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Biomedical subjects

J Bogaert

Publications and source records attributed to J Bogaert.

At least 37 records · Page 2Linked to original sources
PubMed2000

Remote myocardial dysfunction after acute anterior myocardial infarction: impact of left ventricular shape on regional function: a magnetic resonance myocardial tagging study.

OBJECTIVES: We sought to evaluate regional morphology and function in patients in their first week after having a reperfused anterior myocardial infarction (MI) using magnetic resonance (MR) myocardial tagging. BACKGROUND: The mechanism of myocardial dysfunction in the remote, noninfarct-related regions is an unresolved issue to date. METHODS: Sixteen patients with a first reperfused transmural anterior MI were studied with MR tagging at 5 +/- 2 days after the event, and the results were compared with those of an age-matched control group regions. The left ventricle (LV) was divided into infarct, adjacent and remote regions. Magnetic resonance tagging provided information on the regional ventricular morphology and function. RESULTS: Morphologically, an increase of the circumferential radius of curvature was found in the remote myocardium, whereas the longitudinal radius of curvature was increased in all regions of the LV. A significant increase in apical sphericity was also found. A significant reduction in strain and function was found not only in the infarct region, but also in the adjacent and remote myocardium. The loss in regional ejection fraction in the remote myocardium (61.4 +/- 11.7% in patients vs. 68.7 +/- 10.0% in control subjects, p < 0.0001) was related to a significant reduction of the longitudinal and circumferential strain, whereas systolic wall thickening was preserved. CONCLUSIONS: Remote myocardial dysfunction contributes significantly to the loss in global ventricular function. This could be secondary to morphologic changes in the infarct region, leading to an increased systolic longitudinal wall stress without loss of intrinsic contractility in the remote regions.

Adult↗
PubMed2000

Positron emission tomography scan in the diagnosis and follow-up of aortitis of the thoracic aorta.

We report a case of a 62-year-old female patient with an inflammatory reaction of the thoracic aortic wall. The diagnosis was made by computed tomographic (CT) scan, magnetic resonance imaging (MRI) and positron emission tomographic scan with 18-fluorodeoxyglucose (FDG-PET). The patient was treated with corticosteroids. The inflammatory parameters as well as FDG-uptake on PET scan returned to normal. Due to its aspecific presentation, the diagnosis of aortitis is often hard to establish. With this case the possible role of FDG-PET scan as a valuable tool in the diagnosis and monitoring of this inflammatory aortic disorder was demonstrated.

Aorta, Thoracic↗
PubMed2000

A case report of a patient with a large aneurysmatic coronary artery fistula.

A coronary artery fistula is a rare congenital malformation, which can become symptomatic in adulthood. This report describes a 65-year-old patient with a large aneurysmatic fistula who presented with signs of heart failure. Angiographically a large aneurysmatic fistula was found running from the left coronary artery to the junction of the superior vena cava and the right atrium.

Aged↗
PubMed2000

Radiology of lung trauma.

Trauma caused by motor vehicle accidents is the leading cause of death among people under the age of 40 years. Pulmonary injuries can be caused by direct trauma to the lungs or can be related to indirect effects of the trauma. The most important pulmonary injuries include lung contusion, pulmonary laceration, aspiration, lung atelectasis, and ARDS. Injuries caused by direct trauma may be visible either at the side of trauma or on the opposite side: the contre-coup effect. Conventional chest film is the most important imaging technique for initial evaluation and follow-up of patients with trauma to the lungs. However, CT is more sensitive and specific to detect and identify pulmonary lesions.

Accidents, Traffic↗
PubMed1999

Noninvasive measurements of infarct size after thrombolysis with a necrosis-avid MRI contrast agent.

