A. Scherer

Magnetic resonance imaging of bone marrow changes in Gaucher disease during enzyme replacement therapy: first German long-term results

Abstract.Objective:. Since 1991, enzyme replacement therapy (ERT) has been available for patients with Gaucher disease in Germany. The aim of this study was to analyse the MR pattern of bone marrow involvement and response to ERT in Gaucher disease type I. Patients and design:. Thirty patients with Gaucher disease type I had MRI examinations prior to initiation of ERT with alglucerase/imiglucerase and during follow-up. Median MR follow-up and duration of ERT were 36 months. Coronal T1- and T2-weighted spin-echo images of the lower extremities were obtained to evaluate changes in the appearance of yellow marrow. MR images were categorized as having either a homogeneous (type A) or non-homogeneous patchy (type B) appearance of bone involvement and response to ERT was assessed by two radiologists. Results:. Overall, 19 of 30 patients (63%) showed an increased signal intensity on T1- and T2-weighted images after 36 months of ERT, consistent with partial reconversion of fatty marrow during treatment. Focal bone lesions surrounded by a low signal intensity (SI) rim did not respond to ERT, suggesting bone infarcts. Of the 11 patients with bone infarcts (low SI rim lesion), 82% had the non-homogeneous type B pattern (P=0.0021). In 86% of patients with splenectomy, bone infarcts were seen (P<0.05). Conclusions:. MRI using T1- and T2-weighted spin-echo sequences is a valuable, non-invasive method for monitoring bone marrow response in patients receiving ERT. A non- homogeneous patchy signal intensity of bone marrow involvement correlates with the presence of bone infarcts (P=0.0021).

ECG-gated Nonenhanced 3D Steady-State Free Precession MR Angiography in Assessment of Transplant Renal Arteries: Comparison with DSA

PURPOSE To evaluate noncontrast material-enhanced steady-state free precession (SSFP) magnetic resonance (MR) angiography in the assessment of transplant renal arteries (RAs) by using digital subtraction angiography (DSA) as the reference standard. MATERIALS AND METHODS This prospective study was approved by the institutional review board; written informed consent was obtained from all participants. In 20 renal allograft recipients scheduled for DSA, the transplant RAs were assessed with electrocardiographically gated nonenhanced SSFP MR angiography performed at 1.5 T; the degree of stenosis was compared with that of DSA. Subjective image quality for SSFP MR angiography was assessed independently by two radiologists on a four-point scale (from 1, nondiagnostic to 4, excellent) in four predefined segments (I, the iliac artery; II, the main transplant artery; III, segmental branches; and IV, parenchymal branches). Sensitivity, specificity, and accuracy of SSFP MR angiography for the detection of relevant (> or =50%) transplant RA stenosis (TRAS) were calculated on a per-artery basis. RESULTS One patient was excluded because SSFP MR angiography failed to adequately visualize the allograft vasculature owing to low cardiac output. The mean image quality assessed by both readers was 3.98 +/- 0.16 (standard deviation), 3.5 +/- 0.68, 2.71 +/- 1.12 and 2.03 +/- 1.09 for segments I, II, III, and IV, respectively (kappa = 0.80). DSA helped identify eight relevant (> or =50%) stenoses in six transplant RAs. Kinking of the transplant artery without relevant stenosis was found in seven patients. The degree of stenosis was overestimated in three patients by using SSFP MR angiography. As compared with DSA, the sensitivity, specificity, and accuracy of SSFP MR angiography to help detect relevant TRAS were 100% (six of six), 88% (14 of 16), and 91% (20 of 22), respectively. CONCLUSION Nonenhanced SSFP MR angiography is a reliable alternative imaging technique for the assessment of transplant RAs in patients for whom contrast-enhanced MR angiography is contraindicated.

Hybrid 18F-FDG PET-MRI of the hand in rheumatoid arthritis: initial results.

