Comparisons of multi b-value DWI signal analysis with pathological specimen of breast cancer.

Previous studies have reported that the signal attenuation of diffusion weighted magnetic resonance imaging for tumor tissues displays a non-monoexponential biexponential decay, and the apparent diffusion coefficients (ADCs) can be divided into a fast and slow diffusion component by using a simple biexponential decay model. The purpose of this study is to examine the non-monoexponential character of the diffusion weighted magnetic resonance imaging signal attenuations of breast cancers, estimate the fast and slow diffusion components, and compare them with the extra- and intracellular component information obtained from the pathological specimens. Twenty-two subjects having breast cancers underwent diffusion weighted magnetic resonance imaging using six b-values up to 3500 s/mm(2) and the signal attenuations were analyzed using the biexponential function. The derived slow component fraction correlated with the cellular fraction and the ADCs converged to 0.2-0.3 × 10(-3) mm(2) /s for the higher cellular fractions. The ADCs of the fast component ranged from 1.3 to 3.9 × 10(-3) mm(2) /s and showed no correlation with the extracellular components. This result suggests that the main reason for the decreasing ADC of a breast tumor is the decreasing fraction of the fast component and the increasing fraction of the slow component having a low ADC rather than the decreasing ADC of the fast component by the restricted water diffusion in the reduced extracellular spaces.

Spinal curvature and characteristics of postural change in pregnant women.

OBJECTIVE: Pregnant women often report complaints due to physiological and postural changes. Postural changes during pregnancy may cause low back pain and pelvic girdle pain. This study aimed to compare the characteristics of postural changes in pregnant compared with non-pregnant women. DESIGN: Prospective case-control study. SETTING: Pregnancy care center. POPULATION: Fifteen women at 17-34 weeks pregnancy comprised the study group, while 10 non-pregnant female volunteers comprised the control group. METHODS: Standing posture was evaluated in the sagittal plane with static digital pictures. Two angles were measured by image analysis software: (1) between the trunk and pelvis; and (2) between the trunk and lower extremity. Spinal curvature was measured with Spinal Mouse® to calculate the means of sacral inclination, thoracic and lumbar curvature and inclination. MAIN OUTCOME MEASURES: The principal components were calculated until eigenvalues surpassed 1. RESULTS: Three distinct factors with eigenvalues of 1.00-2.49 were identified, consistent with lumbosacral spinal curvature and inclination, thoracic spine curvature, and inclination of the body. These factors accounted for 77.2% of the total variance in posture variables. Eleven pregnant women showed postural characteristics of lumbar kyphosis and sacral posterior inclination. Body inclination showed a variety of patterns compared with those in healthy women. CONCLUSIONS: Spinal curvature demonstrated a tendency for lumbar kyphosis in pregnant women. Pregnancy may cause changes in spinal curvature and posture, which may in turn lead to relevant symptoms. Our data provide a basis for investigating the effects of spinal curvature and postural changes on symptoms during pregnancy.

[Investigation of a phantom for diffusion weighted imaging that controlled the apparent diffusion coefficient using gelatin and sucrose].

When studying diffusion weighted imaging(DWI), it is important to create a phantom that has a reliably controlled diffusion coefficient. In this study, we investigated phantoms to control both the diffusion coefficient and the T2-value by changing the concentration of gelatin or sucrose and MnCl(2), respectively. The results showed that the diffusion coefficient decreased linearly with increases in the gelatin or sucrose concentration, and decreasing of their relaxation times was observed. By properly adjusting the MnCl(2) concentrations, we were able to equalize the T2-values between phantoms having different gelatin or sucrose concentrations. Temperature dependence of the diffusion coefficient was also revealed. This phantom can be made stable for a few months by adding a small amount of NaN(3) as an antiseptic agent, has a diffusion coefficient similar to that of neural tissue or clinical tumor, and is able to control the T2-value properly. We consider this phantom suitable for studying SE-type DWI and contributes to elucidation of this technique.

[Development of comprehensive image processing technique for differential diagnosis of liver disease by using multi-modality images-pixel-based cross-correlation method using a profile-].

Imaging techniques such as high magnetic field imaging and multidetector-row CT have been markedly improved recently. The final image-reading systems easily produce more than a thousand diagnostic images per patient. Therefore, we developed a comprehensive cross-correlation processing technique using multi-modality images, in order to decrease the considerable time and effort involved in the interpretation of a radiogram (multi-formatted display and/or stack display method, etc). In this scheme, the criteria of an attending radiologist for the differential diagnosis of liver cyst, hemangioma of liver, hepatocellular carcinoma, and metastatic liver cancer on magnetic resonance images with various sequences and CT images with and without contrast enhancement employ a cross-correlation coefficient. Using a one-dimensional cross-correlation method, comprehensive image processing could be also adapted for various artifacts (some depending on modality imaging, and some on patients), which may be encountered at the clinical scene. This comprehensive image-processing technique could assist radiologists in the differential diagnosis of liver diseases.

[Improvement of overall performance for lung nodule detection in chest CT images].

