Biomedical subjects

Jacques Remy

Publications and source records attributed to Jacques Remy.

At least 19 recordsLinked to original sources

PubMed2006

Pulmonary arteriovenous malformation treated with embolotherapy: systemic collateral supply at multidetector CT angiography after 2-20-year follow-up.

PURPOSE: To retrospectively evaluate frequency of systemic arterial collateral supply to treated pulmonary arteriovenous malformations (PAVMs) in long-term follow-up with multi-detector row helical computed tomography (CT). MATERIALS AND METHODS: Institutional review board approval was obtained, with waiver of informed consent. Thirty-two patients (19 male, 13 female; mean age, 43 years) underwent follow-up multi-detector row helical CT angiography of the chest (collimation, 16x0.75 mm) 2 or more years after embolotherapy of PAVMs. The study group had a history of successful embolotherapy of 53 PAVMs and a mean of 9 years of follow-up (range, 2-20 years). A search for abnormal systemic arteries was based on analysis of thin-collimated contiguous transverse CT scans and two- and three-dimensional images including maximum intensity projections and volume-rendered images. Statistical comparison was performed with the Fisher exact test (categoric variables) and Wilcoxon rank sum test (continuous variables). RESULTS: At CT, 13 patients (group 1) had abnormally enlarged systemic arteries and 19 patients (group 2) had no abnormal arteries. In group 1, 32 abnormally enlarged arteries were seen-five bronchial and 27 nonbronchial arteries (14 inferior phrenic, six musculophrenic, five internal mammary, two intercostal). The degree of enlargement was moderate for 26 arteries and marked for six. There were no significant differences between groups for (a) clinical characteristics of patients, including history of surgery before or after embolotherapy (P=.7); (b) anatomic structures of treated PAVMs; and (c) embolization procedures and their effectiveness. The number of patients with features suggestive of lung infarction in the days or months after embolotherapy was significantly higher in group 1 (P=.04). On CT angiograms, the number of patients with features suggestive of sequelae of lung infarction was significantly higher in group 1 (P=.02). There were no symptomatic differences attributable to systemic collateral supply between groups; in particular, there was no hemoptysis in group 1. CONCLUSION: Abnormally enlarged systemic arteries were present in 13 of 32 patients, in whom there was a significantly higher frequency of clinical and/or radiographic features suggestive of lung infarction after embolotherapy.

Adult↗

PubMed2006

Coronary artery imaging during preoperative CT staging: preliminary experience with 64-slice multidetector CT in 99 consecutive patients.

The purpose of this study was to evaluate the clinical feasibility of coronary artery imaging during routine preoperative 64-slice MDCT scans of the chest. Ninety-nine consecutive patients in sinus rhythm underwent a biphasic multidetector-row spiral CT examination of the chest without the administration of beta-blockers, including an ECG-gated acquisition over the cardiac cavities, followed by a non-gated examination of the upper third of the thorax. Data were reconstructed to evaluate coronary arteries and to obtain presurgical staging of the underlying disease. The percentage of assessable segments ranged from 65.4% (972/1,485) when considering all coronary artery segments to 88% (613/693) for the proximal and mid segments, reaching 98% (387/396) for proximal coronary artery segments. The 387 interpretable proximal segments included 97 (97%) LM, 99 (100%) LAD, 96 (97%) LCX and 95 (96%) RCA with a mean attenuation of 280.70+/-52.93 HU. The mean percentage of assessable segments was significantly higher in patients with a heart rate <or=80 bpm (n=48) than in patients with a heart rate greater than 80 bpm (n=35) (80+/-11% vs. 72+/-13%; P=0.0008). Diagnostic image quality was achieved in all patients for preoperative staging of the underlying disorder. The mean estimated effective dose was 12.06+/-3.25 mSv for ECG-gated scans and 13.88+/-3.49 mSv for complete chest examinations. Proximal and mid-coronary artery segments can be adequately evaluated during presurgical CT examinations of the chest obtained with 64-slice MDCT without the administration of beta-blockers.

Adult↗

PubMed2006

Coronary imaging quality in routine ECG-gated multidetector CT examinations of the entire thorax: preliminary experience with a 64-slice CT system in 133 patients.

