One-year follow-up and convalescence evaluated by nuclear medicine studies and 24-hour holter electrocardiogram in 11 patients with myocardial injury due to a blunt chest trauma.

BACKGROUND: There are few reports on long-term convalescence with regard to cardiac injury caused by blunt chest trauma. Nuclear medicine study of the heart (NMSH) in the early stages of injury is reportedly superior to detect the correlation between injury and fatal arrhythmia. Therefore, we prospectively performed NMSH and Holter electrocardiogram (ECG) in the early and chronic stages for a cardiac injury patient, and we longitudinally examined the recovery process and the occurrence of fatal arrhythmia. METHODS AND RESULTS: A total of 202 patients with blunt chest trauma were admitted to our hospital between April 2006 and January 2007. Of 65 patients who were diagnosed with cardiac injury by ECG, a myocardial enzyme, or cardiac ultrasonography, 11 were enrolled in this study because they agreed to outpatient visiting for regular examinations for 1 year. NMSH showed positive findings in 6 of the 11 patients in the acute period of <1 month. Twelve months later, five patients improved but still exhibited protracted cardiac damage without complete recovery. Among the six patients in whom NMSH showed positive findings, Holter ECG indicated an abnormal finding in two patients in the acute period and in four patients in the chronic period, and detected one patient with a nonsustained ventricular tachycardia in the chronic period. CONCLUSION: Cardiac injuries may exacerbate cardiac functions and lead to fatal arrhythmia during the chronic period. Therefore, evaluating recovery for at least 12 months after myocardial damage is necessary to prevent sudden cardiac death.

Two cases in which myocardial injury could be only evaluated by nuclear medicine studies on electric shock patients whose electrocardiogram and myocardial enzyme levels were normal.

Heart injury due to electric shock is currently diagnosed based on electrocardiogram (ECG) changes or elevated levels of myocardial enzymes or both. However, the rate at which ECG detects abnormalities is very low; thus, the estimated rate of the diagnosis of myocardial damage due to electric shock is lower than the actual rate. The method of nuclear medicine study of the heart is superior with regard to evaluating transient ischemia, such as angina pectoris, in patients whose ECG and myocardial enzyme levels are normal. Therefore, we attempted to diagnose transient myocardial damage in electric shock patients by using nuclear medicine study of the heart.

Diagnostic performance of diffusion-weighted magnetic resonance imaging in esophageal cancer.

The purpose of this study was to assess the value of diffusion-weighted magnetic resonance imaging (DWI) in detecting esophageal cancer and assessing lymph-node status, compared with histopathological results. DWI was prospectively performed in 24 consecutive patients with esophageal cancer, using the diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) sequence. DWIBS images were fused with T2-weighted images, and independently and blindly evaluated by three board-certified radiologists, regarding primary tumor detectability and lymph-node status. Apparent diffusion coefficients (ADCs) of the primary tumor and lymph nodes were also measured. Average primary tumor detection rate was 49.4%, average patient-based sensitivity and specificity for the detection of lymph-node metastasis were 77.8 and 55.6%, and average lymph-node group-based sensitivity and specificity were 39.4 and 92.6%. There were no interobserver differences among the three readers (P < 0.0001). Mean ADC of detected primary tumors was 1.26 +/- 0.29x10(-3) mm(2)/s. Mean ADC of metastatic lymph nodes (1.46 +/- 0.35x10(-3) mm(2)/s) was significantly higher (P < 0.0001) than that of nonmetastatic lymph nodes (1.15 +/- 0.24 mm(2)/s), but ADCs of both groups overlapped. In conclusion, this study suggests that DWI only has a limited role in detecting esophageal cancer and nodal staging.

[Continuous speech recognition system for radiological reporting: comparison with experience of dictation].

