Diagnostic value of ex-vivo three-dimensional micro-computed tomography imaging of primary nonhematopoietic human bone tumors: osteosarcoma versus chondrosarcoma.

BACKGROUND: Osteosarcoma and chondrosarcoma are the most common nonhematopoietic primary malignancies of bone. However, unusual radiographic appearances can lead to delay in diagnosis and confusion with benign diseases. PURPOSE: To evaluate the feasibility of micro-computed tomography (CT) for the analysis of primary, nonhematopoietic human bone tumors ex vivo. MATERIAL AND METHODS: Samples from 12 human bone specimens (osteosarcoma, n=6; chondrosarcoma, n=6) obtained for diagnostic purposes were scanned using industrial X-ray film without amplifier foil and scanned with micro-CT (7- and 12-microm-cubic voxels). Trabecular bone CT "density" and tumor matrix CT "density" were determined, and results were compared with those obtained from a detailed conventional histopathologic analysis of corresponding cross-sections. The significance of differences in grayscale measurements was tested with analysis of variance. RESULTS: Micro-CT provided quantitative information on bone morphology equivalent to histopathological analysis. We established grayscale measurements by which tumor matrices of chondrosarcoma and osteosarcoma could be radiographically categorized following histological classifications (P<0.001). CONCLUSION: Micro-CT is feasible for the analysis and differentiation of human osteosarcoma and chondrosarcoma.

Quantification of in-stent restenosis parameters in rabbits by Micro-CT.

PURPOSE: The well-defined model of angioplasty and stent implantation in the rabbit aorta is useful in experimental studies of restenosis. This study was performed to evaluate the feasibility of Micro-CT for quantification of in-stent restenosis in a rabbit aortic in-stent-restenosis model. MATERIAL AND METHODS: To induce in-stent restenosis seven female New Zealand rabbits underwent balloon dilation and denudation prior to stenting the abdominal aorta. After six weeks on atherogenic diet, animals were killed and the aorta was perfused with contrast agent. Micro-CT morphometric analysis of balloon and stent injured arteries obtained by 700 transverse sections (voxel size 10 microm) was compared to conventional histological analysis. RESULTS: Intimal hyperplasia was present in stented and balloon injured arteries with a moderate intimal area assessed by Micro-CT and conventional histology (3.91 +/- 0.5 mm(2) vs. 4.18 +/- 0.42; r = 0.9). High significant correlations between Micro-CT image analysis and conventional histomorphometry were obtained for lesion size, size of media, size of lumen and stent area (r = 0.84 to 0.96). CONCLUSION: Micro-CT is feasible for quantitative information about restenosis following balloon angioplasty and stent implantation and has the potential to become a standard technique in many laboratories which will augment serial histology as the reference method for ex-vivo studies of restenosis.

Measurement of single kidney contrast media clearance by multiphasic spiral computed tomography: preliminary results.

OBJECTIVE: We present preliminary results of a new method (hereinafter called 'CT-clearance') to measure single kidney contrast media clearance by performing multiphasic helical CT of the kidneys. CT-clearance was calculated according to an extension of the Patlak-Plot. In contrast to prior investigators, who repeatedly measured a single slice, this method makes it possible to calculate single kidney clearance from at least three spiral CTs, utilizing the whole kidney volume. METHODS: Spiral CT of the kidneys was performed unenhanced and about 30 and 100 s after administration of about 120 ml iopromide. Sum-density of the whole kidneys and aortic density was calculated from this data. Using this data, renal clearance of contrast media was calculated by CT-clearance in 29 patients. As reference, Serum-clearance was calculated in 24 patients by application of a modified one-exponential slope model. Information on the relative kidney function was gained by renal scintigraphy with Tc99m-MAG-3 or Tc99m-DMSA in 29 patients. RESULTS: Linear regression analysis revealed a correlation coefficient of CT-clearance with Serum-clearance of r=0.78 with Cl (CT) [ml/min]=22.2+1.03 * Cl (serum), n=24. Linear regression of the relative kidney function (rkf) of the right kidney calculated by CT-clearance compared to scintigraphy results provided a correlation coefficient r=0.89 with rkf(CT)[%]=18.6+0.58 * rkf(scintigraphy), n=29. CONCLUSION: The obtained results of contrast media clearance measured by CT-clearance are in the physiological range of the parameter. Future studies should be performed to improve the methodology with the aim of higher accuracy. More specifically, better determination of the aortic density curve might improve the accuracy.