To evaluate image quality in the assessment of the coronary arteries during routine ECG-gated multidetector CT (MDCT) of the chest. One hundred and thirty three patients in sinus rhythm underwent an ECG-gated CT angiographic examination of the entire chest without beta-blockers with a 64-slice CT system. In 127 patients (95%), it was possible to assess the coronary arteries partially or totally; coronary artery imaging failed in six patients (5%), leading to a detailed description of the coronary arteries in 127 patients. Considering ten coronary artery segments per patient, 75% of coronary segments were assessable (948/1270 segments). When the distal segments were excluded from the analysis (i.e., seven coronary segments evaluated per patient), the percentage of assessable segments was 86% (768/889 proximal and mid coronary segments) and reached 93% (474/508) when assessing proximal segments exclusively. The mean number of assessable segments was significantly higher in patients with a heart rate < or =80 bpm (n=95) than in patients with a heart rate >80 bpm (n=38) (p<0.002). Proximal and mid-coronary segments can be adequately assessed during a whole-chest ECG-gated CT angiographic examination without administration of beta-blockers in patients with a heart rate below 80 bpm.

Adolescent↗

PubMed2006

Integrated cardio-thoracic imaging with ECG-Gated 64-slice multidetector-row CT: initial findings in 133 patients.

The purpose of this study was to investigate the possibility of assessing the underlying respiratory disease as well as cardiac function during ECG-gated CT angiography of the chest with 64-slice multidetector-row CT (MDCT). One hundred thirty-three consecutive patients in sinus rhythm with known or suspected ventricular dysfunction underwent an ECG-gated CT angiographic examination of the chest without beta-blockers using the following parameters: (1) collimation: 32 x 0.6 mm with z-flying focal spot for the acquisition of 64 overlapping 0.6-mm slices (Sensation 64; Siemens); rotation time: 0.33 s; pitch: 0.3; 120 kV; 200 mAs; ECG-controlled dose modulation (ECG-pulsing) and (2) 120 ml of a 35% contrast agent. Data were reconstructed: (1) to evaluate the underlying respiratory disease (1-mm thick lung and mediastinal scans reconstructed at 55% of the R-R interval; i.e., "morphologic scans") and (2) to determine right (RVEF) and left (LVEF) ventricular ejection fractions (short-axis systolic and diastolic images; Argus software; i.e., "functional scans"). The mean heart rate was 73 bpm (range: 42-120) and the mean scan time was 18.11 +/- 2.67 s (range: 10-27). A total of 123 examinations (92%) had both lung and mediastinal images rated as diagnostic scans, whereas 10 examinations (8%) had non-diagnostic images altered by the presence of respiratory-motion artifacts (n = 4) or cyclic artifacts related to the use of a pitch value of 0.3 in patients with a very low heart rate during data acquisition (n = 6). Assessment of right and left ventricular function was achievable in 124 patients (93%, 95% CI: 88-97%). For these 124 examinations, the mean RVEF was 46.10% (+/- 9.5; range: 20-72) and the mean LVEF was 58.23% (+/- 10.88; range: 20-83). In the remaining nine patients, an imprecise segmentation of the right and left ventricular cavities was considered as a limiting factor for precise calculation of end-systolic and end-diastolic ventricular volumes. The mean (+/- SD) DLP value of the examinations was 279.86 (+/- 117.50) mGy.cm. Assessment of underlying respiratory disease and cardiac function from the same data set was achievable in 92% of the patients with ECG-gated 64-slice MDCT.

Adolescent↗

PubMed2006

Pulmonary arteriovenous malformations treated with embolotherapy: helical CT evaluation of long-term effectiveness after 2-21-year follow-up.

