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Biomedical subjects

J A Verschakelen

Publications and source records attributed to J A Verschakelen.

At least 19 recordsLinked to original sources
PubMed2006

Additional value of integrated PET-CT in the detection and characterization of lung metastases: correlation with CT alone and PET alone.

The purpose was evaluating retrospectively the additional value of integrated positron emission tomography (PET) and computed tomography (CT) in the detection of pulmonary metastases in comparison with CT and PET alone. Fifty-six lung nodules, divided into three groups according their size, detected in 24 consecutive patients with a known primary tumor were retrospectively evaluated with integrated PET-CT, CT and PET. The nature of these nodules was determined by either histopathology or a follow-up of at least 6 months. The CT and PET images of the integrated PET-CT were evaluated separately by a radiologist and a nuclear medicine physician, the integrated PET-CT images were evaluated by a chest radiologist and nuclear medicine physician in consensus. The investigators were asked to search lung nodules and to determine whether these nodules were metastases or not. Sensitivity and accuracy for CT, PET and integrated PET-CT for characterization of all pulmonary nodules were, respectively: 100%, 90%, 100% and 57%, 55%, 55%. There was no significant difference in the characterization of pulmonary nodules between integrated PET-CT and CT alone (P=1.000) and PET alone (P=0.1306). An accurate evaluation is only possible for lesions larger than 1 cm.

Adult↗
PubMed2006

Additional value of PET-CT in the staging of lung cancer: comparison with CT alone, PET alone and visual correlation of PET and CT.

Integrated positron emission tomography (PET) and computed tomography (CT) is a new imaging modality offering anatomic and metabolic information. The purpose was to evaluate retrospectively the accuracy of integrated PET-CT in the staging of a suggestive lung lesion, comparing this with the accuracy of CT alone, PET alone and visually correlated PET-CT. Fifty patients undergoing integrated PET-CT for staging of a suggestive lung lesion were studied. Their tumor, node, metastasis (TNM) statuses were determined with CT, PET, visually correlated PET-CT and integrated PET-CT. These TNM stages were compared with the surgical TNM status. Integrated PET-CT was the most accurate imaging technique in the assessment of the TNM status. Integrated PET-CT predicted correctly the T status, N status, M status and TNM status in, respectively, 86%, 80%, 98%, 70% versus 68%, 66%,88%, 46% with CT, 46%, 70%, 96%, 30% with PET and 72%, 68%, 96%, 54% with visually correlated PET-CT. T status and N status were overstaged, respectively, in 8% and 16% with integrated PET-CT, in 20% and 28% with CT, in 16% and 20% with PET, in 12% and 20% with visually correlated PET-CT and understaged in 6% and 4% with integrated PET-CT, versus 12% and 6% with CT, 38% and 10% with PET and 12% with visually correlated PET-CT. Integrated PET-CT improves the staging of lung cancer through a better anatomic localization and characterization of lesions and is superior to CT alone and PET alone. If this technique is not available, visual correlation of PET and CT can be a valuable alternative.

Adult↗
PubMed2005

Virtual bronchoscopy: accuracy and usefulness--an overview.

Multidetector CT generated virtual bronchoscopy (VB) represents one of the most recent developments in three-dimensional (3D) visualization techniques which allows a 3D evaluation of the airways down to the sixth- to seventh-generation. In comparison with real bronchoscopy, VB has some advantages: it is a non-invasive procedure that can visualize areas inaccessible to the flexible bronchoscope. Virtual bronchoscopy is able to evaluate bronchial stenosis and obstruction caused by both endoluminal pathology (tumor, mucus, foreign bodies) and external compression (anatomical structures, tumor, lymph nodes), can be helpful in the preoperative planning of stent placement and can be used to evaluate surgical sutures after lung transplantations, lobectomy or pneumectomy. In children, in some indications, VB can replace fiber optical bronchoscopy (FB) when this technique is considered too invasive. Finally, VB can also be used to evaluate anatomical malformations and bronchial variants. Virtual bronchoscopy is accurate but its accuracy is not 100% because false-positives and false-negatives occur. Virtual bronchoscopy contributes to a better understanding of tracheo-bronchial pathology. Fiber optical bronchoscopy will, without doubt, remain the golden standard but it can be expected that in the near future, the technique of VB will find a place in the daily routine.

Bronchial Diseases↗
PubMed2004

Multidetector CT-generated virtual bronchoscopy: an illustrated review of the potential clinical indications.

Multidetector computed tomography-generated virtual bronchoscopy (VB) is a recent technical development that allows visualisation of the lumen and wall of the trachea and proximal part of the bronchial tree. A dynamic image is produced that resembles what is seen with fibreoptic bronchoscopy (FB). Although the technique has not yet reached daily clinical practice and it can never replace FB, performing VB can be useful in well-defined clinical situations. In this paper, the value and limitations of virtual bronchoscopy will be reviewed, to illustrate the potential role of virtual bronchoscopy in the evaluation of trachea and bronchial tree pathology.

Biopsy↗
PubMed2002

Computed tomography in staging for lung cancer.

