Stefan Paris

Static magnetic resonance imaging of the pelvic floor muscle morphology in women with stress urinary incontinence and pelvic prolapse

In a study, the magnetic resonance imaging (MRI) findings of 69 women were analyzed to define the typical MRI appearance of the pelvic floor musculature in healthy subjects (n = 20) and women with urinary incontinence (UI) and/or genitourinary prolapse (GP) (n = 49).

MR imaging of septic sacroiliitis.

Abstract Objective. To investigate the diagnostic value of magnetic resonance (MR) imaging in detecting septic sacroiliitis and to determine whether the MR characteristics allow this entity to be differentiated from sacroiliitis in spondylarthropathy (SpA). Patients and design. The imaging findings of 11 patients with septic sacroiliitis were retrospectively analyzed by two experienced radiologists. Radiographic surveys of the pelvis as well as computed tomography (CT) and MR images of the sacroiliac joints were available in all cases. Seven of the patients additionally underwent a follow-up MR examination. The MR imaging protocol comprised combinations of coronal and transverse T1-weighted spin-echo (SE) or fast SE sequences, T2-weighted gradient-echo (GE) sequences and short tau inversion recovery sequence (STIR) sequences as well as dynamic contrast- enhanced T1-weighted acquisitions. Results. Three patients with a short disease history showed anterior and/or posterior subperiosteal infiltrations (”lava cleft phenomenon”), transcapsular infiltrations of juxta-articular muscle layers, which obscured the fasciae, and periarticular bone marrow edema. The eight patients with more advanced stages of sacroiliitis additionally showed abscess formation, sequestration, and erosion. At follow-up MR examination (n=7) under systemic antibiotic treatment, the morphologic characteristics showed progression (n=1), regression (n=4), unchanged findings (n=1), or a mixed response (n=1). Clinical improvement precedes resolution of the MR findings. Conclusions. Anterior and/or posterior subperiosteal infiltrations and transcapsular infiltrations of juxta-articular muscle layers were depicted in all patients. These MR imaging findings are characteristic of septic sacroiliitis and may be used to differentiate this entity from sacroiliitis in SpA.

Use of contrast-enhanced MR imaging to detect sacroiliitis in children.

Abstract Purpose. To verify the diagnostic value of contrast-enhanced MR imaging compared with conventional radiography in the diagnosis of sacroiliitis in children. Design and patients. Radiography and MR imaging of the sacroiliac joints were performed in 185 children subdivided into the following groups according to the modified European Spondyloarthropathy (SpA) Study Group (ESSG) criteria: group 1, undifferentiated spondyloarthropathy (uSpA) (n=53, 94.5% HLA-B27+); group 2, differentiated SpA (n=45, 93.3% HLA-B27+); group 3, patients with no signs of SpA other than oligoarthritis (n=39, 92.3% HLA-B27+); group 4, HLA-B27+ controls with various other non-SpA diagnoses (n=22); and group 5, HLA-B27– controls with various other non-SpA diagnoses (n=26). Radiographs were evaluated on the basis of the modified New York criteria independently by three experienced radiologists masked to the clinical data. In a second step, the same radiologists independently evaluated the MR images without knowledge of the clinical data and radiographic findings using the recently published criteria developed by our group. These criteria allow differentiation of acute and chronic inflammatory changes. Results. Radiography demonstrated sacroiliitis in 18 patients: 4 of 53 in group 1 (7.5%), 14 of 45 in group 2 (31%), but none in groups 3, 4 and 5. In contrast, MR imaging demonstrated acute and/or chronic sacroiliitis in 44 patients: 18 of 53 in group 1 (34%), 21 of 45 in group 2 (46.7%) and 5 of 39 in group 3 (12.8%), but none in groups 4 and 5. The percentage of sacroiliitis detected by MR imaging was significantly higher than that detected by radiography (P<0.001). Conclusion. Contrast-enhanced MR imaging is a useful method for detecting sacroiliitis in children. Advantages of contrast-enhanced MR imaging compared with conventional radiography are a higher sensitivity due to the ability to document early and acute changes and the absence of radiation exposure.

