Biomedical subjects

S Trattnig

Publications and source records attributed to S Trattnig.

At least 91 records · Page 5Linked to original sources

PubMed1997

Diagnosis of lateral ankle ligament injuries. Comparison between talar tilt, MRI and operative findings in 112 athletes.

We evaluated the reliability of the radiographic talar tilt test by MRI examinations in 112 athletes with injuries to the lateral ligaments of the ankle. 25 athletes with a talar tilt > 15 degrees were treated operatively. Intraoperative findings and the talar tilt test were compared with MR imaging results. Our results suggest that MRI is a reliable method for diagnosing injuries of the lateral ankle ligaments. The talar tilt test cannot evaluate the specific pathology of lateral ankle ligaments, but it was reliable in indicating complete double-ligament ruptures (anterior talofibular and calcaneo-fibular ligaments), when talar tilt was 15 degrees or more than on the uninjured side.

Adolescent↗

PubMed1997

Comparison of T2-weighted and fluid-attenuated inversion-recovery fast spin-echo MR sequences in intracerebral AIDS-associated disease.

PURPOSE: To compare the value of fast fluid-attenuated inversion-recovery (FLAIR) with T2-weighted fast spin-echo MR imaging in the detection of acquired immunodeficiency virus (AIDS)-related lesions of the brain. METHODS: Forty-four human immunodeficiency virus (HIV)-positive patients were examined with both sequences on either a 1.0-T or a 1.5-T MR system. The number, size, location, and conspicuity of the lesions were evaluated by two independent observers. Contrast ratios between lesions and normal brain/cerebrospinal fluid were determined, and contrast-to-noise ratios were calculated. RESULTS: FLAIR was found to be superior to T2-weighted fast spin-echo in detection of small lesions and of lesions located in cortical/subcortical regions and deep white matter. The two techniques were equal in delineation of lesions larger than 2 cm and for lesions located in the basal ganglia and posterior fossa. In 24 patients, more lesions were detected with the FLAIR fast spin-echo technique. Lesion/cerebrospinal fluid contrast ratios and contrast-to-noise ratios were significantly higher for the FLAIR fast spin-echo sequences than for the T2-weighted fast spin-echo sequences. CONCLUSION: FLAIR allows early detection of small lesions in subcortical and cortical locations, especially in HIV encephalitis. Because of its improved lesion detection rate and greater overall lesion conspicuity, we believe FLAIR is useful in the evaluation of subtle changes in the brains of AIDS patients with central nervous system disease, and could even replace the T2-weighted fast spin-echo technique.

AIDS Dementia Complex↗

PubMed1996

Stenoses of the first segment of the vertebral artery: difficulties in angiographic diagnosis.

Pathology at the origin of the vertebral artery may be the cause of incapacitating vertebrobasilar insufficiency (VBI). Preoperative diagnosis is made primarily on angiographic criteria. We compared intraoperative and angiographic findings in 30 patients and found important diagnostic discrepancies in patients with a caudal, ventral or dorsal origin of the vertebral artery. In their angiograms, vessel superimposition led us to over look 3 ostial stenoses and 10 stenoses due to kinking. Angiographic assessment of patients with VBI can be difficult. Adequate visualisation of the origin of the vertebral artery is mandatory for accurate diagnosis.

Aged↗

PubMed1996

Effects of umbilical arterial catheterization on mesenteric hemodynamics.

Impairment of mesenteric blood flow due to the use of umbilical artery catheters (UAC) may increase the risk of necrotizing enterocolitis (NEC) in newborn infants. We used Duplex Doppler sonography to investigate the degree of vessel obstruction due to UAC and their effect on visceral hemodynamics in 12 newborn infants. Ultrasonography was performed before and immediately after removal of the UAC, which was positioned above the ostia of the celiac and superior mesenteric arteries (SMA). Vessel diameter, peak systolic blood flow velocity (PSFV), end diastolic blood flow velocity (EDFV), and Pourcelot's resistance index (RI) were measured in the celiac trunk and the SMA within 1 cm of their origins. Removal of the UAC led to a significant increase in mean PSFV (celiac trunk: 50 cm/s +/- 15 vs 62 cm/s +/- 0.22, P < 0.05; SMA: 52 cm/s +/- 0.17 vs 72 cm/s +/- 0.21, P < 0.05). RI increased from 0.7 +/- 0.14 to 0.74 +/- 0.13 and from 0.73 +/- 0.1 to 0.76 +/- 0.13 for the celiac trunk and SMA, respectively. The EDFV and vessel diameters did not change significantly after UAC removal. Our results suggest that UAC cause a decrease in mesenteric blood flow. Therefore, their use in hemodynamically unstable neonates or in those with gastrointestinal disease should be very carefully considered.

Blood Flow Velocity↗

PubMed1996

Stable xenon CT in patients with chronic cerebrovascular disease.

Xenon-enhanced CT (XeCT) is a method of measuring regional cerebral blood flow (rCBF). Although it is used for acute and perioperative assessment the ability of XeCT to show hypoperfused areas in vivo, as compared with morphological imaging modalities other than noncontrast CT, is not defined. Correlation with MRI helps to define the smallest detectable hypoperfused area. We examined 17 patients 6 weeks after acute cerebral infarcts with CT, XeCT and MRI and the findings were compared. All examinations were performed with the same slice angulation and thickness and the sizes of the abnormal areas were measured. XeCT showed a high correlation with MRI, but less so with conventional CT. Lesions appeared significantly smaller on CT than on XeCT or MRI. No significant difference between MRI and XeCT changes was found. The minimal lesion on MRI correlating with a hypoperfused area on XeCT was 0.8 cm2, whereas lesions measuring less than 0.5 cm2 on MRI could not be detected on XeCT. The good correlation between XeCT and MRI underlines the reliability of rCBF examinations with XeCT. A significant difference between CT and XeCT findings shows the difficulty of interpreting hypoperfused regions only by correlation with CT. Combined XeCT and MRI gives a better estimate of the vascular state of the brain.

