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Biomedical subjects

F Kainberger

Publications and source records attributed to F Kainberger.

At least 37 records · Page 2Linked to original sources

[Apophyseal damage in adolescent athlete].

The increasing demands on the adolescent athlete in high performance sports puts high biomechanical stress on the growing structures of the active and passive locomotor system. The "growing factor" itself increases stretching forces on tendon insertions, which are often overloaded when a physical demanding sport is performed additionally. The apophysis is an ossification nucleus near the tendon insertion, which appears before the growing age resumes and these apophysis finally fuses with the adjacent bone. The tensile forces from vigorous sports activity leads to a chronic or acute avulsion of the ossifying tendon insertion. The radiological appearance of this apophyseal damage with ossification and osteolytic processes is sometimes difficult with respect to differential diagnoses. Apophyseal impairment is associated with pain, tenderness to palpation and decreased muscle function. If it is not diagnosed and treated properly it can lead to end of career in many adolescent athletes.

Adolescent↗

[Trends in Vienna radiology--from roentgen laboratory to university clinic for radiodiagnosis].

In Vienna/Austria, with leading representatives of the so-called second Viennese medical school at the turn of the 19th to the 20th century, the detection of x-rays by W. C. Röntgen was observed with special interest. In the general hospital of Vienna, where still today the medical school of the university of Vienna is hosted, high research activities to understand the origin and the effects of X-rays were performed. Guido Holzknecht (1872-1931) was the first chairman of the central roentgen laboratory. Today, the scientific and the clinical activities at the department of diagnostic radiology are manifold and virtually all fields of imaging are covered.

Austria↗

[Computer-assisted radiologic quantification of hand and foot changes in rheumatoid arthritis].

Driven by the increasing implementation of electronical picture archiving and communications system (PACS) into every days practice a fully operative Java application software was developed to support the efficacy of the scoring process in rheumatoid arthritis. This software, namely the "Rheuma-Coach" offers the possibility to use the Larsen- or the Ratingen-Score. We measured time savings of approximately 20% per case if this computer assistance was used. The lack of a standard for the positioning of limbs was confirmed.

Arthritis, Rheumatoid↗

[High resolution magnetic resonance tomography and ultrasound imaging of the Achilles tendon].

Increasing sporting activities of high-ranking athletes as well as of the general population have led to a higher number of lesions of the Achilles tendon. Radiological investigations of this tendon are requested more often and the resolution of MR and ultrasound images has been improved significantly. Intratendinous lesions can be detected and may be differentiated from normal collagen fibers.

Achilles Tendon↗

[Radiologic progression of rheumatoid arthritis in early basic drug therapy].

For therapy and follow-up control in early disease modifying antirheumatic drug (DMARD) treated rheumatoid arthritis (RA), objective quantification is still lacking. Therefore, radiological analyses are considered the most appropriate method. One aim of this study was to retrospectively determine the time-dependent progression of joint damage in RA patients on DMARDs. Outpatient records and radiographs from hands and feet of 54 RA patients on DMARDs were evaluated. Radiographs were quantified by using the original Larsen score and a newly developed computer-assisted quantification software. Our observations showed that radiologically-detectable damage in all patients, regardless of their treatment, is most pronounced during the first year of disease, being mitigated and generally progressing linearly in the subsequent years. Cumulative ESR correlated with RA progression, and its reduction with therapeutic efficacy.

Antirheumatic Agents↗

[Dose classification in digital roentgen diagnosis: clinical applications].

Technological improvements in digital radiography and computed tomography have led to a substantial increase of radiation dose that subjectively cannot be detected. In order to reduce dose in a form that may be used in clinical practise, the quality of digital radiograms and computed tomography images should be classified in three classes. Low-dose investigations are indicated in children, in case of therapy control and for imaging organs with high differences in tissue contrast. High-dose investigations are scarcely indicated and middle-dose investigations should be performed in all other remaining clinical situations. Dose recommendations given by vendors in radiology should be viewed critically.