A simple and rapid method for postmortem radiographic investigation of lung fine structure.

Radiologic pathologic correlation of lung specimens requires a gas content identical to intravital conditions. Methods of air drying and formalin steam fixation are well known but time consuming. A new, rapid method is presented: the lungs are inflated with compressed air, frozen in liquid nitrogen, and cut into slices. Radiographs taken with soft tissue technique demonstrate structural details down to 200-300 mu. The excellent state of preservation also permits excellent quality of microscopic slides.

Standardized fixation of human lung for radiology and morphometry; Description of a "two chamber"-system with formaldehyde vapor inflation.

In order to obtain optimal preservation of lungs for histology, morphometry and radiology a two-chamber system of lung fixation with hot formaldehyde vapor is introduced. Compared with other procedures this system offers small dead space and ensures quick and thorough fixation by imitating "inspiration" and "expiration". Volume- and pressure-regulated "breathing" enables fixation in a stage of the respiration cycle, which can be chosen. This procedure can be used routinely in the autopsy room. The only serious drawback seems to be air pollution, if the chambers are not absolutely insulated.

[Volume controlled fixation of the lung by formalin vapor (author's transl)]. / Die röntgenologische Feinstruktur der Lunge. I. Volumenkontrollierte Fixierung isolierter Lungen mit Formalindampf.

A new method of lung fixation by formalin vapor is presented. A simple Engstrøm type respirator modified for postmortem formalin insufflation of the lung was developed. Rapid fixation requires use of hot formalin vapor which would destroy available equipment. The main advantage compared to other described methods beside the constant volume is sufficient stirring of formalin and formalin vapor. In order to prevent condensation of water within the lung parenchyma any cooling of the vapor should be avoided. If the lungs are fixed by this method the tissue will stiffen in a position between in- and exspiration. Slices of 1 cm are cut. Radiographs in soft tissue technique guarantee unusual high resolution. Positive findings are identified easily and furthermore studied by microscopy: the direct correlation between X-ray finding and microscopy becomes possible.

[Radiologically implanted subcutaneous tunneled central venous catheters for dialysis: the course and complications]. / Radiologisch implantierte subkutan getunnelte zentrale Venenkatheter zur Dialyse: Verlauf und Komplikationen.

PURPOSE: The aim of the present study was to evaluate the efficacy of fluoroscopically controlled implantation of subcutaneous tunneled single- or double-lumen-catheters for short- and long-term dialysis. PATIENTS AND METHODS: In total, 104 patients were implanted with either a single-lumen Demer catheter or a Permcath double-lumen catheter into the subclavian vein under fluoroscopic control. RESULTS: In 99 of 104 cases (= 95.2%) the implantation remained without complications. Implantation-related occurrences included one pneumothorax, one mediastinal haematoma and one death. 61.5% of the indwelling catheters remained in situ for the intended duration. In 78% of the patients, dialysis was carried out to completion. 37 explantations (38.3%) were required due to various factors including infection (5), thrombosis (3), dislocation (9) and malfunction (20). The average duration of implantation was 59.1 days (range 1-851 days). CONCLUSIONS: Fluoroscopic-controlled implantation of subcutaneous tunneled catheters for dialysis is superior to surgically implanted catheters with regard to lower rates of infections and is equally reliable in respect of rates of complication and patency. Thus, this mode of implantation is a safe and reliable alternative to other procedures as access for haemodialysis.

[Differential diagnosis of acral blood circulation disorders using intra-arterial DSA of the hand]. / Differentialdiagnostik akraler Durchblutungsstörungen mittels intraarterieller DSA der Hand.

32 patients with secondary Raynaud's syndrome and known basic disease (thromboangiitis obliterans, arterial sclerosis, collagenosis) were examined by high-resolution arterial subtraction angiography. There were typical organic fixed vessel irregularities in relation to the extent of the disease. In early stages, however, the functional vasospastic disorder dominates. The extent and the reversibility of the vasospasm were documented after pharmacological treatment. Pharmacoangiography of the hand can therefore be used as helpful method in the differential diagnosis and therapy of Raynaud's syndrome.

