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Biomedical subjects

G Bongartz

Publications and source records attributed to G Bongartz.

At least 19 recordsLinked to original sources
PubMed2000

Retroisthmic cleft: a stress fracture of the lamina.

The retroisthmic cleft is a rarely diagnosed defect in the lamina of the lumbar spine. It has always been considered a congenital anomaly. This is the first report we are aware of showing radiological changes in a retroisthmic cleft over a period of time. The follow-up of this patient over a period of 6 years, the radiological and scintigraphic appearances and a review of the literature suggests that the retroisthmic cleft is a stress fracture of the lamina.

Adult↗
PubMed1999

[Pathological deglutition pattern after tumor surgery of the oro- and hypopharynx. Analysis by differentiated deglutition].

Dysphagia is a common complaint following surgical intervention in the oral cavity and hypopharynx, often leading to prolonged postoperative recovery. Videofluoroscopy allows detailed visualization of deglutition, demonstrating the morphology as well as the functional aspects. Therefore, videofluoroscopy provides the basis for further therapeutic management. We discuss the pathology of deglutition in 19 patients recovering from tumor surgery of the oro- and hypopharynx. In most cases the results demonstrated severe impairment of both the oral and pharyngeal phase of deglutition. Our data emphasize the importance of the oral phase of deglutition for preparation and initiation of the following phases.

Deglutition Disorders↗
PubMed1999

Detection of pulmonary nodules with overlapping vs non-overlapping image reconstruction at spiral CT.

The aim of this study was to analyze whether overlapping image reconstruction increases numbers of pulmonary nodules detected at helical CT. Forty-eight helical CT scans (21 with a slice thickness of 10 mm; 27 with a slice thickness of 5 mm) of patients with known pulmonary nodules were reconstructed both with overlapping and non-overlapping image reconstruction. Two readers recorded number and size of pulmonary nodules as well as diagnostic confidence. With overlapping image reconstruction each reader diagnosed more pulmonary nodules (slice thickness 10 mm: +24.0 and +26.7%, both p < 0.01; slice thickness 5 mm: +9.5 and +11.9%, both not significant) and more "definite" nodules (slice thickness 10 mm: +20.3%, p < 0.05, and +30.8%, p < 0.005; slice thickness 5 mm: +18.0 and +17.0%, both p < 0.05). Nodules diagnosed with overlapping image reconstruction only were almost exclusively smaller than the slice thickness. The increase in number of nodules detected was not associated with a decrease in diagnostic confidence. Overlapping image reconstruction improves detection of pulmonary nodules smaller than the slice thickness at spiral CT.

Adolescent↗
PubMed1999

CT-guided intratumoral gene therapy in non-small-cell lung cancer.

The objective of this study was to prove the principle of CT-guided gene therapy by intratumoral injection of a tumor suppressor gene as an alternative treatment approach of incurable non-small-cell lung cancer. In a prospective clinical phase I trial six patients with non-small-cell lung cancer and a mutation of the tumor suppressor gene p53 were treated by CT-guided intratumoral gene therapy. Ten milliliters of a vector solution (replication-defective adenovirus with complete wild-type p53 cDNA) were injected under CT guidance. In four cases the vector solution was completely applied to the tumor center, whereas in two cases 2 ml aliquots were injected into different tumor areas. For the procedure the scan room had been approved as a biosafety cabinet. Gene transfer was assessed by reverse transcription and polymerase chain reaction in biopsy specimens obtained under CT guidance 24-48 h after therapy. Potential therapeutic efficacy was evaluated on day 28 after treatment using spiral CT. The CT-guided gene therapy was easily performed in all six patients without intervention-related complications. Besides flu-like symptoms, no significant adverse effects of gene therapy were noted. Three of the four patients with central injection exhibited gene transfer in the posttreatment biopsy. Gene transfer could not be proven in the two patients with multiple 2 ml injections. After 28 days, four of the six patients showed stable disease at the treated tumor site, whereas other tumor manifestations progressed. Computed tomography-guided injections are an adequate and easy-to-perform procedure for intratumoral gene therapy.

Adenoviridae↗
PubMed1999

MR angiography: supra-aortic vessels.