We have developed an automated computerized schema for the detection of lung nodules in 3D CT images obtained by helical CT. In our previous schema, linear discriminant analysis (LDA) and a rule-based method with 53 image features were employed in order to reduce false positives. However, several false positives have remained. Therefore, in this study, we improved the false-positive reduction technique by using the edge image and radial image analysis. Overall performance for the detection of lung nodules was greatly improved. Sensitivity was higher than that of our previous study. Moreover, we evaluated the overall performance of the new scheme by using 69 cases acquired from four hospitals. The average number of false positives was 5.2 per case at a percent sensitivity of 95.8%. Our new scheme would assist in the detection of early lung cancer.

[Movement analysis of chest MR image under rest breath using realignment of SPM].

Analyses of diaphragm and chest wall motion are good indicators to evaluate clinical status and pulmonary function before and after surgery for respiratory disease. Noninvasive MR images using fast gradient recalled echo techniques recently have received a great deal of attention for their assessment of inspiratory motion. However, it is laborious to analyze a large number of dynamic MR images. Therefore, we performed movement analyses of chest 2D MR images by using the public domain software statistical parametric mapping(SPM)Realignment sub-routine, which is commonly used for the motion correction of brain functional MRI analyses. First, dynamic 2D MR images of a glue-stick phantom were measured as a simple reciprocal movement model and were numerically analyzed by the SPM Realignment. The resulting translation to each axis coincided with the measured values. Then the dynamic images of normal volunteers under free breathing were analyzed by the same method, and we found that the inspiratory motions were quantitatively shown as the translation to each axis. These results revealed that the SPM Realignment is a useful tool for screening the magnitude and characteristics of inspiratory motion.

[Development of computer-aided diagnostic system for detection of lung nodules in three-dimensional computed tomography images].

We have developed an automated computerized method for the detection of lung nodules in three-dimensional (3D) computed tomography (CT) images obtained by helical CT. In this scheme, a lung segmentation technique for the determination of the nodule search area is performed based on a gray-level thresholding technique. To enhance lung nodules, we employed the 3D cross-correlation method by using a 3D Gaussian template with zero-surrounding as a model of lung nodule. False positives are then eliminated by using a rule-base with 53 features. For further reduction of false positives, we performed linear discriminant analysis using these 53 features. The average number of false positives was 6.7 per case at a percent sensitivity of 85.0%. This computerized scheme will be useful to radiologists by providing a "second opinion" in case of possible early lung cancer.

Biexponential Signal Attenuation Analysis of Diffusion-weighted Imaging of Breast.

PURPOSE: in vivo, the attenuation of diffusion-weighted imaging (DWI) signal at high b-values is sometimes nonlinear when plotted with semilogarithmic function and is fit well by a biexponential function. Previous reports have indicated that the fast and slow component fractions of the apparent diffusion coefficient (ADC) can be derived by biexponential fitting and that these fractions correspond to the actual diffusion components in the extra- and intracellular space. In this study, we investigated the clinical utility of DWI for the breast by performing DWI using multiple b-factors on healthy volunteers and clinical subjects, analyzing the signal by fitting it with a biexponential equation, and comparing the fitting parameters of breast lesions. PATIENTS AND METHODS: we investigated 8 healthy women as normal cases and 80 female patients with a total of 100 breast tumors (42 benign, 58 malignant tumors) as clinical cases. We performed DWI using 12 b-values for the healthy cases and 6 b-values for the clinical cases, up to a maximum b-value of 3500 s/mm(2). RESULTS: decay of DWI signal of normal mammary glands, most cysts, and some fibroadenomas showed a monoexponential relationship, and conversely, that of intraductal papilloma (IDP) and malignant tumors was well fitted by a biexponential function. Comparison of parameters derived from biexponential fitting demonstrated no significant difference between benign and malignant lesions. For malignant tumor subtype, the fast component fraction of noninvasive ductal carcinoma was statistically greater than that of invasive ductal carcinoma. CONCLUSIONS: although the parameters from biexponential fitting may reflect the character of tumor cellularity, because pathological diagnosis was performed with an emphasis on cell configuration or shape rather than cellularity, it was difficult to distinguish malignant from benign tumors, including many IDPs, or to distinguish tissue types using DWI signal attenuation alone.

Anti-allergic substances contained in the pollen of Cryptomeria japonica possess diverse effects on the degranulation of RBL-2H3 cells.

Following prolonged exposure to some of the flavonoids with RBL-2H3 cells, secretion of hexosaminidase, a granule constituent, stimulated by an immunologic was enhanced. RBL-2H3 cells do not normally respond to polybasic secretagogues, but as reported here, they do so after prolonged exposure. Effect of flavonoids on secretion of hexosaminidase was also investigated. Of the thirteen flavonoids, quercetin and fisetin were the most potent inhibitors. A structure-activity study indicated that the position, number, and substitution of the hydroxy group of the B ring and saturation of the C2-C3 bond are important factors affecting flavonoid inhibition of secretary granules in RBL-2H3 cells.