BACKGROUND: Gadophrin-2 is a new MRI contrast agent with high affinity for necrotic myocardium. The aim of the study was to evaluate whether noninvasive measurements of infarct size after thrombolysis are possible with gadophrin-2-enhanced MRI. METHODS AND RESULTS: Coronary artery thrombosis was induced in 3 groups of dogs by the copper-coil technique. Thrombolytic therapy together with aspirin and heparin was initiated after 90 minutes of occlusion. One day (group A), 2 days (group B), or 6 days (group C) after infarction, gadophrin-2 was injected intravenously (50 micromol. kg-1). In vivo T1-weighted segmented turbo-FLASH, in vivo T2-weighted segmented half-Fourier turbo spin echo (HASTE), and T1- and T2-weighted spin-echo MRI of the excised heart were performed 24 hours after gadophrin-2 injection. Regions of strong enhancement were observed on T1-weighted images. Planimetry of short-axis MR images and of corresponding triphenyltetrazolium chloride (TTC)-stained left ventricular (LV) slices showed a close correlation between the enhanced areas and TTC-negative areas for both in vivo (r2=0.98, P<0.0001; mean difference, 0.9+/-2.0% [SD] of the LV volume [LVV]) and postmortem (r2=0.99, P<0.0001; mean difference, 0.9+/-1.4% of LVV) measurements. T2-weighted images overestimated the infarct size by 8.1+/-5.4% of LVV. The mean infarct size was 10.8+/-11.6% of LVV (group A), 22.4+/-11.7% (group B), and 5.1+/-9.3% (group C). CONCLUSIONS: In this animal model, in vivo gadophrin-2-enhanced MRI could precisely determine infarct size after thrombolytic therapy. This technique may be very useful for the noninvasive evaluation of infarct size after reperfusion for AMI.

Animals↗
PubMed1999

Time-resolved MR angiography of the upper abdomen: initial clinical experience.

In this study, thirty-eight patients with a variety of upper abdominal diseases were examined with three-dimensional time-resolved MR angiography (7 sec/data set). Visualisation of arterial and venous anatomy was excellent in the majority of patients. Moreover, subtraction images could be calculated and organ perfusion could be assessed. It is concluded that this technique opens new perspectives for a comprehensive evaluation of vascular and parenchymal disease.

Abdomen↗
PubMed1999

Three-dimensional MR angiography in the evaluation of thoracic outlet syndrome.

OBJECTIVE: The objective is to present our initial experience with the combination of three-dimensional time-resolved contrast-enhanced MR angiography and T1-weighted spin-echo imaging for investigation of vascular compression related to thoracic outlet syndrome. CONCLUSION: In patients with clinical signs of thoracic outlet syndrome suggesting vascular elongation or compression, this technique proves to be robust, and its results are comparable to those of conventional catheter angiography. Our results allow precise identification of the anatomic structure(s) responsible for the clinical symptoms and show the effect of arm hyperabduction on the patency of the subclavian vessels.

Adult↗
PubMed1999

Role of radiology in lung transplantation.

Lung transplantation has been used successfully since 1983 as treatment for terminal stages of chronic progressive lung disease of various origin. Based on the primary pathology, a single lung transplant, a double lung transplant or a heart-lung transplant is performed. The importance of radiology in detecting postoperative complications is well known. This article gives a short overview of the most common complications after lung transplantation with special attention to the specific radiological features and most suited examination techniques. We preferred grouping the complications in function of the affected structure. Postoperative standard radiography of the thorax is performed daily during admission (first recumbent, later standing) and regularly after release from the hospital. Computerised tomography and high-resolution CT of the chest are performed on specific indications. Other less frequently used radiological techniques are transoesophageal ultrasound, pulmonary artery angiography and fluoroscopy.

Anastomosis, Surgical↗
PubMed1998

Non-invasive imaging of the great vessels of the chest.

Several excellent imaging modalities are available for studying the great vessels of the chest noninvasively. Besides computed tomography (CT), magnetic resonance imaging (MRI) and echocardiography (in particular the transesophageal approach) can accurately depict abnormalities of the thoracic vasculature, and are a valuable substitute for contrast angiography in most circumstances. The aim of this paper is to provide a comprehensive review of the current contribution of CT and MRI to the diagnosis of great vessel pathology of the chest.

