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Biomedical subjects

P Grenier

Publications and source records attributed to P Grenier.

At least 55 records · Page 3Linked to original sources
PubMed1997

Cylindrical bronchiectasis: diagnostic findings on thin-section CT.

OBJECTIVE: The aim of this study was to determine the frequency of diagnostic findings of bronchiectasis on thin-section CT and the usefulness of those findings in distinguishing patients with cylindrical bronchiectasis from healthy subjects. MATERIALS AND METHODS: The study was retrospective and included 26 healthy adults, 10 consecutive patients with surgically proven cylindrical bronchiectasis, and 49 patients who had been prospectively diagnosed at three institutions as having cylindrical bronchiectasis. All patients had 1.0- to 1.5-mm-collimation CT scans obtained at 10-mm intervals through the chest. The CT scans were independently reviewed in random order by two chest radiologists. RESULTS: Findings in patients with bronchiectasis that were not seen by either observer in any of the healthy subjects included visualization of a bronchus within 1 cm of the costal pleura and visualization of a bronchus abutting the mediastinal pleura. The two observers saw these findings on 96 (81%) and 63 (53%) of 118 CT scans in the 59 patients with bronchiectasis, respectively. Lack of tapering of bronchi was seen in five (10%) of 52 reviews in healthy subjects compared with 95% of reviews in patients with bronchiectasis. Bronchoarterial ratios greater than 1 were identified in 11 (21%) of 52 reviews in healthy subjects compared with 95% of reviews in patients with bronchiectasis. We calculated good agreement between the two observers (kappa values equal to or greater than .63). CONCLUSION: In most cases, thin-section CT allows reliable distinction of patients with cylindrical bronchiectasis from healthy subjects.

Adult↗
PubMed1997

[Cystic compression of the suprascapular nerve. Value of imaging. Apropos of 6 cases and review of the literature].

Six cases of suprascapular nerve entrapment by a ganglion cyst within the spinoglenoid notch or developed from the glenoid labrum are reported. Causes of injury or entrapment of the suprascapular nerve are described including traction or kinking of the nerve, trauma, repetitive exercise, or compression by ganglion cyst. The patients had non specific pain, weakness, and atrophy of the spinatus musculature. Electromyography showed evidence of denervation atrophy. Patients had plain radiographs, arthrography, CT-arthrography, magnetic resonance imaging (MRI) and MR-arthrography. Masses that caused suprascapular nerve entrapment were well localized and characterized wit magnetic resonance imaging, reflecting the superior soft-tissue contrast of this modality. In addition, MRI may demonstrate atrophy of the spinatus muscles. MR-arthrography allows to visualize lesions of the glenoid labrum and in some cases, demonstrates cysts filling.

Adult↗
PubMed1996

Abnormalities of the airways and lung parenchyma in asthmatics: CT observations in 50 patients and inter- and intraobserver variability.

The purpose of the study was to evaluate the CT abnormalities of airways and lung parenchyma in asthmatic patients and to assess inter- and intraobserver variability for these abnormalities. The CT scans of 50 asthmatic patients and 10 healthy volunteers were assessed independently by four independent chest radiologists who were masked with respect to the clinical information. Bronchiectasis involving mostly subsegmental and distal bronchi was noted in 28.5% of the asthmatic subjects and none of the non-asthmatics. Bronchial wall thickening, small centrilobular opacities and decreased lung attenuation were observed in 82%, 21% and 31% of asthmatic patients respectively, compared with 7%, 5% and 7% of healthy subjects. The intra- and inter-observer agreements for these four CT abnormalities were measured by the kappa statistic and ranged from 0.60 to 0.79 and from 0.40 to 0.64, respectively. It is concluded that asthmatic patients may exhibit bronchial wall thickening, bronchiectasis and morphological abnormalities suggestive of distal airways disease that can be assessed on CT scans with a clinically acceptable observer variability.

Adult↗
PubMed1996

Pulmonary tuberculosis: comparison of CT findings in HIV-seropositive and HIV-seronegative patients.

