Structural white matter changes in adolescents and young adults with maple syrup urine disease.

OBJECTIVE: To get insight into the nature of magnetic resonance (MR) white matter abnormalities of patients with classic maple syrup urine disease (MSUD) under diet control. METHODS: Ten patients with classic MSUD and one with a severe MSUD variant (mean age 21.5 ± 5.1 years) on diet and 11 age and sex-matched healthy subjects were enrolled. Apart from standard MR sequences, diffusion weighted images (DWI), diffusion tensor images (DTI), and magnetization transfer images (MT) were obtained and comparatively analyzed for apparent diffusion coefficient (ADC), tensor fractional anisotropy (FA) and MT maps in 11 regions of interest (ROI) within the white matter. RESULTS: In MSUD patients DWI, DTI and FA showed distinct signal changes in the cerebral hemispheres, the dorsal limb of internal capsule, the brain stem and the central cerebellum. Signal intensity was increased in DWI with a reduced ADC and decreased values for FA. MT did not reveal differences between patients and control subjects. CONCLUSION: Signal abnormalities in the white matter of adolescents and young adults under diet control may be interpreted as consequence of structural alterations like dysmyelination. The reduced ADC and FA in the white matter with preserved MT indicate a reduction in fiber tracks.

[Case-based interactive PACS learning: introduction of a new concept for radiological education of students]. / Fallbasiertes interaktives "PACS-learning": Vorstellung eines neuen studentischen Lehrkonzepts für die Radiologie.

PURPOSE: Medical curricula are currently being reformed in order to establish superordinated learning objectives, including, e.g., diagnostic, therapeutic and preventive competences. This requires a shifting from traditional teaching methods towards interactive and case-based teaching concepts. Conceptions, initial experiences and student evaluations of a novel radiological course Co-operative Learning In Clinical Radiology (CLICR) are presented in this article. MATERIALS AND METHODS: A novel radiological teaching course (CLICR course), which combines different innovative teaching elements, was established and integrated into the medical curriculum. Radiological case vignettes were created for three clinical teaching modules. By using a PC with PACS (Picture Archiving and Communication System) access, web-based databases and the CASUS platform, a problem-oriented, case-based and independent way of learning was supported as an adjunct to the well established radiological courses and lectures. Student evaluations of the novel CLICR course and the radiological block course were compared. RESULTS: Student evaluations of the novel CLICR course were significantly better compared to the conventional radiological block course. Of the participating students 52% gave the highest rating for the novel CLICR course concerning the endpoint overall satisfaction as compared to 3% of students for the conventional block course. The innovative interactive concept of the course and the opportunity to use a web-based database were favorably accepted by the students. Of the students 95% rated the novel course concept as a substantial gain for the medical curriculum and 95% also commented that interactive working with the PACS and a web-based database (82%) promoted learning and understanding. CONCLUSION: Interactive, case-based teaching concepts such as the presented CLICR course are considered by both students and teachers as useful extensions to the radiological course program. These concepts fit well into competence-oriented curricula.

[Increasing number and improved survival of patients with hepatocellular carcinoma from 1988 to 2007: data of a German university clinic]. / Zunahme und verbessertes Überleben des hepatozellulären Karzinoms im Zeitraum von 1988 - 2007: Daten einer deutschen Universitätsklinik.

