Evaluation of coronary artery disease by computed tomography angiography in patients treated for childhood Hodgkin's lymphoma.

PURPOSE To detect pathologies in coronary arteries by computed tomography angiography (CTA) in survivors of childhood Hodgkin's lymphoma who have been treated with radiotherapy and/or cardiotoxic agents. PATIENTS AND METHODS Patients with HL who have been in remission for at least 2 years after completion of therapy were included. CBC, lipid profile, urine analysis, brain natriuretic peptide, troponin-T, creatinine kinase-myocardial band, ECG, telecardiography, echocardiography, and CTA of the patients were performed. Cardiac vascular abnormalities were noted. Results A total of 119 patients were included in the study. In 19 patients (16%), we found coronary artery abnormalities. There was a significant difference between the patients who received mediastinal radiotherapy and those who did not (P = .02). By multivariate analysis, in patients receiving mediastinal radiotherapy the risk of developing a coronary artery abnormality was found to increase 6.8 times compared with patients who did not receive mediastinal radiotherapy (P = .009). Stent implantation was performed in a 28-year-old patient because of critical stenosis in right coronary. In two patients some irregularities were detected both in CTA and conventional angiography, and they remained in close follow-up. A 22-year-old patient whose CTA showed critical stenosis in his left anterior descending artery refused the conventional angiography. CONCLUSION To our knowledge, this is the first large study using CTA for detection of coronary abnormalities in patients treated for HL in pediatric age group. Coronary CTA is a minimally invasive tool for early diagnosis of coronary artery disease in patients who were treated with mediastinal radiotherapy and/or cardiotoxic chemotherapy.

Myocardial bridging as evaluated by 16 row MDCT.

PURPOSE: The purpose of this study is to find out the prevalence, appearance and clinical symptoms of myocardial bridging (MB) by MDCT coronary angiography (CTA). MATERIALS AND METHODS: A total of 280 (50 females) consecutive patients followed with coronary artery disease or postoperative stent and bypass control, underwent CTA performed by 16-MDCT scanner between January 2006 and April 2006. Short axis multiplanar reformatted images were evaluated. MBs were classified as complete and incomplete bridges with respect to continuity of the myocardium over the tunneled segment of left anterior descending artery (LAD) in interventricular groove and the cut-off value is 1.3mm. Patients diagnosed with MB on CTA who had prior catheter angiography studies were re-evaluated for the presence of MB. RESULTS: One hundred and twenty MBs [98 (81.6%) on LAD, 2 (1.6%) on diagonal branch, 11 (9.1%) on obtuse marginal, 4 (3.3%) on right coronary artery, 5 (4.1%) on ramus intermedius artery] were detected in 108 (38.5%) patients. Eighty-five (70.8%) of bridged segments in 79 (28.2%) patients were complete and the rest [35 (29.2%) in 34 (12.1%) patients] were incomplete. In 12 patients two MBs (either on different arteries or on the same artery) were detected. The length of bridged segments in patients with complete and incomplete MBs varied between 4-50.9mm (mean 18mm) and 4-37.3mm (mean 13.6mm), respectively, and the depth of myocardium over the artery ranged between 1-6.4mm (mean 2.3mm) and 1-1.2mm (mean 1mm), respectively. Thirty (27.7%) out of 108 patients, in whom MB was detected on CTA, were found to have correlative catheter angiography studies, retrospectively and MB was detected only in 4 (13.3%) out of 30 patients. CONCLUSION: MDCT coronary angiography is a non-invasive, efficient method in the diagnosis of MB avoiding the procedural risks that catheter angiography carries. MDCT coronary angiography allows direct visualization of the bridge itself and may thus give the opportunity to differentiate between complete and incomplete myocardial bridges.

Imaging characteristics of Takayasu arteritis.

Takayasu arteritis is a rare, large-vessel vasculitis in which the nonspecific systemic inflammatory symptoms are followed by inflammation of the aorta and its major branches. The inflammation of this vessel leads to progressive luminal stenosis or aneurysm formation resulting in limb or organ ischemia. Although conventional angiography is still accepted as the gold standard modality, the information obtained is limited to the vessel lumen. Multidetector computed tomographic angiography and magnetic resonance angiography can provide valuable information not only regarding intraluminal pathologies but also concerning the thickening of the vessel wall, which may be the earliest manifestation of the disease.

Myocardial bridging on MDCT.