PURPOSE: To determine the differences in the computed tomographic (CT) appearance of pulmonary tuberculosis (TB) between patients with and patients without human immunodeficiency virus (HIV) infection. MATERIALS AND METHODS: CT scans and chest radiographs of 42 HIV-seropositive and 42 HIV-seronegative patients with pulmonary TB were reviewed. CD4 T-lymphocyte counts, measured in 40 seropositive patients, were at least 200 cells per microliter in 10 patients and were less that 200 cells per microliter in 30. RESULTS: Seropositive patients had a higher prevalence of lymphadenopathy at chest radiography (P< .05). The seropositive patients had a lower prevalence of consolidation (P< .05), cavitation (P< .01), and postprimary pattern (P< .05) at CT. HIV-seropositive patients had a higher frequency of miliary (P< .01) and extrapulmonary disease (P< .001). Similar features of pulmonary TB were observed in seropositive patients with mild and severe immunosuppression. CONCLUSION: HIV-seropositive patients had a lower prevalence of localized parenchymal disease and a higher prevalence of disseminated disease at CT.

AIDS-Related Opportunistic Infections↗
PubMed1996

Bronchiectasis: comparative assessment with thin-section CT and helical CT.

PURPOSE: To compare thin-section computed tomography (CT) and helical CT in the detection and assessment of the extent of bronchiectasis. MATERIALS AND METHODS: Both thin-section and helical CT scans were obtained in 50 consecutive patients with clinical symptoms suggestive of bronchiectasis. Thin-section CT was performed with 1.5-mm collimation and 10-mm intervals, and helical CT was performed with 3-mm collimation and a pitch of 1.6 during a 24-second breath hold. Three observers evaluated 593 segments on CT scans both independently and in consensus. Radiation dose was measured for both techniques. RESULTS: Bronchiectasis was noted in 77 segments (22 patients) on thin-section CT scans compared with 90 segments (26 patients) on helical CT scans. No findings were positive for bronchiectasis on only thin-section CT scans. Interobserver agreement was statistically significantly better (P < .05) in identification of segments that were positive for bronchiectasis on helical CT scans (kappa = 0.87) than on thin-section CT scans (kappa = 0.71). Total skin dose of radiation delivered with helical CT was 3.4 times greater than that delivered with thin-section CT. CONCLUSION: Helical scanning can improve CT depiction of bronchiectasis but with an increase in radiation exposure to the patient. It should be used in patients considered for surgery or for thin-section CT scans that are difficult to interpret.

Adult↗
PubMed1996

Osteoid osteoma: CT-guided percutaneous excision confirmed with immediate follow-up scintigraphy in 16 outpatients.

PURPOSE: To evaluate treatment of osteoid osteoma with computed tomography (CT)-guided percutaneous excision and immediate follow-up scintigraphy. MATERIALS AND METHODS: Sixteen consecutive adolescent and adult patients underwent CT-guided percutaneous excision of a nidus with 14-gauge biopsy cutting needles, with local anesthesia. After the presence of nidus was confirmed at immediate follow-up scintigraphy, curettage of the bored cavity was performed to remove any residual fragments of the nidus. Scintigraphic and histologic findings were correlated. RESULTS: The nidus was removed successfully in 14 of the 16 patients, with no complications (mean follow-up, 15 months; range, 3-25 months). In five of the 14 patients, immediate follow-up scintigraphy showed incomplete resection of the nidus and immediate second resection was successful. Surgical resection was necessary in two of the 16 patients. CONCLUSION: CT-guided percutaneous excision with immediate follow-up scintigraphy was safe and effective for localization and removal of osteoid osteoma in outpatients.

Adult↗
PubMed1996

[Comparative evaluation of iopamidol 300 versus 370 during spiral x-ray computed tomographic studies of the thorax].