Adult↗

[Kinematic magnetic resonance tomography in functional disorders of joints and vertebral articulations].

Imaging studies of peripheral joints and of vertebral junctions are of major importance in the diagnosis of many degenerative diseases of the musculoskeletal system. Radiograms with flexion and extension views are regarded as standard for diagnosing abnormalities of the spine, the patello-femoral joint, and other articulations. With magnetic resonance imaging (MRI), kinematic studies can be performed analogously. With high gradient field strengths and in-phase and opposed-phase gradient echo sequences it is possible to study the motion of joints continuously. First results show that this technique may be added to static magnetic resonance imaging sequences in certain cases with hypermobility or instability of the knee and other major joints.

Ankle Joint↗

[Bone metastases: new trends in diagnostic imaging].

Skeletal metastases are common in patients with cancers of the breast, lung, kidneys, prostate, and thyroid gland. Two main aspects have to be considered in diagnostic imaging. Screening in patients with known primary tumor. Triphasic Sczintigraphy is the imaging modality of choice for this purpose, however, whole-body-magnetic resonance imaging seems to be a potential alternative. Evaluation of suspicious skeletal lesions, which is currently dominated by magnetic resonance imaging. New perspectives for preoperative staging as well as for reconstruction- and implant-surgery are made available by multidetector-row-computed tomography. Non-invasive techniques, such as diffusion weighted imaging, positron emission tomography and positron emission tomography/computed tomography are now available, which seem to have potential for reliable tissue characterization. This feature is critical for monitoring treatment response in oncology.

Biopsy↗

[Value of roentgen diagnosis in recognition of primary and potentially malignant bone tumors].

To assess the efficiency of plain radiographs for the detection of primary and potentially malignant bone tumors a retrospective study in 70 patients with histologically proven bone sarcomas was performed. Plain radiographs were the first imaging modality in most cases and for many patients the basic step leading to further diagnostic investigations. With young patients suffering from bone pain imaging work-up was obtained immediately, whereas older patients showed significant delay until radiographs were performed. The findings of this study suggest that radiography is an effective tool for the diagnosis of primary and potentially malignant bone tumors and that physicians should think of bone tumors also when patients beyond the adolescence have focal bone pain.

Adolescent↗

Imaging features of iliopsoas bursitis.

The aim of this study was firstly to describe the spectrum of imaging findings seen in iliopsoas bursitis, and secondly to compare cross-sectional imaging techniques in the demonstration of the extent, size and appearance of the iliopsoas bursitis as referenced by surgery. Imaging studies of 18 patients (13 women, 5 men; mean age 53 years) with surgically proven iliopsoas bursitis were reviewed. All patients received conventional radiographs of the pelvis and hip, US and MR imaging of the hip. The CT was performed in 5 of the 18 patients. Ultrasound, CT and MR all demonstrated enlarged iliopsoas bursae. The bursal wall was thin and well defined in 83% and thickened in 17% of all cases. The two cases with septations on US were not seen by CT and MRI. A communication between the bursa and the hip joint was seen, and surgically verified, in all 18 patients by MR imaging, whereas US and CT failed to demonstrate it in 44 and 40% of the cases, respectively. Hip joint effusion was seen and verified by surgery in 16 patients by MRI, whereas CT (4 of 5) and US ( n=12) underestimated the number. The overall size of the bursa corresponded best between MRI and surgery, whereas CT and US tended to underestimate the size. Contrast enhancement of the bursal wall was seen in all cases. The imaging characteristics of iliopsoas bursitis are a well-defined, thin-walled cystic mass with a communication to the hip joint and peripheral contrast enhancement. The most accurate way to assess iliopsoas bursitis is with MR imaging; thus, it should be used for accurate therapy planning and follow-up studies. In order to initially prove an iliopsoas bursitis, US is the most cost-effective, easy-to-perform and fast alternative.

Bursitis↗

Adenovirus-based overexpression of tissue inhibitor of metalloproteinases 1 reduces tissue damage in the joints of tumor necrosis factor alpha transgenic mice.