[Chondromalacia patellae--arthrographic observations on the genesis and diagnosis of cartilaginous damage (author's transl)]. / Die Chondromalacia patellae--Arthrographische Beobachtungen zur Genese und Diagnose.

Thanks to recent advances in arthrography, diagnosis of cartilaginous lesions has increasingly become a task of the radiologist. An accurate assessment of the cartilage of the femoropatellar joint can be established via double-contrast technique and so-called "défilé" projections, whereas the axial projection of the patella without contrast medium shows only secondary arthrotic changes of bone and is unsuitable for demonstrating early cartilaginous damage. The classification of dysplastic patellae into different types according to Wiberg and Baumgartl yields a statistical correlation with the frequency of chondromalacia, but does not give any conclusive evidence in individual cases. A special influence on joint mechanics and the development of chondromalacia patellae is exercised by a cartilaginous ridge of the medial patellar facette.

[Radiologic aspects of lung morphology: lobulus and acinus (author's transl)]. / Die röntgenologische Feinstruktur der Lunge.

Primary lobule, acinus and secondary lobule are the three basic elements of lung tissue. In order to visualize these structures slices of fixed lungs are documented radiologically by plain films, angio-, and bronchograms. Characteristic pathologic alterations of these elements are edema and inflammation. Both lesions present with atypical radiological pattern. In pneumonia it is shown, that differentiation of air conducting structures of the bronchial tree and structures which are involved in gas exchange appears most valuable for interpretation of confluent densities. According to our experience based upon examination of 143 lung specimens separation into lobules is pathophysiological more important than the organisation into the next smaller unit--the acini: patterns of acinar radiodensities are extremely rare and might sometimes be imitated by peribronchial infiltrations.

[Ectopic gastric mucosa in the duodenal bulb]. / Ektope Magenschleimhaut im Bulbus duodeni.

The radiological and clinical findings of 12 patients with ectopic gastric mucosa in the duodenal bulb are presented. This is a defined disease with characteristic radiological features: multiple small nodular defects of the contrast medium of 1-3 mm diameter. Histology shows complete heterotopia. Pathogenesis and clinical significance are discussed with reference to the literature on this subject.

[The value of magnetic resonance imaging in the clinical course of osteochondrosis dissecans in the knee and ankle joints]. / Die Bedeutung der Magnetresonanztomographie für die Verlaufskontrolle der Osteochondrosis dissecans am Knie- und Sprunggelenk.

PURPOSE: Definition of the prognostic value of clinical and morphological findings in the mid-term follow-up of OCD of the femoral condyle and talus. Demonstration of the consolidation of OCD on MRI depending on different therapies. MATERIALS AND METHODS: 76 patients were examined before and at an average of 30 months after conservative or surgical therapy using T1 and T2 weighted SE and 3D-FISP sequences and contrast enhanced studies. Six clinical (age, gender, site, duration and severity of symptoms, therapy) and six morphological (size, signal intensity, fragmentation, contrast enhancement, condition of cartilage, staging) data were registered on first MRI and correlated with the degree of consolidation of OCD (partial and complete remission, no change and progression) on control MRI. RESULTS: Patients under 17 years showed partial or complete remissions in 73%, those of 17 years or older in 33%. Conservatively treated patients had a higher remission rate (54%) than those treated with different surgical techniques (drilling 50%, refixation 43%, abrasio 38%). Small OCDs had a higher remission rate than large lesions (63% vs. 33%). OCDs covered with intact cartilage healed better than lesions with chondral defects (61% vs. 26%). Contrast enhancing fragments had a better prognosis than non-enhancing lesions (100% vs. 40%). CONCLUSIONS: Prognosis of OCD can be better estimated when size of OCD, condition of cartilage and enhancement of contrast agent is graduated with MRI and patient age is registered. The consequences for therapy planning are great.

[Temporary cava filter: effective prophylaxis of pulmonary embolism in venous thrombosis in the region of the pelvic vascular system and the inferior vena cava?]. / Temporärer Kavafilter: Effektive Prophylaxe von Lungenembolien bei venösen Thrombosen im Bereich der Beckenstrombahn und der Vena cava inferior?

