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Philippe A Grenier

Publications and source records attributed to Philippe A Grenier.

14 recordsLinked to original sources
PubMed2006

Management of an incidentally discovered pulmonary nodule.

The incidental finding of a pulmonary nodule on computed tomography (CT) is becoming an increasingly frequent event. The discovery of such a nodule should evoke the possibility of a small bronchogenic carcinoma, for which excision is indicated without delay. However, invasive diagnostic procedures should be avoided in the case of a benign lesion. The objectives of this review article are: (1) to analyze the CT criteria defining benign nodules, nodules of high suspicion of malignancy and indeterminate nodules, (2) to analyze the diagnostic performances and limitations of complementary investigations requested to characterize indeterminate lung nodules, (3) to review the criteria permitting to assess the probability of malignancy of indeterminate nodules and (4) to report on the new guidelines provided by the Fleischner Society for the management of small indeterminate pulmonary nodules, according to their prior probability of malignancy.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2006

Fusion of the midplane with the left intersectional plane: a liver anatomical variation revisited with multidetector-row CT.

This article updates the description of an anatomical variation of the liver, in which the gallbladder is adjacent to the ligamentum teres, that was described until now as "right-sided ligamentum teres and right umbilical portion of the portal vein". A study of eight patients showing this anatomical variation has led to a new archetypal anatomical description of the hepatic and portal veins, using multidetector-row computed tomography (MDCT) with three-dimensional (3D) volume-rendering (VR) reconstructions. While 2D axial imaging gave the same information, MDCT imaging with VR reconstructions provided a clear 3D visualization of this anatomical variation. Typical features can be described as follows: (1) juxtaposition of the ligamentum teres and the gallbladder; (2) typical portal vein branching with a right posterior branch, a left posterior branch and a main medial branch that terminates in the ligamentum teres; (3) two main hepatic veins and a hypotrophied medial hepatic vein. We think, based on the direct comparison of anatomical findings and knowledge of chronological embryological development, that this abnormality results from the defective development of the central part of the liver and not from the persistence of the right rather than the left umbilical vein. Because of the presence of only one medial plane, containing both the gallbladder and the ligamentum teres, we propose renaming it "fusion of hepatic planes".

Adult↗
PubMed2006

Variability in the efficacy of interferon-alpha in Erdheim-Chester disease by patient and site of involvement: results in eight patients.

OBJECTIVE: Erdheim-Chester disease (ECD) is a rare, non-Langerhans form of histiocytosis of unknown origin, characterized by infiltration of tissues by spumous histiocytes. ECD features heterogeneous systemic manifestations, and the general prognosis remains poor despite various treatment options. METHODS: We treated 8 patients with multisystemic ECD with subcutaneous interferon-alpha (IFNalpha) at a dosage of 3-9 x 10(6) units 3 times weekly, for a median duration of 23 months (range 1-46 months). RESULTS: Treatment was generally well tolerated, and side effects remained limited to fever following injections. Treatment was discontinued in 1 patient, because of severe depression. During treatment, some manifestations of ECD disappeared (i.e., xanthelasma, exophthalmos, papilledema, and intracranial hypertension). The efficacy of IFNalpha on cardiovascular ECD was variable, however. Treatment resulted in partial regression of "coated aorta" in some cases and clear failure in others; 2 patients died. The level of C-reactive protein diminished sharply in 5 patients. CONCLUSION: IFNalpha might be a valuable first-line therapy for prolonged treatment of ECD. However, the efficacy of IFNalpha varies among patients and according to the sites of disease involvement, and symptoms may fail to respond to treatment, especially in patients with severe multisystemic forms of ECD with central nervous system and cardiovascular involvement.

Adolescent↗
PubMed2005

Bone involvement in Erdheim-Chester disease: imaging findings including periostitis and partial epiphyseal involvement.