OBJECTIVE: Rheumatoid arthritis is a prototype of a destructive inflammatory disease. Inflammation triggered by the overexpression of tumor necrosis factor alpha (TNFalpha) is a driving force of this disorder and mediates tissue destruction. Since matrix metalloproteinases (MMPs) are among the molecules activated by TNFalpha, we hypothesized that overexpression of their natural inhibitor, tissue inhibitor of metalloproteinases 1 (TIMP-1), in TNFalpha transgenic mice could inhibit the development of destructive arthritis. METHODS: Systemic treatment was carried out by replication-defective adenoviral vectors for TIMP-1, beta-galactosidase, or phosphate buffered saline (PBS), which were applied once at the onset of arthritis. Clinical, serologic, radiologic, and histologic outcomes were assessed 18 days after the treatment. RESULTS: The AdTIMP-1 group showed significantly reduced paw swelling and increased grip strength compared with the 2 control groups, whereas total body weight, TNFalpha, and interleukin-6 levels were similar in all 3 groups. Radiographic assessment revealed a significant reduction of joint destruction in the AdTIMP-1 group; this was confirmed by histologic analyses showing reduced formation of pannus and erosions in the AdTIMP-1 group compared with the AdLacZ and PBS control groups. The formation of arthritis-specific autoantibodies to heterogeneous nuclear RNP A2 was not observed in the AdTIMP-1 group but was present in the 2 control groups. CONCLUSION: These results indicate a central role of MMPs in TNFalpha-mediated tissue damage in vivo and a promising therapeutic role for TIMP-1.

Adenoviridae↗

Skeletal cystic angiomatosis with severe hip joint deformation resembling massive osteolysis.

An aggressive destruction pattern resulting in joint deformation has not been described in skeletal cystic angiomatosis (SCA) so far. We present the case of a 6-year-old boy with such findings strongly resembling Gorham's disease (massive osteolysis). Since the prognosis of the latter entity tends to be less favorable than in SCA, particularly SCA without extraskeletal involvement, careful differentiation of both disorders appears to be important.

Angiomatosis↗

In-vitro assessment of a registration protocol for image guided implant dentistry.

In this study a computer aided navigation technique for accurate positioning of oral implants was assessed. An optical tracking system with specially designed tools for monitoring the position of surgical instruments relative to the patient was used to register 5 partially or completely edentulous jaw models. Besides the accuracy of the tracking system, the precision of localizing a specific position on 3-dimensional preoperative imagery is governed by the registration algorithm which conveys the coordinate system of the preoperative computed tomography (CT) scan to the actual patient position. Two different point-to-point registration algorithms were compared for their suitability for this application. The accuracy was determined separately for the localization error of the position measurement hardware (fiducial localization error-FLE) and the error as reported by the registration algorithm (fiducial registration error-FRE). The overall error of the navigation procedure was determined as the localization error of additional landmarks (steel spheres, 0.5 mm diameter) after registration (target registration error-TRE). Images of the jaw models were obtained using a high resolution CT scan (1.5 mm slice thickness, 1 mm table feed, incremental scanning, 120 kV, 150 mAs, 512 x 512 matrix, FOV 120 mm). The accuracy of the position measurement probes was 0.69 +/- 0.15 mm (FLE). Using 3 implanted fiducial markers, FRE was 0.71 +/- 0.12 mm on average and 1.00 +/- 0.13 mm maximum. TRE was found to be 1.23 +/- 0.28 mm average and 1.87 +/- 0.47 mm maximum. Increasing the number of fiducial markers to a total of 5 did not significantly improve precision. Furthermore it was found that a registration algorithm based on solving an eigenvalue problem is the superior approach for point-to-point matching in terms of mathematical stability. The experimental results indicate that positioning accuracy of oral implants may benefit from computer aided intraoperative navigation. The accuracy achieved compares well to the resolution of the CT scan used. Further development of point-to-point/point-to-surface registration methods and tracking hardware has the potential to improve the precision of the method even further. Our system has potential to reduce the intraoperative risk of causing damage to critical anatomic structures, to minimize the efforts in prosthetic modelling, and to simplify the task of transferring preoperative planning data precisely to the operating room in general.

