Biomedical subjects

F Kainberger

Publications and source records attributed to F Kainberger.

At least 91 records · Page 5Linked to original sources

PubMed1997

Impact of spinal degenerative changes on the evaluation of bone mineral density with dual energy X-ray absorptiometry (DXA).

The purpose of this study is to evaluate degenerative factors in a postmenopausal patient group and differentiate the influence on bone mineral density (BMD) measurements by dual-energy X-ray absorptiometry (DXA). The patients and methods included an investigation of 144 postmenopausal women (mean 63.3 years) with PA-DXA of the spine. Degenerative factors (osteophytes, osteochondrosis, scoliosis, and vascular calcification) were evaluated from plain lumbar radiographs, their estimated probability was analyzed as a function of age, and their influence on BMD measured by PA-DXA was determined. The results of the study revealed osteophytes in 45.8%, vascular calcifications in 24.3%, scoliosis in 22.2%, osteochondrosis in 21.5%. The estimated probability for degenerative factors increased from 35 to 80% in the 55- to 70- year age group. Osteophytes and osteochondrosis were associated with up to a 14% increase in BMD values (P < 0.001). Vascular calcifications showed a positive trend, whereas scoliosis did not show a discernible influence.We concluded that degenerative factors, except for scoliosis, showed an influence on BMD as measured by DXA. Their prevalence increased rapidly between 55 and 70 years of age. Interpretation of PA-DXA spine data for subjects of or above this age range should be complemented by plain film radiographs.

Absorptiometry, Photon↗

PubMed1997

Degenerative joint disease: cartilage or vascular disease?

The aetiology of degenerative joint disease is multifactorial, but one main cause is overloading (mechanical stress). While until recently it was well accepted that this represented primarily a disorder of cartilage with reactive subchondral changes, there is now some evidence that it might be primarily a subchondral problem with secondary changes in the articular cartilage. Early subchondral changes include redistribution of blood supply with marrow hypertension, oedema and probably micro-necrosis. These findings are very similar to those in avascular necrosis of bone and raise the question of a vascular aetiology. While these first reports need further proof, it seems clear that the articular cartilage and subchondral regions are one functional unit, in which the subchondral region is more stress sensitive. Recently described channels connecting these two regions strengthen this opinion. These new concepts are exciting and may make a major impact in the near future on the management of and research into degenerative joint disease.

Bone and Bones↗

PubMed1997

Imaging of tendons--adaptation, degeneration, rupture.

Tendon imaging is mainly performed with ultrasonography (US) and magnetic resonance imaging (MRI) and has been improved within the last years because of technical advancements and a better understanding of tendon pathology. Several concepts concerning the etiology and the course of tendon diseases have influenced image interpretation and vice versa. Adaptive mechanisms within the tendon tissue against stress can be observed mainly on histologic specimens and not macroscopically or with in-vivo imaging. Degeneration may occur in the form of tendinitis, peritendinitis, enthesitis, or myotendinal junction abnormality. Distinct imaging findings exist for most of these forms. Many concepts that have been developed to explain tendon degeneration have been applied on virtually all tendons in the human body. They can be grouped into those which focus on hypovascularization, on biomechanical overload, and on degeneration secondary to other underlying disease. Tendon rupture seems, in many cases, to be the final stage of tendinitis. From this point of view, imaging may be used to predict the risk of tendon rupture together with other intrinsic and with extrinsic parameters. These considerations result in the concept of the "vulnerable zone" and of the "critical phase" in which tendon ruptures may predominantly occur.

Adaptation, Physiological↗

PubMed1997

Spiral CT evaluation of deep venous thrombosis.

Spiral CT venography is a technical innovation in vascular imaging that can optimize vessel contrast in the deep venous system and, therefore, is an accurate diagnostic tool to detect deep venous thrombosis. Compared with conventional venography, the amount of contrast material can be reduced by 80%. While using spiral CT as the primary imaging technique for the detection of pulmonary embolism, the cause of embolism can be evaluated within a short period of additional imaging time without further patient mobilization. This review outlines fundamental techniques in spiral CT venography and summarizes our clinical experience at Vienna University Medical Center.

Adult↗

PubMed1997

Lactosorb panel and screws for repair of large orbital floor defects.

In a series of five patients with extensive fractures of the orbital floor, we used a biodegradable sheet for bridging of the bony defects. To achieve optimal support of the orbital contents in their anatomically correct position, we fixed the sheet with at least two resorbable screws to the infraorbital rim. This new technique appears to be superior to conventional methods because it offers reproducible results without the need for secondary interventions.

Adolescent↗

PubMed1996

Vascular reconstruction for limb salvage in sarcoma of the lower extremity.