Magnetic resonance angiography (MRA) has become an imaging modality which comprises various techniques based on two concepts: methods relying on the natural flow effects, the time-of-flight and phase-contrast technique, either in two- or three-dimensional acquisition mode, and the more recently developed contrast-enhanced (CE) MRA methods. The main indications for evaluation of the supra-aortic vessels are, firstly, the grading of carotid artery stenoses caused by an atherosclerotic process, and secondly, the evaluation of dissections of the cervical arteries because this disease plays an important role as a cause for stroke especially in younger patients. The various MRA techniques in their application to the main pathologies encountered at the supra-aortic vessels are presented, and recent developments in the promising field of CE MRA are discussed.

Angiography, Digital Subtraction↗
PubMed1999

Effect of combined mouth closure and chin lift on upper airway dimensions during routine magnetic resonance imaging in pediatric patients sedated with propofol.

BACKGROUND: In pediatric patients, obstruction of the upper airway is a common problem during general anesthesia. Chin lift is a commonly used technique to improve upper airway patency. However, little is known about the mechanism underlying this technique. METHODS: The authors studied the effect of the chin lift maneuver on airway dimensions in 10 spontaneously breathing children (aged 2-11 yr) sedated with propofol during routine magnetic resonance imaging. The minimal anteroposterior and corresponding transverse diameters of the pharynx were determined at the levels of the soft palate, dorsum of the tongue, and tip of the epiglottis before and during the chin lift maneuver. Additionally, cross-sectional areas were calculated at these sites, including tracheal areas 2 cm below the glottic level. RESULTS: Minimal anteroposterior diameter of the pharynx increased significantly during chin lift at all three levels in all patients. The diameters of the soft palate, tongue, and epiglottis increased from 6.7+/-2.8 mm (SD) to 9.9+/-3.6 mm, from 9.6+/-3.6 mm to 16.5+/-3.1 mm, and from 4.6+/-2.5 mm to 13.1+/-2.8 mm, respectively. The corresponding transverse diameter of the pharynx also increased significantly at all three levels in all patients but without significant predominance. The diameters at the levels of the soft palate, tongue, and epiglottis increased from 15.8+/-5.1 mm to 22.8+/-4.5 mm, from 13.5+/-4.9 mm to 18.7+/-5.3 mm, and from 17.2+/-3.9 mm to 21.2+/-3.7 mm, respectively. Cross-sectional pharyngeal areas increased significantly at all levels (soft palate, from 0.88+/-0.58 cm2 to 1.79+/-0.82 cm2; tongue, from 1.15+/-0.45 cm2 to 2.99+/-1.30 cm2; epiglottis, from 1.17+/-0.70 cm2 to 3.04+/-0.99 cm2), including the subglottic level (from 0.44+/-0.15 cm2 to 0.50+/-0.14 cm2). CONCLUSIONS: This study shows that all children had a preserved upper airway at all measured sites during propofol sedation. Chin lift caused a widening of the entire pharyngeal airway that was most pronounced between the tip of the epiglottis and the posterior pharyngeal wall. In pediatric patients, chin lift may be used as a standard procedure during propofol sedation.

Child↗
PubMed1999

Selection of patients for carotid thromboendarterectomy: the role of magnetic resonance angiography.

It has been shown in clinical trials that patients with high grade symptomatic carotid stenosis benefit from carotid thromboendarterectomy. Because of the invasiveness and the costs of intra-arterial digital subtraction angiography, the current standard of reference for the grading of carotid stenosis, magnetic resonance angiography, has become a technique of utmost interest for evaluation of the carotid arteries. The time-of-flight and the newly developed contrast-enhanced magnetic resonance angiography techniques are discussed. At present, we recommend computer enhanced magnetic resonance angiography for screening procedures and for the post-operative follow-up. For pre-operative evaluation we still recommend intra-arterial digital subtraction angiography.

Angiography, Digital Subtraction↗
PubMed1999

Life-threatening spontaneous retroperitoneal bleeding: a rare complication of oral anticoagulation.

