Biomedical subjects

H Imhof

Publications and source records attributed to H Imhof.

At least 145 records · Page 8Linked to original sources

PubMed1996

[Primary chronic polyarthritis of the knee joint].

Rheumatoid arthritis is a chronic, multisystemic disease. The characteristic feature is persistent inflammatory synovitis. The knee joint is commonly involved with synovial hypertrophy, chronic effusion, and frequently ligamentous laxity. Pain and swelling behind the knee may be caused by extension of inflamed synovium into the popliteal space (Baker's cyst). Plain radiographs of the knee joint remain the basic radiological procedure, although early in the disease they might not provide significant changes. Sonography sufficiently reveals synovial fluid and Baker cysts, but cannot be recommended for evaluation of synovial proliferations or pannus formation. Computer tomography has only limited indications and may be used for the evaluation of subtle erosive lesions or the quantitation of osteoporotic changes. Magnetic resonance imaging has shown excellent visualization of cartilage, fluid, synovium and soft tissues and is the method of choice for the demonstration of early affection and the evaluation of pannus activity and therapy control. With administration of contrast agents (gadolinium), dynamic studies may demonstrate inflammatory activity. Modern MR sequences, such as T1 SE "fat sat" or magnetization transfer, further improve the discrimination of cartilage, pannus and synovial fluid.

Arthritis, Rheumatoid↗

PubMed1996

[MR imaging in gout].

The appearance of gouty tophus in magnetic resonance imaging (MRI) is characteristic. On T1- and T2-weighted SE images, the signal intensity of tophaceous lesions is similar to that of muscles. According to the histology, T2-weighted SE images demonstrate extremely hyperintense signals, which reflect the high protein content in the amorphous center of the tophus. The microscopic urate crystals deposited there have no MRI signal and are of no further diagnostic impact. Vascularized granulation tissue surrounding the tophus center enhance after intervenous application of contrast agents (Gadolinium). The inflamed tophus is associated with local edema, causing high signal intensity. MRI is superior to plain radiography for early detection of intraosseous tophi. Involvement of anatomical structures such as ligaments and tendons can be evaluated sufficiently. For peripheral joints, axial slice orientation is most helpful.

Adult↗

PubMed1996

[MRI-guided MRI arthrography of the shoulder].

PURPOSE: To develop an MR-guided technique for joint puncture in MR arthrography of the shoulder and to confirm the intracapsular position of the needle tip by visualization of the flow of contrast media into the joint. MATERIALS AND METHODS: Three unfixed human shoulder joint specimens were examined on a LOT unit. The optimal point of entrance and depth for joint puncture were estimated by means of MR-compatible markers on the skin. Needle orientation and localization of the needle tip (MR-compatible 22-gauge needle) in the shoulder joint were monitored by rapid localizer gradient-echo sequences in two or thogonal planes. To confirm the intracapsular position of the needle tip, diluted gadolinium-DTPA was administered via a long connecting tube and the flow of contrast media into the joint was viewed directly on an LCD screen using real-time MR imaging (local look technique). RESULTS: The MR-compatible markers on the skin allowed determination of the optimal point of entrance and estimation of the depth for joint puncture. Passive visualization of the MR-compatible needle due to spin dephasing and signal loss provided adequate localization of the intra-articular needle tip position in all specimens, although significant artefacts were present on rapid localizer gradient-echo sequences with an increase in width of the apparent needle shaft. Real-time MR imaging of the flow of contrast media was possible using the local look technique and the LCD screen of the MR unit and allowed confirmation of the intracapsular position. CONCLUSION: MR-guided joint puncture and real-time MR-assisted contrast media application results in improved MR-arthrography and may replace conventional fluoroscopic guidance.

Contrast Media↗

PubMed1996

[Infectious spondylitis in adults].