BACKGROUND AND OBJECTIVES: Hepatocellular carcinoma (HCC) ranks sixth regarding prevalence and third regarding mortality among malignant tumours worldwide. The aim of the present study was to determine changes of clinical-epidemiological parameters and survival rates during two decades. PATIENTS AND METHODS: A total of 441 consecutive patients with HCC admitted to the University Clinic Düsseldorf between January 1988 and December 2007 were included. For comparison, this time period was divided into two decades (1988 - 1997 and 1998 - 2007). RESULTS: The number of newly diagnosed HCCs has tripled in the years 1998 - 2007 compared to the years 1988 - 1997. HCV-associated HCCs increased from 28 % in the years 1988 - 1997 to 38 % (p < 0.05) in the years 1998 - 2007. Tumour size, Okuda and BCLC stages decreased during the observation period (both p < 0.001 and p < 0.05). Median overall survival improved during the observation period from 6 [95 % CI: 4.83 - 7.17] to 9 months ]95 % CI: 7.31 - 10.69]; p < 0.0001) as did the 1-year and 5-year survival rates from 22 % to 42 % (p < 0.019) and from 0 % to 9 % (p < 0.001), respectively. The proportion of treated patients compared to patients with best supportive care as well as the proportion of patients receiving a multimodal therapy compared to patients with a single treatment regimen increased in the second decade (55 % vs. 79 %: p < 0.005; 5.4 % vs. 23 %: p < 0.0001). Multimodal therapy was an independent predictor for prolonged survival in a multivariate analysis including Child-Pugh score, BCLC stage, tumour size, and gender (odds ratio 2,77; 95 % CI: 1.44 - 5.31). CONCLUSION: Improved screening as well as broader and improved treatment options may have contributed to the increasing survival rates.

[Diagnosis of focal liver lesions in cirrhotic patients: comparison of contrast-enhanced ultrasound using sulphur hexafluoride (SF6) microbubbles and MRI using Gd-EOB-DTPA]. / Vergleich der kontrastverstärkten Sonografie und der MRT mit Gd-EOB-DTPA zur Diagnostik fokaler Leberläsionen bei Patienten mit Leberzirrhose.

AIM: The diagnostic accuracies of contrast-enhanced sonography and hepatobiliary contrast-enhanced MRI of the liver in evaluating focal liver lesions in patients with liver cirrhosis were compared. MATERIAL AND METHODS: In 33 patients (25 men, 8 women, mean age 63.2 ± 11.2 years) MRI of the liver using Gd-EOB-DTPA (Primovist®, Bayer Schering Pharma, Berlin) was performed. Axial T(2)-weighted, unenhanced T(1)-weighted and enhanced T(1)-weighted scans during arterial, portal venous and late phases were acquired, followed by coronary T(1)-weighted and axial fat-suppressed T(1)-weighted scans 15 minutes post contrast application. In all patients within 4 weeks contrast-enhanced sonography using sulfur hexafluoride microbubbles (SonoVue®, Nycomed, Germany) was obtained. RESULTS: Cirrhosis of the liver was related to viral infection in 45.4% and to alcoholism in 39.4%. All hepatic lesions were confirmed by histologic examination. Sensitivity and specificity of MRI were 90.2% and 83.3%, compared to contrast-enhanced sonography with 92.7 % and 50 %, respectively. Positive and negative predictive values were 97.4% and 55.5 % for MRI and 90.5% and 50% for contrast-enhanced sonography, respectively. DISCUSSION: In this retrospective study MRI using Gd-EOB-DTPA as well as contrast-enhanced sonography using sulfur hexafluoride microbubbles gave excellent results in detecting HCC in patients suffering from liver cirrhosis. Although the specificity was higher for MRI, the accuracy showed no significant difference between these two imaging techniques.

[Evaluation of ADC mapping as an early predictor for tumor response to chemotherapy in recurrent glioma treated with bevacizumab/irinotecan: proof of principle]. / Evaluation des ADC-Mappings als Prädiktor für ein Ansprechen von Glioblastomrezidiven auf eine Therapie mit Avastin.

PURPOSE: The assessment of the radiological response of recurrent glioma is based on the Macdonald or RECIST criteria 8 to 10 weeks from the start of treatment. Magnetic resonance imaging using an apparent diffusion coefficient map may provide an earlier measure for predicting the response to therapy of recurrent glioma. MATERIALS AND METHODS: Twelve patients with recurrent high-grade glioma were enrolled in a feasibility study of pretreatment MRI on day 1, intra-treatment MRI in week 3, and post-treatment MRI in week 12. Prognostically relevant ADC values (ADCprog) of each recurrent glioma at 3 weeks were calculated as a function of their pre- and intra-therapy ADC values (ADCpre - ADCintra = ADCprog). Because we hypothesized that smaller ADC values correlate with less Brownian motion of water molecules in the extracellular space and that a higher cell density may restrain this water diffusion, we set smaller ADC values at a second time point as "progressive disease" (PD) and higher ADC values as "partial response" (PR). A change in ADCprog of less than 10 × 10⁻6mm² /sec was set as "stable disease" (SD). The ADCprog values were always calculated before the final scan after 3 months was performed. The readers were blinded to the future development of the tumor. RESULTS: In 10 of the 12 patients we could correctly predict the tumor response to chemotherapy. One patient died before the three-month control, and one recurrent glioma did not develop as predicted. ADC mapping is found to predict patient response at 3 weeks from the start of treatment, revealing that early changes in tumor diffusion values could be used as a prognostic indicator also for chemotherapeutically treated recurrences of high-grade glioma.