OBJECTIVES: To examine the patency and limb-salvage characteristics of vascular reconstruction in patients with sarcomas of the lower extremity who had been treated with limb-preserving resection and to examine patient survival during a long follow-up period. DESIGN: Retrospective cohort study. SETTING: University hospital, tertiary referral center. PATIENTS: From 1984 to 1992, 14 patients underwent limb-preserving resection of sarcomas in the proximal lower extremity, with 20 vascular reconstructions performed. OUTCOME MEASURES: Color Doppler scans documented patency of the vascular reconstructions. Clinical evaluation included functional results in terms of limb movement and quality of life. Local tumor control and systemic recurrence were examined by repeated radiologic examination. Overall survival as well as time and cause of death were assessed. RESULTS: A total of 13 patients had patent vascular grafts, while the venous graft became occluded in 1 patient. Limb function was rated as excellent or good in 9 patients, as fair in 3, as poor in 1, and could not be clinically estimated in 1. Postoperative thrombosis of the venous graft was detected in 3 patients and was effectively managed by thrombectomy in 2. Three patients underwent reoperation because of hematoma or complications caused by local infection. The tumor endoprosthesis had to be replaced in 3 patients. During follow-up periods that ranged from 15 to 132 months (mean, 55 months), 4 patients died. In all of these patients the cause of death was systemic recurrence in the lung. Two additional patients developed pulmonary metastases, but at the time of this report, they were still alive as long as 132 months after operative resection or chemotherapy. No local recurrence was found. CONCLUSION: Limb-preserving resection of sarcoma of the lower extremity can be performed with satisfactory function of the limb maintained, even if it becomes necessary to resect the femoral vessels. Autologous venous graft for vascular reconstruction is the treatment of choice. In spite of the high incidence of metastases, considerable long-term survival is possible.

Adolescent↗

PubMed1996

[Differential diagnosis of diseases of the Achilles tendon. A clinico-sonographic concept].

Ultrasound of the Achilles tendon is a suitable means of differentiating various diseases of the tendon and the surrounding tissue. Different forms of degenerative disease (tendinitis, peritendinitis or bursitis, fibroosteitis, and Haglund's disease) can be discriminated from rheumatic and metabolic diseases. Congenital and developmental abnormalities can also be detected. Tendon degeneration mainly occurs in the ventral part of the medial third of the tendon ("critical zone"). Immature tissue in this area leads to temporary [correction of temorary] instability of the tendon with a high risk of rupture ("vulnerable phase"). With sonography, lesions of the Achilles tendon are visible early in the course of the disease.

Achilles Tendon↗

PubMed1996

[MRI and ultrasound in rheumatology].

Technical innovations and software improvements in magnetic resonance imaging (MRI) and high-resolution sonography (US) have definitely influenced the diagnostic imaging of rheumatic diseases. For MRI, improvements in surface coils, dedicated low-field systems (0.2 T), and software improvements (shorter acquisition times and refinements of fat suppressing techniques) must be mentioned. For sonography, the main innovations concern the development of higher transducer frequencies (7-15 Mhz) and power Doppler imaging. Clinical evaluations have shown that MRI and US are most useful in cases of suspected rheumatic disease with negative plain film radiographs and for documenting the course of the disease, diagnosing of early rheumatoid arthritis, making a differential diagnosis in clinically unclear rheumatic diseases, investigating vascularization, and quantifying pannus formation. In order to improve diagnostic efficacy the role of MRI and US in the management of patients with rheumatic disease should be reconsidered.

Arthritis, Rheumatoid↗

PubMed1996

[Ultrasound morphology of the Achilles tendon and differential diagnosis].

AIM: To correlate sonographic findings and clinical disorders of the Achilles tendon, considering newer aspects of their etiology and pathogenesis. METHOD: In a retrospective cross-sectional study the sonographic findings in 52 patients with tendonitis, heel swelling, or suspected rupture were analysed and correlated with the final diagnosis. Tendon lesions due to lipid storage diseases or rheumatic diseases were analysed on the basis of reports in the literature. RESULTS: Ultrasound abnormalities were found in 41 of the 52 symptomatic patients (40 degenerative changes of the tendon and/or the peritendinous tissue, 1 inflammatory rheumatologic process, 1 metabolic disorder, 8 ruptures, 2 congenital or developmental abnormalities). Ultrasound signs were not specific for each of the diagnoses but typical combinations of distinctive signs together with clinical findings led to the correct diagnoses. CONCLUSION: Patients with suspected lesions of the Achilles tendon should undergo an ultrasound investigation both to promote the exact diagnosis and to define the extent of the disease.

Achilles Tendon↗

PubMed1996

MRI in assessment of the systemic manifestations of rheumatological disease.