In adults, infectious spondylitis is a rare but severe disease, caused by a bacterial thrombus in tissue of reduced resistance. In conventional radiographs initial findings are a narrowing of the intervertebral space, local osteoporosis and poorly defined erosive borders of the vertebral endplates. These changes can be found at least three to six weeks after the onset of disease. However, in Szintigraphy and MRT pathologic alterations are evident after ten to twelve days. Thus, early diagnosis and treatment becomes possible. In early stages of the disease a localized lysis surrounded by a reactive sclerosis appears in predisposed areas of the vertebral body (subchondral, anterobasal, ventral, central). Apparently, a soft tissue tumor is associated. Sclerosis and reduction of the soft tissue tumor are the first signs of repair processes. After at least 12 weeks, computed tomography can reveal typical sintering of the vertebral body and occasionally the development of a bony sequester. In addition, MRT as well as CT can be helpful in the detection and localization of complications as abscesses or affection of the vertebral canal. The tuberculous spondylitis can sometimes cause difficulties in differential diagnosis. Clinical findings, affection of several vertebral bodies, large soft tissue tumors with appearance of calcification as well as not typical locations are strongly suggestive of tuberculous spondylitis, but these findings are not specific of the disease. Degenerative disorders such as erosive osteochondrosis or changing due to chronic dialysis (e.g. amyloid or crystal arthropathies) may cause even more problems in differential diagnosis. Typical for a blastomatous process is the integrity of the interverebral disc space, which is a rare finding in spondylitis.

Adult↗

PubMed1996

[MR arthrography of the shoulder joint in a postoperative patient sample].

Indications of MR arthrography were analyzed in this prospective study. The aim was to evaluate possible advantages over conventional MRI, establish diagnostic criteria and to analyze its meaning further for the therapeutic management of postoperative patients. MR arthrography was performed in eight patients who had undergone surgical repair of rotator cuff lesions (modified Neer acromioplasty) and in six patients who had undergone arthroscopic therapy of recurrent unidirectional dislocation of the shoulder by combined arthroscopic intra- and extracapsular repair. MR investigations were performed before and after application of a contrast solution (2 mmol Gd-DTPA). All patients suffered from chronic postoperative pain. In patients with rotator cuff lesions, a partial tear could be verified in one patient and excluded in all others. In patients after arthroscopic therapy by combined intra- and extracapsular repair, a radiologically patulous-appearing capsule correlated with clinically recurrent dislocations. In all other patients diagnostic criteria, such as distribution of the intra-articular contrast solution, proliferation of scar tissue, nodular appearance of the glenohumeral ligaments and capsule thickness, correlated with a regular postoperative status. MR arthrography of the shoulder represents a promising method in the evaluation of the postoperative shoulder. It might further improve the evaluation of reactive capsule alterations, scar tissue proliferation, and the labroligamentous complex, as well as the ability to differentiate partial and complete rerupture from degenerative changes of the rotator cuff.

Adult↗

PubMed1996

MRI of microadenomas in patients with hyperprolactinaemia.

MRI is a sensitive tool for the investigation of pituitary microadenomas but cannot be used as a screening investigation. To establish a strategy for the use of MRI in patients with hyperprolactinaemia we investigated 74 women with serum prolactin levels above 52 ng/ml for the presence of microadenomas. We examined 55 premenopausal and 19 postmenopausal women, using a 1.5 T unit. We used T1-weighted spin-echo sequences, with coronal and sagittal images before and after intravenous gadolinium. We found microadenomas in 38 patients (51.3%), macroadenomas in 6 (8.1%) and an infundibular glioma in 1;29 patients had a normal pituitary gland (39.2%). The size of the adenomas was related to the prolactin level, and the mean level in patients with MRI evidence of adenomas was higher than in patients without microadenomas (155.72 +/- 131.01 ng/ml versus 110.14 +/- 80.86 ng/ml). The probability of the presence of an adenoma increased with rising serum prolactin levels. We suggest MRI in patients with prolactin levels more than 100 ng/ml. In patients on oestrogen therapy MRI should be performed with only slightly elevated prolactin levels. Evidence of a microadenoma should be considered in planning further therapy, especially concerning the use of hormone replacement therapy or of bromocriptine.

Adenoma↗

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

[Injuries to the lateral ligaments of the ankle joint: study technic and demonstration by means of MRI].

PURPOSE: To evaluate the visualisation and extent of injury of lateral ankle ligaments using MRI. METHODS: 56 patients with the clinical diagnosis of sprained ankles were investigated. Evaluation of the anterior (AFTL) and posterior fibulotalar ligament (PFTL) was performed with the foot in dorsiflexion (20 degrees) and of the fibulo calcanear ligament (FCL) in plantarflexion (45 degrees). Axial T1w-SE and T2w-TSE images were obtained. Full-length visualisation of ligaments in one slice and the extent of injury were evaluated. 12 ankle injuries were confirmed by operation. RESULTS: With MRI full-length visualisation of lateral ankle ligaments was possible in 86%. A partial/complete rupture of the AFTL was noticed in 33/64% and of the FCI in 29/39%, and of the PFTL in 27/5%. Sensitivity/specificity of MRI when compared to surgery was 100/100% for injuries of the AFTL, 64/100% for the FCL, and 33/78% for the PFTL. CONCLUSION: Full-length visualisation of ligaments, achieved by appropriate combination of foot position and imaging plane is essential for evaluation of injured ankle ligaments on MRI. High assessment for ligamentous injuries on MRI in relation to surgery was found.