[Image quality in multidetector CT of paranasal sinuses: potential of dose reduction using an adaptive post-processing filter]. / Bildqualität in der Multidetektor-CT der Nasennebenhöhlen: Potenzial zur Dosisreduktion bei Anwendung eines adaptiven Nachverarbeitungsfilters.

PURPOSE: Evaluation of subjective image quality in dose-reduced multi-detector CT (MDCT) of paranasal sinuses using a 2D non-linear adaptive post-processing filter (2D-NLAF). MATERIALS AND METHODS: MDCT of paranasal sinuses was simulated using a human head phantom at a Somatom Sensation Cardiac 64 (Siemens, Erlangen). At constant collimation (64 × 0.6 mm) und pitch (p = 1), the tube current (50, 100, 200 mAs) and tube potential (80, 100, 120 kVp) were modified. The radiation exposure was represented by CTDIvol. Four independent blinded radiologists evaluated the image quality of axial 2 mm images and coronal reformations concerning the assessment of "fractures" and "soft tissue processes". The subjective image quality of original and post-processed images using a 2D-NLAF (SharpViewCT®, Sweden) was graded on a 5-point scale ("1" excellent - "5" not adequate) and compared. RESULTS: Compared to the protocol with the best image quality (120kVp/ 200 mAs) 2D-NLAF led to a significant improvement in the subjective image quality at 100 kVp/ 100 mAs (score "1.4" with filter versus "2.2" without) and 120 kVp/ 50 mAs ("1.6" versus "2.0") (p < 0.03) particularly for high contrasts ("fractures", p < 0.001). In "soft tissue processes", 2D-NLAF provided improved quality from "2.1" to "1.4" (p < 0.04) at 100 kVp/ 100 mAs. Down to a CTDIvol of 8 mGy, the image quality was rated "good", and down to 5 mGy "diagnostic". CONCLUSION: The phantom study indicates a dose reduction potential in MDCT of paranasal sinuses up to 58% compared to a standard dose protocol using a 2D-NLAF without an essential loss of image quality. 2D-NLAF is particularly effective at 100 kVp/ 100 mAs and 120 kVp/ 50 mAs.

[MRI bone marrow findings in 63 patients with type I Gaucher disease]. / MRT der Knochenmarkverändungen bei 63 Patienten mit Morbus Gaucher Typ I.

PURPOSE: To determine whether MR bone marrow findings in Gaucher patients may help to identify patients at high risk of developing severe Gaucher bone complications exemplified by avascular necrosis (AVN) of the femoral head. MATERIALS AND METHODS: MR images were obtained in 63 Type I Gaucher patients through a standard protocol using coronal T 1 and T 2-weighted sequences of the lower extremities. The location and extent of infiltrated marrow was established using a semi-quantitative MRI scoring method (Düsseldorf Gaucher score, DGS) and the morphological pattern of bone marrow involvement determined (whether homogeneous type A or non-homogeneous type B). The active marrow process with bone edema and AVN of the femoral head were also analyzed. RESULTS: Bone marrow involvement was observed in femoral sites more than in tibial sites. A high DGS was significantly correlated with type B morphology and femoral AVN (both p < 0.0001). Splenectomized patients showed a significantly higher Düsseldorf Gaucher score and type B morphology than non-splenectomized patients (both p < 0.05). AVN was seen in 46 % of patients with type B morphology versus 3 % in type A morphology (p < 0.0001). DGS and morphology of bone marrow involvement were not significantly correlated with active marrow processes. CONCLUSION: Type B marrow morphology and extensive marrow packing were significantly associated with AVN of the femoral head (both p < 0.0001). These patterns are considered predictive and may be employed in a disease management context to alert physicians to the need for urgent therapeutic measures.