PURPOSE: A retrospective study was performed to assess the role of iodine concentration on the opacification of different vascular compartments of the chest with a nonionic contrast agent (Iopamidol) during routine spiral CT examination. MATERIAL AND METHOD: 105 injected spiral CTs of the chest were studied. 50 examinations were done with Iopamidol 300 (iodine concentration 300 g/L) (I300). 55 examinations were done with Iopamidol 370 (iodine concentration 370 g/L) (I370). A constant 24- g total iodine dose was delivered with no difference in the injected iodine flow rates (respectively 0.6 and 0.55 g/s). Images were scored for opacification success, opacification quality and for artefacts in each vascular, of the chest. RESULTS: There was no statistically significant difference in opacification success or in opacification quality, in each chest vascular compartment between the group receiving I300 and the group receiving I370. Artefact frequencies on the lower part of superior vena cava were however different, 24% and 41.8% respectively. CONCLUSION: For a constant injected iodine flow rate, a moderate increase in iodine concentration, with decreased injection volume and flow rate, had little or no effect on opacification of the aorta and the pulmonary artery. The presence of artefacts on the lower part of the superior vena cava would suggest that the use of lower concentration contrast media would be advisable for specific vena cava examinations.

Adult↗
PubMed1996

Interlobular septal thickening: patterns at high-resolution computed tomography.

Thickening of the interlobular septa is a common and easily recognizable finding at high-resolution computed tomography (HRCT; 1-2 mm collimation high-spatial-frequency reconstruction algorithm). Interlobular septal thickening at HRCT can be smooth, nodular, or irregular in contour. It may be due to fluid, cellular infiltration, or fibrosis. Apparent thickening of septa at HRCT may also be due to abnormalities in the periphery of the secondary pulmonary lobule adjacent to but not involving the interlobular septa. This article illustrates the patterns of interlobular septal thickening at HRCT in various disease entities.

Adult↗
PubMed1995

[Imaging of COPD].

Standard chest radiographs have been shown to be insensitive for the diagnosis of morphologic abnormalities of airways. Computed tomography is the most sensitive and specific investigation to diagnose emphysema. However, as emphysema may be missed on computed tomography, this investigation cannot be used to definitely rule out the diagnosis. Computed tomography may contribute to the investigation of bronchiolitis, and it is now considered as the gold standard for establishing the diagnosis of bronchiectasis. Imaging may contribute to identify complications such as bronchopulmonary infection, pulmonary hypertension, pneumothorax, cancer of the lung, compressive bullae, and pulmonary embolism.

Bronchiolitis↗
PubMed1995

CT assessment of bronchi in sarcoidosis: endoscopic and pathologic correlations.

PURPOSE: To evaluate the computed tomographic (CT) appearance of bronchi in patients with sarcoidosis and to correlate CT, endoscopy, and bronchial biopsy findings. MATERIALS AND METHODS: Sixty patients with sarcoidosis underwent CT and tracheobronchial endoscopy. CT findings of abnormalities of the bronchial walls and lumina were compared with endoscopic and biopsy findings. RESULTS: CT scans showed bronchial abnormalities in 39 patients (65%). CT and endoscopic findings were concordant in only 35 cases. However, CT showed abnormal lumina in 14 patients and endoscopy showed mucosal thickening in 12 of these 14 patients. CT findings of bronchial abnormalities were associated with the presence of bronchial granulomas (P < .0001). CT scans showed that, of the 37 patients with biopsy results of granulomatosis, 84% had thickened bronchial walls and 35% had luminal abnormalities. Eight CT findings were false-positive, and six were false-negative for the presence of granulomas. CONCLUSION: Bronchial involvement in sarcoidosis was detected at CT in 65% of cases. CT can help predict whether bronchial granulomas will be found in cases of sarcoidosis.

Adult↗
PubMed1995

Radiographic abnormalities in tuberculosis and risk of coexisting human immunodeficiency virus infection. Results from Dar-es-Salaam, Tanzania, and scoring system.