OBJECTIVE: The aim of this study is to show the usefulness of MDCT in the diagnosis of myocardial bridging. Although most of the time myocardial bridging is a benign condition, it may be associated with myocardial ischemia and secondary complications. Therefore, it is important to be able diagnose the presence of myocardial bridging. CONCLUSION: MDCT is an effective noninvasive method for the diagnosis of myocardial bridging because MDCT can show the length and the depth of the tunneled artery and the diameter and percentage of stenosis in the segments showing myocardial bridging in the systolic and diastolic phases. Moreover, MDCT is efficient in showing the presence of other coronary artery, myocardial, epicardial, and neighboring thoracic abnormalities.

Impact of scanning direction on heart rate at certain levels of heart in electrocardiogram-gated 16-multidetector computed tomography angiography of coronary artery bypass grafts.

OBJECTIVE: To assess impact of scanning direction on heart rates at certain levels of heart in electrocardiogram-gated 16-multidetector computed tomography (MDCT) detection of coronary artery bypass grafts and native coronary arteries. METHODS: Ninety patients with 219 grafts were studied by 16-MDCT. Forty-five patients were scanned craniocaudally. The remaining 45 patients were scanned caudocranially. Heart rates at each level were noted and compared between the 2 groups. RESULTS: The difference between mean heart rates of craniocaudal and caudocranial groups was found to be statistically significant at midcardiac, internal mammary artery origin, and cardiac base levels (P < 0.05). For the remaining levels, there was no statistically significant difference in mean heart rates. CONCLUSIONS: Performing electrocardiogram-gated 16-MDCT angiography for the evaluation of coronary arteries and bypass grafts in caudocranial direction provides lower heart rate at midcardiac and cardiac base levels of the heart, which are more prone to motion artifacts.

Does 16-MDCT angiography scanning direction affect image quality of coronary artery bypass grafts and the native coronary arteries?

To assess the impact of scanning direction on the image quality of coronary artery bypass grafts (CABGs), native coronary arteries (NCAs) were examined by electrocardiographically (ECG) gated 16-row multidetector computed tomography (16-MDCT). Eighty-two patients with 209 grafts were studied by 16-MDCT. Forty-one patients with 111 grafts were scanned craniocaudally. Forty-one patients with 98 grafts were scanned caudocranially. CABG, native coronary arteries were examined in four (proximal, middle, distal, distal anastomoses), three (proximal, middle, distal) segments, respectively. Subjective image quality on a four-point scale was calculated for segments. Scores of groups were compared. Results Image quality scores of proximal, distal segments of the right coronary artery (RCA) were better in caudocranially scanned group (P<0.05). When we subgrouped patients according to initial heart rates (IHR) (group 1, <65 beats/min; group 2, > or =65 beats/min), there was no statistical significance between image quality scores of coronary arteries, CABG when IHR was <65 beats/min in groups regardless of scanning direction. Scores of anastomotic segment of CABG to RCA, middle segments of circumflex coronary artery, proximal and distal segments of RCA in caudocranially scanned group were better when the IHR is > or =65 beats/min compared with the craniocaudally scanned group. When the IHR of the patient is > or =65 beats/min, performing ECG-gated 16-MDCT angiography in the caudocranial direction provides better image quality for evaluation of coronary arteries and CABGs.

Assessment of the radial artery and hand circulation by computed tomography angiography: a pilot study.

OBJECTIVES: The radial artery (RA) is increasingly being used as a coronary bypass graft. Results of a previous study using Doppler ultrasound and histopathologic examinations indicated that the RA has a higher incidence of preexisting intimal hyperplasia, medial calcification, and atherosclerosis than the internal thoracic artery. The aims of this study were to evaluate the use of computed tomographic angiography (CTA) to display hand collateral circulation, to define the criteria for an abnormal CTA test result, and to demonstrate usefulness of CTA as an alternative to conventional angiography for evaluation of the radial artery. MATERIALS AND METHODS: Sixteen patients scheduled for coronary artery bypass grafting entered this study. We performed 32 examinations of forearm and hand arterial anatomy in these patients. CTA was performed in patients with a normal Allen test result, except 1 patient who had a persistent median artery. Soft tissue density forehand roentgenography was performed in all patients before the CTA evaluation. There was no selection of patients in relation to patient characteristics. As a risk factor for radial artery calcification, 6 of the patients had diabetes mellitus, 6 had aortofemoral occlusive disease, and 4 had a history of smoking. RESULTS: Bilateral forearm arteries were visualized in all patients. Severe RA calcification was found in 1 patient, and distal occlusion was found in another patient. Focal RA calcification was noted in 2 patients. In the remaining patients no radial artery calcification or occlusion was noted. Anatomic variation of the upper limb arteries was shown in 2 patients; these variations were persistent median artery with absence of the radial and ulnar arteries and high bifurcation of the radial artery from the brachial artery. CONCLUSION: CTA is useful and safe for detection of radial artery calcific disease and assessment of the forehand circulation and its anatomic variations. Preoperative imaging of the RA is a means to avoid unnecessary forearm exploration or inadvertent use of a diseased conduit in coronary artery bypass candidates with multiple risk factors such as diabetes mellitus.