A novel MRI-biomarker candidate for Alzheimer's disease composed of regional brain volume and perfusion variables.

BACKGROUND: Earlier evidence indicates that regional cerebral volume (rVOL) and blood flow (rCBF) variables carry independent information on incipient and early Alzheimer's disease (AD) and combining these modalities may increase discriminant performance. We compared single variables and combinations regarding their power for optimizing diagnostic accuracy. METHODS: Twelve cognitively normal elderly controls (CN), 30 subjects with mild cognitive impairment (MCI) and 15 with mild AD were examined by structural and perfusion-weighted magnetic resonance imaging (MRI) in single sessions at 1.5 Tesla. rVOLs were measured by manual volumetry, and rCBFs were calculated with a ROI-based co-localization technique. RESULTS: Applying single MRI variables for the differentiation of AD versus CN, the area under curve (AUC) of receiver operating characteristic curves (ROCCs) was highest for rVOL variables (maximum of 0.972 for right amygdala). A composite marker selected and weighted by logistic regression containing left amygdalar rCBF, left hippocampal and right amygdalar rVOLs gave a diagnostic accuracy for AD versus CN of 100%. Internal cross-validation revealed a reliability of 88.9%. CONCLUSIONS: Whilst external revalidation is mandatory employing a naturalistic sample containing disease controls, our phase I/II findings demonstrate that deducing composite markers from multimodal MRI acquisitions can optimize diagnostic accuracy for AD.

Non-enhanced 3D MR angiography of the lower extremity using ECG-gated TSE imaging with non-selective refocusing pulses--initial experience.

PURPOSE: To evaluate non-enhanced 3D MR angiography using turbo spin echo (TSE) imaging with non-selective refocusing pulses (NATIVE SPACE MRA) for the visualization of the arteries of the lower extremity. MATERIALS AND METHODS: Three-station imaging (iliac arteries, femoral arteries, arteries of the lower leg) was performed in 8 healthy volunteers and 3 patients with peripheral artery disease (PAD) using a 1.5 T MR scanner. In 8 healthy volunteers, 4 different acquisition schemes were performed with the following imaging parameters: S 1: acquisition with every heartbeat (RR = 1), spoiler gradient of 25 % (SG = 25 %); S 2: RR = 1, SG = 0 %; S 3: RR = 2, SG = 25 %; S 4: RR = 2, SG = 0 %. The subjective image quality on a 4-point-scale (4 = excellent to 1 = not diagnostic) and relative SNR were assessed. In 3 patients with peripheral artery disease (PAD), SPACE MRA was performed for assessment of stenosis. RESULTS: The mean subjective image quality was significantly lower for the iliac arteries compared to the femoral arteries and arteries of the lower leg (p < 0.0001). The subjective image quality for acquisition scheme S 1 was significantly lower than the image quality for S 3 and S 4 for the iliac arteries (p < 0.01), while the subjective image quality for acquisition scheme S 2 was significantly lower than S 3 and S 4 for the femoral arteries and the arteries of the lower leg (p < 0.01). The relative SNR was significantly higher for acquisition schemes S 3 and S 4 as compared to S 1 and S 2 (p < 0.0001) for all regions. SPACE MRA disclosed 7 significant stenoses in 3 PAD patients. CONCLUSION: ECG-gated SPACE MRA is a promising imaging technique for non-enhanced assessment of the arteries of the lower extremity.

Circulating osteogenic cells: characterization and relationship to rates of bone loss in postmenopausal women.