Magnetic resonance imaging (MRI) has emerged as complementary imaging modality to conventional radiography. The same diagnostic rules that are used in the interpretation of the routine radiographs should be applied to the analysis of MR images with the macroscopic spread of the disease as a main diagnostic clue. MRI has been shown to be a sensitive tool in detecting early arthritic changes and erosions, inflammation in periarticular tendons and tendon sheaths, and in juxtaarticular bursae. MRI plays a pivotal role in diagnosis of arthritis of the craniocervical junction and its complications. It also has been used effectively to detect insufficiency fractures and osteonecrosis. MRI may be important in diagnosing early arthritis, in specifying the differential diagnosis of rheumatic disease, and in selecting subgroups of patients to provide tailored therapeutic regimens.

Arthritis, Rheumatoid↗

PubMed1996

[Current aspects in diagnosis and therapy of carotid artery kinking].

Elongation, coiling and/or kinking of the interal carotid artery occur in 10-25% of the population. While coiling of the internal carotid artery is ascribed to embryological causes, elongation and kinking are due to atherosclerosis or fibromuscular dysplasia. Seventy-seven patients with carotid kinking were examined using different diagnostic imaging methods. Of these, 64 underwent surgery because of cerebrovascular symptoms that ranged from local disturbances, vertigo, diplopia and cerebrovascular insufficiency producing ischemic attacks or infarction. The treatment of choice was surgical correction of the carotid kinking in symptomatic cases and, if indicated, endarterectomy of atherosclerotic lesions of the internal carotid artery to prevent ischemic stroke. Because of the anatomical position of the interal carotid artery kink there is a potential risk of complications in head and neck surgery. For this reason, the presence of carotid kinking should be excluded preoperatively by means of non-invasive diagnostic imaging, such as afforded by ultrasonic testing. The merits of the different diagnostic imaging methods to diagnose internal carotid artery disease were compared and discussed.

Brain Ischemia↗

PubMed1996

[The shoulder joint--diagnostic imaging].

In the assessment of shoulder joint abnormalities plain films must still be used today as primary imaging modality. For soft tissue, cartilage, tendon and ligament lesions, CT with arthrography and particularly MRI with arthrography is available today. Especially latter method leads to a significantly extended diagnosis, which in many cases implies a major therapeutical significance.

Arthritis↗

PubMed1995

[Malignant neoplasms after kidney transplantation: value of an annual radiological screening program].

PURPOSE: To evaluate the prevalence of malignant neoplasms after renal transplantation by means of a radiological screening programme and to determine the role of some clinical and demographic parameters concerning pathogenesis of these malignancies. MATERIAL AND METHODS: Between November 1992 and June 1994 in a prospective study 504 consecutive renal allograft recipients (331 m, 173 f) aged 51 +/- 13 years underwent routine abdominal ultrasound examinations including the renal transplant and p.a. and lateral chest x-rays once a year. RESULTS: This screening programme revealed 11 malignant neoplasms in 11 patients (2.2%). We detected 6 renal cell carcinomas (RCC) in the patient's native kidneys, two RCCs in two renal allografts, two non-Hodgkin-lymphomas in the liver and the renal allograft, respectively, and one ovarial carcinoma. Patients with renal cell carcinomas in the native kidneys were significantly older than allograft recipients without tumors. The presence of acquired cystic kidney disease (ACKD) seems to be an additional risk for the development of RCC. There were no significant differences in the time on dialysis, the time with functional renal allograft, and the immunosuppressive therapy. CONCLUSION: Yearly abdominal ultrasound screening including the renal allograft is a valuable tool for the early detection of neoplasms in asymptomatic renal allograft recipients. However, routine yearly chest x-rays should not be performed in renal allograft recipients without preexisting tumours.

Adult↗

PubMed1995

[Ultrasound diagnosis of the popliteal fossa].

Sonography of the knee is a well-established method for the diagnosis of palpable tumors. However, evaluation of the menisci, cruciate ligaments, and hyaline cartilage is controversial. Despite the variable echogenicity and extension of different diseases, many distinct sonographic signs are different in cysts, solid neoplasms, and vascular diseases. The investigator must be familiar with various patterns of popliteal cyst formation: crescent-shaped, cross-shaped, slitlike, and grape-like cysts. Because of diagnostic and economic reasons the following concept should provide guidance when diagnosing lesions of the popliteal fossa: the first step of diagnostic imaging should include plain film radiography and sonography. In a second step MRI and/or arthroscopy should be performed.

Aneurysm↗

PubMed1995

[Aneurysmal bone cysts].

