients with symptomatic myeloma. The fat-signal fraction was calculated from the ratio of the signal intensity in the fat image divided by the signal intensity of the corresponding ROI in the in-phase IDEAL image. The t test was used to compare the asymptomatic and symptomatic groups. ROC curves were constructed to determine the ability of variables to discriminate between symptomatic and asymptomatic myeloma. Results Univariate analysis showed that β2-microglobulin and bone marrow plasma cell percent (BMPC%) were significantly higher and fat-signal fraction was significantly lower with symptomatic myeloma than with asymptomatic myeloma. Areas under the curve were 0.847 for β2;-microglobulin, 0.834 for fat-signal fraction, and 0.759 for BMPC%. Conclusion The fat-signal fraction as a biomarker for multiple myeloma enables discrimination of symptomatic myeloma from asymptomatic myeloma. The fat-signal fraction offers superior sensitivity and specificity to BMPC% of biopsy specimens.

Multiple Myeloma: Microstructural Analysis of Lumbar Trabecular Bones in Patients without Visible Bone Lesions—Preliminary Results

PURPOSE To evaluate the accuracy of trabecular analysis of the lumbar spine by using multidetector computed tomography (CT) in differentiating multiple myeloma patients without spinal fractures from control subjects. MATERIALS AND METHODS This retrospective single-institution study was approved by the institutional review board, with a waiver of informed consent. Spinal microarchitecture was examined by using 64-detector row CT in 29 patients with multiple myeloma and 51 control subjects. The patients were 13 men and 16 women (mean ages, 71.1 and 69.2 years, respectively). By using multidetector CT data, eight parameters were calculated for the L3 vertebral trabeculae with a three-dimensional image analysis system. The χ(2) test was used to select a preliminary set of predictors for multiple myeloma. A multivariable generalized linear model was constructed to identify parameters that could be used to differentiate between patients and controls. Parameters with findings of P < .05 were included in the multivariable model. RESULTS Generalized linear models showed that mean trabecular thickness (TbTh) (patients, 703.7 μm ± 46.7 [standard deviation]; controls, 661.1 μm ± 35.7) and fractal dimension (FD) (patients, 2.23 ± 0.24; controls, 2.41 ± 0.15) in men (P = .05 and .03, respectively) and degree of anisotropy (DA) (patients, 1.63 ± 0.23; controls, 1.38 ± 0.10) in women (P = .02) had significant effects in differentiation between patients and controls. CONCLUSION Significant differences were observed in spinal microarchitecture between control subjects and multiple myeloma patients without pathologic fractures. Independent predictors of multiple myeloma included TbTh and FD in male patients and DA in female patients.

Evaluation of lumber nerve root compression using thin-slice thickness coronal magnetic resonance imaging: three-dimensional fat-suppressed multi-shot balanced non-steady-state free precession versus threedimensional T1-weighted spoiled gradient-recalled echo

PurposeThe aim of this study was to compare the three-dimensional fat-suppressed balanced non-steady-state free precession (3D FS-nSSFP) sequence and the 3D T1-weighted spoiled gradient-recalled echo (3D T1-GRE) sequence for evaluating lumbar nerve root compression with continuous thin-slice coronal magnetic resonance (MR) images.Materials and methodsThe institutional review board approved this study, and written informed consent was obtained from all 35 patients. We optimized continuous 2.5-mm thick lumbar coronal images with 3D FS-nSSFP and 3D T1-GRE. We calculated the contrast-to-noise ratio (CNR) for nerve roots and other structures on images with the two sequences. With knowledge of the final diagnosis, we assessed the visibility of nerve root compression on these images.ResultsThe CNR values of nerve roots were significantly higher on images with 3D FS-nSSFP than on those with 3D T1-GRE. These continuous thin-slice coronal images facilitated visualization of nerve root compression in >91% of patients. There was no statistically significant difference between the two sequences in the detection of nerve root compression.ConclusionContinuous thin-slice coronal MR images using 3D FS-nSSFP and 3D T1-GRE sequences are sufficient to evaluate lumbar nerve root compression, and 3D FS-nSSFP is superior to 3D T1-GRE for depiction of lumbar nerve roots.

Effect of lapatinib on hepatic parenchymal enhancement on gadoxetate disodium (EOB)-enhanced MRI scans.

We present changes seen on hepatobiliary phase (HBP)-gadoxetate disodium (EOB)-enhanced magnetic resonance image of a woman with liver metastases who was treated with lapatinib. After treatment, the HBP images appeared like portal venous phase images. This suggests that lapatinib, an inhibitor of organic anion transporting polypeptide 1B1, one of the substrates of EOB, inhibits EOB uptake by hepatocytes. In patients treated with lapatinib, the ability to diagnose liver tumors on HBP images may be compromised.