In a patient on oral anticogulation with sudden onset of loin pain, the possibility of spontaneous bleeding in the retroperitoneum must be considered in the differential diagnosis of renal colic. This rare pathology can be life-threatening, and rapid diagnosis with ultrasound and computerized tomography of the abdomen must be made. If the patient is hemodynamically stable, a conservative approach is justified. Otherwise, emergency nephrectomy may be needed. As patients become older and indications for anticoagulant therapy become more common, we will probably have to face more of these rare bleeding complications in the future. We report such a case.

Administration, Oral↗
PubMed1999

Helical CT of pulmonary nodules in patients with extrathoracic malignancy: CT-surgical correlation.

OBJECTIVE: Our aim was to assess the sensitivity of helical CT for revealing pulmonary nodules. Thoracotomy with palpation of the deflated lung, resection, and histologic examination of palpable nodules was used as the gold standard. SUBJECTS AND METHODS: Thirteen patients underwent helical CT (slice thickness, 5 mm; reconstruction intervals, 3 mm and 5 mm; interpreted by two independent observers). Subsequently, patients underwent unilateral (n = 6) or bilateral (n = 7) surgical exploration, and CT-surgical correlation of 20 lungs was performed. RESULTS: Ninety nodules were resected (61 were smaller than 6 mm; 13 were 6-10 mm; 11 were larger than 10 mm; in five nodules, the size was not recorded at surgery). Sixty-nine nodules were located in the pulmonary parenchyma and 21 in the visceral pleura. Of the 90 lesions, 43 (48%) were found on histology to represent metastases. For lesions detected by at least one observer, the sensitivity of helical CT was 69% for intrapulmonary nodules smaller than 6 mm, 95% for intrapulmonary nodules larger than or equal to 6 mm, and 100% for histologically proven intrapulmonary metastases larger than or equal to 6 mm. For lesions smaller than or equal to 10 mm, sensitivity was better using a reconstruction interval of 3 mm rather than of 5 mm. CONCLUSION: In this study, the sensitivity of helical CT exceeded the sensitivity of conventional CT in previous reports. However, because of limitations in the detection of intrapulmonary nodules smaller than 6 mm and of pleural lesions, complete surgical exploration should remain the procedure of choice in patients undergoing pulmonary metastasectomy. Preoperative helical CT should be used to guide the surgeon to lesions that are difficult to palpate.

Adult↗
PubMed1998

Gene therapy with cytokine-transfected xenogeneic cells in metastatic tumors.

On the basis of compelling preclinical data in cats and dogs we initiated a clinical gene therapy study in nine patients with advanced solid tumors using xenogeneic fibroblasts secreting human IL-2 (Vero-IL-2 cells). Cohorts of three successive patients with tumors accessible to CT- or ultrasound-guided injection were treated repeatedly with 5 x 10(5), 5 x 10(6), or 5 x 10(7) Vero-IL-2 cells. Endpoints of the study were feasibility, toxicity, and clinical and biological effects of this novel approach to immunotherapy of cancer. Histopathological, immunological and molecular analyses were performed on biopsy specimens of tumors and blood samples from before, during and after treatment. Low levels of serum antibodies to Vero cells developed in 2/9 patients. Analysis of tumor biopsies showed increased expression of CD3 mRNA and enhanced tumor infiltration with varying lymphocyte subpopulations after treatment. In addition, monoclonal alterations of the TCR repertoire of blood and tumor lymphocytes were observed. Treatment was well tolerated and toxicity consisted of transient fever in one patient and short-lived, mild itching and erythema in two others. One patient with soft tissue sarcoma showed a more than 90% and more than 50% reduction of the volume of two distant, non-injected metastases, respectively, lasting for 22+ months. Four other patients showed stabilization of their disease for three to nine months, among whom was a patient with melanoma who developed marked vitiligo. We conclude that repeated injection of up to 5 x 10(7) Vero-IL-2 cells was safe and showed biological and clinical activity in heavily pretreated patients with advanced solid tumors. Further evaluation of intratumoral application of Vero-IL-2 seems warranted.

Adult↗
PubMed1998

[Pathologic swallowing pattern after tumor surgery of oro- and hypopharynx. Analysis with differentiated deglutition imaging].