PURPOSE: To compare rates of accuracy of recognition between experienced dictators and inexperienced ones in using an enrollment-less continuous speech recognition (CSR) system of radiological reporting, and to evaluate the usefulness of the system. MATERIALS AND METHODS: Twenty board-certified radiologists were classified into 2 groups: a group of 10 members with more than 6 years' experience of conventional dictation by transcriptionist (group A) and a group of 10 members with no experience of dictation (group B). All radiologists created fresh radiological reports on sets of images using free-style dictation in the reports. We counted errors and total words in the reports individually, and compared the rates of accuracy of word recognition in the two groups. We used a CSR system AmiVoice (Advanced Media, Inc., Tokyo, Japan). RESULTS: The average rate of accuracy of word recognition was 96.42 +/- 1.68% in group A and 95.92 +/- 1.15% in group B. There was no significant difference in accuracy rate between the two groups. CONCLUSION: The accuracy of word recognition was independent of the experience of dictation, and the enrollment-less CSR system of radiological reporting was considered convenient and useful.

Diffusion weighted whole body imaging with background body signal suppression (DWIBS): technical improvement using free breathing, STIR and high resolution 3D display.

PURPOSE: To examine a new way of body diffusion weighted imaging (DWI) using the short TI inversion recovery-echo planar imaging (STIR-EPI) sequence and free breathing scanning (diffusion weighted whole body imaging with background body signal suppression; DWIBS) to obtain three-dimensional displays. MATERIALS AND METHODS: 1) Apparent contrast-to-noise ratios (AppCNR) between lymph nodes and surrounding fat tissue were compared in three types of DWI with and without breath-holding, with variable lengths of scan time and slice thickness. 2) The STIR-EPI sequence and spin echo-echo planar imaging (SE-EPI) sequence with chemical shift selective (CHESS) pulse were compared in terms of their degree of fat suppression. 3) Eleven patients with neck, chest, and abdominal malignancy were scanned with DWIBS for evaluation of feasibility. Whole body imaging was done in a later stage of the study using the peripheral vascular coil. RESULTS: The AppCNR of 8 mm slice thickness images reconstructed from 4 mm slice thickness source images obtained in a free breathing scan of 430 sec were much better than 9 mm slice thickness breath-hold scans obtained in 25 sec. High resolution multi-planar reformat (MPR) and maximum intensity projection (MIP) images could be made from the data set of 4 mm slice thickness images. Fat suppression was much better in the STIR-EPI sequence than SE-EPI with CHESS pulse. The feasibility of DWIBS was showed in clinical scans of 11 patients. Whole body images were successfully obtained with adequate fat suppression. CONCLUSION: Three-dimensional DWIBS can be obtained with this technique, which may allow us to screen for malignancies in the whole body.

[Evaluation of 18F-FDG PET in acute ischemic stroke: assessment of hyper accumulation around the lesion].

PURPOSE: Although pathophysiology of cerebrovascular disease has been reported previously, few clinical studies of glucose metabolism in acute stroke have been published. Purpose of this study is to evaluate glucose metabolism in acute stroke patients by 18F-FDG PET. SUBJECTS AND METHODS: Twenty-four patients with acute ischemic stroke were involved in this study. All subjects underwent MRI (conventional T1- and T2-weighted images, diffusion-weighted imaging, and MR angiography), CT and 18F-FDG PET. 18F-FDG PET was performed within 1 to 7 days after the first episode. 18F-FDG PET images were visually evaluated as well as MRI and CT images. RESULTS: Four patients out of 24 showed no abnormal 18F-FDG accumulation, while MRI demonstrated abnormal signal area and abnormal vascular findings that suggested acute stroke. Decreased 18F-FDG accumulation corresponding with abnormal signal area on MR images was noted in 20 cases. In 7 cases among these 20 with decreased 18F-FDG, hyper accumulation of 18F-FDG was recognized around the decreased accumulation area. CONCLUSION: Increased 18F-FDG accumulation (increased glucose metabolization) around the lesion may be due to: 1) acceleration of anaerobic glycolysis, 2) activated repair process of damaged brain tissue, i.e., phagocytosis and gliosis, and 3) neuronal excitation by excito-toxic amino acids which can be released after ischemia.