Radiation dose reduction at MDCT with iterative reconstruction for prenatal diagnosis of skeletal dysplasia: preliminary study using normal fetal specimens.

OBJECTIVE The purpose of this study was to investigate to what degree the radiation dose can be reduced without affecting the ability to evaluate normal fetal bones at MDCT with iterative reconstruction. MATERIALS AND METHODS Fifteen normal fetal specimens immersed in containers (30- and 35-cm diameter) were scanned with a 64-MDCT scanner, with tube voltage of 100 kVp and tube current of 600, 300, 150, 100, and 50 mA. Images were subjected to adaptive statistical iterative reconstruction (ASIR). The fetal dose was measured using glass dosimeters. We calculated the relative ratio of the dose at 600 mA. Image quality was evaluated on maximum-intensity-projection and volume-rendering images. Two radiologists recorded the visualization scores of five regions. Images at 600 mA were considered to be standard. RESULTS With the 30-cm-diameter container, the fetal dose was 10.15 mGy (relative ratio, 100%) at a tube current of 600, 51% at 300, 25% at 150, 17% at 100, and 9% at 50 mA. With the 35-cm-diameter container the fetal dose was 10.01 mGy (relative ratio, 100%) at 600, 47% at 300, 24% at 150, 17% at 100, and 8% at 50 mA. Visual evaluation showed that in both containers, with ASIR 90%, there was a statistically significant difference between 50-and 600-mA images (p<0.01) but not between 600-mA images and those acquired at 100, 150, and 300 mA (p=0.08-1.00). CONCLUSION The fetal radiation dose for the evaluation of normal fetal bones can be reduced by 83% with ASIR 90%.

Multidetector Computed Tomography-Based Microstructural Analysis Reveals Reduced Bone Mineral Content and Trabecular Bone Changes in the Lumbar Spine after Transarterial Chemoembolization Therapy for Hepatocellular Carcinoma

Purpose It is well recognized that therapeutic irradiation can result in bone damage. However, long-term bone toxicity associated with computed tomography (CT) performed during interventional angiography has received little attention. The purpose of this study was to determine the prevalence of osteoporosis and trabecular microstructural changes in patients after transarterial chemoembolization (TACE) for hepatocellular carcinoma therapy using an interventional-CT system. Materials and Methods Spinal microarchitecture was examined by 64-detector CT in 81 patients who underwent TACE, 35 patients with chronic hepatitis, and 79 controls. For each patient, the volumetric CT dose index (CTDIv) during TACE (CTDIv (TACE)), the dose-length product (DLP) during TACE (DLP (TACE)), and CTDIv and DLP of routine dynamic CT scans (CTDIv (CT) and DLP (CT), respectively), were calculated as the sum since 2008. Using a three dimensional (3D) image analysis system, the tissue bone mineral density (tBMD) and trabecular parameters of the 12th thoracic vertebra were calculated. Using tBMD at a reported cutoff value of 68 mg/cm3, the prevalence of osteoporosis was assessed. Results The prevalence of osteoporosis was significantly greater in the TACE vs. the control group (39.6% vs. 18.2% for males, P<0.05 and 60.6% vs. 34.8% for females, P<0.01). Multivariate regression analysis demonstrated that sex, age, and CTDIv (CT) significantly affected the risk of osteoporosis. Of these indices, CTDIv (CT) had the highest area under the curve (AUC) (0.735). Correlation analyses of tBMD with cumulative radiation dose revealed weak correlations between tBMD and CTDIv (CT) (r 2 = 0.194, P<0.001). Conclusion The prevalence of osteoporosis was significantly higher in post TACE patients than in control subjects. The cumulative radiation dose related to routine dynamic CT studies was a significant contributor to the prevalence of osteoporosis.

Cutaneous complications after transcatheter arterial treatment for hepatocellular carcinoma via the internal mammary artery: how to avoid this complication.