Aorta, Thoracic↗
PubMed1998

Expiratory CT in cigarette smokers: correlation between areas of decreased lung attenuation, pulmonary function tests and smoking history.

The aim of this study was to determine the correlation between cigarette-smoke-related bronchial disease and air trapping as assessed by expiratory high-resolution CT (HRCT) scans. Thirty healthy subjects (11 non-smokers, 7 ex-smokers for > 2 years, 12 current smokers; age range 35-55 years) with a smoking history between 0 and 28.5 pack-years underwent pulmonary function tests (PFT) and HRCT in inspiration and expiration in supine and prone position. The extent of air trapping was scored in ventral and dorsal aspects of the upper, middle and lower lung portions. In 24 subjects (7 non-smokers, 7 ex-smokers, 10 current smokers) areas of focal air trapping were found, and were present significantly more often in dependent lung portions (p < 0.05) compared with non-dependent portions. No significant differences were found between apical and basal lung zones. Scores of focal air trapping were not significantly different between smokers and ex-smokers, but were significantly lower (p < 0.05) in non-smokers and showed a significant (p < 0.0005) correlation with pack-years. The degree of air trapping was also associated with several lung function tests, especially RV, DLCO, FRC, FEV1 and FEV1/VC. Air trapping is seen in smokers with normal PFT and correlates with the severity of the smoking history, independently of current smoking status.

Adult↗
PubMed1998

Lymph node staging in non-small-cell lung cancer with FDG-PET scan: a prospective study on 690 lymph node stations from 68 patients.

PURPOSE: To compare the accuracy of computed tomography-(CT) scan and the radiolabeled glucose analog 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) visually correlated with CT (PET + CT) in the locoregional lymph node (LN) staging of non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Sixty-eight patients with potentially operable NSCLC underwent thoracic CT, PET, and invasive surgical staging (ISS). Imaging studies were read prospectively and blinded to the surgical and pathologic data. A five-point visual scale was used for the interpretation of LNs on PET. Afterwards, with knowledge of the pathology, the relationship between standardized uptake values (SUVs) and the presence of metastasis in LNs was explored in a receiver operating characteristic (ROC) analysis, and the likelihood ratios (LRs) for SUVs of LNs were determined. RESULTS: ISS was available for 690 LN stations. CT correctly identified the nodal stage in 40 of 68 patients (59%), with understaging in 12 patients and overstaging in 16 patients. PET + CT was accurate in 59 patients (87%), with understaging in five patients and overstaging in four patients. In the detection of locally advanced disease (N2/N3), the sensitivity, specificity, and accuracy of CT were 75%, 63%, and 68%, respectively. For PET + CT, this was 93%, 95%, and 94% (P = .0004). In the ROC curve, the best SUV threshold to distinguish benign from malignant LNs was 4.40. The analysis with this SUV threshold was not superior to the use of a five-point visual scale. The LR of a SUV less than 3.5 in an LN was 0.152; for a SUV between 3.5 and 4.5, it was 3.157; and for a SUV greater than 4.5, it was 253.096. CONCLUSION: PET + CT is significantly more accurate than CT alone in LN staging of NSCLC. A five-point visual scale is as accurate as the use of an SUV threshold for LNs in the distinction between benign and malignant nodes. The very high negative predictive value of mediastinal PET could reduce the need for mediastinal ISS in NSCLC substantially.

Adult↗
PubMed1997

Follow-up of aortic dissection: contribution of MR angiography for evaluation of the abdominal aorta and its branches.