There is increasing evidence that osteogenic cells are present not only in bone marrow (BM) but also in peripheral blood (PB). Since staining for alkaline phosphatase (AP) identifies osteoprogenitor cells in BM, we sought to further characterize BM versus PB hematopoietic lineage negative (lin-)/AP+ cells and to compare gene expression in PB lin-/AP+ cells from postmenopausal women undergoing rapid versus slow bone loss. PB lin-/AP+ cells were smaller than their BM counterparts, and both were negative for the pan-hematopoietic marker, CD45. BM and PB lin-/AP+ cells were capable of mineralization in vitro. Using whole genome linear amplification followed by quantitative polymerase chain reaction (QPCR) analysis, we found that relative to the BM cells, PB lin-/AP+ cells expressed similar levels of a number of key osteoblast marker genes (runx2, osterix, osteopontin, OPG, periostin), consistent with the PB cells being in the osteoblastic lineage. Importantly, however, compared to the BM cells, PB lin-/AP+ cells expressed lower levels of mRNAs for AP, type I collagen, and for a panel of proliferation markers, but higher levels of osteocalcin, osteonectin, and PTHR1 mRNAs, as well as those for RANKL and ICAM-1, both of which are important in supporting osteoclastogenesis. Using microarray followed by QPCR analysis, we further demonstrated that, compared to postmenopausal women undergoing slow bone loss, PB lin-/AP+ cells from women undergoing rapid bone loss expressed lower levels of mRNAs for hydroxyprostaglandin dehydrogenase, interferon regulator factor 3, Wnt1-induced secreted protein 1, and TGFbeta2, but higher levels of the Smad3 interacting protein, zinc finger DHHC-type containing 4 and col1alpha2. These data thus demonstrate that while PB lin-/AP+ cells express a number of osteoblastic genes and are capable of mineralization, they are a relatively quiescent cell population, both in terms of cell proliferation and matrix synthesis. However, their higher expression of RANKL and ICAM-1 mRNAs as compared to BM lin-/AP+ cells suggests a role for the PB lin-/AP+ cells in regulating osteoclastogenesis that warrants further investigation. Our study also provides "proof-of-concept" for the use of PB lin-/AP+ cells in clinical-investigative studies, and identifies several pathways that could potentially regulate rates of bone loss in postmenopausal women.

[Dose reduction and image quality in MDCT of the upper abdomen: potential of an adaptive post-processing filter]. / Dosisreduktion und Bildqualität in der MDCT des Oberbauchs: Potenzial eines adaptiven Nachverarbeitungsfilters.

PURPOSE: To evaluate the effects of a 2D non-linear adaptive post-processing filter (2D-NLAF) on image quality in dose-reduced multi-detector CT (MDCT) of the upper abdomen. MATERIALS AND METHODS: MDCT of the upper abdomen was simulated on a 64-slice scanner using a multi-modal anthropomorphic phantom (CIRS, Norfolk, USA). While keeping the collimation (64 x 0.6 mm) and pitch (p = 1) unchanged, the tube current (100 - 500 mAs) and tube potential (80 - 140 kVp) were varied to perform MDCT as high dose (CTDI > 20), middle dose (CTDI 10 - 20) and low dose (CTDI < 10) level protocols. Four independent blinded radiologists evaluated axial images with a thickness of 7 and 3 mm with respect to the presentation of "mesenteric low contrast lesions", "liver veins", "liver cysts", "renal cysts" and "big vessels". The subjective image quality of original data and post-processed images using a 2D-NLAF (SharpViewCT, Linköping, Sweden) was graded on a 5-point scale (from "1" not visible to "5" excellent) and statistically analyzed. The effective dose (E) was estimated using commercial software (CT-EXPO). RESULTS: For all protocol groups, 2D-NLAF led to a significant improvement in subjective image quality for all examined lesions (p < 0.01), particularly at the protocols of middle dose (E: 5 - 8 mSv) and low dose level (E: 1 - 5 mSv). A maximum effect was seen in middle dose protocols for "low contrast lesions" (score "3.3" with filter versus "2.5" without) and "liver veins" ("4.5" versus "3.9"). CONCLUSION: The phantom study indicates a potential dose reduction of up to 50 % in MDCT of the upper abdomen by use of a 2D-NLAF, which should be further examined in clinical trails.

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.

OBJECTIVE: To 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. METHODS: The 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. RESULTS: Bone 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. CONCLUSION: MPH-SPECT is sensitive to early changes in ERA and EOA and permits them to be distinguished by their patterns of uptake.