PURPOSE: To retrospectively review the bone findings at radiography, scintigraphy, computed tomography (CT), and magnetic resonance (MR) imaging in 11 patients with immunohistochemical and histologic proof of Erdheim-Chester disease. MATERIALS AND METHODS: This study was designed as a retrospective review; approval of the institutional review board and patient consent were not required for this type of study. Eleven patients (eight men and three women; mean age, 49 years; range, 17-68 years) with Erdheim-Chester disease underwent conventional radiography of the skeleton and bone scintigraphy. Two patients underwent CT of the femora and 10 underwent CT of the skull. Eight patients underwent MR imaging. Conventional radiographs, bone scintigrams, CT scans, and MR images were reviewed in consensus by four musculoskeletal radiologists. RESULTS: All 11 patients had involvement of the long bones and normal axial skeleton, hands, and feet. Bilateral and symmetric osteosclerosis of the diaphysis of the long bones was present in 52 (26 pairs) (98%) of the 53 bone lesions visible on conventional radiographs. Osteosclerosis was heterogeneous in 65% of the patients and homogeneous in 35%. Diaphysis was involved in 100% and metaphysis in 44 (83%) lesions. Partial epiphyseal involvement sparing the subchondral bone was present in 24 (45%) lesions. Periostitis was seen in 35 (66%) and endosteitis in 50 (94%) of the 53 long bones involved. Bone scintigraphy depicted tracer uptake in all bone lesions visible on radiographs. Skull and face bone lesions were present in two patients. MR imaging depicted a replacement of the normal fatty bone marrow by heterogeneous signal intensity on T1- and T2-weighted spin-echo images. Lesion extent, epiphyseal involvement, and periostitis were clearly depicted at MR imaging. CONCLUSION: This series provides a detailed description of bone involvement in Erdheim-Chester disease. Periostitis and partial epiphyseal involvement of the long bones are also features of this disease. (c) RSNA, 2005.

Adolescent↗
PubMed2005

Detection of altered lung physiology.

CT scanners provide an accurate high resolution assessment of airway- and lung diseases. New post processing techniques contribute to quantitative assessment of lung volumes, airway dimensions and extent of lung disease. The ability to seperate airway predominant from parenchymal--predominant pathology in COPD may in the future prove usefull in applying specific therapies and monitoring them.

Humans↗
PubMed2005

Idiopathic interstitial pneumonias: CT features.

Idiopathic interstitial pneumonias comprise usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP), desquamative interstitial pneumonia (DIP), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), cryptogenic organizing pneumonia (COP), acute interstitial pneumonia (AIP), and lymphoid interstitial pneumonia (LIP). Each of these entities has a typical imaging and histologic pattern, although in practice the imaging patterns may be variable. Each entity may be idiopathic or may be secondary to a recognizable cause such as collagen vascular disease or inhalational exposure. The diagnosis of idiopathic interstitial pneumonia is made by means of correlation of clinical, imaging, and pathologic features. The characteristic computed tomographic (CT) features of UIP are predominantly basal and peripheral reticular pattern with honeycombing and traction bronchiectasis. NSIP is characterized by predominantly basal ground-glass opacity and/or reticular pattern, often with traction bronchiectasis. DIP and RB-ILD are smoking-related lung diseases characterized by ground-glass opacity and centrilobular nodules. COP is characterized by patchy peripheral or peribronchovascular consolidation. AIP manifests as diffuse lung consolidation and ground-glass opacity. LIP is associated with a CT pattern of ground-glass opacity sometimes associated with perivascular cysts.

Biopsy↗
PubMed2002

Non-invasive detection of liver fibrosis: Is superparamagnetic iron oxide particle-enhanced MR imaging a contributive technique?