Normal morphology of sacroiliac joints in children : magnetic resonance studies related to age and sex

Abstract Objective. To determine in a prospective study the normal MRI morphology of the sacroiliac joints (SIJs) in relation to age and sex during adolescence. Design and patients. A total of 98 children (63 boys, mean age 12.7±2.8 years; 35 girls, mean age 13.7±2.3 years), ranging in age from 8 to 17 years, with juvenile chronic arthritis (JCA) but without signs of sacroiliitis fulfilled the study prerequisites (no back pain and no pathologic changes of the SIJs on physical examination before MRI in a 1.5-year follow-up). An additional eight HLA-B27-negative boys and eight HLA-B27-negative girls without arthritis served as controls. The MRI protocol comprised a T1-weighted SE sequence, an opposed-phase T2*-weighted GE sequence, and a dynamic contrast-enhanced study in single-section technique. Results. Noncontrast MRI permitted differentiation of “open” from ossified segmental and lateral apophyses of the sacral wings, with a significant difference in age (P <0.05) between children with open and ossified apophyses. Ossification of the apophyses of the sacral wings was seen significantly earlier (P <0.05) in girls than in boys. Girls also had a significantly higher incidence of transitional lumbosacral vertebrae, pelvic asymmetries, and accessory joints. In the contrast-enhanced opposed-phase MRI study, normal cartilage of the SIJs showed no contrast enhancement whereas the joint capsule showed a moderate enhancement. Conclusion. There are significant age- and sex-related differences in the normal MRI morphology of juvenile SIJs. Our findings might serve as a standard of comparison for the evaluation of pathologic changes – in particular for the early identification of juvenile sacroiliitis.

Die Wertigkeit der Magnetresonanztomografie (MRT) bei der Diagnostik von Übergangsfrakturen im Bereich der distalen Tibia

ZusammenfassungZur Untersuchung der Frage, in welcher Hinsicht ein mehrdimensionales bildgebendes Verfahren konventionellen Röntgenbildern bei der Diagnostik multiplanarer Übergangsfrakturen überlegen ist, wurde in einem Zeitraum von 18 Monaten bei 15 Frakturen im Bereich der distalen Tibia, bei denen im konventionellen Röntgenbild der Verdacht auf eine Epiphysenfugenbeteiligung bestand, eine MRT durchgeführt, mit der eine röntgenstrahlenfreie, mehrdimensionale Darstellung der verletzten Region möglich ist.Anschließend wurden MRT- und Röntgenbilder dieser Patienten anonymisiert und von 4 unabhängigen Befundern hinsichtlich des Frakturtyps, des Frakturverlaufes und der Frakturdislokation befundet.Die Diagnose der Übergangsfraktur wurde in beiden bildgebenden Verfahren bei 12 von 15 Patienten korrekt gestellt.Die Standardröntgenaufnahmen zeigten sich jedoch der MRT bei der Befundung der Übergangsfrakturen hinsichtlich der oben genannten Kriterien deutlich unterlegen. In den Nativröntgenaufnahmen wurde der Frakturtyp in 2 Fällen fehlklassifiziert, 2 von 3 Rotationsfehlern wurden übersehen, des Weiteren kam es zu Fehlinterpretationen der maximalen Fragmentdislokation von durchschnittlich 0,5 mm.Zur exakten Befunderhebung von Übergangsfrakturen bedarf es eines zusätzlichen, mehrdimensionalen, bildgebenden Verfahrens. Dabei ist die MRT der konventionellen Röntgendiagnostik aufgrund fehlender Strahlenbelastung sowie der Möglichkeit der Beurteilung von ligamentären und kartilaginären Läsionen überlegen.AbstractThe rare transitional fractures occur in adolescents at a time of incomplete desis of the epiphysis. The anatomy of this fracture type is complex with the fracture line running in multiple planes. Conventional plain film radiographs often underestimate the extent and geometry of the fracture due to its transverse components.This study was performed to asses the benefit of MR-imaging compared to plain film radiographs in diagnosis and analysis regarding fracture-type, anatomy and dislocation of fracture.During a time period of 18 months we treated 15 patients with a fracture of the distal tibial epiphysis. In addition to plain film radiographs they got MRI of the distal tibia. Plain film radiographs and MRI were anonymized and diagnosed by 2 surgeons and 2 radiologists.12 transitional fractures were diagnosed in plain radiographs as well as MRI, but regarding our criteria as above, we found two wrong classifications of fracture-type, an underestimation of fracture dislocation of an average of 0,5 mm in plain film radiographs and two rotational dislocations were missed.The MRI was found to provide anatomical detail and information superior to plain film radiographs.

Role of magnetic resonance imaging in the diagnosis of distal tibia fractures in adolescents.

