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C P Heussel

Publications and source records attributed to C P Heussel.

At least 19 recordsLinked to original sources
PubMed2002

Radiological imaging as the basis for a simulation software of ventilation in the tracheo-bronchial tree.

The inhaled route is a promising new way for administering drugs to the human body. Flow and particle deposition in the human respiratory tract depends on the individual's anatomy as well as on the drug composition. A European Framework V Program supported project is currently developing a simulation tool for assessment of drug distribution and deposition. This tool relies heavily on the input of radiological data sets, which are obtained in humans. Both high temporal and spatial resolutions are required, and CT and MRI (including hyperpolarized helium-3 MRI) are applied. The radiological data are integrated into computation fluid dynamics software, which is capable of assessing air-flow profiles and compartmental behaviours. This is complemented by pharmacokinetic models, which should result in a simulation tool that will be of use for the theoretical design of new inhaled therapies. This article describes the special imaging requirements of each region of the respiratory tract and the feasibility of these sophisticated radiological techniques with a view of using these data in a simulation model of the lung.

Administration, Inhalation↗
PubMed2002

[Pulmonary structure and function].

Computed tomography (CT) is the method of choice for the morphological assessment of pulmonary structure. Airways. pulmonary parenchyma and their pathologies are shown with high spatial resolution. Airway diseases exhibit bronchial dilatation, wall thickening and an increased visibility in the lung periphery. CT is also the imaging gold standard for the detection and the characterisation of emphysema because a high degree of concordance with histopathological studies. Centrilobular, panlobular and paraseptal emphysema can be differentiated. CT can also provide functional information. Paired inspiratory and expiratory scans with or without spirometric triggering allow to evaluate obstruction of the small airways (airtrapping). On the basis of CT-data lung volumes can be semented. Cine-CT allows to visualise motion of the central airways. e.g. in tracheomalacia, to assess regional ventilation to calculate pulmonary time constants. and to display the co-ordinated or dissociated motion of the thoracic wall and the diaphragm. Beyond the mere high-resolution visualisation of the structure of the lung the application of these CT-strategies makes a regional assessment of pulmonary function possible.

Humans↗
PubMed2002

[Determination of the distribution volume of contrast media solutions injected intrahepatically: pre-pilot studies for intratumoral gene therapy].

PURPOSE: Determination of the intrahepatic distribution volume of two contrast media (CM) by CT-guided application in an ex-vivo and an in-vivo model (pig liver). MATERIAL AND METHODS: In pig livers ex-vivo and in-vivo, 131 CT-guided injections of two different CM (Imagopaque(R), Visipaque(R)) were performed using catheters and cannula with and without side-holes and documented by spiral CT. The distribution pattern was assessed visually: interstitial, subcapsular, vascular/tubular, the distribution volume was quantified using a density mask (thresholds 70/400 HE). RESULTS: Purely interstitial applications were achieved more frequently in-vivo than ex-vivo (p = 0.001). There were no relevant differences between the two CM. Catheters without side-holes led to more interstitial CM depots than catheters with side-holes (p = 0.005). The mean distribution volume was larger with catheters with side-holes (ex-vivo 103 cm(3), in-vivo 19 cm(3)) than with catheters without side-holes (ex-vivo 67 cm(3), in-vivo 13 cm(3)) (p = 0,01). At the same time, the mean density with catheters with side-holes (102 HE) was lower than with catheters without side-holes (115 HE) (p = 0.005). CONCLUSION: Marked differences of the CM distribution volumes were observed between ex-vivo and in-vivo studies in the pig model. Catheters with side-holes are far superior to catheters without.

Animals↗
PubMed2002

[Morphologic and functional assessment of vascular abnormalities of the pulmonary vasculature by breath-hold MR techniques].

PURPOSE: To evaluate breath-hold MR techniques for morphologic and functional assessment of vascular abnormalities of the pulmonary vasculature. PATIENTS AND METHODS: 13 patients aged 11 to 60 years with different vascular abnormalities of the pulmonary vasculature (5 patients with 16 arteriovenous malformations, 8 patients with partial anomalous pulmonary venous return) underwent MR imaging at 1.5 T. For morphological assessment, a contrast-enhanced 3D MR angiography (ce-MRA) was performed after a timing run. Segmented cine- and velocity-encoded GRE sequences were used for delineation of associated cardiac septal defects and for determination of systemic left-to-right or intrapulmonary shunt volumes. Selective intra arterial digital subtraction angiography, cardiac catheterization, and the intraoperative situs served as reference standards. RESULTS: Ce-MRA allowed for detection of all vascular abnormalities and for anatomic characterization of 14/16 arteriovenous malformations. Flow measurements in the feeding arteries allowed for determination of intrapulmonary shunt volumes in 4/5 patients. Flow measurements performed in the pulmonary arteries and the ascending aorta enabled determination of systemic left-to-right shunting in patients with anomalous pulmonary venous return. Cine-sequences clearly depicted associated cardiac septal defects. CONCLUSION: Breath-hold MR techniques allow for morphological and functional characterization of vascular anomalies of the pulmonary vasculature. Therefore, they are the non-invasive method of choice for planning further treatment.