Algorithms↗

Placement of endosteal implants in the zygoma after maxillectomy: a Cadaver study using surgical navigation.

Endosteal implants facilitate obturator prosthesis fixation in tumor patients after maxillectomy. Previous clinical studies have shown, however, that the survival of implants placed into available bone after maxillectomy is generally poor. Nevertheless, implants positioned optimally in residual zygomatic bone provide superior stability from a biomechanical point of view. In a pilot study, the authors assessed the precision of VISIT, a computer-aided surgical navigation system dedicated to the placement of endosteal implants in the maxillofacial area. Five cadaver specimens underwent hemimaxillectomy. The cadaver head was matched to a preoperative high-resolution computed tomograph by using implanted surgical microscrews as fiducial markers. The position of a surgical drill relative to the cadaver head was determined with an optical tracking system. Implants were placed into the zygomatic arch, where maximum bone volume was available. The results were assessed using tests for localization accuracy and postoperative computed tomographic scans of the cadaver specimens. The localization accuracy of landmarks on the bony skull was 0.6 +/- 0.3 mm (average +/- SD), as determined with a 5-df pointer probe; the localization accuracy of the tip of the implant burr was 1.7 +/- 0.4 mm. The accuracy of the implant position compared with the planned position was 1.3 +/- 0.8 mm for the external perforation of the zygoma and 1.7 +/-1.3 mm for the internal perforation. Eight of 10 implants were inserted with maximal contact to surrounding bone, and two implants were located unfavorably. Reliable placement of implants in this region is difficult to achieve. The technique described in this article may be very helpful in the management of patients after maxillary resection with poor support for obturator prostheses.

Cadaver↗

Quantitative US of the calcaneus: cutoff levels for the distinction of healthy and osteoporotic individuals.

PURPOSE: To calculate cutoff levels for quantitative ultrasonography (US) performed to distinguish healthy individuals and those with osteoporosis identified with dual x-ray absorptiometry. MATERIALS AND METHODS: In 1,357 patients (856 females, aged 55.1 years +/- 15.4 [mean +/- SD]; 501 males, aged 50.4 years +/- 15), bone mineral density measurements of the lumbar spine (posteroanterior, L1 through L4) and femoral neck were obtained, and quantitative US was performed to determine the stiffness of the calcaneus. Individuals with a T score less than -2.5 (osteoporotic) at the spine and femur were identified, and upper T-score cutoff values (3 SDs from the mean) in the groups of male and female patients with osteoporosis were identified. RESULTS: Females with dual x-ray absorptiometric values that were indicative of osteoporosis of the spine had an upper T-score cutoff value of -1.0 (males, -0.2). Females who had femoral osteoporosis showed an upper quantitative US T-score cutoff value of -0.6 (males, 0). CONCLUSION: Cutoff values may permit the use of quantitative US to screen for the presence of osteoporosis in the spine and femur. Quantitative US will help to prevent unnecessary dual x-ray absorptiometric and conventional radiographic examinations.

Absorptiometry, Photon↗

[Paget disease or fibrous dysplasia of the radius?--A case report].

A 46 years old man, who showed a painful and progressive deformity of the left radius, is presented. After some months a fracture within the affected bone area occurred. The diagnostic procedures including X-ray, MRI, scintigraphy and histology were controversial. Both fibrous dysplasia and Paget's disease of bone were suspected. The critical analysis of all results concluded that the most likely diagnosis was fibrous dysplasia. Unaware of the diagnostic discrepancies, the patient received a therapy with pamidronate 3 x 60 mg intravenously, which improved symptoms. After 14 months, the patient complained again about pain in the left radius. After a second therapy with pamidronate the patient currently exhibits no symptoms. The controversial diagnostic results and the applied therapeutic procedure are discussed.

Diagnosis, Differential↗