This prospective study was performed to assess the benefits of magnetic resonance imaging (MRI) compared with plain radiographs in the diagnosis and analysis of transitional fractures in terms of fracture type, anatomy, and dislocation. During a 24-month period, 22 adolescents with a fracture of the distal tibial epiphysis were treated. In addition to plain film radiographs, MR images of the distal tibia were also obtained. Plain film radiographs and MR images were randomized and diagnosed by two surgeons and two radiologists. Fifteen transitional fractures were diagnosed using plain radiographs, while 17 transitional fractures could be found with MRI. Fracture type was misclassified, fracture displacement was underestimated in general, and rotational displacements were not visualized on plain film radiographs. MRI was found to provide anatomic detail and information superior to plain film radiographs.

Is decreased ventricular volume a correlate of positive clinical outcome following shunt placement in cases of normal pressure hydrocephalus

It is well known that in patients with communicating hydrocephalus or normal pressure hydrocephalus, ventricular volume decreases following implantation of differential pressure valved shunts. Hydrostatic valves (Miethke dual-switch valves) were implanted in 60 normal pressure hydrocephalus patients at Unfallkrankenhaus Berlin between September 1997 and September 2001. One year postoperatively, these patients underwent CT scan, and their ventricular size was ascertained using the Evans index. Although 77% of these patients showed no postoperative change in ventricular volume, 65% nonetheless showed good to excellent clinical improvement, 13% satisfactory improvement and 22% no improvement. A moderate reduction in ventricular size was observed in 17% of the patients in our cohort. 40% of these patients showed good to excellent clinical improvement, 20% satisfactory improvement, and 40% unsatisfactory improvement. A marked reduction in ventricular size was observed in 6% of our patients. Of these latter patients, 50% showed good to excellent outcomes, while 50% had unsatisfactory outcomes. The favorable outcomes following implantation of a hydrostatic shunt in patients with normal pressure hydrocephalus did not correlate with decreased ventricular volume one year after operation. Better clinical outcomes were observed in patients with little or no alteration in ventricular size than in patients with a marked decrease in ventricular size. Postoperative change in ventricular volume should be assessed differently for patients with normal pressure hydrocephalus than in patients with hypertensive hydrocephalus.

Wertigkeit der Magnetresonanztomographie in der Diagnostik von TFCC-Läsionen

ZusammenfassungBei klinischem Verdacht auf eine Läsion des ulnokarpalen Komplexes (TFCC) werden Bild gebende Verfahren eingesetzt, um die Differenzialdiagnosen einzuschränken und unnötige invasive Eingriffe zu vermeiden. Der TFCC kann nicht mehr nur arthrographisch, sondern inzwischen auch magnetresonanztomographisch dargestellt werden. Die Treffsicherheit der MRT ist u. a. von der angewendeten Technik, der Erfahrung des Untersuchers und der Lokalisation der Pathologie abhängig. Ulnar gelegene Läsionen sind schlechter darzustellen als zentrale und radialseitige, zudem scheint die Spezifität der Magnetresonanztomographie für TFCC-Läsionen geringer zu sein als ihre Sensitivität. Auch in der klinischen Praxis sind anscheinend falsch-positive MRT-Diskusbefunde eher problematisch als übersehene Läsionen. Trotz dieser Einschränkungen ist die MRT das am besten zur Abklärung einer vermuteten TFCC-Läsion geeignete Bild gebende Verfahren. Um optimale Ergebnisse zu erzielen, sind neben Erfahrung und guter Untersuchungstechnik ein kooperativer Patient und ausreichende klinische Informationen notwendig. Die intraartikuläre Kontrastmittelapplikation führt zu einer deutlichen Verbesserung der Aussagekraft, bleibt jedoch wegen des erhöhten Aufwands und der Invasivität speziellen Indikationen vorbehalten.AbstractWhen a clinical examination gives rise to the suspicion of a lesion of the triangular fibrocartilage complex (TFCC), diagnostic imaging is performed to limit the differential diagnoses and to avoid unneccessary invasive procedures. MRI has lately come to be regarded as an alternative to arthrography in such cases. The diagnostic accuracy of MRI in the evaluation of TFCC lesions depends, among other things, on the imaging technique used, the experience of the practitioner conducting the examination and the localisation of the lesion. Lesions on the ulnar side are more difficult to diagnose than central or radial lesions. The specificity of MRI for TFCC lesions is lower than its sensitivity, false-positive results seem to be more of a problem than undetected lesions in day-to-day clinical practice. Despite these limitations, MRI is still the best imaging modality for assessment of a suspected TFCC pathology. Optimal results can only be achieved by an experienced practitioner using a focused imaging technique in a cooperative patient, and then only if sufficient clinical information is available. The intraarticular administration of contrast medium clearly improves the prognostic value but is confined to specific indications owing to the added cost and the invasiveness (although this is limited).