Computed tomography (CT) provides the most detailed imaging information, hence it is generally used as a routine imaging procedure in the tumour, node, metastasis (TNM)-staging of patients with lung cancer. However, despite the continuously ongoing process of improvement in CT scanning in which today's CT scanners combine fast acquisition, fast data reconstruction and high detail, the technique has important limitations. CT can, in some cases, very accurately show tumour extent within, and predict spread beyond the lung. However, the question of whether the tumour has invaded the chest wall or the mediastinum and, if so, whether it is still potentially surgically curable often remains unanswered. In addition, the only sign for predicting lymph node involvement using CT is enlargement. Many studies have shown that this sign is not very reliable. CT is also, with success, being used to evaluate distant metastases although other techniques such as ultrasound and magnetic resonance imaging can have similar or higher accuracies. Despite these well-known limitations, computed tomography will most likely stay the routine imaging procedure for determining resectability and for assessing intra- and extrathoracic spread of lung cancer. The improvement in technology will probably result a better T-staging. The role of computed tomography in nodal staging remains important. It offers the surgeon a road map of the lymph nodes and guides towards the nodes that need biopsy. Combining computed tomography with positron emission tomography, when it becomes more widely available, will add functional images to the detail of computed tomography and will not only improve nodal staging but will probably also allow a better evaluation of distant metastasis and reduce the number of unnecessary interventional procedures.

Humans↗
PubMed2001

Surface of localized pleural plaques quantitated by computed tomography scanning: no relation with cumulative asbestos exposure and no effect on lung function.

To evaluate if there is a relation between the size of asbestos plaques and the level of past exposure and pulmonary function, we measured the surface of localized pleural plaques found on high-resolution (HR) CT scan, using a computerized video display unit-imaging system, in 73 workers (mean age, 43.5 yr) who had worked from 23 to 27 yr in an asbestos-cement factory. Their estimated cumulative exposure to asbestos ranged from 16.4 to 98.7 fiber-years/ ml (mean, 26.3 fiber-years/ml). Lung function measurements included lung volumes, maximal expiratory flows, and diffusing capacity. A control group of 21 workers was examined by the same procedures. Plaques were detected by CT in 51 (70%) asbestos-exposed subjects and in none of the control subjects. The average calculated plaque surface was 47.9 +/- 61.7 cm2 (median, 22.1 cm2; range, 0 to 278.4 cm2). There was no relation between plaque surface and cumulative asbestos exposure (p = 0.24). In the 51 subjects with pleural plaques, the surface of the pleural lesions was not related to cumulative asbestos exposure, or to smoking history or time since first exposure. Neither the presence nor the extent of the plaques was correlated with lung function parameters.

Asbestosis↗
PubMed2001

Observer variation in computed tomography of pleural lesions in subjects exposed to indoor asbestos.

To assess the reliability of computed tomography (CT) in detecting discrete pleural lesions, the interobserver and intra-observer variability in reading the conventional and high-resolution CT (HRCT) scans of 100 volunteers, who had worked for > or = 10 yrs in a building with known asbestos contamination, was evaluated. In the first session, pleural abnormalities were detected by a single radiologist (A1) in 13 subjects. In the second session, the scans were read again independently by the same radiologist (A2) and two other experienced radiologists (B, C). The final decision for the presence of pleural lesions was made in a final consensus reading. This gave a diagnosis of pleural abnormalities in 18 subjects, of whom eight (44%) had been detected by all three readers, five (28%) by two readers and four (22%) by only one reader; one scan, rated normal by all readers during the second session, was reconsidered because pleural abnormalities had been noted at the first reading (A1). The intra-observer agreement for reader A was good (kappa (kappa) 0.68) but the interobserver agreement between the readers was only fair to moderate (weighted kappa: A2-B=0.43, A2-C = 0.45, B-C = 0.26) in the second reading session. In conclusion, when looking for the prevalence of pleural lesions in indoor asbestos exposed subjects, the potential lack of consistency in reporting the presence of small pleural abnormalities must be borne in mind and strict precautions must be taken.

Adult↗
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

Mediastinal lymph node staging with FDG-PET scan in patients with potentially operable non-small cell lung cancer: a prospective analysis of 50 cases. Leuven Lung Cancer Group.

STUDY OBJECTIVE: To compare the performance of CT, radio-labeled 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) blinded to CT, and FDG-PET visually correlated with CT, in the detection of N2 metastatic mediastinal lymph nodes (MLN) in patients with non-small cell lung cancer (NSCLC) and to hypothesize how PET could influence our actual mediastinal staging procedures. SETTING: Tertiary university hospital. PATIENTS AND METHODS: In 50 patients with potentially operable NSCLC, thoracic CT, PET, and invasive surgical staging were performed. Blinded prospective interpretation was performed for each test and compared with surgical pathology results. Abnormalities on each of these staging examinations were recorded on a standard MLN map. RESULTS: The sensitivity, specificity, and accuracy in detecting N2 disease of CT was 67%, 59%, and 64%, respectively. Results of PET blinded to CT were significantly better (p=0.004): 67%, 97%, and 88%, respectively. For PET visually correlated with CT, this was 93%, 97%, and 96%, respectively. In 22 patients, both CT and PET were normal, and this was correct in all cases. CONCLUSIONS: PET was significantly more accurate than CT in the MLN staging in NSCLC. Both examinations were complementary, since visual correlation with the anatomic information on CT improved the reader's ability to discriminate between hilar vs subaortic MLN FDG uptake, and between paramediastinal tumor vs tracheobronchial MLN FDG uptake. If the results can be confirmed in larger numbers of patients, PET could reduce the need for invasive surgical staging remarkably.

