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Biomedical subjects

F Kainberger

Publications and source records attributed to F Kainberger.

At least 19 recordsLinked to original sources

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↗

[Tendon overuse syndrome: imaging diagnosis].

Injuries of muscles and tendons occur commonly during various sporting activities and in most cases the athletes feel such an accident to be sudden and unavoidable. The rupture of a tendon, however, has to be considered in many cases as the final stage of a long-standing progressive degeneration of collagen fibers. This process can be described as "tendon overuse syndrome (TOS)". Diagnostic imaging modalities, especially sonography and MRI, are suitable to detect and analyse the different stages of this syndrome and the degree of morphological abnormalities. The first stage is painful functional derangement, followed by tendovaginitis, peritendinitis, or bursitis. The third stage is tendinosis resulting from biomechanical or ischaemic injury of tendon fibers which may eventually be followed by partial or complete rupture. Regional or individual specifications of these four stages may occur at anatomically predisposing sites, so-called critical zones, or during periods of specific proneness, the vulnerable phases.

Athletic Injuries↗

[Radiologic imaging of degenerative and inflammatory joint diseases in women].

Pain in joints and other structures of the musculoskeletal system is a common complaint in women. It may occur as functional pain, in many cases as inflammatory episode of arthrosis or of metabolic joint disease, sometimes as early manifestation of rheumatoid disease. With conventional radiography, high-resolution sonography, and MR imaging it is possible to classify many of these clinical syndromes. A semiquantitative assessment of inflammatory activity can be made by analysing the degree of joint effusion, the thickness of the synovium and the extent of hypervascularisation.

Arthralgia↗

[Temporomandibular joint pain: radiological diagnosis].

Pain in the temporomandibular joint is often the result of internal derangement, other causes are traumatic, functional or inflammatory processes. Conventional radiography is indicated in case of suspected trauma or for specialised preoperative measurements to plan the treatment of various facial dysplasias. MRI and CT should be used in the context with the results of clinical investigation and of axiography to differentiate the various functional and morphological abnormalities of this joint.

Diagnosis, Differential↗

[Glossary].

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Internet↗

[The pharynx. The imaging of its normal anatomy].

BACKGROUND: The pharynx, being part of the digestive as well as the respiratory system, is embedded in the complex spatial anatomy of the neck and, due to its function and location, represents a very sophisticated region. DIAGNOSIS: Cross-sectional imaging with CT and MR imaging plays an indispensable complementary role to clinical work-up, as far as submucosal and deep cervical spaces are concerned. However, as dysphagia is a common symptom in clinical practice, interpretation of double contrast studies and videofluoroscopic investigations are also on frequent demand in the daily routine. CONCLUSION: Close interdisciplinary co-operation and the radiologist's familiarity with the anatomy of the region are required in order to use the diagnostic tools in an optimal fashion.

Cineradiography↗

[Radiologic quantification of joint changes. A methodological overview].

Osteoarthritis as well as rheumatoid arthritis lead to chronical progressive destruction of diseased joints. As aggressive new treatments need to be evaluated, plenty of (semi-) quantitative methods for the radiological joint evaluation had been developed. They lack sufficient reproducibility due to their low objectivity. Modern approaches of computer-assisted radiological quantification should increase the reproducibility and efficiency of radiological scoring. Automatically calculated, computer-assisted measurements of joint space, cartilage- and synovial volume, periarticular assessment of bone mineral density and quantitative analysis of the subchondral plate will have major impact on the radiological routine of the future.

Arthritis, Rheumatoid↗

Long-term home exercise program: effect in women at high risk of fracture.

OBJECTIVE: To determine whether a better outcome in terms of physical frailty could be achieved with a regular home exercise program in women at high risk of fracture. DESIGN: Prospective long-term observational study. SETTING: Outpatient clinic of physical medicine and rehabilitation. PARTICIPANTS: Women with a history of postmenopausal fractures and an age-adjusted low bone mass, as determined 7 to 12 years earlier. INTERVENTION: Home exercise program. OUTCOME MEASURES: Thirty-three women were followed. The exercise group and control group were compared with regard to fracture rates, episodes of falling, neuromuscular performance (one-leg stance, chair rise, body sway, tandem walk, tapping test), and bone mineral density (BMD). RESULTS: Twenty-five women with a mean age of 73.8+/-5.7 yrs appeared for the investigation. An exercise program had been prescribed in 19 women, and six served as controls. Seven women of the exercise group (36.8%) regularly performed the exercises. No differences between participants of the groups in terms of fracture rates, falling episodes, neuromuscular performance, and BMD were observed. CONCLUSION: It appears that a home exercise program does not affect the outcome of postmenopausal women at high risk of fracture.

Aged↗

Subchondral bone and cartilage disease: a rediscovered functional unit.

The role of subchondral bone in the pathogenesis of cartilage damage has likely been underestimated. Subchondral bone is not only an important shock absorber, but it may also be important for cartilage metabolism. Contrary to many drawings and published reports, the subchondral region is highly vascularized and vulnerable. Its terminal vessels have, in part, direct contact with the deepest hyaline cartilage layer. The perfusion of these vessels accounts for more than 50% of the glucose, oxygen, and water requirements of cartilage. Bony structure, local metabolism, hemodynamics, and vascularization of the subchondral region differ within a single joint and from one joint to another. Owing to these differences, repetitive, chronic overloading or perfusion abnormalities may result in no pathological reaction at all in one joint, while in another joint, these same conditions may lead to osteonecrosis, osteochondritis dissecans, or degenerative changes. According to this common etiological root, similar pathological reactions beginning with marrow edema and necrosis and followed by bone and cartilage fractures, joint deformity, and insufficient healing processes are found in osteonecrosis, osteochondritis dissecans, and degenerative disease as well.

Biomechanical Phenomena↗