O. Söllner

Magnetic resonance imaging in the diagnosis of acute injured distal tibiofibular syndesmosis.

RATIONALE AND OBJECTIVES This study assessed the diagnostic potential of magnetic resonance imaging for the evaluation of the tibiofibular syndesmosis. METHODS A total of 38 patients with an acute ankle trauma and clinical suspicion of a syndesmotic tear were prospectively studied with conventional plain film radiography and magnetic resonance imaging. Magnetic resonance imaging studies included plain T1-weighted (T1-w) and T2-weighted (T2-w) sequences and contrast-enhanced T1-w sequences 0 to 3 days after trauma. All images were read by two independent radiologists before surgical intervention. Sensitivity and specificity were determined for the two observers and the concordance of the two observers were calculated using the interobserver analysis (Kappa-Test). Intraoperative inspection (n = 21) revealed rupture of the anterior tibiofibular ligament (ATIF) in 15 patients, intact ATIF in 6 patients, and intact posterior tibiofibular ligament (PTIF) in 21 cases. Clinical and follow-up examinations revealed an intact syndesmotic complex in another 17 patients. RESULTS Primary diagnostic criteria for diagnosing a ligamentous tear included tibiofibular diastasis in conventional plain films; nonvisualization of the ATIF; an abnormal course, a wavy, irregular contour of the ligament; increased signal intensity of the ligament in T2-w sequences, in plain T1-w sequence, and marked enhancement in T1-w after contrast. Important secondary signs were defined as joint fluid in the tibiofibular space and prolapse of interspace fat. Highest diagnostic accuracy was achieved if three or more diagnostic criteria could be visualized. Both readers performed best with the enhanced T1-weighted and the T2-weighted images in transverse orientation. The interobserver analysis resulted in high concordance: Kappa = 0.9 (confidence interval: 0.76 to 1.00) for all patients, and in Kappa = 0.76 (confidence interval: 0.45 to 1.0) for surgically treated patients. CONCLUSIONS Magnetic resonance imaging of the syndesmotic complex is a highly sensitive and specific tool for the pretherapeutic-evaluation of syndesmotic injury.

Neoadjuvant Transarterial Chemoembolization (TACE) before Percutaneous MR-guided Laser-induced Thermotherapy (LITT): Results in Large-sized Primary and Secondary Liver Tumors

Summary Objectives: To evaluate the clinical value of neoadjuvant transarterial chemoembolization (TACE) before MR-guided laser-induced thermotherapy (LITT) for different large-sized liver tumors. Materials and methods : Repeated TACE were performed in 289 patients (mean 4.1 per patient) with unresectable HCC (n = 48) or liver metastases (n = 241) in a neoadjuvant intention using 10 mg/m 2 mitomycin as chemotherapeutic agent and 10 ml/m 2 lipiodol and microspheres for vessel occlusion. Tumor volume was measured by MR-imaging. As soons as the diameter of the tumor was observed to have decreased to less than 50 mm, the patients were treated with MRI-guided LITT 4 to 6 weeks after embolization. Survival rates of the different liver tumors of the combined protocol were compared to the results of the patients who were treated only with TACE or with the results of the patients who were treated directly with LITT. Results: In the neoadjuvant group repeated TACE enabled a reduction in tumor size and tumor perfusion in 166 patients (80 cases of metastases of colorectal cancer, 39 cases of metastases of breast cancer, 12 cases of metastases of other primary tumors, 3 cases of carcinoids and 32 cases of HCC), forming the basis of the performance of 322 (mean 2.0) MR-guided LITT procedures. The median survival period for patients with HCC was after the first treatment 25.0 months for the TACE group, 33.3 months for the LITT group and was statistically significant higher with 36.0 months in the patients with the combined treatment. In contrast to this the median survival for patients with colorectal liver metastases was 15.2 months for the TACE group, 23.6 months for the neoadjuvant treated patients and 32.6 months for the patients treated only with LITT. Conclusion: The combined treatment protocol (TACE followed by MR-guided LITT) appears to be a safe and effective treatment of large unresectable liver tumors. The combination of TACE and LITT results in significant superior survival rates in comparison to the results of TACE alone. HCC showed a better response to the treatment than liver metastases.

Wertigkeit der hochauflösenden MRT für die Darstellung normaler und pathologischer Strukturen des Innenohres