First, we evaluated the age profile and chest radiographic abnormalities in 146 patients from Dar-es-Salaam, Tanzania, with new-onset intrathoracic tuberculosis (pulmonary, pleural, or hilar/mediastinal adenopathy), to identify features that were associated with human immunodeficiency virus (HIV) seropositivity or seronegativity; then, we combined these data with those from a companion investigation in Burundi to develop a simple scoring system to predict HIV serologic status. Using agreed-upon criteria and simplified reporting forms, initial chest radiographs were reviewed by three readers, first independently and then at a consensus conference. Of the 146 patients, 80 (55%) were HIV seropositive and 66 were seronegative. More seropositive than seronegative subjects were 31 to 40 yr old (p = 0.03). Because the radiographic characteristics of the two serologic groups were similar in Tanzania and Burundi, we combined the data for stepwise logistic regression that revealed four highly significant variables: age, small lesions, location, and lymphadenopathy. From these, we obtained an equation to calculate the probability that a given tuberculosis patients was HIV seropositive and then we derived a scoring system that in its simplest form (threshold) predicted serologic status correctly in 68.1% of patients; a graded scale was even more accurate in the high (89.1%) and low (82.6%) ranges. This scoring system should be useful when serologic testing is unavailable or refused.

AIDS-Related Opportunistic Infections↗
PubMed1995

Radiographic abnormalities in tuberculosis and risk of coexisting human immunodeficiency virus infection. Methods and preliminary results from Bujumbura, Burundi.

We evaluated the age profile and chest radiographic abnormalities in 158 patients from Bujumbura, Burundi, with new-onset intrathoracic tuberculosis (pulmonary, pleural, or hilar/mediastinal adenopathy), to identify features that were associated with and would allow prediction of HIV seropositivity or seronegativity. Using agreed-upon criteria and prepared reporting forms, initial chest radiographs were reviewed by three readers, first independently and then at a consensus conference. Of the 158 patients, 105 (66%) were HIV seropositive and 53 patients were seronegative. Seropositive subjects (mean age, 35.8 yr) were older (p = 0.001) than seronegative subjects (mean age, 29.4 yr). Significant or borderline differences between HIV-seropositive and -seronegative patients included the frequency of small nodular lesions (p = 0.03), upper lobe cavitation (p = 0.05), and lymphadenopathy (p = 0.12), and the location of parenchymal abnormalities (p = 0.0006). Stepwise logistic regression revealed four important variables: age, small lesions, location, and lymphadenopathy; these were then used to derive an equation to calculate the probability that a given tuberculosis patient was HIV seropositive. Our mathematical model fit the observed data and the equation predicted serologic findings reasonably well. We conclude that it is possible to determine with useful probability a Burundian tuberculosis patient's HIV serologic status.

AIDS-Related Opportunistic Infections↗
PubMed1995

[Normal and pathological MRI aspects of the posterolateral corner of the knee].

The purpose of the study is to compare normal PLC anatomy and its MRI appearance, with the various lesions observed in MRI, from the simple popliteus tendinous contusion to the complete PLC rupture. For this specific work on PLC lesions, we selected 61 examinations among the traumatic knees explored during the last 3 years. Surgical correlation is obtained for the 61 patients. MRI examinations are performed on a 0.5 T. unit with gradient echo T1, T1 and T1 GD-DOTA IV. Normal PLC anatomy is compared to the dissection of 4 anatomic subjects. Normal MRI slices are evaluated with this reference analysis. The principle anatomical structures of the PLC include the lateral collateral ligament, the popliteus tendon, the arcuate ligament, the fabello fibular ligament, the posterolateral condylar capsule, and the posterior horn of the lateral meniscus. Surgical findings confirm PLC lesion for 58 patients with 3 false positive. Diagnosis of these lesions is important because chronical posterolateral laxity is secondary to the destabilisation of lateral condyle. Unrecognised and untreated posterolateral instability may result in failure of ACL reconstruction. When clinical tests are doubtful or complex, or the examination very painful, MRI evaluates completely the traumatic knee and particularly the PLC.

Humans↗