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Siegfried Trattnig

Publications and source records attributed to Siegfried Trattnig.

27 records · Page 2Linked to original sources
PubMed2003

MR contrast agent at high-field MRI (3 Tesla).

Tumor-to-brain contrast after gadolinium administration using MP-RAGE and T1-SE scans in patients with primary and secondary brain tumors was significantly higher at 3 T than at 1.5 T. The subjective assessment of cumulative triple-dose 3 Tesla images obtained the best results in the detection of brain metastases compared with other sequences followed by 1.5 T cumulative triple-dose enhanced images. In macroadenomas of the hypophysis, contrast-enhanced 3 T MRI was superior to standard MRI in the diagnosis of cavernous sinus infiltration and in visualization of cranial nerves within the cavernous sinus. Due to higher spatial resolution, contrast-enhanced MR venography at 3 T showed more details in and around tumors than at 1.5 T, additionally enhanced by stronger susceptibility weighting and higher signal-to-noise ratio at 3 T. In summary, administration of gadolinium-based contrast agent produces higher contrast between tumor and normal brain at 3 T than at 1.5 T, helps to detect more cerebral metastases at 3 T versus 1.5 T in single and cumulative triple dose, improves the evaluation of macroadenomas of the hypophysis, and makes MR venography at 3 T clinically attractive with increase in spatial resolution within the same measurement time, thus providing more detailed information.

Adenoma↗
PubMed2003

Effect of contrast dose and field strength in the magnetic resonance detection of brain metastases.

PURPOSE: To compare the diagnostic efficacy of a standard and cumulative triple dose of magnetic resonance (MR) imaging contrast agent in the evaluation of brain metastases using a high-field 3.0 T MR unit versus a standard field 1.5 T MR unit. METHODS: Twenty-two patients with suspected brain metastases were examined at both field strengths using identical postcontrast coronal 3D gradient echo with magnetization preparation, which was adjusted separately for each field strength. In both groups initially, iv injection of 0.1 mmol/kg body weight gadolinium chelate (gadodiamide) and thereafter, 0.2 mmol/kg body weight gadodiamide were administered. Subjective assessment of the images was performed independently by 3 neuroradiologists. Objective measurement of signal-to-noise and contrast-to-noise ratios was obtained. RESULTS: The subjective assessment of cumulative triple-dose 3.0 T images obtained the best results compared with other sequences, detecting 84 metastases, followed by 1.5 T cumulative triple-dose enhanced images with 81 brain metastases. The objective assessment confirmed those results, showing significantly higher signal-to-noise and contrast-to-noise ratios with 3.0 T than with 1.5 T. CONCLUSIONS: Cumulative triple-dose images of both field strengths were superior to standard field strengths. However, administration of gadodiamide contrast agent produces higher contrast between tumor and normal brain on 3.0 T than on 1.5 T, resulting in better detection of brain metastases and leptomeningeal involvement.

Aged↗
PubMed2003

High-resolution three-dimensional contrast-enhanced blood oxygenation level-dependent magnetic resonance venography of brain tumors at 3 Tesla: first clinical experience and comparison with 1.5 Tesla.

RATIONALE AND OBJECTIVES: To evaluate the clinical potential of high-resolution 3D contrast-enhanced blood oxygenation level-dependent MR-Venography (CE-MRV) for primary brain tumors and metastases at 3 Tesla (T) in comparison to 1.5 T. METHODS: Eighteen patients with brain tumors were examined using CE-MRV after application of a standard dose of MRI contrast agent (0.1 mmol/kg gadodiamide). CE-MRV is based on a high-resolution 3D flow-compensated gradient-echo sequence with long echo times that uses the contrast-enhanced blood oxygenation level-dependent effect. This technique was performed using the same volume coverage and acquisition time at both field strengths after performing standard imaging sequences. RESULTS: The higher spatial resolution of CE-MRV at 3 T showed more details within and around tumors than at 1.5 T. Visibility was enhanced by stronger susceptibility weighting and higher intrinsic signal-to-noise at 3 T. Compared with standard imaging protocols, additional information characterized as tubular and nontubular hypointense structures were found within or around lesions on CE-MRV images. CONCLUSIONS: Acquisition of CE-MRV data at 3 T enables spatial resolution to be increased within the same measurement time and with the same volume coverage compared with 1.5 T, thus providing more detailed information. The method may also show the potential to estimate oxygen supply of tumors, especially at high field strengths.

Adult↗
PubMed2003

[Imaging of tumors of the pituitary gland].

Macrotumors of the sella region usually involve the suprasellar and less commonly the parasellar space. The suprasellar extension of pituitary adenoma, meningeoma, craniopharyngioma, and hypothalamic or chiasmatic glioma count for the most frequent neoplastic entities. In macroadenomas of the pituitary gland invasion of parasellar spaces may occur in 6-10%. Imaging techniques are directed to increase the likelihood of surgical cure and to detect aggressive tumour invasion into surrounding tissues. A dedicated classification basing on indirect MRI signs of tumour extension has been established. With high-resolution high-field (3T) MRI the sella region may be displayed to provide better information compared to lower field strengths.

Adenoma↗
PubMed2002

Microsurgical management of postoperative disc space infection.