ZusammenfassungZiel dieser Studie war die Überprüfung der Wertigkeit von hochauflösenden T2-gewichteten TSE-Sequenzen für die Darstellbarkeit normaler anatomischer und pathologischer Strukturen im Bereich des Innenohres und des inneren Gehörgangs. Insgesamt wurden 30 Probanden ohne klinische Symptomatik und 73 Patienten mit den klinischen Zeichen einer Innenohrerkrankung an einem 1,5-Tesla-MRT-Gerät mit der Kopfspule untersucht. Es kamen neben den konventionellen T2- und T1-gewichteten Sequenzen stark T2-gewichtete hochauflösende TSE-Sequenzen (TR/TE=4797/400) in transversaler und sagittaler Schichtorientierung zum Einsatz. Aus den transversalen TSE-Datensätzen wurden MIP-Rekonstruktionen angefertigt. Bei allen Probanden und 59 von 73 Patienten kamen die Kochlea, die Canales semicircularis lateralis, anterior und posterior sowie die Nervi facialis, cochlearis, vestibularis superior und inferior regelrecht zur Darstellung. Bei Patienten mit einem intrameatalen (n=3) oder intra-/extrameatalen (n=2) Akustikusneurinom gelang es, die exakte Lagebeziehung zwischen Tumor und nervalen Strukturen zu dokumentieren. Bei einem Patienten, der für eine Kochlea-Implantation vorgesehen war, zeigte sich eine Aplasie der Nervi cochlearis, vestibularis superior und inferior. Dieser Patient wies zudem eine Aplasie des Canalis semicircularis lateralis rechtsseitig auf. Bei einem Patienten mit einem Vestibularisneurinom zeigte sich eine Aplasie des Canalis semicircularis lateralis und posterior. Die hochauflösende MRT des Innenohres ermöglicht die exakte Darstellung normaler anatomischer und pathologischer Strukturen im Submillimeterbereich in einer Untersuchungszeit von 15 bis 20 min. Die MIP-Rekonstruktionen erlauben eine deutliche und präzise Darstellung der flüssigkeitsgefüllten Strukturen des Innenohres.SummaryOur aim was to evaluate the diagnostic potential of high resolution T2-weighted TSE sequences for the visualization of normal anatomical and pathological structures of the inner ear. Thirty volunteers without clinical findings and 73 patients with pathologic clinical findings were examined at a 1.5 Tesla scanner using a head coil. High resolution heavily T2-weighted sequences (TR/TE=4797/400) were used as well as conventional T2- and T1-weighted sequences in transverse and sagittal slice orientation. The high resolution T2-weighted images were used for MIP reconstructions. All volunteers and 59/73 patients demonstrated normal findings of the cochlea and the canales semicircularis posterior, anterior and lateralis and the facial, cochlear, superior and inferior vestibular nerve. Three patients demonstrated an intracanalicular and 2 an intra-/extracanalicular schwannoma of the vestibular nerve. A clear relationship between the nerves and the tumors could be demonstrated. One patient showed an aplasia of the superior and inferior vestibular nerve as well as the cochlea nerve and an aplasia of the lateral semicircular canal of the right side. One patient with a neurinoma of the vestibular nerve showed an aplasia of the lateral and posterior semicircular canal. High-resolution MRI of the inner ear enables the visualization of the submillimeter anatomical structures in an imaging time between 15 to 20 min. The MIP reconstructions provide a clear and precise presentation of the fluid content in the inner ear.

Langzeitergebnisse der MR-gesteuerten LITT bei Lebermetastasen eines Mammakarzinoms

Ziele: Analyse der Uberlebens- und lokalen Tumorkontrolle nach LITT Behandlung von Lebermetastasen eines Mammakarzinoms. Methode: Zwischen 10/1993 und 10/2003 wurden 642 Lebermetastasen eines Mammakarzinoms in 514 Sitzungen bei 267 Patienten therapiert. Die Uberlebensraten (ULR) wurden mit der Kaplan-Meier Methode berechnet. Bei 8,0% der Patienten lagen Rezidivmetastasen nach Leberteilresektion vor, 47,1% hatten Metastasen in beiden Leberlappen und 24,5% lehnten eine Leberteilresektion ab. Bei 18,0% war die Lokalisation der Metastasen so ungunstig, dass die Resektion von den Chirurgen abgelehnt worden ist und 2,3% hatten allgemeine Kontraindikation zur Resektion. Ergebnis: Bei allen Patienten konnte die Behandlung in Lokalanasthesie ambulant durchgefuhrt werden. Die mittlere Uberlebenszeit betrug ab Diagnosedatum der gelaserten Metastase 4,7 Jahre (95% Konfidenzintervall 4,2–5,3 Jahre). Die 1-Jahres Uberlebensrate betrug 95%, 2-Jahres ULR betrug 79%, die 3-Jahres ULR betrug 62% und die 5-Jahres ULR 44%) Die mittlere Uberlebenszeit ab erster LITT-Behandlung betrug 4,1 Jahre (95% KI: 3,5–4,7 Jahre). Es bestanden keine statistisch signifikanten Unterschiede hinsichtlich des Uberlebens der Patienten in Abhangigkeit von der Indikation (p>0,05), synchroner (19,4% der Patienten) bzw. metachroner (80,6% der Patienten) Metastasierung und Grose der behandelten Metastase. Patienten mit Knochenmetastasen zum Zeitpunkt der ersten LITT-Behandlung hatte ebenfalls statistisch keine signifikant schlechtere Uberlebensrate als Patienten ohne Knochenmetastasen Schlussfolgerung: Die LITT stellt eine minimal invasive Methode zur lokalen Ablation von Lebermetastasen eines Mammakarzinoms dar und resultiert in sehr guten Langzeitergebnissen hinsichtlich Uberlebensrate und lokaler Tumorkontrollrate.