Kontrastmittelverstärkte MRT-Zisternographie zur Detektion von Liquorfisteln nach frontobasaler Verletzung

ZusammenfassungHintergrund: Die Lokalisation von Liquorfisteln ist insbesondere bei geringer oder nur intermittierend auftretender Liquorrhö schwierig. Die koronale CT-Zisternographie ist artefaktanfällig gegenüber metallhaltigem Zahnersatz und stellt eine hohe Strahlenbelastung dar. Die native MR-Zisternographie mit stark T2-gewichteten Sequenzen hat Schwierigkeiten bei der Differenzierung von Liquor gegenüber Schleimhautveränderungen und Blut. Ziel der vorliegenden Analyse war es, die Möglichkeiten der MR-Zisternographie nach intrathekaler Gadoliniumapplikation zur Detektion von Liquorfisteln zu prüfen. Patienten und Methode: Es wurden die Daten von zehn Untersuchungen an neun Patienten (vier weibliche, fünf männliche) mit klinischem Verdacht auf eine Rhinoliquorrhö nach Verletzung der Schädelbasis ausgewertet. Die Indikationsstellung basierte jeweils auf einer Einzelfallentscheidung bei noch nicht zugelassener intrathekaler Applikation von Gadolinium. Es erfolgte eine koronale hoch auflösende Computertomographie, eine native MR-Zisternographie einschließlich T1-gewichteter Sequenzen, die nach intrathekaler hoch verdünnter Gadoliniumapplikation kombiniert mit einem nichtionischen Röntgenkontrastmittel wiederholt wurden. Die Untersuchungsergebnisse wurden mit den intraoperativen Befunden verglichen. Ergebnisse: MR-tomographisch wurde in sieben Fällen eine Liquorrhö dokumentiert, davon vier mit direktem Liquornachweis in der Fistel und drei mit Liquornachweis nasal und entsprechender ursächlicher Defektdarstellung. In zwei Fällen wurde keine Liquorrhö gefunden; die Patienten wurden bei unauffälligem klinischen Verlauf ohne Hinweis auf Liquorrhö nicht operiert. In einem Fall gelang lediglich die Defektdarstellung ohne direkten Fistelnachweis bei klinisch gesicherter Liquorrhö. Die CT-Zisternographie bestätigte in vier Fällen die Liquorrhö, davon wurde lediglich einmal die Liquorfistel direkt dargestellt. Schlussfolgerung: Insgesamt ist die kontrastmittelverstärkte MR-Zisternographie eine risikoarme, effektive und leicht durchzuführende invasive Ergänzung zur CT- und nativen MR-Zisternographie für die Lokalisation von Liquorfisteln bei kleinen Defekten oder störenden Schleimhautveränderungen/Hämatom in der interessierenden Region.AbstractBackground: The localization of cerebrospinal fluid fistula is difficult especially in the presence of only slight or intermittently occurring liquorrhea. Coronal CT-cisternography is highly susceptible to artifacts due to metallic dental material and has the known radiation risk. In MR-cisternography it is difficult to differentiate between cerebrospinal fluid and mucosal swelling, other fluids or hematoma. The aim of this investigation was to evaluate the potential of contrast-enhanced MR-cisternography in the detection of cerebrospinal fluid fistulae. Patients and Method: Ten examinations on nine patients (four female, five male) with clinically suspected cerebrospinal fluid leakage after frontobasal injury were analyzed. Actually the intrathecal application of gadolinium is not approved. The indication for each of the examinations therefore had to be based on an individual decision. Coronal high-resolution computed tomography was done, followed by MR-cisterography including T1-weighted MR-sequences, which were repeated after intrathecal highly diluted gadolinium application combined with a nonionic contrast media. The results were compared to the intraoperative findings. Results: With MR-examination in seven cases liquorrhea was seen: in four cases cerebrospinal fluid was directly visualized in the fistula, in three cases there was cerebrospinal fluid in the nasal cavity and a corresponding frontobasal defect. In two cases no cerebrospinal fluid leakage could be demonstrated and in the clinical course of these patients liquorrhea neither could be proved. In one case of clinically demonstrated liquorrhea only the bony lesion could be visualized in CT- and MR-imagaes. CT-cisternography confirmed four cases of cerebrospinal fluid leakage, in only one case the fistula could directly be demonstrated. Conclusion: Constrast-enhanced MR-cisternography seems to be an effective, poor-risk and easy to perform additional imaging technique for the localization of cerebrospinal fluid fistula, especially in the presence of only small dural lesions or interfering hematoma and mucosal swelling in the region of interest.