MDCT angiography of the extremities in pediatric patients: initial experience.

OBJECTIVE: We studied the feasibility of extremity MDCT angiography in pediatric patients with congenital anomalies, an extremity mass, and a suspected arterial occlusion. CONCLUSION: In pediatric patients, MDCT angiography of the extremities with a short imaging time and a low dose of contrast material is feasible and can be used as a noninvasive alternative to conventional angiography.

Determination of the width of the presacral space on magnetic resonance imaging.

Presacral space enlargement may be the first sign of certain diseases. The normal width of the presacral space has not been widely investigated and in all previous studies was calculated from lateral radiographs obtained at barium enema examination. Our study determined the normal width of the presacral space on MRI and investigated a possible difference between men and women. The width of the presacral space was measured retrospectively from sagittal T2-weighted MR images of 193 patients (87 males; 106 females, aged 18-83 years). Presacral space width was measured separately for S1, S2, and S3 vertebral levels from the anterior surface of the vertebral bodies to the closest part of the posterior wall of the rectum. Differences between male and female subjects were analyzed by t-tests. Normal mean widths of the presacral space in men and women were 16.2 mm and 11.9 mm for S1, 14.9 mm and 11.2 mm for S2, and 13.0 mm and 10.6 mm for S3, respectively. Measurements of the presacral space width in men were significantly larger than in women at all three levels (P < 0.001 for S1, P < 0.001 for S2, P = 0.006 for S3). In summary, the presacral space width measured on MRI was found to be significantly larger in the male than in the female population.

CT virtual bronchoscopy in the evaluation of children with suspected foreign body aspiration.

OBJECTIVE: Computed tomography (CT) virtual bronchoscopy is a noninvasive technique that provides an internal view of trachea and major bronchi by three-dimensional reconstruction. The aim of this study was to investigate the usefulness of virtual bronchoscopy in the evaluation of suspected foreign body aspiration in children. MATERIALS AND METHODS: Twenty-three children (12 girls, 11 boys) with a mean age of 2.4 years (8 months-14 years) who were admitted to emergency room with a suspicion of foreign body aspiration were included in this study. Chest radiograms, spiral computed tomography scans and virtual bronchoscopy images were obtained. Then, rigid bronchoscopy was performed within 24 h. RESULTS: CT virtual bronchoscopy and conventional bronchoscopy revealed the location of the foreign body in seven patients. It was in the right main bronchus in four patients, in the right lower lobe bronchus in one patient, and in the left main bronchus in two patients. There was no discordance between two modalities. CT examination revealed hyperaeration of the ipsilateral lung in four patients, hyperaeration of the ipsilateral lung and mediastinal shift in one patient and bronchiectatic changes in one patient. CT detected no additional finding in one patient with a foreign body in the right main bronchus. In 10 of 16 patients without foreign body, CT examination demonstrated atelectasis, infiltration, peribronchial thickening, and paratracheal lymphadenpoathy. CONCLUSION: Helical CT scanning with virtual bronchoscopy should be performed in only selected cases with suspected foreign body aspiration. When the chest radiograph is normal and the clinical diagnosis suggests aspirated foreign body, helical CT and virtual bronchoscopy can be considered in order to avoid needless rigid bronchoscopy.

[Staging of urinary bladder tumors with CT and MRI]. / Mesane kanserlerinin BT ve MRG ile evrelendirilmesi.

PURPOSE: The purpose of this study was to evaluate the performance of spiral CT and MRI in patients with bladder tumor. MATERIALS AND METHODS: In this study, patients with suspected urinary bladder tumor were evaluated by abdominal CT and MRI. This study included 32 patients. In 23 cases, transurethral resection (TUR), and in 9 cases radical cystectomy was performed. Additionally, pelvic lymph node dissection was performed in 9 patients. RESULTS: According to the pathological results of TUR-performed patients; the accuracy of spiral CT and MRI in preoperative staging of bladder tumors was 41.6% and 83.3%, respectively. The accuracy of spiral CT and MRI in preoperative staging of bladder tumors were 66.6% and 77.7% in patients who underwent radical cystectomy. Pelvic lymph node involvement was evaluated properly with MRI and CT. CONCLUSION: In the preoperative staging of bladder tumors, MRI is superior to CT. The superiority is more definite especially in early stage tumors.

