Präoperative prognostische Faktoren in der Bildgebung bei malignen Hirntumoren im Kindesalter

Material und Methoden: 43 von 169 Patienten wurden in einer multizentrischen prospektiven Studie evaluiert. Das Studienprotokoll umfaßte axiale Computer- und Magnetresonanztomographien (MRT) vor und nach intravenöser Kontrastmittelkapplikation. In der MRT wurden obligat T1- und T2-gewichtete Sequenzen und fakultativ protonengewichtete Sequenzen ausgewertet. Untersucht wurden die morphologischen Kriterien Tumorgröße, Tumorlokalisation, tumorinduziertes Hirnödem, Masseneffekt des Tumors auf die Umgebung, Liquorzirkulationsstörung sowie die tumoreigenen Bildgebungskriterien CT-Dichte, Verkalkungen, liquide Formationen, Kontrastmittelaufnahme und Abgrenzbarkeit des Tumors nach Kontrastmittelapplikation. In der statistischen Analyse wurde hierbei zwischen dem klinischen Verlauf und dem Überleben der Kinder bei Beobachtungszeit von 3,2 Jahren differenziert. Hierbei wurde im klinischen Verlauf nach kompletter und partieller Remission (good responder) sowie nach unveränderte Tumor(rest)ausdehnung nach Operation und fortschreitendem Tumorleiden (poor responder) unterschieden. Der klinische Verlauf wurde mittels chi2-Test, das Überleben mittels log-rank-Test der Kaplan-Meier Analyse evaluiert. Ergebnisse: Als einziger prognostisch ungünstiger Parameter im Hinblick auf den klinischen Verlauf, nicht aber hinsichtlich des Überlebens grenzte sich der Masseneffekt des Tumors auf seine Umgebung ab: über 71 Prozent der Patienten mit einen nur lokal komprimierenden Effektes des Tumors auf seine Umgebung waren good responder, während 75 Prozent der Kinder mit Mittellinienverlagerung oder Hernierung von Hirnanteilen infolge des Tumors poor responder waren. Im Überleben zeigte sich hierbei jedoch kein statistisch faßbarer Unterschied. Schlußfolgerung: Der einzige sich prognostisch ungünstig auf den klinischen Verlauf auswirkende morphologische Parameter in der Schnittbildgebung bei malignen Hirntumoren im Kindesalter war in der durchgeführten Studie des Masseneffekt des Tumors auf seine Umgebung, wobei eine Mittellinienverlagerung oder Hernierung von Hirnanteilen eine ungünstigere Prognose aufwiesen als ein lokal komprimierender Tumoreffekt

Ovarian Torsion in a Teenage Girl with Genitourinary Anomaly.

We present the clinical presentation, sonography, CT, and MR imaging as well as correlative intra-operative and gross pathological findings of ovarian torsion in a 14-year-old girl. Our findings are discussed in the context of prior imaging studies performed for the evaluation of ovarian torsion. Ovarian torsion is not an uncommon cause of acute abdominal pain in children and teenage girls. Diagnosis of this entity can be difficult based on clinical presentation or on imaging appearance alone

Ovarian Torsion in a Teenage Girl with Genitourinary Anomaly

We present the clinical presentation, sonography, CT, and MR imaging as well as correlative intraoperative and gross pathological findings of ovarian torsion in a 14-year-old girl. Our findings are discussed in the context of prior imaging studies performed for the evaluation of ovarian torsion. Ovarian torsion is not an uncommon cause of acute abdominal pain in children and teenage girls. Diagnosis of this entity can be difficult based on clinical presentation or on imaging appearance alone. Case Report A 14-year-old girl suddenly developed right lower quadrant pain associated with nausea while showering. After an initial evaluation at an outside hospital, she was transferred to our institution. Patient denied fevers, chills, dysuria, urinary frequency, diarrhea, and constipation. She was G0 with no sexual activity. She has had irregular cycles lasting 2-3 months since she was 11, the last of which was too long ago for her to remember. Her past medical history was unremarkable. She had no allergies and denied tobacco, alcohol, illicit drug and medication use. Physical exam was remark-Citation: Taheri MR, Dubinsky TJ, Kolokythas O. Ovarian torsion in a teenage girl with genitourinary anomaly. Radiology Case Reports. [Online] 2008;3:155. Copyright: © 2008 The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs 2.5 License, which permits reproduction and distribution, provided the original work is properly cited. Commercial use and derivative works are not permitted. Abbreviations: CT, computed tomography; MRI, magnetic resonance imagin