Adolescent↗
PubMed2002

[Prospective feasibility study of chest X-ray vs. thoracic MRI in breath-hold technique at an open low-field scanner].

PURPOSE: MR investigations using a breath-hold sequence at an open low-field MR had to be compared to chest X-rays in patients with a wide spectrum of cardio-thoracic pathologies. MATERIAL AND METHODS: 114 patients and three volunteers who actually received a chest X-ray due to different indications underwent triplanar breath-hold (17 - 20 s) True-FISP sequence using a 0.2 T low-field MR (Siemens Magnetom Open, TR/TE/alpha: 7.3/3.5/80 degrees, SD: 10 mm, Pixel: 2.81 x 1.41 mm) a mean of 5.1 (+/- 8.2) days later. RESULTS: Signal-to-noise ratio as basics for pattern recognition was 3.2 in nodule, 5.0 in infiltration, and 12.0 in effusion, and therefore True-FISP is usable for the detection of these findings. MRI demonstrated nodules (89 % vs. 57 %), infiltration (81 % vs. 71 %), pleural effusions (86 % vs. 75 %), pericardial effusions (100 % vs. 21 %) and pulmonary congestion (90 % vs. 80 %) clearly more frequently compared to chest X-ray. DISCUSSION: MRI of the lung has been implemented successfully at an open low-field MR system. Diagnostic safety and accuracy are at least comparable to those of chest X-ray. The lack of superimposition led to a major improvement in the detection of pericardial effusions and nodules, and an increase in identification of infiltration, pleural effusion, and pulmonary congestion.

Adolescent↗
PubMed2001

[Surgical management of pulmonary artery sarcoma].

BACKGROUND AND OBJECTIVES: Pulmonary artery sarcoma is a rare neoplasm and possibly unnoticed cause of pulmonary hypertension. The presentation is one of central pulmonary artery obstruction and progressive right-heart failure. In most cases, the diagnosis of malignancy is confirmed post mortem. We report the outcome of eight patients with primary pulmonary artery sarcomas. METHODS: Eight patients (four female, four male, mean age 48,2 years, preop. NYHA functional class III/IV: n = 5/3) were referred for further evaluation of pulmonary hypertension. Malignancy was suspected in six of these patients by means of computed tomography (CT) and magnetic resonance tomography (MRT). In two patients diagnosis was established during pulmonary thromboendarterectomy based on histological examination of frozen sections. Operative procedures consisted of gross tumor resection with prosthetic replacement (n = 3) or reconstruction (n = 5) of central parts of the pulmonary vessels. Additional pneumonectomy was necessary in two patients, resection of metastases in one patient. Seven patients received adjuvant radio- and/or chemotherapy. RESULTS: There were no postoperative deaths. 3 months after surgery, all patients demonstrated improvement in hemodynamics and exercise tolerance. Four patients died 7, 9, 18 and 19 months after surgery, respectively. Two patients are alive 3 and 39 months after primary surgery with evidence of pulmonary metastases. Two patients are alive in complete remission 25 and 65 months postoperatively. CONCLUSIONS: In patients with primary pulmonary artery sarcoma, emphasis must be placed on early identification which can be achieved by CT and MRT. Radical surgical resection currently offers the best chance for survival. Adjuvant therapy might bring additional benefit.

Adult↗
PubMed2001

Adenovirus-mediated wild-type p53 gene transfer in patients receiving chemotherapy for advanced non-small-cell lung cancer: results of a multicenter phase II study.

