A successful endovascular treatment for complicated acute type B aortic dissection.

A young male patient with Marfan syndrome suffered from acute type B aortic dissection with visceral organ malperfusion. The thoracic stent grafting was urgently performed with a successful outcome. This study reports a potential endovascular approach to treat complicated acute type B aortic dissection in a Marfan syndrome patient.

Diagnostic accuracy of 64-slice multi-detector CT in assessment of coronary artery stenosis.

Objective: To investigate the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of noninvasive coronary artery assessment. Methods: A total of 559 patients with suspected coronary artery disease had undergone noninvasive coronary CT angiography. The 78 patients (55 men and 23 women) had consecutively received a 64-slice multi-detector row CT (MDCT) examination, as well as invasive coronary angiography, within the three months period of the study. The coronary CT angiography was retrospectively reviewed by two radiologists. The degree of coronary stenosis was compared with invasive conventional angiography. Results: The coronary CT angiography of 1,032 segments in 78 patients were evaluated. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of coronary CT angiography for the detection of coronary artery stenosis were 71.1%, 98.4%, 89.4%, 94.7%, and 94.0% respectively. Conclusion: Coronary CT angiography using a 64-slice MDCT implies the reliable detection of coronary artery stenoses with high diagnostic accuracy.

Influence of heart rate on image quality to identify the best cardiac phase in 16-slice coronary CT angiography.

OBJECTIVE: To identify the best cardiac phase in different patient's heart rate on 16-slice coronary CT angiography. MATERIAL AND METHOD: The patients who had undergone coronary CT angiography with 16 multi-detector rows CT at Siriraj Hospital between September 2003 and August 2004. For each patient, the image reconstruction based on relative timing was performed placed at center of 35% to 85% of the R-R interval with step increments 10%. The authors created six data sets (35%, 45%, 55%, 65%, 75%, and 85% of R-R interval) throughout the cardiac cycle. The coronary arteries were reviewed based on cross-sectional images and reformat images. The authors inspected all data sets and selected the cardiac phase that contained the best image quality for each coronary artery. RESULTS: Five hundred sixty four vessels were evaluated in the 141 patients (83 men, 58 women). The mean patient age was 63.3 +/- 16.7 years (range 4-89 years). Mean patient heart rate was 65.7 +/- 16.5 beats per minute (bpm), range 46-104 bpm. The most coronary arteries were well demonstrated at center of 75% of R-R interval (66.8%). Ninety-eight patients (69.5%) required one phase that provided best overall image quality and motion free delineation for four coronary arteries. Forty-three patients (30.5%) required combination of data from each phase to achieve motion free images. CONCLUSION: The best cardiac phase of evaluate coronary artery in 16 slices coronary CT angiography in the patient's heart rate below 70 bpm is 75% of cardiac cycle (mid to late diastole). In patients with a heart rate 71-80 bpm, the authors required a combination of images from 45% and 75% of cardiac cycle to completely evaluate all coronary arteries. In patients with a heart rate above 80 bpm, 45% of cardiac cycle (end-systole) is the best phase.

Assessment of coronary artery stenosis with 16 slices multidetector CT.

Objective: To investigate the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of noninvasive coronary computer tomography (CT) for assessment of coronary arteries. Methods: The total of 330 patients who were suspected to have coronary artery disease underwent noninvasive coronary CT angiography. The 26 patients (male 14: female 12) had consecutively undergone a 16 slices multi-detector row CT, as well as invasive coronary angiography, within a 3 months period. The coronary CT angiography was retrospectively reviewed by two radiologists. The degree of coronary stenosis was compared with invasive conventional angiography. Results: The coronary CT angiography of 306 segments in 26 patients was evaluated. The 306 segments were divided into proximal 155 branches and distal 151 branches. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of coronary CT angiography for coronary artery stenosis were 76.9%, 91.7%, 65.6%, 95.1%, and 89.2% respectively. The sensitivity and specificity of proximal coronary artery stenosis 155 segments were 85.7%, and 90.8%, respectively. The sensitivity and specificity for 151 distal branches were 58.8% and 92.5%, respectively. Conclusion: Coronary CT angiography using 16 slices multi-detector row CT allows for the reliable detection of coronary artery stenoses with a high diagnostic accuracy.

The new effective tool for data migration from old PACS (Rogan) to new PACS (Fuji Synapse) with integrated Thai patient names.

OBJECTIVE: To investigate consuming time and amount of data transfer for PACS data migration from the existing system to a new one by using new developed software tools. MATERIAL AND METHOD: The authors have developed a migration tool for PACS data migration and integrated Thai names into a new PACS by the following steps. First, look up the existing database table for hospital number (HN) and image names for each series number. Second, directly retrieve image from storage. Third, get the Thai name by searching HN from the hospital information system (HIS). Then, send the new study to the new PACS via hospital level 7 (HL7) message. Finally, send images to the new PACS. RESULTS: The data were migrated from the existing PACS, integrated Thai name and sent them to the new PACS. The total migrated images of CR, CT and MR were 296,269, 692,860 and 42,941 images respectively. The average migrated images per series for CR, CT and MR were about 1.01, 89.84 and 15.53 images in successive order. The consuming time for data migration of CR, CT and MR were 685.8, 283.4 and 34.8 hours, respectively. CONCLUSION: The authors successfully developed new application tool for PACS migration that used to migrate data from the existing PACS to the new one, which are powerful and highly flexibility tools, and including patient Thai name in patient information during data migration.

Comparison of image quality of coronary CT angiography between 16 and 64 slices MDCT.