[Cardiac pathologies incidentally detected with non-gated chest CT]. / Inzidentelle Pathologien des Herzens im Thorax-CT.

Cardiac imaging using electrocardiogram-gated multi-detector computed tomography (MDCT) permits noninvasive diagnosis of congenital and acquired cardiac pathologies and has thus become increasingly important in the last years. Several studies investigated the incidence and relevance of incidental extracardiac structures within the lungs, mediastinum, chest wall, and abdomen with gated coronary CT. This resulted in the general acceptance of the review of extracardiac structures as a routine component of coronary CT interpretation. On the other hand radiologists tend to neglect pericardial and cardiac pathologies in non-gated chest CT, which is primarily performed for the evaluation of the respiratory system or for tumor staging. Since the introduction of multi-detector spiral CT technology, the incidental detection of cardiac and pericardial findings has become possible using non-gated chest CT. This article reviews the imaging appearances and differential diagnostic considerations of incidental cardiac entities that may be encountered in non-gated chest CT.

[Functional MRI of transplanted kidneys using diffusion-weighted imaging]. / Funktionelle MRT der Transplantatnieren: klinische Wertigkeit der Diffusionsbildgebung.

PURPOSE: Contrast-enhanced MRI is considered problematic in renal allograft recipients due to the association of gadolinium administration and the development of NSF. Therefore, we assessed the clinical value of mono- and biexponential analysis of diffusion-weighted imaging (DWI). MATERIALS AND METHODS: A total of 32 patients were divided into four groups: (a) patients with stable function of renal allograft for at least 6 months, (b) patients with acute deterioration of allograft function, patients who recently underwent transplantation (< 14 days) with good (c) or decreased (d) renal function. T 2w ax. and T 1w cor. and a diffusion-weighted sequence with 16 b-values (b = 0 - 750 s/mm (2)) were performed on a 1.5 T scanner (Magnetom Avanto, Siemens Medical Solutions). ROI-based analysis of the renal cortex was analyzed using the software "Table Curve 2D". RESULTS: Monoexponential analysis showed an ADC (mono) of 1961 +/- 104 1801 +/- 150, 2053 +/- 169 and 1720 +/- 191 10 (-6)mm (2) /sec for patient group a, b, c and d respectively. The difference in ADC (mono) between group (a) and (b) (p < 0.006) and between group (c) and (d) (p < 0.04) was statistically significant. Biexponential analysis revealed a mean perfusion fraction of 0.21, 0.23, 0.32 and 0.24 for group (a), (b), (c) and (d), respectively. Biexponential ADC showed a higher numerical accuracy. There were no statistically significant inter-group differences in diffusion (ADC (D)) and perfusion (ADC (P)). CONCLUSION: Unenhanced evaluation of renal allografts with DWI is feasible. ADC (mono) of renal cortex correlates with renal function. The significance of the higher numerical accuracy of biexponential analysis in clinical settings requires further evaluation in larger-scale studies.

[Bony pathologies of the metacarpophalangeal joints in early rheumatoid arthritis: comparison of MRI and high-resolution SPECT]. / Knöcherne Pathologien der Metacarpophalangeal-Gelenke bei früher rheumatoider Arthritis: Vergleich zwischen MRT und hochauflösender SPECT.

AIM: Comparison of MRI with a newly developed high-resolution multi-pinhole single photon emission computed tomography (MPH-SPECT) regarding the detection of bony pathologies of the metacarpophalangeal (MCP) joints in patients with early rheumatoid arthritis (ERA). MATERIALS AND METHODS: The clinically dominant hand of 15 patients with ERA (disease duration 6 months) was examined using MRI and MPH-SPECT. The evaluation of MRI was achieved according to RAMRIS criteria and for the MPH SPECT regarding pathological tracer uptake and distribution. Image fusions of MRI and MPH-SPECT were provided and the two methods were compared. RESULTS: In MRI 12 of 15 patients showed arthritic joint pathologies, while 8 patients exhibited soft tissue and bony changes. 4 patients had only soft tissue inflammation (synovitis) with a normal bone signal. In MPH-SPECT 10 of 15 patients showed pathologically increased bone metabolism. The fusion images presented a high agreement of the pathological changes in both methods, while areas with increased bone metabolism were not only present in the case of erosions, but also in the case of bone edema. In 2 patients increased bone metabolism was detectable in areas of MR tomographic normal bone, while a clear surrounding synovitis was present in each case here. CONCLUSION: The comparison of MPH-SPECT with MRI proves that the latter is a sensitive procedure for the detection of bony pathologies of MCP joints in ERA. A normal bone signal in MRI does not exclude early changes in bone metabolism in cases of severe synovialitis.