We analysed seventeen patients with septic postoperative spondylodiscitis (POD) who were managed by early microsurgical removal of the infected necrotic tissue, application of a closed suction-irrigation system (for a mean of 6.7 days), and early mobilisation. The POD was diagnosed clinically by elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) values and radiographically by computerised tomography scanning or magnetic resonance imaging. According to the sensitivity studies of the obtained pathogens, systemic antibiotics were given, followed by early mobilisation of all patients in a light cast corset. Immediate pain relief was noted in all patients except one, who required a third operation that was followed by rapid clinical improvement. Bacteriological diagnosis was obtained in 88% of the patients. Excellent or good clinical long-term results were achieved in 82% of the patients, whereas 18% had poor results. Elevated ESR/CRP values returned to normal ranges within 6 to 44 days (mean 15 days) after reoperation. All but one patient tolerated early mobilisation (within 2 to 4 weeks) well without any complication. Early microsurgical removal of the necrotic and infected tissue and application of a closed suction-irrigation system supported by specific antibiotic therapy should be considered an effective means to treat POD, thereby avoiding a prolonged period of unpleasant immobilisation for the patient.

Adult↗
PubMed2002

Imaging articular cartilage defects in the ankle joint with 3D fat-suppressed echo planar imaging: comparison with conventional 3D fat-suppressed gradient echo imaging.

PURPOSE: To shorten the examination time for articular cartilage imaging, using a recently developed three-dimensional (3D) multishot echo planar imaging (EPI) sequence with fat saturated (FS), compared to a conventional 3D fat-saturated spoiled gradient echo sequence (3D FS GRE). MATERIAL AND METHODS: There were 32 consecutive patients with ankle joint disorders who underwent magnetic resonance imaging (MRI) in a 1.0-T unit. Hyaline cartilage was imaged with a 3D FS EPI sequence and a 3D FS GRE sequence. Image assessment criteria included lesion conspicuity, contrast between different types of normal tissue, and image artifacts. In addition, contrast-to-noise ratios (CNRs) of cartilage vs. joint fluid and bone marrow were measured. RESULTS: The 3D FS EPI sequence provided a high CNR between cartilage and subchondral bone, similar to that of the 3D FS GRE sequence. The CNR between cartilage and effusion was significantly lower on the 3D EPI sequence due to the higher signal intensity of fluid. Both sequences were equal in lesion detection ability. The image quality of the 3D FS GRE sequence was slightly higher than that of the 3D FS EPI, but the difference was not statistically significant. CONCLUSION: We conclude that the 3D FS EPI sequence is comparable to the 3D FS GRE sequence in the detection of cartilage lesions, with the additional advantage of reduction in scan time by a factor of 4.

Adolescent↗
PubMed2002

Magnetic resonance imaging contrast enhancement of brain tumors at 3 tesla versus 1.5 tesla.

RATIONALE AND OBJECTIVES: To compare the diagnostic efficacy of a standard dose of MRI contrast agent in the evaluation of primary brain tumors and metastases using a high-field 3 tesla MR unit versus a 1.5 tesla MR unit. METHODS: Sixteen patients with brain tumors were examined at both field strengths using identical axial T1-SE protocols pre- and postcontrast (0.1 mmol/kg gadolinium), and postcontrast coronal 3D GRE with magnetization preparation (MP-RAGE), which was adjusted separately for each field strength. Evaluation of the images was performed quantitatively and, in the case of T1-SE images, also by visual assessment. RESULTS: Tumor-to-brain-contrast after gadolinium administration using statistical evaluation of MP-RAGE scans was significantly higher at 3 tesla (97.5) than at 1.5 tesla (46.3). The same was true for T1-SE sequences (93.0 vs. 72.1). Signal enhancement of the lesions in T1-SE sequences was not significantly different between both field strengths. CONCLUSIONS: Administration of a gadolinium contrast agent produces higher contrast between tumor and normal brain at 3 tesla than at 1.5 tesla.

Adult↗
PubMed1998

Positioning device for optimal active kinematic real-time magnetic resonance imaging of the knee joint: a technical note.

OBJECTIVE: A prototype of a positioning device created especially for the diagnostic imaging of the patellofemoral joint was developed in order to achieve reproducible examination conditions. DESIGN: For this purpose a clinical trial on healthy test persons was carried out under real examination conditions. BACKGROUND: A special real-time MRI technique (Local-Look-technique) makes the analysis of active functional motion images possible. A prerequisite for this technique is accurate reproducible positioning of the knee joint in the MRI unit. METHODS: This positioning device was evaluated during a total of 50 examinations of the knee joints of five healthy test persons. The right patellofemoral joint of each test person was examined twice at different time points in order to check the reproducibility of all examination conditions. Comparing two examination series from the same individual, reproducibility of MRI slices was guaranteed by using identical anatomical landmarks. Image quality and test-retest reliability were analyzed on the computer screen. RESULTS: Optimal desired fixation of the leg in the MRI tube using the device was accomplished in all cases. The extent of motion of the knee joints ranged from 38 degrees (n = 2) to 40 degrees (n = 3) of flexion to full extension, which was satisfactory for the evaluation of the patellofemoral joint. Free movement of the patella and the lower leg was observed. The active functional MRI examination using this device was satisfactory and reproducible as assessed by test-retest reliability. CONCLUSIONS: The positioning device is a useful development in achieving active functional real-time MRI evaluation of the knee and patellofemoral joint. Using this diagnostic tool, reproducible quantitative examinations can now be easily performed. The reproducibility and high reliability as well as its simplicity of operation render this diagnostic tool suitable for use in orthopedics and traumatology.

Journal Article↗