PURPOSE: To assess the temporary Günther filter system concerning handling, complication rate and efficacy in respect to prophylaxis of pulmonary embolism. PATIENTS AND METHODS: 45 temporary Günther filters were placed in 44 patients (mean age 46 years) with deep venous thrombosis of the iliac and/or inferior vena cava. RESULTS: The mean time until filter retrieval was 6.1 +/- 4.1 days (maximum 14 days) dependent on the success of either thrombolytic therapy or thrombus consolidation. 27 patients underwent systemic thrombolytic therapy (61%), three patients (7%) received local thrombolysis. 14 patients (32%) were treated with heparin in a therapeutic dosage (PTT > 60 sec). We observed four complications (8.8%): one accidental arterial puncture (carotid artery on attempting an internal jugular vein approach), one infection located at the puncture site and one caval vein thrombosis in a patient with known heparin-associated thrombocytopenia. One patient died of pulmonary embolism despite correct filter positioning. CONCLUSION: Percutaneous placement of inferior vena cava filters is therefore an easy, safe and effective prophylaxis in respect of pulmonary embolism if combined with thrombolytic therapy or therapeutic heparinisation.

[Investigation of radiologic lung fine structure by freezing of inflated specimens in liquid nitrogen (author's transl)]. / Die röntgenologische Feinstruktur der Lunge. II. Gefrierhärtung isolieter Lungen in flüssigem Stickstoff.

Radiologic pathologic correlation of lung specimens requires a gas content identical to intravital conditions. Methods of air drying and formalin steam fixation are well known but time consuming. A new, quick method is presented: The lungs are inflated with compressed air, frozen in liquid nitrogen, and cut into slices. Radiographs taken in soft tissue technique will demonstrate structural details down to 200--300 mu. The excellent state of preservation enables unusual quality of microscopic slides, as well.

[Shoulder arthrography in rheumatoid arthritis]. / Schulterarthrographie bei rheumatoider Arthritis.

Shoulder arthrography in a patient with rheumatoid arthritis is performed to differentiate between a rheumatoid flare and limitation of motion secondary to tear in the rotator cuff. Accurate diagnosis is important because of the therapeutic implications. The arthrographic findings characteristic of rheumatoid involvement of the shoulder joint are nodular filling defects of the joint, the subacromial and subdeltoideal bursa in case of rotator cuff tear, irregular capsular attachment, contracted joint space and visualized lymphatic drainage. A dilatation of the biceps tendon sheath has not been shown.

[Sonography in callus distraction of the hypoplastic mandible]. / Einsatz der Sonographie bei der Kallusdistraktion am hypoplastischen Unterkiefer.

OBJECTIVES: Since the early 1990's when callus distraction of hypoplastic mandibles was developed, surgeons have been looking for a reliable method to monitor distraction treatment. X-rays films resulted in insufficient quality of images of low calcified structures and are only of little support in follow-up. Therefore, a standardised protocol using ultrasound was introduced. METHODS: 24 patients were included (aged 4 - 29 years with hemifacial microsomy [19], mandibulary micrognathia [5]), 20 intraoral (Howmedica-Leibinger/Mühlheim) and 9 extraoral distractors (Normed/Tuttlingen). Standard procedures for intra- and extraoral distraction were carried out and all postsurgical treatment steps were monitored by ultrasound. RESULTS: The mineralisation of the neocallus shows the following sequence: echogenic dots, needles directed along the distraction direction, bands, plaques, and modulation of the neocompacta. Additional therapeutically relevant questions of distraction distance, inflammation or occurrence of pus, arising during treatment were answered by sonography. Distance measurements could be performed reliably. CAT scan and MRI cannot be carried out because of metal artefacts. X-ray pictures like orthopantomogram and Clementschisch projection cannot show the early mineralisation and do not allow an exact distance measurement. CONCLUSIONS: Sonography is a effective, method to investigate the callus field without using X-rays and supports monitoring and decision making in distraction treatment of hypoplastic mandibles.

[Comparison of different MRT techniques in the diagnosis of degenerative cartilage diseases. In vitro study of 50 joint specimens of the knee at T1.5]. / Vergleich von verschiedenen MRT-Techniken in der Diagnose von degenerativen Knorpelerkrankungen--In-vitro-Studie an 50 Gelenkpräparaten des Knies bei 1,5T.