PurposeTo lower the rate of cutaneous complications after transcatheter arterial treatment for hepatocellular carcinoma (HCC) via the internal mammary artery (IMA) we retrospectively assessed the complications.Materials and methodsWe reviewed cutaneous complications in 14 patients with 18 HCCs who had undergone 17 treatment procedures via the IMA, including selective transcatheter arterial infusion chemotherapy with Lipiodol (Lip-TAI) (n = 3), selective Lip-TAI + transcatheter arterial embolization (TAE) (n = 3), nonselective Lip-TAI (n = 1), nonselective Lip-TAI + TAE (n = 5), and nonselective TAE (n = 5). The filling and nonfilling of subcutaneous vessels with Lipiodol was examined on postoperative computed tomography (CT) scans.ResultsSkin rash (n = 3) and ulceration (n = 1) occurred after 4 of 17 (24%) procedures: two of three selective Lip-TAI procedures and two of five nonselective Lip-TAI + TAE procedures. The doses of chemotherapeutic agents for tumor sizes in selective Lip-TAI procedures were higher than those in selective Lip-TAI + TAE procedures. Cutaneous complications were encountered after two of three procedures with filling but not after any of eight procedures without filling.ConclusionA lower dose of chemotherapeutic agents may be less risky when undertaking a selective procedure via the IMA for HCC. If nonselective, TAE alone may be less risky. Postoperative CT may be helpful for predicting cutaneous complications.

Pituitary Volumes and Functions in Children with Growth Hormone Deficiency: Volumetric Magnetic Resonance Findings

Purpose : The purpose of the study was to compare pituitary volumes calculated from magnetic resonance imaging (MRI) in patients with idiopathic growth hormone deficiency (GHD) without structural abnormalities in the pituitary gland with clinical and biochemical features. Methods : This study was designed as a retrospective review and the need for informed consent was waived. MRI of the head was performed for 39 male and 17 female patients ranging in age from 10 to 14 years. Pituitary volumes were calculated from sectional area and ellipsoid formula. Pituitary volumes were compared between boys and girls. Pituitary volumes were also compared with measurements of pituitary function, age, and standard deviation scores (SDS) for height. Results : Whole pituitary volumes in patients were 405.1 ± 150.6 mm3 for the male group and 348.6 ± 161.1 mm3 for the female group. No significant difference was identified between mean pituitary volumes of the female and male groups. A weak correlation was found between pituitary volume and height SDS for boys (ρ = 0.34, p = .03). For girls, a moderate correlation was identified between pituitary volume and FSH level (ρ = 0.67, p < .01). Conclusion : Pituitary volumes of GHD patients correlated with height SDS in boys and FSH levels in girls. Brain MRI can be used not only to rule out anatomical abnormalities of the pituitary gland in GHD patients, but also to assess pituitary functions in clinical settings.

A Longitudinal Computed Tomography Study of Lenalidomide and Bortezomib Treatment for Multiple Myeloma: Trabecular Microarchitecture and Biomechanics Assessed Using Multidetector Computed Tomography

BACKGROUND Bone disease is a common feature in patients with multiple myeloma. In this study, we investigated whether lenalidomide, similar to bortezomib, affects the microarchitecture and biomechanics of bones using clinical CT-based FEM. MATERIALS AND METHODS Bone lesions were evaluated using whole-body 64-section multidetector CT scan. For microstructural- and CT/FEM analyses, the volume of interest was defined as a 10-mm thickness of the central part of the L3 vertebral body. Microstructural parameters and mechanical properties were calculated using a 3-D image analysis system. The changes from baseline to the second examination within groups were calculated. Relationships between baseline disease characteristics and percent changes of trabecular parameters were assessed using Spearman correlation analysis. RESULTS Thirty-two patients were treated with bortezomib and 18 patients were treated with lenalidomide. At the second CT scan, apparent trabecular number, failure load, and stiffness were decreased in the bortezomib group and failure load and stiffness were increased significantly in the lenalidomide group. In the lenalidomide group, response to chemotherapy was positively associated with increases in failure load (ρ = 0.57; P < .05) and stiffness (ρ = 0.50; P < .05). CONCLUSION Lenalidomide treatment resulted in significant increases in CT/FEM-derived estimates of bone strength. Response to chemotherapy predicted lenalidomide-induced bone changes and good responders had increased bone strength.

Usefulness of multi-detector row computed tomography for management of duodenal varices by emergency balloon-occluded retrograde transvenous obliteration

Ectopic varices outside the gastroesophageal region are less common in patients with portal hypertension and liver cirrhosis. Among ectopic varices, bleeding from duodenal varices is often massive and fatal. Several reports have recently described various treatment options for duodenal varices including interventional radiology. It is necessary to thoroughly investigate variceal hemodynamics before conducting interventional radiology. We report a case of bleeding duodenal varices treated successfully with balloon-occluded retrograde transvenous obliteration (B-RTO) after investigating the hemodynamics of the duodenal varices with multi-detector row computed tomography (MDCT). MDCT easily identified the duodenal varices together with the afferent and efferent vessels. Our case suggests the usefulness of MDCT before B-RTO for investigating the hemodynamics and vascular anatomy of the duodenal varices and selection of the most appropriate therapy.