An aneurysmal bone cyst is a tumor-simulating bone lesion, the etiology of which is still unclear and probably inhomogeneous. This type of lesion is mainly observed during the second decade of life and is rarely diagnosed beyond the age of 30 years. It is characterized by hollow spaces consisting of several compartments filled with blood and partially divided by septs consisting of spindle-cell tissue with ample multinuclear giant cells and frequent reactive new bone formation. The locations of preference are the metaphyses of the long bones, the spine and flat bones; however, they can appear in every sort of bone. The radiological picture is characterized by osteolytic expansion of the bone with more or less distinct formation of trabeculae. In the CT image we can often find fluid formation; in MRT images alteration of signals can also be seen, indicating former or fresh bleeding. The primary aneurysmal bone cyst should be distinguished from its secondary counterpart; the latter one is occasionally found in giant cell tumors, chondroblastomas, chondromyxoid-fibromas, osteoblastomas, but also in osteosarcomas. When planning biopsy or therapy, this possibility should be also taken into account. The therapy of choice consists of accurate curettage and autologous or allogenous bone transplantation. To avoid recurrences, curettage should be followed by adjuvant therapy with phenol or cryotherapy. When there are extensive recurrences that can no longer be treated by the surgical method described above, embolization of the nutrient vessels may be curative.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

[New approaches to computer-assisted diagnosis of rheumatologic diseases].

UNLABELLED: Since the 1960s, several knowledge-based systems for computer-assisted diagnosis in radiology have been developed. The great majority of these tools has been implemented as off-line systems. This requires interaction with the system solely for the purpose of consultation and therefore interrupts the radiologist's work flow. This and inadequate man-machine interfaces may have inhibited the routine clinical use of such systems. The goal of this paper is to describe the current research toward the development of the on-line expert system Cadiag-4/Rheuma-Radio. The underlying fundamentals of the system design, including client/server architecture, communication interfaces, and fuzzy set theory and fuzzy logic as methods for knowledge representation and interference, are presented. METHODS: In radiology today, computers are routinely used to acquire radiological images in hospital and radiology information systems (HIS/RIS) and picture archiving and communication systems (PACS). In our approach, we make use of pre-existent sources of information to build an expert system that minimizes the interaction between radiologists and the computer. To handle uncertainty and vagueness of medical knowledge, fuzzy set theory and fuzzy logic are used. Given data of a specific case, a deductive inference procedure combines the observed radiological signs, establishes confirmed and excluded diagnoses as well as diagnostic hypotheses, and provides explanations for these conclusions. Furthermore, proposals for confirmation or exclusion of diagnostic hypotheses are offered. RESULTS: For evaluation purposes, an early prototype of Cadiag-4/Rheuma-Radio was tested on radiological disorders of the hip joint related to rheumatological diseases. Twenty radiological cases were used as test cases, reaching a diagnostic accuracy of about 80%. CONCLUSION: The first results are acceptable and encourage further work to cover the whole area of rheumatologically relevant radiological signs and diagnoses. Furthermore, research into the development of user-oriented data acquisition tools will be carried out.

Arthritis, Rheumatoid↗

PubMed1994

Sonographic detection of internal jugular vein thrombosis after central venous catheterization in the newborn period.

We sonographically investigated the internal jugular veins of 40 children who had undergone catheterization of the vein (group A: silastic catheter, n = 24; group B: polyurethane catheter, n = 16) in the neonatal period. The average age at catheter implantation was 43 +/- 73 days, the average birthweight 2414 +/- 1145 g, and the average gestational age 34.8 +/- 5.0 weeks. We performed follow-up longitudinal and transverse high resolution sonographic scans including routine examination of the contralateral jugular vein at a mean age of 3.7 +/- 1.5 years. In group A thrombotic alterations were detected in 8 aut of 24 patients. In three of these patients we found mild clinical symptoms. In group B thrombotic alterations were detected in 1 aut of 16 patients without clinical symptoms. Mean birthweight (1815 versus 3313 g) and mean gestational age (32.3 versus 38 weeks) were significantly lower and indwelling time of the catheters (18 versus 11 days) was significantly longer in group A. Our results indicate that jugular vein thrombosis is a frequent long-term complication in neonates after jugular vein catheterization. High resolution ultrasonography is an adequate method for detecting jugular vein thrombosis and should therefore routinely be performed for long-term follow-up.

Catheterization, Central Venous↗

PubMed1994

[Color Doppler ultrasound of gallbladder varicose veins in children. A rare sign of portal hypertension].

In a retrospective study of 21 children with portal hypertension (P. H.) four patients (19.2%) presented with gallbladder varices as documented by colour-coded Doppler sonography (CCDS) gallbladder varices (GV). Three of four patients with GV had portal vein thrombosis, one patient had cholestatic cirrhosis. Thickening of the gallbladder wall with serpentine anechoic structures was visible in all cases. Blood flow could be documented within the widened veins of the gallbladder wall in 3 of the 4 patients with duplex Doppler US, but in all patients with CCDS. US follow-up studies within 3-5 years were done on 2 patients and showed that GV appeared 2 years after the clinical diagnosis of P. H. With CCDS, varices of the gallbladder wall may be diagnosed readily and differentiated from other diseases associated with thickening of the gallbladder wall.

Adolescent↗