Assessment of three different software systems in the evaluation of dynamic MRI of the breast.

OBJECTIVE: The aim was to compare the diagnostic performance and handling of dynamic contrast-enhanced MRI of the breast with two commercial software solutions ("CADstream" and "3TP") and one self-developed software system ("Mammatool"). MATERIALS AND METHODS: Identical data sets of dynamic breast MRI from 21 patients were evaluated retrospectively with all three software systems. The exams were classified according to the BI-RADS classification. The number of lesions in the parametric mapping was compared to histology or follow-up of more than 2 years. In addition, 25 quality criteria were judged by 3 independent investigators with a score from 0 to 5. Statistical analysis was performed to document the quality ranking of the different software systems. RESULTS: There were 9 invasive carcinomas, one pure DCIS, one papilloma, one radial scar, three histologically proven changes due to mastopathy, one adenosis and two fibroadenomas. Additionally two patients with enhancing parenchyma followed with MRI for more than 3 years and one scar after breast conserving therapy were included. All malignant lesions were classified as BI-RADS 4 or 5 using all software systems and showed significant enhancement in the parametric mapping. "CADstream" showed the best score on subjective quality criteria. "3TP" showed the lowest number of false-positive results. "Mammatool" produced the lowest number of benign tissues indicated with parametric overlay. CONCLUSION: All three software programs tested were adequate for sensitive and efficient assessment of dynamic MRI of the breast. Improvements in specificity may be achievable.

[Evaluation of malformations of the fetal central nervous system using fetal MRI]. / Das fetale MRT in der pränatalen Beurteilung von ZNS-Störungen.

PURPOSE: Ultrasound as the primary prenatal screening modality is used to detect fetal anomalies. Aim of the study was to prove the additional value of fetal magnetic resonance imaging (MRI). MATERIALS AND METHODS: In 25 pregnant women (age 30.6 +/- 4.8; 24 single and one twin pregnancy) with pathologic findings of the central nervous system detected by obstetric ultrasound, a fetal MRI was performed. All sequences (T2w-HASTE, TRUEFISP, T 1w-FLASH 2D, DWI) were performed using the breath-hold technique. The results were compared to postnatal MRI or ultrasound scan findings and tested for correlation with the clinical course and development of these children. RESULTS: Three to seven days after ultrasound, an MRI of all 26 fetuses without sedation was performed (26.6 +/- 4.0 GW). One healthy twin was not included in this study. MRI confirmed the ultrasonographic diagnosis in 7 cases. Compared to ultrasound, an additional pathology could be detected by MRI in 8 cases. In 10 cases ultrasound diagnosis was overruled by MRI. Prenatal MRI findings were confirmed by postnatal imaging in 18 children. The clinical course was predictable in 8 of 15 cases, depending on the pathology detected. Three newborns died in the perinatal period. CONCLUSION: Our results showed that fetal MRI has a high impact as an addition to ultrasound in evaluating congenital CNS pathology. Fetal MRI has become a helpful device for advising parents. However, clinical course and development still cannot be predicted based on MRI findings alone.

[Analysis of 64-row multidetector CT images for preoperative angiographic evaluation of potential living kidney donors]. / Analyse der mehrphasigen 64-Zeilen-Multidetektor-Computertomographie zur präoperativen angiographischen Evaluation potenzieller Lebendnierenspender.