Adolescent↗

PubMed1996

[Hallux rigidus operated on by Keller and Brandes method: radiological parameters of success and prognosis].

PURPOSE: The aim of this study was to evaluate the pre- and postoperative radiographic findings of hallux rigidus treated with Keller and Brandes arthroplasty to determine the radiographic outcome and to identify a prognostic marker. METHODS: 83 patients with a total of 121 cases of hallux rigidus operated using Keller and Brandes arthroplasty were followed up (mean 9.7 y). A comparison of the pre- and postoperative radiographs, the clinical and subjective findings was predicated on a five point scale: 1. percentage of proximal phalanx resected ( < 33%, 33-50%, > 50%), 2. joint space, 3. ratio of the length of the first and second metatarsals, 4. first intermetatarsal angle, and 5. hallux valgus angle. RESULTS: In the patient group which had 33-50% of the proximal phalanx excised (n = 67. 55%) the highest patient satisfaction was observed (96%). If resection of the proximal phalanx exceeded 50% (n = 13. 11%), non physiologic dorsiflexion of the toe occurred and patients were dissatisfied (62%). Excision of less than 33% of the hallux (n = 41. 34%) was associated with a recurrent hallux rigidus. No other evaluated radiological parameter proved to be of significance. CONCLUSION: The most important radiological parameter in the evaluation of the outcome of Keller and Brandes arthroplasty as a surgical treatment method for hallux rigidus was the percentage of the proximal phalanx which had ben excised.

Adult↗

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

[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

Vegetable oil as an MR contrast agent for rectal applications.

The purpose of this study was to evaluate the feasibility of pure vegetable oil as an MR contrast agent for rectal applications. The hypothesis was that vegetable oil highlights the lumen of the rectum after rectal application as a positive contrast medium and offers additional contrast qualities using fat suppression techniques. Eleven MRI examinations were performed on 11 subjects (five healthy volunteers, all males, mean age 35 yr; and six patients, three males, three females, mean age 49 yr). Peanut oil, 200 ml, was applied rectally. In addition, 0.1 mmol/kg GD-DTPA was administered intravenously to the six patients only. Conventional T1-weighted SE sequences and T1-weighted SE images with fat suppression were obtained. Criteria for image evaluation were: overall image quality; uniformity of contrast distribution; chemical shift artifact; and delineation of the rectal wall. Side effects were assessed. There were no complaints reported by the 11 subjects. The image quality was sufficient in all studies. In all five of the volunteers and five of the six patients, the distribution of oil was uniform. Chemical shift artifacts did not deteriorate image quality. After rectal application of vegetable oil, the delineation of the rectal wall was sufficient with and without fat suppression techniques. Vegetable oil highlights the lumen of the rectum in MRI studies and offers additional contrast qualities with fat suppression techniques, acting as a positive as well as a negative contrast agent, depending on the chosen sequence.

Administration, Rectal↗

PubMed1995

Comparison of magnetic resonance tomography with computerized axiography in diagnosis of temporomandibular joint disorders.

This study compared the accuracy of two noninvasive methods, computerized axiography and magnetic resonance tomography (MRT), in diagnosing temporomandibular joint (TMJ) disorders. Forty-seven subjects underwent axiography and subsequent assessment of the TMJ by MRT. The statistical analysis referred to the correlations of the most relevant clinical diagnoses, i.e., no appreciable disease, disk displacement with reposition, disk displacement without reposition, morphologic alterations, and hypermobility of the condyle. In 70% of the disk-displacement-with-reposition and disk-displacement-without-reposition patient groups, axiography and MRT gave the same information. In other patient groups, the axiography findings agreed with the MRT findings in 45% of the cases. It was concluded that although a large percentage of morphologic alterations could be detected by MRT, axiography determined the dysfunctional dynamics more clearly.