PURPOSE: To retrospectively evaluate the long-term results of transcatheter embolotherapy of pulmonary arteriovenous malformations (PAVMs) with helical computed tomography (CT). MATERIALS AND METHODS: Neither institutional review board approval nor patient consent was required for this retrospective study. Thirty-eight patients underwent follow-up helical chest CT 2-21 years after successful embolotherapy of 64 PAVMs. Four outcome categories were analyzed on the basis of the PAVM morphologic changes and perfusion findings seen on CT angiograms: successful treatment (marked reduction or disappearance of the aneurysmal sac), partially successful treatment (reduced size of the aneurysmal sac and pulmonary vessels, with feeding artery[ies] less than 3 mm in diameter, deemed too small to be occluded), partially failed treatment (reduced size of the aneurysmal sac and pulmonary vessels, with feeding artery[ies] larger than 3 mm and additional embolotherapy required), and failed treatment (similar size of or interim growth in the aneurysmal sac, with unchanged or enlarged pulmonary vessels). chi(2) or Fisher exact tests were used to analyze categorical variables; Mann-Whitney rank tests were used to analyze continuous variables. P < .05 was considered to indicate statistical significance. RESULTS: Long-term follow-up of the 64 occluded PAVMs revealed successful treatment of 30 (47%), partially successful treatment of 18 (28%), partially failed treatment of two (3%), and failed treatment of 14 (22%) PAVMs. The overall treatment success rate was 75% (47% plus 28%). Delayed recanalization requiring repeat embolotherapy occurred in 12 (19%) cases. No relationship between failed treatment and number of coils deposited in the feeding arteries was found. The frequency of gastrointestinal tract and/or hepatic arteriovenous fistulas at initial diagnosis (P = .01) and/or the interim development of pulmonary hypertension with or without heart failure (P = .01) was significantly higher in patients with at least one PAVM for which embolotherapy failed (n = 9) than in patients who underwent successful or partially successful embolotherapy of all PAVMs (n = 29). CONCLUSION: Long-term CT follow-up of initially successfully treated PAVMs revealed successful embolotherapy of 75% and partially or completely failed embolotherapy of 25% of PAVMs.

Adolescent↗

PubMed2006

Multi-detector row CT angiography of pulmonary circulation with gadolinium-based contrast agents: prospective evaluation in 60 patients.

PURPOSE: To prospectively evaluate gadolinium dose safety and effectiveness for 16-detector pulmonary computed tomographic (CT) angiography. MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. Sixty patients with contraindications to iodine underwent CT of the pulmonary circulation with 0.5 mmol/L gadolinium chelate given at either 0.3 (n = 29, group A) or 0.4 (n = 31, group B) mmol/kg; clinical and biologic tolerances were evaluated. Enhancement of central and segmental pulmonary arteries was measured (poor enhancement, <100 HU; good, 100-150 HU; excellent, >150 HU). Subsegmental artery enhancement was assessed as similar or inferior to that of segmental arteries. Confidence in analysis of the pulmonary arterial bed was graded according to arterial enhancement: Grades 1-3, diagnostic images; grade 4, nondiagnostic. The main effectiveness parameter for comparison between groups A and B was diagnostic value of CT angiograms. Nonparametric statistics were used to analyze results. RESULTS: The mean (+/- standard deviation) contrast material volume was 50.09 mL +/- 8.45 (all patients: range, 30-64 mL; group A: 46.54 mL +/- 8.59; group B: 53.42 mL +/- 6.92). Diagnostic images were obtained in 55 (92%) patients, and confident analysis of pulmonary arteries to the subsegmental level was achieved in 26 (grade 1, 44%) and to the segmental level, in 21 (grade 2, 35%). Mean attenuation was higher in group B than in group A in central (180.61 HU +/- 53.85 vs 148.14 HU +/- 52.61; P = .04) and segmental (201.59 HU +/- 54.70 vs 164.73 HU +/- 59.26; P = .03) arteries. Number of diagnostic CT angiograms was higher (P = .02) in group B (n = 31 [100%]) than in group A (n = 24 [83%]). In both groups, mean enhancement of pulmonary arteries was significantly higher at 80 or 100 kV than at 120 kV. Renal function was impaired in two group A patients. CONCLUSION: Gadolinium chelates may be used as an alternative CT contrast agent in patients who cannot receive iodine.

Adult↗

PubMed2006

MDCT of right ventricular function: comparison of right ventricular ejection fraction estimation and equilibrium radionuclide ventriculography, part 1.

OBJECTIVE: The aim of this study was to calculate right ventricular ejection fraction by use of ECG-gated MDCT and to compare the results with those of equilibrium radionuclide ventriculography. SUBJECTS AND METHODS: Forty-nine consecutively examined patients (30 men, 19 women; mean age, 59 years) with known or suspected right ventricular dysfunction secondary to bronchopulmonary (n = 30) or pulmonary vascular (n = 19) disease underwent ECG-gated 16-MDCT angiography of the heart (rotation time, 0.42 second; 120 kV; 300 mAs; collimation, 12 x 0.75 mm; pitch, 0.2) after CT angiographic examination of the entire thorax according to a standard protocol. Biphasic administration of a 30% contrast agent was systematically performed (phase 1, 90 mL at 3 mL/s; phase 2, 30 mL at 1.5 mL/s); no patient received additional medication. Right ventricular ejection fraction was calculated after two reviewers in consensus determined the reconstruction windows and segmentation of the right ventricular cavity on a series of diastolic and systolic short-axis images. The results were compared with those of equilibrium radionuclide ventriculography. RESULTS: At data acquisition, the mean (+/- SD) heart rate of the study group was 82 +/- 13.87 beats per minute (BPM) (range, 51-115 BPM). ECG showed a sinus rhythm in 30 (61%) of the patients and irregular cardiac rhythm in 19 (39%) of the patients. Agreement between the two techniques was estimated by intraclass correlation coefficient (0.77), the method of Bland and Altman (limits of concordance, -14.9 and 13.7), and percentage of variability between two measurements expressed by mean absolute percentage error (12.1%). The estimated effective dose for heart examination was 7.48 mSv with CT and 5 mSv with scintigraphy. The mean effective dose for the chest and heart CT examinations was 11.64 mSv. CONCLUSION: Right ventricular ejection fraction can be reliably estimated with 16-MDCT in unselected patients.