Spin-echo MR is an established method to evaluate thoracic aortic dissections, but is not well suited to study the abdominal aorta. In this study we evaluated whether MR angiography could provide a complete examination of the abdominal aorta. In 28 patients (40 MR studies) with suspected (n = 6) or known (n = 34) aortic dissection, MR studies were performed. Thoracic aorta was evaluated with spin-echo and gradient-recalled-echo MR imaging. Axial two-dimensional time-of-flight MR angiography with thin overlapping slices was used to study the abdominal aorta. Intermediate and high signal intensity on MR angiography was interpreted as patent flow, and low signal was interpreted as thrombus. The presence of an intima flap and the re-entry site could be depicted in all MR studies. Thrombus in the false channel was seen in 8 studies. The origin of the abdominal visceral branches and their relation to the false-true channel could be depicted, except in 4 of 80 renal arteries studied. Extension of the dissection into the coeliac trunk was seen in 2 and in the superior mesenteric artery in 10 studies. Dilatation of the suprarenal abdominal aorta was seen in 20 studies, and of the infrarenal aorta in 9 studies. MR angiography provides valuable information about the abdominal aorta and its branches in patients with aortic dissection. This makes MR imaging appealing as the preferred imaging modality for the diagnosis and follow-up of aortic dissection.

Aortic Dissection↗
PubMed1997

Localization and determination of infarct size by Gd-Mesoporphyrin enhanced MRI in dogs.

BACKGROUND: Accurate localization and sizing of a myocardial infarction are necessary for clinical decision making and even more in research. Gd-Mesoporphyrin enhanced magnetic resonance imaging (MRI) was recently shown to specifically delineate necrosis in liver tumors, renal and muscle necrosis and myocardial infarction in rats. In this study, we investigated this technique's potential to accurately delineate myocardial infarction in a larger animal species, the dog. METHODS: Myocardial infarction was induced in 8 dogs by ligation of the left anterior descending coronary artery, 4 of which were reperfused after 3 hr Gd-Mesoporphyrin (0.05 mmol/kg) was injected intravenously 210 min after the onset of ischemia (n = 6) or after 24 hr in 2 dogs with non-reperfused infarctions. MRI was performed 10 hr after administration of Gd-Mesoporphyrin. In vivo MRI consisted of EKG-triggered, respiratory gated T1-weighted spin echo and segmented turboFLASH long and short axis measurements. Post-mortem, a spin echo short axis measurement was repeated. Infarct size was determined planimetrically by TTC staining of left ventricular slices. RESULTS: In all instances, there was a very close qualitative agreement between the MRI and TTC defined myocardial infarction. Quantitatively, the linear regression from post-mortem MRI to TTC determined infarct size yielded a result very close to the line of identity (regression coefficient: 0.980 +/- 0.026, p < 0.000001, adjusted R2 = 0.964). CONCLUSION: We conclude that Gd-Mesoporphyrin enhanced MRI is a promising tool for the accurate delineation of myocardial infarction.

Animals↗
PubMed1997

Left ventricular myocardial tagging.

Nuclear Magnetic Resonance myocardial tagging is a potent non-invasive technique which enables the quantification of myocardial deformation, globally but also regionally at different time points during the cardiac cycle. By the use of presaturating pulses prior to the actual imaging sequence non-invasive markers or tags can be placed on the myocardium at end diastole, which move and deform with the underlying myocardium on which they were inscribed. Through combination of perpendicular sets of short- and long-axis images with tags, a three-dimensionally reconstructed left ventricle is obtained, subdivided in 32 myocardial cuboids for which the 3D coordinates of the corners are known at different time points in the cardiac cycle. From these data global and regional strains and quantitative measures of shape can be computed.

Adult↗
PubMed1996

Esophageal tuberculosis mimicking malignancy.

A case of pulmonary and esophageal tuberculosis in an 82-year-old female is presented. Esophageal tuberculosis is very rarely seen in Europe and the United States, but the disease is still endemic in India. The major differential diagnosis is esophageal malignancy. Findings that can suggest the diagnosis are tracheo-esophageal fistula formation, enlarged, centrally necrotizing lymph nodes, and a micronodular lung pattern.

Aged↗