Adolescent↗

PubMed1995

[The civil law liability in radiology. An analysis of the administration of justice].

This study comprises 76 published judgments by German and Austrian civil courts between 1966 and 1993 concerning liability in the field of radiology. There has been a marked increase in the number of legal proceedings in the 1980's and even more so in the second half of this decade. This is due to an increased tendency to sue doctors without any legal cause in the hope of possible compensation. In 40.8% of the cases the doctor was held liable and required to compensate the patient for personal injury and suffering pain. Most of the cases were related to complications during the examination procedure. The reason most frequently cited by the courts for sentencing doctors was the fact that they did not previously inform the patient adequately about the examination and its possible consequences.

Austria↗

PubMed1995

Follow-up of spongiosa plugs with contrast enhanced magnetic resonance imaging.

The aim of this study was to evaluate the extent and duration of the revascularization process in spongiosa plugs when a fibrin sealant was used. 20 patients with tumour-like lesions, benign tumours and tumours with a potential for malignant transformation were studied. After intralesional tumour removal, the defect was filled with homologous spongiosa either combined with or without a fibrin sealant, according to a prospective randomization. Magnetic resonance imaging (MRI) follow-up examinations were performed within 1 week, and 1.5, 3, 4.5, 6, 8, 12, 24 and 36 months after surgery. Those patients without a fibrin sealant showed an increased revascularization zone up to the sixth week. Patients treated with fibrin, however, showed increased revascularization up to 3 months. In the 25% percentile the extent as well as the rate of revascularization is higher in those with a fibrin sealant. It is of clinical relevance that no revascularization should be expected at 3 months after surgery, which is easily demonstrated by MR follow-up.

Adolescent↗

PubMed1995

[Systemic diseases and blastomas of the foot].

Analysis of roentgenograms by location, pattern of destruction, classification of tumor matrix and periosteal new bone formation, together with clinical data, preserves valuable information for discrimination of neoplasms in the foot. Furthermore, specific information on tumor histology and tumor extension in the bone marrow and soft tissues can be obtained by CT and MRI. Preoperative staging, guided biopsy of tumor tissue, monitoring of chemotherapeutic response and postoperative observation are further indications for MRT and other modern imaging modalities.

Bone Marrow↗

PubMed1995

[Trauma of the ligaments and tendons. Examination technique and detection in MRI].

For stress radiography, the inversion stress test can be performed during radiographic examination and widening of the lateral joint space can be measured quite accurately. However, there is no general agreement on the meaning of various degrees of talar tilt. Today MRI allows evaluation of the integrity of injured ankle ligaments. The major difficulty in MRI is inconsistency in visualization by inadequate appreciation of the three-dimensional orientation of each ankle ligament. The appropriate combination of foot position and imaging plane is very important to achieve the best visualization of each ligament. Using this technique, 52 patients with sprained ankles underwent MRI. The integrity of rupture of the collateral lateral ligaments was obtained in all 52 ankles. Full-length visualization is essential for evaluation of the ankle ligaments with MRI. In these 52 patients the ankle of tilt on the stress X-ray was compared with the rate of MRI findings showing an injury affecting two ligaments We found that none of the patients in whom the angle of lateral tilt was less than 5 degrees had rupture of two lateral ligaments, while 32% of patients with angles of tilt of 6-14 degrees and 42% of those with angles of tilt over 15 degrees on stress X-ray had two ruptured lateral ligaments. When a stress X-ray with a 6-14 degrees angle of tilt suggests only slight ligamentous injury, MRI could be indicated in specific cases to allow identification of the 32% with rupture of two ligaments. The only practical means of imaging tendons is high-frequency ultrasound and MRI.(ABSTRACT TRUNCATED AT 250 WORDS)

Achilles Tendon↗

PubMed1995

[Sinus tarsi syndrome. MRI diagnosis].

Sinus tarsi syndrome is a well-defined clinical pathological entity. The sinus tarsi is an anatomic space between the inferior aspect of the talus and the superior aspect of the calcaneus, anterior to the posterior subtalar joint. The entire space is filled with fat, five ligaments and vessels. MRI demonstrates characteristic findings with obliteration of normal fat and lack of visualization of the ligaments. This syndrome is relatively frequent and is related to trauma in about 70% in association with the lateral collateral ligament and tibialis posterior tendon injuries. In the remaining 30% the reason is an inflammatory condition.

Calcaneus↗