PURPOSE: To study the additional benefit from adenoviral p53 gene therapy in patients undergoing first-line chemotherapy for advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Twenty-five patients with nonresectable NSCLC were enrolled in an open-label, multicenter phase II study of three cycles of regimen A, carboplatin (area under the curve, 6; day 1) plus paclitaxel (175 mg/m(2), day 1), or regimen B, cisplatin (100 mg/m(2), day 1) plus vinorelbine (25 mg/m(2), days 1, 8, 15, and 22) in combination with intratumoral injection of 7.5 x 10(12) particles of SCH 58500 (rAd/p53, day 1). Responses of individual tumor lesions were assessed after each cycle, and gene transfer was examined in posttreatment tumor biopsies using reverse transcriptase polymerase chain reaction. RESULTS: There was no difference between the response rate of lesions treated with p53 gene therapy in addition to chemotherapy (52% objective responses) and lesions treated with chemotherapy alone (48% objective responses). Subgroup analysis according to the chemotherapy regimens revealed evidence for increased mean local tumor regressions in response to additional p53 gene therapy in patients receiving regimen B, but not in patients receiving regimen A. There was no survival difference between the two chemotherapy regimens, and the median survival of the cohort was 10.5 months (1-year survival, 44%). Transgene expression was confirmed in tumor samples from 68% of patients, and toxicities attributable to gene therapy were mild to moderate. CONCLUSION: Intratumoral adenoviral p53 gene therapy appears to provide no additional benefit in patients receiving an effective first-line chemotherapy for advanced NSCLC.

Adenoviridae↗
PubMed2001

Dynamic (19)F-MRI of pulmonary ventilation using sulfur hexafluoride (SF(6)) gas.

A new method for dynamic imaging of pulmonary wash-in and wash-out kinetics of inhaled sulfur hexafluoride (SF(6)) gas was developed. Measurements at the fluorine-19 Larmor frequency were performed in pigs using a gradient echo pulse sequence with 0.5 ms echo time and a measurement time of 9.1 s per image. Dynamic MRI was performed during wash-in and wash-out of SF(6) gas in mechanically ventilated porcine lungs. A postprocessing strategy was developed for quantitative determination of wash-out time constants in the presence of noise. Mean wash-out constants were 4.78 +/- 0.48 breaths vs. 4.33 +/- 0.76 breaths for left and right lung when ventilation was performed with low tidal volume, and 1.73 +/- 0.16 breaths vs. 1.85 +/- 0.11 breaths with high tidal volume ventilation. In conclusion, breath-hold MRI of SF(6) gas is feasible in large animals. Moreover, regional wash-in and wash-out kinetics of SF(6) can be determined noninvasively with this new method. Potential human applications are discussed. Magn Reson Med 45:605-613, 2001.

Animals↗
PubMed2001

[Multi-rotation CT and acute respiratory distress syndrome. Animal experiment studies].

PURPOSE: Aim of the study was to investigate alveolar inspiration and expiration using multiscan CT. Results of a visual assessment using a scoring system were compared with density ranges known to represent alveolar ventilation best. METHOD: Pigs were examined before and after lavage-induced ARDS. All animals were examined using dynamic multiscan CT. The visual assessment was done by a scoring system proposed by Gattinoni. The results were compared with planimetric determination of defined density ranges. RESULTS: In the healthy lung, the visual analysis showed higher scores at lower airway pressures with a marked gradient, whereas at higher pressures neither opacities nor gradients were observed. In ARDS-lungs, the scores were double as high as in healthy lungs at low pressures. At the same time the differences between inspiration and expiration were minor. There was good correlation between lung density measurements and lung opacities under different airway pressures. In healthy lungs, the greatest area increase is found between -910 and -700 HU. The biggest area growth in the ARDS-model is observed between -910 and -300 HU. CONCLUSION: Dynamic multiscan CT allows for determining different ventilation-relevant lung compartments and lung density ranges.

Animals↗
PubMed2001

[New developments in MRI of the thorax].

MRI was not used often for lung imaging due to technical and physical limitations. Recent developments have considerably improved anatomical MR imaging, and at the same time new perspectives for functional imaging emerged. They consist of functional investigations of pulmonary perfusion (contrast agents, MR angiography) and ventilation (inhaled contrast aerosols, oxygen, hyperpolarized noble gases [He-3, Xe-129] and fluorinated gases [SF6]). New parameters can be measured: homogeneity of ventilation, lung volumes, airspace size, intrapulmonary oxygen partial pressure, dynamic ventilation distribution and ventilation/perfusion ratios. MRI-inherent advantages are: lack of radiation, high spatial and temporal resolution, and a broad range of functional information. MRI of lung ventilation seems to be more sensitive in the detection of ventilation defects than scintigraphy, CT or pulmonary function tests. By combining the new strategies the radiologist will be capable to improve specificity of the investigations and to characterize lung function impairments. The joint assessment of ventilation and perfusion will play a major role in this development.

Contrast Media↗
PubMed2001

Paired inspiratory/expiratory spiral CT and continuous respiration cine CT in the diagnosis of tracheal instability.