The purpose of our study was to evaluate the ability of superparamagnetic iron oxide (SPIO)-enhanced MR imaging to detect liver fibrosis in patients with chronic liver disease and to compare the findings with histopathological data. Sixty-seven patients with chronic hepatitis ( n=58) or focal nodular hyperplasia (FNH; n=9) were studied using a 1.5-T MR system. The protocol included proton density-weighted, T2-weighted spin-echo (SE) and fast SE (FSE) sequences before and after SPIO administration and T2*-weighted gradient-recalled-echo (GRE) sequences after SPIO. Pre- and post-contrast T2-weighted and T2*-weighted sequences were retrospectively evaluated by three independent observers for evidence of non-tumor hypersignal intensities. Three liver patterns were considered: thick reticulations; thin reticulations; and/or multiple areas of hypersignal intensities. Unenhanced or enhanced patterns were compared with histopathological specimens, which had been obtained by percutaneous biopsy of the right lobe within a maximum of 12 months of MR examination. Liver fibrosis was histologically graded using a five-level scale (F0-F4), according to the METAVIR classification. Histopathology demonstrated significant fibrosis (F2-F4) in 57 patients, non-significant fibrosis in 1 patient (F1), and normal liver surrounding FNH in 9 patients (F0). After SPIO administration, at least one pattern of non-tumor hypersignal intensities was seen in 43 (76%) of the 57 patients with F>/=2 with good agreement (kappa=0.68) compared with 2 (20%) of the 10 F0/1 patients ( p<0.01). Attenuated non-homogeneous liver-signal intensities with persistent thick reticulations, thin reticulations, or multiple areas of hypersignals were observed in, respectively, 30, 52, and 56% of patients with F>/=2 with moderate agreement (kappa=0.51). Before SPIO, MR images were positive in 21 of 57 (37%) F>/=2 and zero F0/1 patients. Post-contrast proton-density-weighted and T2*-weighted GRE were the most sensitive sequences for detecting non-tumor hypersignal intensities. In patients with chronic liver diseases, SPIO-enhanced MR imaging exhibits non-tumor hypersignal intensities indicative of liver fibrosis by decreasing the signal from the non-fibrotic areas where Kupffer cells are present.

Adult↗
PubMed2002

New frontiers in CT imaging of airway disease.

Combining helical volumetric CT acquisition and thin-slice thickness during breath hold provides an accurate assessment of both focal and diffuse airway diseases. With multiple detector rows, compared with single-slice helical CT, multislice CT can cover a greater volume, during a simple breath hold, and with better longitudinal and in-plane spatial resolution and improved temporal resolution. The result in data set allows the generation of superior multiplanar and 3D images of the airways, including those obtained from techniques developed specifically for airway imaging, such as virtual bronchography and virtual bronchoscopy. Complementary CT evaluation at suspended or continuous full expiration is mandatory to detect air trapping that is a key finding for depicting an obstruction on the small airways. Indications for CT evaluation of the airways include: (a) detection of endobronchial lesions in patients with an unexplained hemoptysis; (b) evaluation of extent of tracheobronchial stenosis for planning treatment and follow-up; (c) detection of congenital airway anomalies revealed by hemoptysis or recurrent infection; (d) detection of postinfectious or postoperative airway fistula or dehiscence; and (e) diagnosis and assessment of extent of bronchiectasis and small airway disease. Improvement in image analysis technique and the use of spirometrically control of lung volume acquisition have made possible accurate and reproducible quantitative assessment of airway wall and lumen areas and lung density. This contributes to better insights in physiopathology of obstructive lung disease, particularly in chronic obstructive pulmonary disease and asthma.

Asthma↗
PubMed2002

Mild intermittent asthma: CT assessment of bronchial cross-sectional area and lung attenuation at controlled lung volume.

PURPOSE: To evaluate, with thin-section computed tomography (CT), changes in bronchial cross-sectional area and lung attenuation induced by bronchial stimulation in patients with mild intermittent asthma, at a given lung volume monitored with pneumotachography. MATERIALS AND METHODS: Twelve patients with mild intermittent asthma who were nonsmokers (National Institutes of Health staging) and six nonsmoking healthy volunteers, age and sex ratio-matched, were examined by using helical thin-collimation CT at the level of basal bronchi at 65% of total lung capacity. Three sets of acquisitions were obtained: at baseline and after inhalation of methacholine and then salbutamol. Cross-sectional areas of bronchi greater than 4 mm(2) were segmented and calculated from CT images. Lung attenuation was measured in the anterior, lateral, and posterior areas of the right lung parenchyma. Gas trapping was evaluated by using thin-section CT at residual volume in six of the patients with asthma. Statistical analysis included two factors repeated-measurement analysis of variance and Mann-Whitney and Kruskal-Wallis nonparametric tests. RESULTS: Bronchial cross-sectional areas and lung attenuation did not vary significantly compared with baseline values following bronchial challenge in healthy volunteers or patients with asthma. However, in patients with asthma, bronchial cross-sectional areas were significantly smaller than in healthy volunteers, except after inhalation of salbutamol. Lung attenuation and anteroposterior attenuation gradient were significantly higher in patients with asthma than in healthy patients (P <.001). Air-trapping scores were significantly higher after methacholine challenge. CONCLUSION: Helical thin-collimation CT at controlled lung volume and at full expiration associated with bronchial challenge may help evaluate bronchoreactivity and inflammation in mild intermittent asthma.