Adult↗

PubMed2006

MDCT of right ventricular function: impact of methodologic approach in estimation of right ventricular ejection fraction, part 2.

OBJECTIVE: The purpose of this study was to evaluate the impact of the methodologic approach for MDCT estimation of right ventricular ejection fraction (RVEF). MATERIALS AND METHODS: In 49 consecutive patients (30 men, 19 women; mean age, 59 years) known to have or suspected of having right ventricular (RV) dysfunction secondary to pulmonary disease, 16-MDCT of the heart was performed after standard CT angiographic examination of the entire thorax, with determination of RVEF by two reviewers who had limited experience in cardiac CT. The reconstruction windows were determined using the ECG tracing (reviewer 1) or using transverse test images obtained in 5% steps through the entire R-R interval showing the largest and smallest RV cavity areas (reviewer 2). After manual segmentation of the ventricular cavity on diastolic and systolic short-axis reformations by each reviewer, the end-diastolic and end-systolic RV volumes were calculated, with subsequent determination of the RVEF. CT results were compared with those of equilibrium radionuclide ventriculography. RESULTS: Agreement between the two methods for determining the end-systolic and end-diastolic phases was observed in 61% of cases (n = 30) for the systole and 59% of cases (n = 29) for the diastole. Discordant selections were observed in 39% of cases (n = 19) for determination of the systole and in 41% of cases (n = 20) for determination of the diastole, ranging from 5% to 15% of the R-R interval, suggesting that selection of the reconstruction window on the ECG tracing does not differ significantly from that obtained by the visual analysis of transverse test images. Focusing on the 59 common selections of the reconstruction windows made by the two reviewers, no statistically significant differences were found in the determination of mean (+/- SD) end-diastolic volumes (reviewer 1, 176.21 +/- 67 mL vs reviewer 2, 175.55 +/- 71.24 mL; p = 0.98) and end-systolic (reviewer 1, 97.3 +/- 26.49 mL vs reviewer 2, 96.33 +/- 65.72 mL; p = 0.65), suggesting the lack of operator dependence in the manual-contour drawing process. No significant difference was found between the mean values of RVEF obtained by each reviewer with MDCT and equilibrium radionuclide ventriculography, and there was excellent interobserver agreement with MDCT (intraclass correlation coefficient, 0.86). Using a Bland-Altman approach, the limits of concordance between the two reviewers ranged between -10.2 and 10.9. The mean absolute percentage error for measuring RVEF between the two reviewers was 9.7%. A moderate agreement was found between RVEFs obtained on CT by each reviewer and scintigraphy (intraclass correlation coefficients, 0.76 for reviewer 1 and 0.64 for reviewer 2). CONCLUSION: These results show that RVEF can be accurately assessed with ECG-gated MDCT using commercially available software.

Adult↗

PubMed2005

Safety and effectiveness of gadolinium-enhanced multi-detector row spiral CT angiography of the chest: preliminary results in 37 patients with contraindications to iodinated contrast agents.