Imaging of uncommon retroperitoneal masses

Retroperitoneal masses not arising from major solid organs are uncommon. Although there is no simple method of classifying retroperitoneal masses, a reasonable approach is to consider the masses as predominantly solid or cystic and to subdivide these into neoplastic and nonneoplastic masses. Because the treatment options vary, it is useful to be able to differentiate these masses by using imaging criteria. Although the differential diagnosis of retroperitoneal masses can be narrowed down to a certain extent on the basis of imaging characteristics, patterns of involvement, and demographics, there is still a considerable overlap of imaging findings for these masses, and histologic examination is often required for definitive diagnosis. Computed tomography (CT) and magnetic resonance (MR) imaging play an important role in characterization and in the assessment of the extent of the disease and involvement of adjacent and distant structures. Familiarity with the CT and MR imaging features of various retroperitoneal masses will facilitate accurate diagnosis and staging for aggressive lesions

An MRI-guided HIFU-triggered wax-coated capsule for supertargeted drug release: a proof-of-concept study

Background Externally controlling and monitoring drug release at a desired time and location is currently lacking in the gastrointestinal tract. The aim of the study was to develop a thermoresponsive wax-coated capsule and to trigger its release upon applying a magnetic resonance imaging (MRI)-guided high-intensity focused ultrasound (HIFU) pulse. Methods Capsules containing a lyophilised gadolinium-based contrast agent (GBCA) were coated with a 1:1 (mass/mass) mixture of lanolin and cetyl alcohol (melting point ≈43 °C) and exposed to simulated gastric and intestinal fluids (United States Pharmacopoeia) at 37 °C for 2 and 24 h, respectively. In a HIFU gel phantom, wax-coated capsules (n = 3) were tracked based on their T1- and T2-hypointensity by 1.5-T T1- and T2-weighted MRI pre- and post-exposure to an MRI-guided HIFU pulse. Results Lanolin/cetyl alcohol-coated capsules showed high resistance to simulated gastrointestinal fluids. In a gel phantom, an MRI-guided HIFU pulse punctured the wax coating, resulting in the hydration and release of the encapsulated lyophilised GBCA and yielding a T1-hyperintense signal close to the wax-coated capsule. Conclusion We provide the proof-of-concept of applying a non-invasive MRI-guided HIFU pulse to actively induce the disintegration of the wax-coated capsule, and a method to monitor the release of the cargo via T1-weighted MRI based on the hydration of an encapsulated lyophilised GBCA. The wax-coated capsule platform enables temporally and spatially supertargeted drug release via the oral route and promises to address a currently unmet clinical need for personalised local therapy in gastrointestinal diseases such as inflammatory bowel diseases and cancer.ISSN:2509-928

Comparison of gadolinium-based contrast agents for MR cholangiography in saline, blood and bile: a phantom study

Abstract Background We compared T1- and T2-weighted signal intensities of liver-specific (gadoxetate, gadobenate) and non-specific (gadoterate) gadolinium contrast agents (CAs) in a bile phantom. Methods In a phantom study, gadoxetate, gadobenate, and gadoterate were diluted in saline, blood, and bile at different concentrations (0, 0.25, 0.5. 1, 2.5, 5, 10, and 25 mM) and imaged in a 3-T magnetic resonance imaging (MRI) system using T1- and T2-weighted sequences. The maximum signal intensities of CAs were compared for each sequence separately and across all T1-weighted sequences using one-way ANOVA. Results Using T1-weighted sequences, CA concentration-dependent signal intensity increase was followed by decrease due to T2* effects. Comparing CAs for each sequence in bile yielded higher maximum signal intensities with gadobenate than gadoxetate and gadoterate using T1-weighted spin-echo (p  0.141). Signal reduction with CA concentration-dependent decrease was observed on T2-weighted images. Conclusion In this bile phantom study of gadolinium-based CA, gadobenate and gadoxetate showed high signal intensity with T1-weighted TFE and 3D-mFFE sequences, which supports their potential utility for contrast-enhanced hepatobiliary MRI. Key points • Contrast-enhanced magnetic resonance (MR) cholangiography depends on contrast agent type, kinetics, and concentration in bile, • We compared signal intensities of three contrast agents in a bile phantom study. • Gadobenate, gadoxetate, and gadoterate demonstrated different signal intensities at identical concentrations. • Gadoxetate and gadobenate showed high signal intensities on T1-weighted MR sequences