Abstract18F-fluorodeoxyglucose PET (18F-FDG PET) is highly sensitive to inflammatory changes within the synovial tissue in rheumatoid arthritis (RA). However, the highest spatial resolution for soft tissue can be achieved with MRI. Here, we report on the first true hybrid PET–MRI examination of the hand in early RA exploiting the advantages of both modalities. PET–MRI was performed with a prototype of an APD-based magneto-insensitive BrainPET detector (Siemens Healthcare, Erlangen, Germany) operated within a standard 3T MR scanner (MAGNETOM Trio, Siemens). PET images were normalized, random, attenuation and scatter-corrected, iteratively reconstructed and calibrated to yield standardized uptake values (SUV) of 18F-FDG uptake. T1-weighted TSE in coronal as well as sagittal orientation prior to and following Gadolinium administration were acquired. Increased 18F-FDG uptake was present in synovitis and tenovaginitis as identified on contrast-enhanced MRI. The tracer distribution was surrounding the metacarpophalangeal joints II and III. Maximum SUV of 3.1 was noted. In RA, true hybrid 18F-FDG PET–MRI of the hand is technically feasible and bears the potential to directly visualize inflammation.

Bildgebende Verfahren in der Rheumatologie: Magnetresonanztomographie bei Rheumatoider Arthritis

Zusammenfassung. Die Magnetresonanztomographie (MRT) stellt zur Zeit das modernste und zugleich technisch aufwendigste Schnittbildverfahren der Radiologie dar. Die MRT zeichnet sich dabei gegenüber anderen bildgebenden Verfahren durch einen überlegenen Weichteilkontrast, die Möglichkeit der multiplanaren Darstellung und das Fehlen ionisierender Strahlen aus. Durch adäquate Differenzierung und Abbildung von Weichteil- und knöchernen Veränderungen gewinnt sie bei der Frühdiagnostik und Verlaufskontrolle entzündlich-rheumatischer Gelenkerkrankungen, wie z. B. der Rheumatoiden Arthritis (RA), immer mehr an Bedeutung. Deshalb kommt nicht nur der technischen Qualitätssicherung, sondern vor allem auch der ärztlichen Qualifikation bei der Indikationsstellung, der Durchführung als auch der Auswertung der MRT eine besondere Rolle zu. Diese Entwicklung verlangt daher für den Einsatz der MRT in der Rheumatologie standardisierte Empfehlungen und Untersuchungsprotokolle, welche von Rheumatologen und Radiologen der Kommission “bildgebende Verfahren” der Deutschen Gesellschaft für Rheumatologie (DGRh) zusammengefasst und vorgestellt werden.Summary. Magnetic resonance imaging (MRI) is currently the most modern and, at the same time, most technically advanced instrument of sectional imaging in diagnostic radiology. MRI is superior to other radiological procedures because of its excellent soft-tissue contrast, the possibility of multiplanar imaging and the missing of ionizing radiation. Exact differentiation and imaging of soft tissue and bony alterations is of significant evidence in early diagnosis and monitoring of inflammatory joint diseases, such as rheumatoid arthritis (RA). Besides securing of technical quality management, the physicians qualification in indication, conduction and evaluation of MRI plays a pivotal role. This development of MRI for rheumatological purposes needs standardized recommendations and investigation protocols, which are now summarized and presented by the rheumatologists and radiologists of the study group of “diagnostic imaging procedures” of the German Society for Rheumatology (DGRh).

Early detection of bony alterations in rheumatoid and erosive arthritis of finger joints with high-resolution single photon emission computed tomography, and differentiation between them