OBJECTIVE: To compare the image quality and visibility of coronary arteries that were performed by 16 slices and 64 slices multidetector row CT (MDCT). STUDY DESIGN: Descriptive analysis. MATERIAL AND METHOD: Twenty-eight patients suspected of hearing coronary artery disease had noninvasive coronary CT angiography performed by 16 slices MDCT and 64 slices MDCT Data were retrospectively analyzed and reviewed by two radiologists. Image quality was assessed by using a grading scale from excellent (4) to non-assessable (0) and the rate of displayed coronary branches was calculated. RESULTS: Four hundred twenty coronary CT angiography segments in 28 patients were evaluated. CONCLUSION: Coronary CT angiography using 64 slices multi-detector row CT provides a significantly higher image quality of coronary arteries and their branches compared with 16 slices multi-detector row CT.

Effect of concentration of contrast medium on coronary CT angiography.

OBJECTIVE: To compare concentration of contrast medium for vascular opacification at ascending aorta using retrospective reconstruction of coronary CT angiography. STUDY DESIGN: Retrospective study. MATERIAL AND METHOD: Eighty-four patients undergoing coronary CT angiography with 16 multi-detector rows at Siriraj Hospital between September 2003 and July 2004 were included in this study. The patients were categorized into two groups. The first group was administrated with 350 mgl/ml contrast medium and the second group was administrated with 370 mgl/ml contrast medium. The total amount of contrast medium was about 140 ml (20 ml for timing bolus and 120 ml for CT angiography) in both groups. The CT density on peak contrast administration at ascending aorta was measured and compared between the two groups. RESULTS: The mean density at ascending aorta in 350 mgl/ml and 370 mgl/ml were 362.96 HU (SD 67.53) and 354.44 (SD 59.39), respectively. There was no statistically significant difference in mean density at the ascending aorta between the two groups. CONCLUSION: Administration of contrast medium with different concentrations of 350 or 370 mgl/ml showed no statistical difference on enhancement of the ascending aorta in coronary CT angiography (p < 0.05).

Endovascular abdominal aortic aneurysm repair in high risk patients: outcomes of management.

BACKGROUND: The concomitant cardiopulmonary disease precluded the elective repair for abdominal aortic aneurysm (AAA) with acceptable risk. The endovascular abdominal aortic aneurysm repair (EVAR) has become an alternative method for the treatment of AAA with high-risk comorbidities. OBJECTIVE: Evaluate the results of EVAR in high-risk patients with large AAA. MATERIAL AND METHOD: A prospective study of high-risk patients with large AAA and suitable morphology who underwent EVAR between August 2003 and August 2005 was conducted. The long-term outcomes were observed up to December 2006. The comorbidities, size of aneurysm, types of procedures, operative time, amount of blood loss and transfusion, length of postoperative stay in intensive care unit and hospital, postoperative complications and mortality were analyzed. RESULTS: Eight patients (7 males and 1 female) with the mean age of 71.4 years (range 66-83 years) were included in the present study. The comorbidities were six of compromised cardiac status, one of severe pulmonary disease and one of morbid obesity. The average size of aneurysm was 6.2 +/- 0.64 centimetres. One patient also had large bilateral iliac artery aneurysms. Seven patients underwent EVAR with bifurcated aortic stent graft and one proceeded with aorto uni-iliac stent graft. Three patients underwent preoperative coil embolisation into internal iliac arteries when the distal landing zones at the external iliac arteries were considered. The mean estimated blood loss was 369cc and the mean blood transfusion was 0.88 units. There were no perioperative mortality, early graft occlusion, AAA rupture and open conversion in the present study. One patient had cardiac arrest due to upper airway obstruction but with successful treatment. Type II endoleak was observed in one patient and successfully treated by expectant management. One limb of bifurcated stent graft was occluded at the 5th month post EVAR and was successfully treated by artery bypass surgery at both groins. The 3-year primary graft limb patency was 87.5% (7/8). The survivals of patients at 1, 2 and 3 years were 100%, 100% and 87.5% respectively. The cause of death in one patient was not related to EVAR. CONCLUSION: EVAR may be a safe and effective alternative to open AAA repair especially in high-risk patients.

Technical aspect of CT angiography of lower extremities.

Objective: To assess the less invasive technique of CT angiography for evaluation of lower extremity arteries with nonionic water soluble iodinated contrast medium. Methods: One hundred thirty patients underwent a CT angiography of lower extremity using smart prep technique above the iliac creast 1 inch. and the following parameters: Helical, Rotation time : 0.8 seconds, Rotation length : full, Detector configuration : 16X1.25 mm, Helical thickness : 1.25, Pitch : 1.375:1, Speed : 27.50 mm/rotation, Beam collimation : 20 mm, Image interval : 1.0 mm, Gantry tilt : 0.0, SFOV : large, X-ray energy 140 kV, 260 mA. Results: The data of CT Acquisition and Contrast Medium Parameters were Scanning coverage (mm): 1040 ฑ 88, Scanning duration (sec): 33+ 5, Number of transverse sections: 1063+ 348 iodine dose (g): 89.8+ 5.3, Concentration of contrast medium(mg/ml): 356.7+ 24.4, Volume of contrast medium (ml): 120+ 0, Contrast medium injector rate (ml/sec): 4+ 0, Injection duration (sec): 30+ 0, Scanning -to-injection duration ratio: 1.08+ 0.2, Delay between contrast medium initiation and scanning (sec): 26+ 5.3. Conclusion: The conventional study for lower extremity arteries is conventional angiography which is invasive method. This method required admission and absolute bed rest at least 8-12 hours after procedure. The CT angiography takes advantage over conventional angiography, including 3D volumetric analysis, minimally invasive vascular opacification and depiction of mural calcium. The fastest and more slices of current generation of 16 slices multidetector CT scanner is possible to study entire length of lower extremities.