PURPOSE: An experimental study was performed on joint specimens of the knee to assess the advantages and disadvantages of 14 generally available sequences in cartilage imaging. METHODS: Each of the 50 surgically exposed cadaveric joints of the knee was examined by the following sequences: T1, proton- and T2 weighted spin echo(SE) sequences, proton- and T2 weighted Turbo-SE, T1 weighted SE with fat suppression, MTC combined with T1-weighted SE and T2 weighted FLASH-2 D, STIR, FISP-3 D, FLASH-3 D (with fat suppression), and MR arthrography. We assessed the image quality by a scale, signal to noise-ratio of cartilage and joint fluid, and the accuracy in detection of cartilage lesions. Pathology and arthroscopy were reference methods to MRI, and demonstrated grade 1-4 lesions on 186 of 300 joint facettes. RESULTS: Advanced stages of cartilage lesions (65 grade 3 and 4 lesions) were detected by standard SE sequences in 67-94%. Application of volume techniques (FISP-3 D, FLASH-3 D), high definition matrix (512 pixel), MTC with FLASH-2 D and MR-arthrography improved the sensitivity up to 82-100%. Superficial lesions (65 grade 2 lesions) were demonstrated in 3-38%, and on MR arthrography in 45%. Structural changes (56 Grade 1 lesions) were recorded on MR) in only 10%. CONCLUSIONS: With regard to standard SE sequences, the detectability of cartilage lesions can be improved by techniques that use 512 matrices, selective cartilage imaging, and volume acquisition.

[CT quantification of pleuropulmonary lesions in severe thoracic trauma]. / Computertomographische Quantifizierung pleuropulmonaler Läsionen beim schweren Thoraxtrauma.

PURPOSE: Computed quantification of the extent of pleuropulmonary trauma by CT and comparison with conventional chest x-ray--Impact on therapy and correlation with mechanical ventilation support and clinical outcome. METHOD: In a prospective trial, 50 patients with clinically suspicious blunt chest trauma were evaluated using CT and conventional chest x-ray. The computed quantification of ventilated lung provided by CT volumetry was correlated with the consecutive artificial respiration parameters and the clinical outcome. RESULTS: We found a high correlation between CT volumetry and artificial ventilation concerning maximal pressures and inspiratory oxygen concentration (FiO2, Goris-Score) (r = 0.89, Pearson). The graduation of thoracic trauma correlated highly with the duration of mechanical ventilation (r = 0.98, Pearson). Especially with regard to atelectases and lung contusions CT is superior compared to conventional chest x-ray; only 32% and 43%, respectively, were identified by conventional chest x-ray. CONCLUSION: CT allows rapid classification and quantification of pulmonary lesions after thoracic trauma and provides higher sensitivity and reliability. Because of the great correlation with the extent of artificial respiration in respect of duration and pressure, prognosis of the individual patient, as well as a differential therapy, appear possible.

[After-care problems and complications of percutaneous biliary drainage]. / Nachsorgeprobleme und Komplikationen der perkutanen Gallengangsdrainage.

This is a follow-up study of 171 patients concerning the patients' care and complications following biliary drainage. Complications caused by puncture and drainage are considered separately. External biliary drainage resulted in 39%, internal in 26% with complications. The influence of advantages and side effects upon the indications of biliary drainage is discussed. Prognosis concerning the survival rate depends on the underlying pathology: In obstructive jaundice caused by metastases the patients only survived two months while the mean survival rate in carcinoma of the biliary ducts is 18 months.

[Perorally insertable endotracheal stents made from NiTi memory alloy--an experimental animal study]. / Peroral einführbare endotracheale Stützgerüste aus der Memory-Legierung NiTi--Tierexperimentelle Studie.

NiTi prostheses were perorally inserted in 12 rabbits. The spiral prostheses were overgrown by normal tracheal epithelium over time. No adverse effects due to impairment of the mucociliary clearance and no chondromalacia occurred. We conclude that perorally insertable prostheses made of the shape-memory alloy NiTi may be used as endotracheal or endobronchial prostheses.