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↗
PubMed1995

Left ventricular quantification with breath-hold MR imaging: comparison with echocardiography.

To evaluate the reproducibility of measurements of left ventricular (LV) dimensions, function, and myocardial mass, segmented k-space gradient-recalled-echo (GRE) magnetic resonance (MR) imaging was performed on two occasions on 12 healthy volunteers. To compare the MR data, all volunteers underwent a two-dimensional echocardiography with determination of LV dimensions and function. The left ventricle was imaged during breath-hold by consecutive, contiguous short-axis views at end-diastole and end-systole. An average of eight short-axis views was needed to encompass the whole left ventricle. This fast MR sequence limited the total acquisition time to 12 min. LV volumes and masses were calculated after manual delineation of epicardial and endocardial surfaces by two observers in a blinded fashion. Interstudy variability varied between 4.1% and 10.3% for LV end-diastolic volume and end-systolic volume, respectively. Differences in interobserver variability were smaller and varied between 3.6% and 7.3% for LV ejection fraction and end-diastolic volume, respectively. Intraobserver variabilities ranged between 2.0% and 7.0% for LV ejection fraction and end-systolic volume, respectively. These variability percentages agree very well with other studies in literature using other MR sequences. No significant differences in LV dimensions or function were found between MR imaging and echocardiography. In conclusion, this MR sequence allows fast and reproducible LV quantification.

Adult↗
PubMed1995

Normal thoracoabdominal motions. Influence of sex, age, posture, and breath size.

The purpose of this study was to assess normal values of thoracoabdominal motions (TAM) during spontaneous breathing and vital capacity (VC) maneuvers in relation to sex, age, and body position. For this, 120 healthy subjects from 10 to > 60 yr old were studied using the respiratory inductive plethysmograph (Respitrace). The volume-motion coefficients obtained during quiet breathing for the rib cage (RC) were almost twice those for the abdomen (ABD) and were not influenced by sex or age and also not by posture, except for the increased ABD coefficients in the supine posture (p < 0.05). Under most conditions RC motion predominated over ABD motion, except quiet breathing in the supine position. Sex-related differences in TAM were not found during quiet breathing, yet during VC maneuvers the women were slightly more RC breathing (p < 0.01). Age-related differences were also only significant during VC maneuvers: men of more than 50 yr old especially became less RC breathing. Posture had a very significant effect (p < 0.001) during quiet breathing as well as during VC maneuvers: the RC predominance was greatest in the standing posture and least in the supine posture. During VC maneuvers the subjects became more RC breathers than during quiet breathing (p < 0.001). The X-Y coordinates of RC motion (on the Y axis) versus ABD motion (on the X axis) showed under all conditions a counterclockwise looping during the breathing cycle: the looping was elliptic during quiet breathing but was more irregular and variable during VC maneuvers, and this also depended on body position.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1995

Imaging of laryngeal and tracheal stenosis.

Most laryngeal and tracheal disorders will sooner or later narrow the airway lumen to some degree. Often a presumptive diagnosis may be considered from an evaluation of the history and symptoms. A final diagnosis is often possible by visual inspection through laryngoscopy and tracheo-bronchoscopy, but in the case of submucosal or extrinsic pathology only narrowing of the airway is detected; radiography can be of great value in coming to a definitive diagnosis. After a brief discussion of the normal anatomy of the larynx and cervical trachea, this manuscript reviews the imaging features of several pathological entities causing stenosis of these structures, without being exhaustive. Many radiological procedures of varying complexity have been devised to study these organs; emphasis will be placed on computer tomography (CT) and to a lesser extent on magnetic resonance imaging (MRI), as these imaging modalities usually provide most information.

Adolescent↗
PubMed1995

Computed tomography, magnetic resonance imaging, and digital radiography.

There are three milestones in the history of thoracic radiology. Thoracic radiology started in 1897 when Williams developed thoracic fluoroscopy and introduced the basic concepts of roentgenologic interpretation. At the same time, the first chest films were performed allowing decisive improvement in the diagnosis of many chest diseases. Continuous technical improvement is responsible for the fact that, even today, the conventional chest film remains a highly accurate and frequently used imaging modality. A third milestone was the development of digital radiography and its use in the chest. Computerised tomography changed thoracic imaging dramatically; in a first step mainly as a tool to visualise soft tissue abnormalities and, later on, also as a modality to study lung disease. The recent development of the digital chest radiograph has again added new perspectives to the approach and diagnosis of chest disease.

Belgium↗