PURPOSE: To prospectively evaluate the safety and effectiveness of gadolinium-enhanced multi-detector row spiral computed tomographic (CT) angiography of the pulmonary circulation by using two gadolinium doses in patients with contraindications to iodinated contrast agents. MATERIALS AND METHODS: Study was approved by the Ethics Committee, and written informed consent was obtained. Thirty-seven patients (20 men, 17 women) with contraindications to iodinated contrast agents (allergic reactions, n = 27; impaired renal function, n = 10) underwent CT angiography of the pulmonary circulation in search of acute pulmonary embolism (n = 28) or for management of tumoral disease (n = 9). CT angiography was performed (a) with four-detector row (n = 19) or 16-detector row (n = 18) scanners; (b) at randomly assigned gadolinium doses of either 0.3 mmol per kilogram of body weight (n = 19) or 0.4 mmol/kg (n = 18); and (c) with a systematic evaluation of clinical and biologic tolerance of gadolinium. Comparison of percentages between group 1 and group 2 scans was performed with the chi2 or the Fisher exact test. An unpaired Wilcoxon rank sum test was used for numeric variables. P < .05 was considered to indicate a significant difference. RESULTS: The mean (+/- standard deviation) volume of gadopentetate dimeglumine administered in the overall study group was 48 mL +/- 9.6 (range, 29-65 mL). The level of maximal enhancement in the pulmonary arteries was significantly higher in group 2 than in group 1 (215.8 HU +/- 95 vs 141.3 HU +/- 44) (P = .02) and was maintained throughout the entire region of interest in a greater number of examinations in group 2 than in group 1 (n = 16 [89%] vs n = 2 [10.5%]) (P < .0001). The number of diagnostic CT angiograms was significantly higher in group 2 than in group 1 (n = 17 [94%] vs n = 13 [68%]) (P = .007). Significant but transient reduction of creatinine clearance was observed in one patient with preexisting moderate chronic renal failure (0.3 mmol/kg gadolinium dose). CONCLUSION: High-quality gadolinium-enhanced CT angiograms require the use of 16-detector row CT technology; the doses administered did not alter the renal function except transiently in one patient.

Adolescent↗

PubMed2005

Systemic collateral supply in patients with chronic thromboembolic and primary pulmonary hypertension: assessment with multi-detector row helical CT angiography.

PURPOSE: To compare retrospectively the frequency of systemic collateral supply in patients who have chronic thromboembolic pulmonary hypertension with the frequency of systemic collateral supply in patients who have primary pulmonary hypertension by using multi-detector row helical computed tomographic (CT) angiography. MATERIALS AND METHODS: For this review, neither institutional board approval nor informed consent was required. Thirty-six consecutive patients, including 22 patients (four men, 18 women; mean age, 46.0 years) with chronic thromboembolic pulmonary hypertension (group 1) and 14 patients (five men, nine women; mean age, 63.0 years) with primary pulmonary hypertension (group 2), underwent multisection spiral CT angiography of the pulmonary and systemic circulations with a four- (n = 17) or 16- (n = 19) detector row scanner. CT angiograms were assessed for the presence of abnormal bronchial and/or nonbronchial systemic arteries, CT features of pulmonary hypertension, and right ventricular dysfunction. Vascular and parenchymal signs of chronic pulmonary embolism were specifically analyzed on CT angiograms of group 1 patients. Comparative analyses were performed by using the chi(2) or the Fisher exact test for categoric data. An unpaired bilateral Wilcoxon rank sum test was used for continuous data. A chi(2) goodness-of-fit test was used to compare observed proportions with equal proportions. RESULTS: The degree of pulmonary hypertension was comparable in groups 1 and 2. Abnormally enlarged systemic arteries were identified in 16 (73%) of 22 patients from group 1 and in two (14%) of 14 patients from group 2 (P = .002). The systemic collateral supply in group 1 comprised enlargement of both bronchial and nonbronchial systemic arteries in nine (56%) of the 16 patients; the remaining seven patients had an exclusive enlargement of bronchial systemic arteries (n = 6, 38%) or nonbronchial (n = 1, 6%) systemic arteries. A total of 31 enlarged nonbronchial systemic arteries were depicted, including 13 inferior phrenic arteries, 10 intercostal arteries, seven internal mammary arteries, and one lateral thoracic artery. The mean +/- standard deviation of abnormal nonbronchial systemic arteries per patient was 1.4 +/- 1.9. No relationship was found between the mean number of abnormally enlarged nonbronchial systemic arteries and the CT angiographic features of chronic pulmonary embolism. CONCLUSION: These results demonstrate the higher frequency of abnormally enlarged bronchial and nonbronchial systemic arteries in patients who have chronic thromboembolic pulmonary hypertension compared with patients who have primary pulmonary hypertension; this finding could help distinguish these two entities on CT angiograms.

Adult↗

PubMed2004

Bronchial and nonbronchial systemic arteries at multi-detector row CT angiography: comparison with conventional angiography.