BACKGROUND: Anatomical imaging and the ascertainment of any anomalies in the renal vessels and the ureters are essential in the planning of a kidney donation. The aim of the present study was to assess the value of 64-row multidetector CT in noninvasive examination of the renal vessels and ureters of potential living kidney donors. METHODS: The evaluation embraced 63 living renal donors (LNS) who underwent preoperative CT examination from December 2004 to January 2007. The examinations were all carried out using a Somatom Sensation -Cardiac 64 (Siemens Medical Solutions, Germany). As well as CT angiography (CTA), a venous phase of the abdomen and a late phase after 15 min using low-dose technique were performed for CT urography (CTU). The radiological findings were compared with the surgical results, or with the angiograms in 2 cases. Sensitivity, specificity and both negative and positive predictive value were calculated. RESULTS: In the 63 (31 female, 32 male) donors CTA had a sensitivity of 100% in examination of the main and accessory renal arteries and of 98.3% when the venous and ureteric anatomy were assessed. The sensitivity of low-dose CTU was also 100%. CONCLUSION: The findings recorded in this study indicate that noninvasive preoperative planning with 64-row multidetector CTA and CTU is a reliable "one-stop shopping" method of examination for potential living kidney donors.

The skeletal response to estrogen is impaired in female but not in male steroid receptor coactivator (SRC)-1 knock out mice.

Estrogen (E) is critical for the maintenance of bone mass in both female and male mice and steroid receptor coactivator (SRC)-1 has been shown to be important for mediating E effects on bone, at least in female mice. In the present study, we defined the skeletal phenotype of male SRC-1 knock out (KO) mice and compared it with their female littermates. Further, to determine the role of SRC-1 in mediating effects of E on bone in male mice, we examined the skeletal effects of gonadectomy (gnx) with or without E replacement in male mice and placed these findings in the context of our previous studies in female SRC-1 KO mice. Analysis of a large group of male (WT, n=67; SRC-1 KO, n=56) and female (WT, n=66; SRC-1 KO, n=70) mice showed a significant decrease in trabecular volumetric bone mineral density (vBMD) in SRC-1 KO mice compared to their WT littermates in both genders (male SRC-1 KO, 275+/-3 vs. WT, 295+/-3 mg/cm(3), P<0.001; female SRC-1 KO, 210+/-2 vs. WT, 221+/-2 mg/cm(3), P<0.001). Following gnx and E replacement (10 microg/kg/day), we previously demonstrated that SRC-1 KO female mice have a defect in E action in trabecular, but not in cortical bone. In contrast, we now demonstrate that the same dose of E administered to gnx'd male SRC-1 KO mice was sufficient to prevent trabecular bone loss in these mice. For example, in WT female mice, gnx followed by E replacement maintained spine BMD (1.2+/-3.4% vs. baseline) as compared to gnx without E replacement (-12.7+/-2.6%, P<0.001 vs. sham); this effect of E was absent in SRC-1 KO female mice. By contrast, the identical dose of E was equally effective in maintaining spine BMD in E-treated gnx'd male WT (-5.2+/-5.1% vs. baseline) and male SRC-1 KO (-5.4+/-5.3%) mice, respectively, as compared to gnx'd mice without E treatment (WT, -17.6+/-2.5%, P=0.02; SRC-1 KO, -28.6+/-2.6%, P<0.001 vs. sham). E treatment was effective in suppressing cancellous bone turnover in both gnx'd WT and SRC-1 KO male mice as determined by significant reductions in osteoblast and osteoclast numbers; however, in female mice, E treatment only suppressed bone turnover in WT but not in SRC-1 KO mice. Collectively, these findings demonstrate that loss of SRC-1 results in trabecular osteopenia in male and female mice, but in contrast to female mice, this is not due to any detectable resistance to E action in trabecular bone in male SRC-1 KO mice.

CT-perfusion imaging of the human brain: advanced deconvolution analysis using circulant singular value decomposition.

According to indicator dilution theory tissue time-concentration curves have to be deconvolved with arterial input curves in order to get valid perfusion results. Our aim was to adapt and validate a deconvolution method originating from magnetic resonance techniques and apply it to the calculation of dynamic contrast enhanced computed tomography perfusion imaging. The application of a block-circulant matrix approach for singular value decomposition renders the analysis independent of tracer arrival time to improve the results.