ObjectiveTo evaluate high-resolution multi-pinhole single photon emission computed tomography (MPH-SPECT) for the detection of bony alterations in early rheumatoid arthritis (ERA), early osteoarthritis (EOA) of the fingers and healthy controls.MethodsThe clinically dominant hands of 27 patients (13 ERA, nine EOA, five healthy controls) were examined by MPH-SPECT and bone scintigraphy. Additionally, magnetic resonance imaging (MRI) was performed in the ERA patients. Number of affected joints, localisation, pattern of tracer distribution and joint involvement were scored. Quantitative analysis was achieved by measurement of the region of interest (ROI) in all patients. The MPH-SPECT and MR images were fused in the ERA group.ResultsBone scintigraphy detected fewer joints (26 joints,13/22 patients) with increased tracer uptake than did MPH-SPECT (80 joints, 21/22 patients). Bone scintigraphy did not show recognisable uptake patterns in any group of patients. With MPH-SPECT central tracer distribution was typical in ERA (10/13 patients, EOA 2/9). In contrast, an eccentric pattern was found predominantly in EOA (7/9, ERA 2/13). Normalised counts were 4.5 in unaffected joints and up to 222.7 in affected joints. The mean uptake values in affected joints were moderately higher in the EOA patients (78.75, and 62.16 in ERA). The mean tracer uptake in affected joints was approximately three-times higher than in unaffected joints in both groups (ERA 3.64-times higher, EOA 3.58). Correlation with MR images revealed that bone marrow oedema and erosions matched pathological tracer accumulation of MPH-SPECT in 11/13. MPH-SPECT demonstrated increased activity in 2/13 patients with normal bone marrow signal intensity and synovitis seen on MR images.ConclusionMPH-SPECT is sensitive to early changes in ERA and EOA and permits them to be distinguished by their patterns of uptake.

Molecular imaging of cartilage damage of finger joints in early rheumatoid arthritis with delayed gadolinium-enhanced magnetic resonance imaging.

OBJECTIVE To assess cartilage glycosaminoglycan content and cartilage thickness in the metacarpophalangeal (MCP) joints of patients with early rheumatoid arthritis (RA) and healthy volunteers. METHODS After review board approval and informed consent were obtained, 22 subjects were prospectively enrolled (9 patients with early RA [7 women and 2 men with a mean ± SD age of 49 ± 13 years; range 25-68 years] and 13 healthy volunteers [10 women and 3 men with a mean ± SD age of 51 ± 12 years; range 25-66 years). In a total of 44 MCP joints of the index and middle fingers, measurements of cartilage thickness and delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) index (T1 [msec]) were obtained using the variable flip-angle method and a 3T MR scanner. MRIs were evaluated for bone edema, erosions, and synovitis (using the RA MRI Scoring criteria). Students t-test was used to test the significance of differences between groups. RESULTS The mean ± SD dGEMRIC index was 497 ± 86 msec in healthy volunteers and was significantly lower in the early RA group (421 ± 76 msec) (P = 0.042). There was no joint space narrowing seen on standard radiographs. No significant difference was found between cartilage thickness in patients with early RA and that in controls (index finger mean ± SD 1.27 ± 0.23 mm in RA patients versus 1.46 ± 0.34 mm in controls [P = 0.16] and middle finger 1.26 ± 0.23 mm in RA patients versus 0.97 ± 0.47 mm in controls [P = 0.10]). No significant correlation was noted between cartilage thickness and dGEMRIC index (R = 0.36, P = 0.88 in RA patients; R = 0.156, P = 0.445 in controls). CONCLUSION Our findings indicate that cartilage damage is present in the MCP joints of patients with early RA despite the absence of joint space narrowing on standard radiographs and MRI. Cartilage damage in RA can be imaged with dGEMRIC.

Glioblastoma Multiforme Metastasis Outside the CNS: Three Case Reports and Possible Mechanisms of Escape

Introduction Primary brain and CNS tumor incidence is approximately 19 per 100,000 individuals per year in the United States compared with seven per 100,000 individuals worldwide. Worldwide this accounts for 2% of all primary tumors and 7% of years of life lost from cancer before the age of 70 years. Glioblastoma multiforme (GBM) is also the most aggressive brain tumor with poor prognosis; patients with GBM have a median survival time of about 14 months. GBM metastases outside the CNS are rare, so therapeutic experience with these types of tumors is limited. Normally the brain is immunologically and anatomically separated from the body by the blood brain barrier. Herein, we present the cases of three patients with GBM with extra-CNS metastasis. The variety of metastasis locations demonstrated in these cases helps to illustrate the various mechanism and corresponding risk factors that allow GBM to escape the CNS.