PURPOSE: To retrospectively evaluate bronchial and nonbronchial systemic arteries at multi-detector row helical computed tomography (CT) compared with conventional angiography in patients undergoing endovascular treatment of hemoptysis. MATERIALS AND METHODS: Neither institutional board approval nor informed consent was required. Forty-eight consecutive patients (39 men, nine women; mean age, 55.7 years; range, 20-82 years) with hemoptysis of bronchial and nonbronchial systemic artery origin underwent multi-detector row helical CT angiography of the thorax with use of a four-detector row (n = 31) or 16-detector row (n = 17) scanner prior to embolization. Findings on CT angiograms, including CT scans, maximum intensity projections, and three-dimensional volume-rendered images, were used to evaluate the depiction of bronchial and nonbronchial systemic arteries. Retrospective analysis of the ostium and the course of bronchial and/or nonbronchial systemic arteries on CT angiograms enabled evaluation of the accuracy of this technique in identification of the relevant vasculature. RESULTS: Among the 46 patients initially treated with bronchial artery embolization, 58 bronchial arteries were identified at CT and/or angiography. In 50 (86%) cases, concordant findings were observed with both modalities. In five (9%) cases, CT could not be used to identify the ostia of bronchial arteries. In three (5%) cases, CT depicted bronchial arteries that could not be selectively catheterized. Three-dimensional images were found to be superior to transverse CT scans in depicting the ectopic origin of the bronchial arteries, which enabled the interventional radiologists to perform successful embolization after direct catherization of the ectopic vessel in every case. In five (11%) patients, the nonbronchial systemic origin of bronchial bleeding was identified on CT angiograms. CONCLUSION: Multi-detector row helical CT angiography provides more precise depiction of bronchial and nonbronchial systemic arteries than does conventional angiography.

Adult↗

PubMed2004

Asbestos-related pleuropulmonary diseases: evaluation with low-dose four-detector row spiral CT.

PURPOSE: To evaluate the depiction of lung and pleural asbestos-related lesions with low-dose four-detector row spiral computed tomography (CT). MATERIALS AND METHODS: Eighty-three male workers with a mean duration of occupational exposure to asbestos of 18 years underwent CT as part of a medicolegal investigation. CT examination included low-dose multi-detector row spiral CT of the entire thorax, with reconstruction of contiguous 5-mm-thick images, and thin-section CT, which served as the reference standard for the detection of pleural and parenchymal asbestos-related abnormalities. Two main groups of abnormalities were identified: (a) pleural plaques and diffuse pleural thickening and (b) thickened interstitial short lines, curvilinear subpleural lines, ground-glass opacity with or without bronchiectasis, and honeycombing. The frequencies of the depiction of these abnormalities on the low-dose multi-detector row images and the thin-section images were compared by using the McNemar test. RESULTS: No significant differences were observed between the low-dose and thin-section CT images in the depiction of either (a) parietal pleural fibrosis consisting of pleural plaques (identified in 67 [81%] vs 65 [78%] workers, P =.157), which appeared mainly as thick, calcified pleural linear structures; or (b) features of parenchymal fibrosis, which consisted of various combinations of intralobular and septal lines (identified in 12 [14%] vs 13 [16%] workers, P =.564), subpleural curvilinear lines (identified in 10 [12%] vs eight [10%] workers, P =.157), and ground-glass opacity with (identified in six [7%] vs six [7%] workers) or without (identified in five [6%] vs three [4%] workers, P =.317) traction bronchiectasis. A honeycombing pattern was depicted on only the thin-section CT images (P <.001). Emphysema (identified in 26 [31%] vs 14 [17%] workers at low-dose and thin-section CT, respectively; P <.001) and noncalcified nodules (identified in 18 [22%] workers vs one [1%] worker, P <.001) were depicted significantly more frequently on the low-dose images than on the thin-section images. CONCLUSION: Low-dose multi-detector row spiral CT accurately depicts asbestos-related disease.

Aged↗

PubMed2003

Mediastinal lymphadenopathy in congestive heart failure: a sequential CT evaluation with clinical and echocardiographic correlations.