Ist die Rückbildung der Ventrikelgröße nach Shunt-Operation beim Normaldruckhydrozephalus eine Conditio sine qua non?

ZusammenfassungHintergrund: Nach Shunt-Implantation von konventionellen Differentialdruckventilen bei Patienten mit Hydrocephalus internus oder mit Normaldruckhydrozephalus ist in der Mehrzahl der Fälle eine postoperative Abnahme der Ventrikelweite zu sehen. Patienten und Methoden: Von September 1997 bis Mai 2001 wurden im Unfallkrankenhaus Berlin 60 Patienten mit einem Normaldruckhydrozephalus durch Implantation eines hydrostatischen Ventils (Miethke-Dual-Switch-Ventil) operativ behandelt. Bei allen Patienten erfolgten in einer prospektiven Studie die klinische und eine CT-Untersuchung präoperativ und 1 Jahr nach der Operation. Dabei wurde die Ventrikelgröße mittels Bestimmung des Evans-Index verifiziert. Ergebnisse: 77% der Patienten weisen nur eine geringe oder gar keine Änderung der Ventrikelgröße nach der Operation auf, wobei in dieser Gruppe 65% einen exzellenten bis guten, 13% einen befriedigenden und 22% einen schlechten Krankheitsverlauf haben. Bei 17% der Patienten wurde eine mäßige Rückbildung der Ventrikelweite 1 Jahr nach der Shunt-Operation sichtbar. In dieser Patientengruppe fanden wir in 40% ein exzellentes bis gutes, in 20% ein zufrieden stellendes und in 40% ein schlechtes Outcome. Bei der Patientengruppe mit deutlicher Reduktion der Ventrikelgröße (6%) sind zu je 50% exzellente bis gute bzw. schlechte Krankheitsverläufe zu eruieren. Schlussfolgerung: Nach Implantation eines hydrostatischen Ventils ist ein guter postoperativer Krankheitsverlauf bei Patienten mit einem Normaldruckhydrozephalus in der Mehrzahl der Fälle nicht mit einer Reduktion der Ventrikelweite 1 Jahr nach der Operation vergesellschaftet. Bei Patienten mit einem Normaldruckhydrozephalus ist nach unseren Erfahrungen die Implantation eines Miethke-Dual-Switch-Ventils zu empfehlen.AbstractBackground: After implantation of conventional differential pressure valves in patients with hydrocephalus internus or with normal pressure hydrocephalus, it is known that the ventricle size decreases postoperatively. Patients and Methods: From September 1997 to May 2001 we had treated 60 patients with normal pressure hydrocephalus with implantation of a hydrostatic valve (Miethke-Dual-Switch-Valve) at the Unfallkrankenhaus Berlin. During a time interval of 1 year after operation the patients were again examined clinically and computertomographically and the Evans index was determined as a measure for the ventricle size. Results: 77% of the patients showed no postoperative change of the ventricle size, although in the same group of patients 65% have excellent and good, 13% a satisfactory and 22% no improvement of the clinical symptoms. In 17% of the patients a moderate decrease in the ventricle size was visible. In this group we observed 40% excellent and good, 20% satisfactory and 40% poor postoperative results after shunt operation. In 6% of the patients a distinct decrease of the ventricle size was visible. Each half of this last patient group showed either an excellent and good or a poor outcome. Conclusion: The good postoperative courses of disease after implantation of a hydrostatic valve into patients with normal pressure hydrocephalus are not bound to be connected with a decrease of the ventricle width after 1 year. The patient groups with no change or only little change of the ventricle size respectively show a better course of disease than the group with a clear decrease of the ventricle volume. The postoperative change of the ventricle size must be assessed differently in patients with normal pressure hydrocephalus as compared to patients with hypertensive hydrocephalus.