Evaluation of image quality and spatial resolution of low-dose high-pitch multidetector-row helical high-resolution CT in 11 autopsy lungs and a wire phantom

PURPOSE: The aim of this study was to evaluate whether low-dose high-pitch (6:1) multidetector-row helical high-resolution CT is appropriate for the evaluation of various pulmonary abnormalities, including faint opacities. METHODS: Eleven autopsy lungs were scanned with a multidetector-row CT scanner using 2.5 mm x 4 beam collimation, effective slice thickness 3 mm, 6:1 pitch, 0.8 second gantry rotation speed, 20 cm Display FOV, high spatial frequency (bone) algorithm, and various radiation doses (120 kVp; 160, 80, 40, 24, and 8 mAs). The image quality of each CT set was assessed as adequate or inadequate for diagnosis by two independent observers. In addition, a wire phantom was scanned with the same parameters in order to describe the MTF curves. RESULTS: There was excellent agreement between the observers for the evaluation of image quality (kappa statistic, 0.84). The ratio of images evaluated as inadequate for 8 mAs and 24 mAs was significantly higher than that for 160, 80, and 40 mAs (p<0.01: chi-square test). MTF curves of both 8 and 24 mAs were significantly inferior to those of 40, 80, and 160 mAs (p<0.0 1, Friedman test), while the MTF curve of 40 mAs was relatively inferior to that of 160 mAs (p<0.05, Friedman test). CONCLUSION: More than 40 mAs in combination with 120 kVp is preferable for the evaluation of details of lung parenchyma by high-pitch. multidetector-row helical high-resolution CT.     

Two cases of coronary artery aneurysm including one case of the left main coronary artery aneurysm

We report two cases of coronary artery aneurysm including one case of the left main coronary artery aneurysm. The coronary angiogram of one patient, a 68-year-old male, having anterior chest pain on exertion, revealed left anterior descending coronary artery (segment 6) aneurysm of 7 mm in diameter with 90% stenosis distal to the aneurysm and 75% stenosis in the right coronary artery (segment 2). The coronary angiogram of another patient, a 69-year-old female, having chest pain unrelated to exertion, revealed left main coronary artery aneurysm of 25 mm in diameter and delayed filling of contrast medium into the left anterior descending coronary artery. We decided to operate by the reason of not only significant coronary artery stenosis but risks of myocardial infarction due to embolization inot distal coronary arteries and rupture of the aneurysm. We performed coronary artery bypass graftings using the great saphenous veins and closure of the coronary arteries running into and out the aneurysm under cardiopulmonary bypass. It is recomended that ligation of the coronary arteries connecting to the aneurysm or resection of the aneurysm followed by coronary artery bypass grafting is performed before developing myocardial infarction or rupture of aneurysm.     

Influence of poisonous metals on bone metabolism: III. The effect of cadmium on bone resorption in tissue culture

In order to investigate the effect of cadmium on bone resorption, ⁴⁵Ca-prelabeled tibias from 9-day-old chick embryos were cultivated for 6 days by the stainless-steel grid method and CdCl₂ was added into the culture medium in 0.2 to 30 ppm concentration range as Cd²⁺. ⁴⁵Ca release from bone was significantly enhanced by 1 ppm Cd but inhibited by 30 ppm Cd. Active resorption seems to play an important role in the stimulation of mineral loss in cultured bone by 1 ppm Cd, because the effect of Cd on ⁴⁵Ca release in inactivated bone and on the dissolution of hydroxyapatite was not observed. The latency of bone lysosomal enzyme was unaffected by Cd. One part per million of Cd was found to increase a release of lactic acid from bone, though it suppressed the release of acid phosphatase and hydroxyproline into the medium. From these results, it was shown that Cd had a stimulative effect on demineralization which might be produced, at least partly, by lactic acid, originating possibly from the stimulation of Cd to glycolysis.     

A case of stage IV gastric cancer previously treated with TS-1 completely responding to second-line chemotherapy with weekly paclitaxel therapy

We report herein a case with stage IV gastric cancer previously treated with TS-1 completely responding to second-line chemotherapy with weekly paclitaxel therapy. A 65-year-old female was diagnosed as having type 3 gastric cancer with para-aortic lymph node metastases. She underwent total gastrectomy with extended lymph node dissection on March 2003. Histopathological examination revealed that the tumor was poorly-differentiated adenocarcinoma with para-aortic lymph nodes metastases and completely resected.After the operation,she was treated by adjuvant chemotherapy with TS-1. In March of 2004, she suffered from hematuria, and a CT scan revealed para-aortic lymph nodes metastases and left kidney metastasis. Then, she was treated by a weekly infusion of paclitaxel as second-line chemotherapy. After 3 courses, the tumor disappeared and efficacy was judged as CR. Moreover, CR was maintained after 7 courses. At this writing in January of 2005, she is well and has been treated with paclitaxel without any severe adverse events. Therefore, weekly paclitaxel therapy was considered to be one of the promising second-line chemotherapies for advanced or recurrent gastric cancer previously treated by TS-1.     

Rhythmic EMG and EEG activity during voluntary movement in posthypoxic cortical action myoclonus

A patient with posthypoxic cortical action myoclonus was studied using polygraphic EEG-EMG recording techniques and transcranial magnetic stimulation. The myoclonic jerks were not stimulus-sensitive, and were not associated with enhancement of the somatosensory evoked potential (SEP). The most prominent electrophysiological finding was that rhythmic EMG activity was produced when the patient attempted rapid voluntary movement. EEG-EMG polygraph indicated that the rhythmic EMG activity was preceded by rhythmic activity in the EEG recorded overlying the contralateral central region. The frequency of both EEG and EMG activity was the same (approximately 50 Hz). Treatment using a combination of clonazepam, carbamazepine and primidone diminished the action myoclonus, concomitant with the disappearance of the rhythmic EEG and EMG activity. In the sensorimotor cortex of the normal monkey and humans, oscillatory activity ranging between 20-50 Hz has been recorded in the local field potential. Our findings suggest that cortical hyperoscillation may produce this characteristic rhythmic EEG and EMG activity and may, in turn, be related to cortical action myoclonus.