Arterial Stiffness and Functional Outcome in Acute Ischemic Stroke

OBJECTIVE: Arterial stiffness is a common change associated with aging and can be evaluated by measuring pulse wave velocity (PWV) between sites in the arterial tree, with the stiffer artery having the higher PWV. Arterial stiffness is associated with the risk of stroke in the general population and of fatal stroke in hypertensive patients. This study is to clarify whether PWV value predicts functional outcome of acute ischemic stroke. METHODS: One hundred patients were enrolled with a diagnosis of acute ischemic stroke and categorized into two groups: large-artery atherosclerosis (LAAS) or small vessel disease (SVD) subtype of Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. Each group was divided into two sub-groups based on the functional outcome of acute ischemic stroke, indicated by modified Rankin Scale (mRS) at discharge. Poor functional outcome group was defined as a mRS > or = 3 at discharge. Student's t-test or Mann-Whitney U-test were used to compare maximal brachial-ankle PWV (baPWV) values. RESULTS: Twenty-four patients whose state was inadequate to assess baPWV or mRS were excluded. There were 38 patients with good functional outcome (mRS or = 3). The baPWV values were significantly higher in patients with poor outcome (2,070.05 +/- 518.37 cm/s) compared with those with good outcome (1,838.63 +/- 436.65) (p = 0.039). In patients with SVD subtype, there was a significant difference of baPWV values between groups (2,163.18 +/- 412.71 vs. 1,789.80 +/- 421.91, p = 0.022), while there was no significant difference of baPWV among patients with LAAS subtype (2,071.76 +/- 618.42 vs. 1,878.00 +/- 365.35, p = 0.579). CONCLUSIONS: Arterial stiffness indicated by baPWV is associated with the functional outcome of acute ischemic stroke. This finding suggests that measurement of baPWV predicts functional outcome in patients with stroke especially those whose TOAST classification was confirmed as SVD subtype.

Clinical Evaluation of the JPEG2000 Compression Rate of CT and MR Images for Long Term Archiving in PACS

PURPOSE: We wanted to evaluate an acceptable compression rate of JPEG2000 for long term archiving of CT and MR images in PACS. MATERIALS AND METHODS: Nine CT images and 9 MR images that had small or minimal lesions were randomly selected from the PACS at our institute. All the images are compressed with rates of 5:1, 10:1, 20:1, 40:1 and 80:1 by the JPEG2000 compression protocol. Pairs of original and compressed images were compared by 9 radiologists who were working independently. We designed a JPEG2000 viewing program for comparing two images on one monitor system for performing easy and quick evaluation. All the observers performed the comparison study twice on 5 mega pixel grey scale LCD monitors and 2 mega pixel color LCD monitors, rspectively. The PSNR (Peak Signal to Noise Ratio) values were calculated for making quantitative comparisons. RESULTS: On MR and CT, all the images with 5:1 compression images showed no difference from the original images by all 9 observers and only one observer could detect a image difference on one CT image for 10:1 compression on only the 5 mega pixel monitor. For the 20:1 compression rate, clinically significant image deterioration was found in 50% of the images on the 5M pixel monitor study, and in 30% of the images on the 2M pixel monitor. PSNR values larger than 44 dB were calculated for all the compressed images. CONCLUSION: The clinically acceptable image compression rate for long term archiving by the JPEG2000 compression protocol is 10:1 for MR and CT, and if this is applied to PACS, it would reduce the cost and responsibility of the system.

Islet Cell Tumor Arising from Heterotopic Pancreas in the Duodenum: A Case Report

It is difficult to distinguish an islet tumor originating from heterotopic pancreas tissue from the other submucosal tumors. Although the malignant transformation of a heterotopic pancreas, including islet cell tumor, is extremely rare, it remains an important consideration in the differential diagnosis of duodenal submucosal masses. We have demonstrated the radiologic appearance and the clinical-pathologic findings of a highlighted, rare case of islet cell tumor arising from a heterotopic pancreas in the duodenal wall.

Radiological Findings of Giant Pulmonary Chondromatous Hamartoma: Case Report

Among lung tumors, multiple hamartomas are uncommon and multiple chondromatous hamartomas are extremely rare. In this report, we describe a patient with an interval growth of a giant chondromatous hamartoma with accompanying multiple satellite nodules in the adjacent lung and the parietal pleura. We also present the follow up chest radiograph, computed tomograph, magnetic resonance images and photographs of the operating field of the tumor with pathologic correlation.