The aim of this study was to evaluate the frequency and evolution after treatment of mediastinal lymphadenopathy associated with congestive left heart failure on CT scans in correlation with clinical and echocardiographic findings. Thirty-one consecutive patients with subacute left heart failure underwent a clinical evaluation using the NYHA classification, a CT examination, and transthoracic echocardiography at the time of initial presentation (T1). After initiation of medical treatment (T2), follow-up CT scans were systematically obtained together with a clinical evaluation. At T1, all patients showed severe (type III: n=12, 39%; type IV: n=12, 39%) to moderate (type I, n=1, 3%; type II, n=6, 19%) dyspnea with a mean ejection fraction of 39% (range 22-74%). On initial CT scans, enlarged mediastinal lymph nodes were seen in 13 patients (42%) with blurred contours in 5 patients (16%) and hazy mediastinal fat in 1 patient (3%). Significant decrease in the size of lymphadenopathy was observed between T1 and T2 (T1, n=13, 42% vs T2, n=10, 32%; p<0.05) with a concurrent decrease in the severity of dyspnea (grade III-IV dyspnea at T1, n=24, 78% vs grade I-II dyspnea at T2, n=26, 83.5%). Patients with enlarged lymph nodes at T1 showed: (a) a significantly lower ejection fraction at echocardiography than those without lymphadenopathy (mean+/-SD value: 34+/-12.9 vs 43+/-13.8%; p=0.04); (b) a significantly larger diameter of the right superior pulmonary vein (mean+/-SD value: 17+/-2.75 vs 14+/-3.9 mm; p=0.04); and (c) a higher frequency of abnormal peribronchovascular thickening ( n=5 vs n=1; p=0.06). Mediastinal lymphadenopathy associated with subacute left heart failure was observed in 13 patients (42%), showing regression after initiation of treatment in 8 of 13 patients (62%).

Aged↗

PubMed2003

Multi-detector row spiral CT angiography of the thoracic outlet: dose reduction with anatomically adapted online tube current modulation and preset dose savings.

PURPOSE: To evaluate image quality obtained with anatomically adapted online tube current modulation and preset minimum dose savings at multi-detector row spiral computed tomographic (CT) angiography of the thoracic outlet. MATERIALS AND METHODS: A total of 100 patients were evaluated for thoracic outlet arterial syndrome with spiral CT angiography (collimation, 4 x 1 mm; pitch, 1.75) both with and without dose reduction by means of anatomically adapted online tube current modulation and preset minimum dose savings. Preset minimum savings of 20% and of 32% were applied in two groups of 50 patients (groups 1 and 2). In each group, low-dose scanning was performed in 25 patients in the neutral position and in 25 patients after postural maneuver. Tube current-time product, noise, presence and quality of graininess and of linear streak artifacts on transverse CT scans, and diagnostic value of sagittal reformations and volume-rendered images were evaluated and recorded for each data set. chi2 test was used to compare frequencies; paired Wilcoxon rank test, to compare subjective and objective image quality scores. P <.05 indicated a significant difference. RESULTS: In group 1, mean tube current-time product was 3225 mAs for reference scans and 2101 mAs for low-dose scans (mean reduction, 35%; range, 27%-47%). In group 2, mean was 3070 mAs for reference scans and 2068 mAs for low-dose scans (mean reduction, 33%; range, 17%-38%). In group 1, no differences in frequencies of graininess and linear streaking or in noise level were found between images acquired with or without dose reduction. In group 2, no difference was found in noise level between low-dose and reference scans. On low-dose scans, moderate linear streaking was observed with lower frequency and moderate graininess was observed with higher frequency, but artifacts did not compromise image quality or prevent confident assessment of arterial diameter in the three compartments of the thoracic outlet. CONCLUSION: Online tube current modulation with a preset minimum dose saving of 20% allowed 35% reduction in mean tube current-time product, with no loss in image quality.

Adult↗

PubMed2003

Diagnosis of bronchiectasis with multislice spiral CT: accuracy of 3-mm-thick structured sections.