Adult↗
PubMed2001

Thin-section chest CT findings of primary Sjögren's syndrome: correlation with pulmonary function.

The purpose of this study was to describe thin-section CT findings of lung involvement in patients with primary Sjögren's syndrome (PSS), and to correlate them with pulmonary function tests (PFT). The chest thin-section CT examinations of 35 patients with proven diagnosis of PSS and respiratory symptoms were retrospectively assessed by two observers, in a first step independently with interobserver evaluation, and in a second step in consensus. The extent of the most frequent CT findings was scored. Correlation was made with PFT in 31 of these patients. Three main CT patterns were identified with good interobserver agreement (kappa coefficient 0.71): 19 of 35 (54%) large and/or small airways disease; 7 of 35 (20%) interstitial lung fibrosis (ILF); and 5 of 35 (14%) suggestive of lymphocytic interstitial pneumonia (LIP). The CT scans were normal in 2 patients (6%) and showed only dilatation of pulmonary vessels due to pulmonary arterial hypertension in two others (6%). Airway disease patients had predominantly obstructive profiles (mean FEV(1)/FVC ratio 69.7+/-12.7%, mean MEF(25) 50.1+/-22.9%), whereas patients with ILF and LIP had predominantly restrictive profiles and/or a decreased diffusing lung capacity (mean TLC 87.0+/-26.0 and 64.6+/-18.6%, mean DL(CO) 57.4+/-21.2 and 52.0+/-8.0%). Significant correlation ( p<0.01) was found between the scores of ground-glass attenuation and TLC ( r=-0.84) and DL(CO) ( r=-0.70) and between the score of air trapping and FEV1 ( r=-1.0). In patients with PSS and respiratory symptoms, thin-section CT may provide characterization of lung involvement which correlates with pulmonary function.

Adult↗
PubMedDate not supplied

Multi-detector row CT and postprocessing techniques in the assessment of diffuse lung disease.

Many acute and chronic lung diseases are characterized by diffuse infiltration of the lung parenchyma. High-resolution computed tomography (CT) has been widely accepted as the imaging standard of reference for the assessment of these diseases. However, only approximately 10% of the lung parenchyma is scanned with high-resolution CT, and characteristic foci of disease may be missed. With use of the established characteristic high-resolution CT patterns, multi-detector row chest CT has revolutionized the evaluation of diffuse lung disease. Multi-detector row CT generates isotropic volumetric high-resolution data, allowing contiguous three-dimensional (3D) visualization of the lung parenchyma, with the capacity to create high-quality two-dimensional (2D) and 3D reformatted images. Minimum intensity projection is the postprocessing technique of choice for the detection and characterization of most patterns of diffuse lung disease. Maximum intensity projection (MIP) allows the detection and characterization of micronodules; the recognition of enlarged pulmonary veins, which is extremely useful in the diagnosis of pulmonary edema and the assessment of mosaic perfusion; and differentiation between perilymphatic, miliary, and centrilobular distribution. MIP can also help differentiate between constrictive bronchiolitis and mixed emphysema. Two-dimensional reformatted images are now of equal importance with the 2D axial images in diagnosing specific diffuse lung diseases. In the future, 3D reformatted images may be used to help quantify these disorders.

Adult↗