In tracheo- and bronchomalacia, localisation and determination of collapse is necessary for planning of surgical procedure. We compared inspiratory and expiratory spiral CT, cine CT, bronchoscopy, exemplary cine MR, and evaluated the clinical relevance. Twenty-nine patients (2 follow-ups; mean age 61 years, age range 27-85 years) with suspected or verified tracheal stenosis or collapse (post-tracheotomy: n = 17; neoplasm: n = 5; other: n = 7) underwent paired breath-hold inspiratory and expiratory spiral CT. Forty-five additional cine CT were performed at 1-4 levels (mean 1.5) during continuous respiration (increment 100 ms) to clarify respiratory collapse. The tracheal cross-sectional diameters of both techniques were calculated. Comparison with bronchoscopy, follow-up, and influence upon therapy were evaluated retrospectively. Exemplary comparison with cine MR (8 frames/s) was done in 3 cases. In addition to bronchoscopy, further information concerning localisation, extent, collapse, stability of the tracheal wall, distal portions of the stenosis and extraluminal compressions were obtained. A significantly higher degree and more pathological collapses (> 50%) were seen using cine CT (38%) compared with paired spiral CT (13%; degree: p < 0.0001; number: p < 0.001). The findings changed the further therapeutic procedure in 16 of 29 patients. Further stenoses were excluded and bronchoscopy was verified in another 13 of 29. Temporal resolution of cine CT and cine MR is sufficient; however, spatial resolution of cine MR is inferior. Paired inspiratory and expiratory spiral CT localises tracheal stenoses and demonstrates relevant extraluminal compression. Significantly improved evaluation of respiratory collapse and further information of localised tracheal instability is obtained by cine CT. Cine MR promises more functional information especially due to free choice of imaging plane.

Adult↗
PubMed2001

[Lymphoma-simulating presentation of focal nodular hyperplasia (FNH) of the liver].

UNLABELLED: A 51-year-old woman, who had taken oral contraceptive drugs for 11 years, was referred to our Unit for examination of an asymptomatic 3.6 x 4.1 cm hypoechoic liver mass found by ultrasound examination carried out in the course of gynecological screening. INVESTIGATIONS: Laboratory evaluation revealed mild elevated liver enzymes. Computed tomography exhibited a hypervascularized lesion in segment 4 of the liver resembling a hemangioma or focal nodular hyperplasia but FNH was favored since magnetic resonance imaging showed a central scar within the hepatic lesion. Hepatobiliary scintigraphy was not typical thus an ultrasound-guided needle biopsy was performed. Histological examination revealed lymphoma-like infiltrates close to normal liver cells. However, the molecular biological examination showed oligoclonality of the infiltrating T-cells. Blood examinations, bone-marrow punctuation and CT thorax scan did not show any other lymphoma-like lesion. TREATMENT AND COURSE: After 5, 10 and 15 months the untreated patient was re-examined by MRI. The focal lesion showed an unchanged size and again a FNH-typical imaging. Liver-specific contrast enhancement was not suggestive for lymphoma. The lymphocytes were interpreted as an atypical lymphoid inflammatory infiltrate of a non-neoplastic lesion of the liver. CONCLUSIONS: The focal nodular hyperplasia can be a very difficult diagnosis in imaging and histopathological examinations. The lymphoma of the liver can be a rare but possible differential diagnosis.

Biopsy, Needle↗
PubMed2001

[Artefact reducing in diagnosis of lung embolism using spiral CT with saline bolus].

PURPOSE: To improve the diagnostic efficacy of bolus-enhanced spiral CT (SCT) in the detection of pulmonary embolism using a saline push immediately after bolus injection of the contrast medium. PATIENTS AND METHODS: The study included 90 patients with suspected acute or chronic pulmonary embolism. The CT scan was performed in a caudocephaled direction. In Group I (n = 60) we applied a bolus contrast injection (120 ml, 3 ml/s, 300 mg J/ml), after a median delay of 25 s. Group II (n = 30) had the same contrast injection which was immediately followed by an additional saline push (60 ml, 2 ml/s). Streak artifacts originating from high contrast concentrations in the superior vena cava were rated on a 4-point scale for different locations: right pulmonary artery, pars basalis, truncus anterior, and the segmental upper lobe arteries. RESULTS: The incidence of artifacts in group I was nearly twice as high as in group II. The difference was significant (p < 0.05) for the upper and anterior superior lobe artery, the right pulmonary artery and the pars basalis. CONCLUSION: The presented protocol significantly reduces artifacts mainly by a washout of contrast medium in the superior vena cava.

Adult↗
PubMed2001

[Acute or chronic transplant rejection - high resolution CT of the chest in lung transplant recipients].