Dysphagia is a common complaint following surgical intervention in the oral cavity and hypopharynx, often leading to prolonged postoperative recovery. Videofluoroscopy allows detailed visualization of deglutition, demonstrating the morphology as well as the functional aspects. Therefore, videofluoroscopy provides the basis for further therapeutic management. We discuss the pathology of deglutition in 19 patients recovering from tumor surgery of the oro- and hypopharynx. In most cases the results demonstrated severe impairment of both the oral and pharyngeal phase of deglutition. Our data emphasize the importance of the oral phase of deglutition for preparation and initiation of the following phases.

Barium Sulfate↗
PubMed1998

MR angiography in internal carotid artery dissection: improvement of diagnosis by selective demonstration of the intramural haematoma.

We studied eight consecutive patients with clinical and intra-arterial angiographic (DSA) diagnosis of internal carotid artery (ICA) dissection to analyse the accuracy of MRA in dissections, using a new technique with presaturation pulses. Spin-echo images of the head were followed by three-dimensional time-of-flight (TOF) MRA at the site of the dissection, with and without a special caudal saturation pulse in addition to the cranial one. The accuracy of MRA was assessed in 64 segments of 16 ICA, all examined with DSA and MRA. High-signal intramural haematoma in the ICA at the level of the dissection was observed in all patients either on the maximal-intensity projection (MIP) reconstructions or on the partitions with this presaturation pulse technique. MRA had a sensitivity to detect dissected vessels of 100%. Specificity for vessels correctly identified as not having a lesion was also 100%. There was good correlation between DSA and MRA in demonstrating the site of the dissected ICA segment and the degree of stenosis. In only two cases was there overestimation of the degree of stenosis on the MIP reconstructions of the 3-D MRA.

Adult↗
PubMed1998

Pulmonary circulation.

Evaluation of the pulmonary vasculature is mainly indicated in patients with suspected pulmonary thromboembolism. The routine procedure so far is ventilation-perfusion scintigraphy alone or in combination with diagnostic assessment of the legs to rule out deep venous thrombosis. The results are still not reliable for the majority of patients. In the case of equivocal diagnosis, invasive conventional angiography is considered the gold standard. With steady improvements in tomographic imaging techniques, such as computed tomography (CT) or magnetic resonance imaging (MRI), non-invasive alternatives to the routine diagnostic work-up are given. Helical CT and CTA techniques are already in clinical use and estimated to sufficiently serve the demands for detection/exclusion of pulmonary thromboembolism. The disadvantages mainly concern peripheral disease and reconstruction artifacts. MRI and MR angiography have been implemented in the diagnosis of pulmonary vascular disease since the introduction of contrast-enhanced MRA. In breath-hold techniques, the entire lung vascularization can be delineated and thromboemboli can be detected. The clinical experience in this field is limited, but MRI has the potential to demonstrate its superiority over CT due to its improved delineation of the vascular periphery and the more comprehensive three-dimensional reconstruction.

Aged↗
PubMed1998

Diameter of the common bile duct in the elderly patient: measurement by ultrasound.

We wanted to assess the width of the common bile duct (CBD) in an asymptomatic elderly (> 75 years) population, since no previous report has particularly considered the important age-related increase in CBD diameter for this patient group. CBD width of 92 asymptomatic people over 75 years of age (mean 84.7 years, range 75-96 years) without clinical or laboratory evidence for biliary, hepatocellular or pancreatic disease was measured by real-time high-resolution ultrasound of the upper abdomen. All examinations were performed by one experienced radiologist. Mean values were calculated for three groups: patients with and without cholecystolithiasis and after cholecystectomy. Statistical analysis was carried out by analysis of variance. Considering the measurements of all patients, the mean width (+/- SD) of the CBD was calculated as 6.5 +/- 2.5 mm. The difference between patients without cholecystolithiasis (6.2 +/- 2.3 mm) and patients after cholecystectomy (8.7 +/- 2.9 mm) was statistically significant (P < 0.0001). Cholecystolithiasis (6.0 +/- 1.6 mm) proves not to be an additional factor for CBD widening in comparison with patients without stone disease. The CBD of these very elderly subjects shows a considerable increase in comparison with the recommended borderline values in the ultrasound literature. An upper limit of 10 mm seems reasonable for patients with and without cholecystolithiasis. A significant increase in CBD width after cholecystectomy was found and measurements up to 14 mm may occur. Measurements have to be correlated with clinical and laboratory findings.

Aged↗