[The role of spiral CT in the preoperative evaluation of malignant gastric neoplasms]. / Malign mide tümörlerinin preoperatif degerlendirilmesinde spiral BT'nin rolü.

PURPOSE: The purpose of this study was to evaluate the performance of spiral CT in preoperative staging in patients with gastric cancer. MATERIALS AND METHODS: A total of 28 patients with an established diagnosis of 24 gastric adenocarcinoma, 2 gastric lymphoma, 1 carcinoid tumor, 1 leiomyosarcoma were evaluated with spiral CT for serosal invasion, pancreatic invasion, metastasis and peritoneal involvement. Results were compared with surgical and pathological staging. RESULTS: The accuracy of spiral CT in determining the depth of tumor invasion, pancreatic invasion, lymph node metastasis, peritoneal metastasis, liver metastasis and splenic metastasis were 82% (23/28), 96% (27/28), 82% (23/28), 96% (27/28), 100% (28/28) and 100% (28/28) respectively. The differentiation between T2-T3, T3-T4, N0-N1, N1-N2, N2-N3 were possible in 83% (15/18), 92% (23/25), 79% (15/19), 73% (8/11), and 89% (8/9). The accuracy of spiral CT in overall TNM staging of gastric adenocarcinomas was 67% (16/24). CONCLUSION: Spiral CT is an effective tool in the preoperative staging of gastric malignancies.

CT attenuation of colorectal polypoid lesions: evaluation of contrast enhancement in CT colonography.

The aim of this study was to calculate pre- and postcontrast CT attenuation values of benign colorectal polyp and carcinoma lesions detected by virtual colonoscopy, and to investigate whether contrast enhancement of these lesions can be potentially used for differentiation from residual fluid in the colon. Fifteen benign polyps and 21 colorectal carcinoma lesions detected by virtual colonoscopy in 18 patients were included in our study. All of the polyps and carcinoma lesions were confirmed by colonoscopic biopsy. Measurement of CT attenuation values was performed in precontrast (supine) and postcontrast (prone) scans for each polyp and carcinoma. The CT attenuation values of residual fluid in the colon was also measured from the same location before and after intravenous contrast administration. On unenhanced CT scan mean attenuation values of benign polyps and colorectal carcinomas were 32.4 and 42.6 HU, respectively. Following contrast enhancement, mean attenuation value increased to 78.9 HU for polyps and 90.7 HU for carcinomas. Increase in the CT attenuation values of these lesions was significant ( p<0.0001). Mean CT attenuation value of residual fluid before and after administration of IV contrast were 14.6 and 13.8 HU, respectively. The difference between CT attenuation value of residual fluid in the colon before and after contrast material was not significant ( p=0.29). Colorectal benign polyps and carcinomas demonstrate significant enhancement following contrast administration and use of intravenous contrast material during virtual colonoscopy may help in some cases in differentiating these solid lesions from residual colonic fluid that does not enhance.

CT and MR imaging findings and their implications in the follow-up of patients with intracranial aneurysms treated with endosaccular occlusion with onyx.

BACKGROUND AND PURPOSE: Our purpose was to describe the CT and MR features of intracranial aneurysms occluded with the liquid polymer Onyx. METHODS: At two centers, 35 aneurysms in 33 patients and 11 in nine patients were treated with the polymer. In 17 patients, adjunctive stents were placed at the aneurysm neck. All but three aneurysms originated from the internal carotid artery (ICA). Eighteen were giant; 15, large; and 13, small. Patients underwent pre- and postprocedural CT and/or MR imaging; MR angiograms (MRAs) were available in 22. In 35 patients (38 aneurysms), 3-month and/or 1-year follow-up angiograms were obtained for correlation with sectional images. RESULTS: Except in two small aneurysms, polymer filling created beam hardening artifacts on CT scans. In 10 aneurysms, the polymer did not fill the aneurysm sac entirely; five showed recanalization at follow-up. On MR images (all sequences), the polymer appeared hypointense, probably because of its tantalum content; it did not create artifacts. MRAs falsely suggested reduced or absent ICA flow in 11 of 22 patients, nine of whom with stents. In the rest, MRA provided results comparable to those of selective angiography. In 12 patients, postprocedural imaging revealed new lesions. CONCLUSION: Onyx appears hypointense on MR images, with no artifact, and it does not interfere with MRA except in patients with stents. MR imaging may reveal new parenchymal lesions, even in asymptomatic patients. In the immediate control and follow-up of polymer-treated aneurysms, MR imaging and MRA may be preferred. CT may show the degree of filling in the aneurysmal sac, but Onyx creates artifacts that hinder CT evaluation.