PURPOSE: Aim of the study was to evaluate the postoperative changes in patients with single (SLTX) or double lung transplantation (DLTX) with HRCT and to correlate those findings with the clinical diagnosis. MATERIAL AND METHODS: 29 patients with SLTX (n = 14) or DLTX (n = 15) were observed for more than 6 years after transplantation by HRCT (n = 82). CT examinations were performed in inspiration and expiration (n = 70) with a slice thickness of 1 mm and a feed of 10 mm. The image material was evaluated by 2 experienced radiologists in consensus. Criteria for acute rejection at HRCT were: ground glass opacities and focal air trapping in expiration. Criteria for chronic transplant rejection were: bronchial dilatation, bronchial wall thickening and thickening of interlobar septae. The clinical evaluation consisted of laboratory tests, lung function tests, and bronchoscopy including bronchial lavage in special cases. RESULTS: 20/29 patients are still alive (mean 21 months). 5/9 patients died because of chronic transplantant rejection, 1 patient suffered from a non-Hodgkin's lymphoma localised at the right hilus. Severe threatening pneumonia occurred in 13 cases. 10/29 patients showed symptoms of acute rejection. Expiratory HRCT found a focal air trapping in all cases and extended ground glass opacities in 11/14 cases. Also a bronchial dilatation was observed in more than 50 % (9/14). 12/29 patients suffered from chronic transplant rejection. HRCT showed bronchial dilatation in 26/27 investigations and severe ground glass opacities in 21/27 investigations. Thickening of the interlobal septa as well as centrilobular opacities were found in more than 50 % of the examinations. CONCLUSION: High resolution CT of the chest in patients after lung transplantation is able to show numerous pathological alterations. Without clinical information a confident differentiation in acute or chronic transplant rejection or pneumonia can be difficult or impossible.

Acute Disease↗
PubMed2001

Volumetry of ventilated airspaces by 3He MRI: preliminary results.

RATIONALE AND OBJECTIVES: To develop a validated post-processing routine for volumetry of the ventilated airspaces by 3He MRI. METHODS: 3Helium MRI and pulmonary function tests were performed in seven healthy volunteers. After segmentation of ventilated airspaces, their volumes were calculated. Functional residual capacity (FRC) was used as a reference. For comparison of absolute volumes, correction factors were evaluated. RESULTS: Mean lung volume (+/- standard deviation) calculated from 3He MRI was 4,082 +/- 908 mL and mean FRC was 3,696 +/- 1166 mL, with a mean difference of 386 mL (r = 0.88). After correction for the relative pulmonary air content (factor 0.82), posture (0.72), and the individual tidal volume, 3He MRI volume was 3,348 +/- 744 mL and mean FRC was 3,422 +/- 817 mL, with the mean difference down to -74 mL (r = 0.9). Comparison on an individual basis confirmed an improvement in the estimation of absolute lung volume. CONCLUSIONS: Volumetry of ventilated lung from 3He MRI shows high correlation and good agreement with the results of pulmonary function tests.

Adult↗
PubMed2000

(3)He MRI in healthy volunteers: preliminary correlation with smoking history and lung volumes.

MRI with hyperpolarized helium-3 ((3)He) provides high-resolution imaging of ventilated airspaces. The first aim of this (3)He-study was to compare observations of localized signal defects in healthy smokers and non-smokers. A second aim was to describe relationships between parameters of lung function, volume of inspired (3)He and signal-to-noise ratio. With Ethics Committee approval and informed consent, 12 healthy volunteers (seven smokers and five non-smokers) were studied. Imaging was performed in a 1.5 T scanner using a two-dimensional FLASH sequence at 30V transmitter amplitude (TR/TE/alpha = 11 ms/4.2 ms/<10 degrees ). Known amounts of (3)He were inhaled from a microprocessor-controlled delivery device and imaged during single breath-holds. Images were evaluated visually, and scored using a prospectively defined 'defect-index'. Signal-to-noise ratio of the images were correlated with localization, (3)He volumes and static lung volumes. Due to poor image quality studies of two smokers were not eligible for the evaluation. Smokers differed from non-smokers in total number and size of defects: the 'defect-index' of smokers ranged between 0.8 and 6.0 (median = 1.1), that of non-smokers between 0.1 and 0.8 (median = 0.4). Intraindividually, an anteroposterior gradient of signal-to-noise ratio was apparent. Signal-to-noise ratio correlated with the estimated amount of hyperpolarization administered (r = 0. 77), but not with static lung volumes. We conclude that (3)He MRI is a sensitive measure to detect regional abnormalities in the distribution of ventilation in clinically healthy persons with normal pulmonary function tests.

Adult↗