Thalidomide for the treatment of idiopathic myelofibrosis

Except rare instances of allogeneic stem cell transplantation, treatment of idiopathic myelofibrosis (IMF) is only palliative and based on cytostatic treatment (hydroxyurea and anagrelide), androgen therapy, steroids and splenectomy. Thalidomide is an anti‐angiogenic and immunmodulatory drug with a wide spectrum of activities, which are not clearly understood. Current data suggest that the action of thalidomide is related to several different mechanisms, including suppression of tumor necrosis factor, effects on basic fibroblast growth factor, vascular endothelial growth factor, interleukins and interferons, downregulation of selected cell surface adhesion molecules, and changes in the lymphocyte subsets.

Prospectively Ecg-triggered High-pitch Spiral Acquisition for Cardiac Ct Angiography in Routine Clinical Practice: Initial Results

Purpose: This study was conducted to evaluate the mode of application, image quality (IQ), and radiation exposure resulting from introduction of a prospectively electrocardiogram-triggered high-pitch cardiac computed tomography angiography (CTA) acquisition mode into routine clinical practice. Materials and Methods: A total of 42 prospectively triggered cardiac CTAs were conducted on 34 patients (11 female, 23 male; mean age 56±15 y) using a high-pitch mode (pitch 3.4) on a dual-source CT. In 8 of these patients with higher heart rates or occasional premature ventricular contractions, 2 immediately subsequent CTAs were performed (“double flash protocol”). Subjective IQ was assessed for coronary arteries using a 4-point scale (1=unevaluable to 4=excellent). Contrast-to-noise ratio (CNR) was measured in 9 locations. CT Dose Index and dose-length product were obtained, and the patients’ effective dose was calculated. Results: Mean effective doses were 2.6±1.4 mSv (range: 1.1 to 6.4) for the entire cardiac examination and 1.4±0.7 mSv (0.4 to 3.1) for individual high-pitch cardiac CTA. z-coverage ranged from 9.9 cm in a native coronary CTA to 31.4 cm in a bypass graft case. The overall subjective IQ was good to excellent (mean score: 3.5), with 1.5% unevaluable coronary segments. The “double flash protocol” resulted in a fully diagnostic CT study in all cases just after taking both scans into consideration. The mean CNR of all locations was 19.7±2.6. Conclusion: Prospectively electrocardiograph-triggered high-pitch-mode cardiac CTA is a feasible and promising technique in clinical routine, allowing for evaluation of coronaries at good-to-excellent IQ and providing high CNR and minimal radiation doses. The “double flash protocol” might become a more robust tool in patients with elevated heart rates or premature ventricular contractions.

Diffusion-Attenuated MRI Signal of Renal Allografts: Comparison of Two Different Statistical Models

OBJECTIVE Contrast-enhanced MRI is considered problematic in renal allograft recipients because of the development of nephrogenic systemic fibrosis. Therefore, we assessed the clinical value of a monoexponential model and a distribution function model of diffusion-weighted imaging (DWI) in renal allografts. MATERIALS AND METHODS A total of 23 patients were divided into three groups, as follows: group A, stable renal allograft function for at least 6 months; group B, transplantation within the past 30 days, with good renal allograft function; and group C, an acute deterioration or decrease in renal allograft function. T2-weighted axial, T1-weighted coronal, and a paracoronal DWI sequences with 16 b values (b = 0-750 s/mm(2)) were performed on a 1.5-T scanner. Region of interest-based analysis of the apparent diffusion coefficient (ADC) of the renal cortex was used. RESULTS Monoexponential analysis showed mean (± SD) ADC values of 1932 ± 98, 2095 ± 246, and 1636 ± 200 10-(6) mm(2)/s for patient groups A, B, and C, respectively. The distribution function revealed a mean ADC of 2487 ± 185, 2850 ± 325, and 2142 ± 31410-(6) mm(2)/s for groups A, B, and C, respectively. The difference between groups A and B combined and group C (p < 0.005) was statistically significant for both models. R(2) yielded the best regression of mathematic fitting for the distribution function model (p < 0.0001). DISCUSSION Unenhanced evaluation of renal allografts with DWI correlated well with renal function for both the monoexponential analysis and the distribution function model. There was no statistically significant difference in ADC values and renal allograft function between both types of analysis, but the distribution function showed the best regression.