Aged↗

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

[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

[CT-assisted definition of puncture site and penetration angle for percutaneous lumbar diskectomy].

In 20 consecutive patients submitted to CT evaluation of a suspected disk protrusion at level L4-5, CT measurements to define entry point and penetration angle for percutaneous diskectomy were performed. It was shown that in order to reach the disk center, the entry point had to be more lateral than recommended by most authors. Body height, weight and body surface area were not significantly correlated to entry point position or penetration angle. In particular, the extension of the intervertebral facet joint determined the route of the probe to the disk center. Therefore, CT-assisted planning of the instrument route prior to percutaneous lumbar diskectomy is helpful in defining the proper entry point and penetration angle for safe and effective instrument positioning.

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

[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

Spiral CT angiography: study of stenoses and calcification at the origin of the vertebral artery.

The origin of the vertebral artery may be difficult to show on sonography or conventional angiography. Our aim was to evaluate the accuracy of CT angiography (CTA) in detecting arteriosclerotic changes in the first segment (V1) of the vertebral artery. We performed CTA and intra-arterial digital subtraction angiography (DSA) on 24 patients with vertebrobasilar insufficiency. The ostium and the V1 segment were examined. Stenosis was assessed on a three-grade scale, and calcification and the degree of kinking were recorded. DSA and CTA results were compared. The ostium of the artery was seen in all cases on CTA and in 33 of 47 cases with DSA. All ostial stenoses diagnosed on DSA were seen with CTA. CTA revealed 4 stenoses in cases in which angiography proved inadequate, 11 zones of calcification and 5 cases of luminal reduction due to calcified plaques undetected on DSA. In the V1 segment DSA and CTA showed 3 stenoses, 9 cases of kinking, 1 of coiling and 4 stenoses due to kinking. CTA also demonstrated 4 additional stenoses, 2 cases of kinking and 3 stenoses due to kinking.

Aged↗

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

[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

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

Magnetic resonance imaging of occult scaphoid fractures.

Occult fractures of the scaphoid bone occur frequently and may lead to nonunions. In a prospective blind study, we performed magnetic resonance imaging (MRI) examinations on 32 patients who had sustained a wrist injury and in whom a scaphoid fracture was clinically suspected, but could not be confirmed on the original set of two routine and four scaphoid view radiographs. The MRI examinations were performed an average time of 2.8 days after the trauma. This prospective study proved that MRI is able to diagnose occult scaphoid fractures without delay and without the use of radioactive diagnostic means. Sensitivity and specificity of MRI were 100%. This conventional method could save $7,200 (US) per 100,000 inhabitants in providing an immediate and correct diagnosis and avoiding unnecessary cast immobilization. Additional injuries that may be misdiagnosed by conventional radiographs are also detected with a specificity and sensitivity of 100%.

Adolescent↗

PubMed1996

Monocular elevation paresis and contralateral downgaze paresis from unilateral mesodiencephalic infarction.

A 26 year old woman presented with monocular elevation paresis of the right eye, contralateral paresis of downward gaze, and subtle bilateral ptosis. Magnetic resonance imaging disclosed a unilateral embolic infarction restricted to the mesodiencephalic junction involving the left paramedian thalamus. Preserved vertical oculocephalic movements and intact Bell's phenomenon suggested a supranuclear lesion. This rare "crossed vertical gaze paresis" results from a lesion near the oculomotor nucleus affecting ipsilateral downward gaze and contralateral upward gaze fibres, originating in the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF).

Adult↗

PubMed1996

Comparison between conventional and fast spin-echo stir sequences.

PURPOSE: To evaluate the common characteristics and differences in contrast behavior of short-TI-inversion-recovery (STIR) and short-TI-inversion-recovery fast spin-echo (TurboSTIR) sequences. MATERIAL AND METHODS: Phantoms doped with increasing doses of Gd-DTPA and a pork-fat phantom were used to evaluate the dependence of the STIR and TurboSTIR signals on the T1 relaxation time. Clinical TurboSTIR images were obtained from 30 patients with musculoskeletal abnormalities and compared to conventional STIR images in 15 cases and to postcontrast TurboSTIR images in another 15 cases. RESULTS: In the phantom measurements, a significantly shorter inversion time (TI) was needed to achieve fat suppression on TurboSTIR images, and, with an identical number of signal averages, contrast-to-noise ratios were lower on TurboSTIR images. These differences between STIR and TurboSTIR can be attributed to the contribution of stimulated echoes to overall TurboSTIR signal and can be compensated by a shorter TI and a higher number of signal averages for TurboSTIR, respectively. With these adaptations, clinical TurboSTIR and STIR images showed an identical contrast behavior with fat suppression and a high sensitivity to pathological lesions but TurboSTIR saved a significant amount of scan time and reduced some types of artifacts. Contrast uptake impaired lesion conspicuity on TurboSTIR images. CONCLUSION: TurboSTIR sequences should replace conventional STIR sequences and should be performed before contrast administration.

Adolescent↗