The aim of this study was to evaluate the accuracy of 3-mm-thick reconstructed sections in the diagnosis of bronchiectasis with multislice CT (MSCT). Forty consecutive patients suspected of bronchiectasis (23 females, 17 males; mean age 51 years) underwent MSCT of the entire thorax with a 4x1-mm collimation (120 kV, 0.5 s/rotation, 80 mAs/slice) and a pitch of 1.75. From each data set (mean z-axis coverage: 257 mm; mean duration: 21 s), two series of images were systematically generated: 1-mm (group 1) and 3-mm (group 2)-thick reconstructed scans. Both series of images were obtained at 10-mm intervals and reconstructed with a high-spatial-frequency algorithm. Two observers independently analyzed the presence of bronchiectasis and associated abnormalities in group-1 and group-2 lung images. No significant difference between group 1 and group 2 was found in: (a) the detection of bronchiectasis, identified in 24 patients (60%) in group 1 and in 23 patients (57.5%) in group 2 ( p=0.08); (b) the evaluation of the extent of bronchiectasis, identifying focal bronchiectasis in 10 patients (25%) in group 1 and 7 patients (17.5%) in group 2 ( p=0.39) and multifocal bronchiectasis in 16 patients (40%) in both groups; (c) the characterisation of bronchiectasis (cylindral bronchiectasis: group 1, n=24, 60%; group 2, n=21, 53%, p=0.08); varicose bronchiectasis: group 1, n=5, 12.5%; group 2, n=6, 15%, p=0.56); and cystic bronchiectasis: group 1, n=2, 5%; group 2, n=2, 5%). Apart from the identification of abnormal bronchial wall thickening (group 2, n=35, 87.5%, vs group 1, n=31, 77.5%, p<0.05), recognition of associated bronchopulmonary anomalies did not differ between the two groups. This study demonstrates a comparable accuracy of the 3- and 1-mm-thick reconstructed scans in the detection and characterization of bronchiectasis. These results suggest the potential usefulness of 3-mm-thick scans generated from 4x2.5-mm acquisitions in the screening of bronchiectasis, which would allow a 20% radiation dose reduction compared with the present investigation.

Adult↗

PubMed2003

Pulmonary embolus imaging with multislice CT.

Multiple data support the concept that single-slice and multislice CT have fundamentally modified the diagnostic approach of patients with suspected PE. Although the definitive role of spiral CT angiography in the diagnostic algorithm has yet to be determined, it is clear that CT angiography has numerous advantages compared with other diagnostic tests. Bearing in mind that an effective diagnostic strategy should be as flexible as possible to be applied in every clinical setting, the role of spiral CT angiography in the diagnostic algorithm has to be considered among several practical parameters, such as the experience of the attending physician, degree of severity of the patient's clinical condition, the availability of diagnostic equipment, and specific logistics.

Chronic Disease↗

PubMed2003

High-resolution computed tomography techniques in diffuse parenchymal lung disease and their application to clinical practice.

The remarkable ability of high-resolution computed tomography (HRCT) to provide sufficient detail of both normal and abnormal pulmonary anatomy requires high-quality examinations with considerable attention paid to the technique. Despite the use of optimal scanning protocols, there are well-known limitations of sequential scanning that explain the recent interest in the use of multislice spiral CT for diagnosing lung diseases in routine clinical practice. A basic knowledge of the most recent developments in spiral CT technology appears a necessary prerequisite for those clinicians, pulmonologists, internists, or thoracic surgeons who are involved in the management of diffuse infiltrative lung diseases. This chapter reviews the various aspects of multislice spiral CT technology applied to routine clinical evaluation of diffuse infiltrative lung diseases.

Journal Article↗

PubMed2002

CT angiography of pulmonary embolism in patients with underlying respiratory disease: impact of multislice CT on image quality and negative predictive value.

Our objective was to evaluate the impact of multislice CT (MSCT) on image quality and diagnostic value of spiral CT angiograms. Over an 8-month period (January 2000 to August 2000), 134 consecutive patients, including 55 patients with underlying lung disease, underwent MSCT (group 1). Image quality and diagnostic results of CT angiograms were compared with those obtained in 125 consecutive patients, including 58 patients with underlying lung disease, evaluated with thin-collimation single slice CT (SSCT; group 2) over a similar period of time (January 1999 to August 1999). A 3-month clinical follow-up was systematically obtained in all patients who were not anticoagulated in the two groups. For a significantly longer mean z-axis coverage, the mean duration of data acquisition was significantly shorter with MSCT. The frequency of examinations devoid of motion artifacts was significantly higher in group 1 than in group 2. In the absence of significant difference in the quality of vascular enhancement, mainly coded as good or excellent, the proportion of examinations interpretable down to the subsegmental arteries was higher in group 1 (57.5%) than in group 2 (13%) ( p<0.0001). The benefits of MSCT were more marked for patients with underlying respiratory disease and did not lead to a higher detection rate of peripheral pulmonary embolism. The negative predictive values of single-slice and multislice CT were 100 and 99%, respectively. Improvement in image quality on MSCT scans accounts for the improved diagnostic accuracy of CT angiography, in particular for patients with impaired respiratory function.

Acute Disease↗