Evaluation of fibrotic liver disease with whole-liver T1ρ MR imaging: a feasibility study at 1.5 T.

PURPOSE: To test at 1.5 T whether T1ρ magnetic resonance (MR) imaging of fibrotic liver disease is feasible, to investigate whether liver T1ρ imaging allows assessment of the severity of liver cirrhosis, and to assess the normal liver T1ρ range in healthy patients. MATERIALS AND METHODS: This prospective study was approved by the institutional ethics committee. Written informed consent was obtained. Healthy volunteers (n = 25) and patients (n = 34) with cirrhosis underwent whole-liver T1ρ MR imaging at 1.5 T. Mean T1ρ values were calculated from liver regions of interest. Mean T1ρ values were correlated to clinical data and histopathologic analysis by analysis of variance. Receiver operating characteristic curves were calculated to determine the accuracy of mean T1ρ values for the assessment of Child-Pugh class. RESULTS: Mean T1ρ values of volunteers (mean, 40.9 msec ± 2.9 [standard deviation]; range, 33.9-46.3 msec) were significantly lower than those of patients who were Child-Pugh class A (P < .004), B (P < .001), or C (P < .001), and significant differences were found between each Child-Pugh stage (A vs B, P < .002; B vs C, P < .009; A vs C, P < .001). Liver cirrhosis was confirmed via histologic analysis in all patients with liver biopsy. Mean T1ρ values did not correlate with necroinflammatory activity (r = 0.31; P = .23), degree of steatosis (r = -0.016; P = .68), or presence of iron load (r = 0.22; P = .43). Mean T1ρ values performed well by assessing the Child-Pugh stage, with receiver operating characteristic areas of 0.95-0.98. Intraclass correlation coefficient values ranged between 0.890 and 0.987, which indicated excellent imaging and reimaging reproducibility and interobserver and intraobserver variability. CONCLUSION: Whole-liver T1ρ MR imaging at 1.5 T to detect and assess human liver cirrhosis is feasible. Further investigation and optimization of this technique are warranted to cover the entire spectrum of fibrotic liver disease.

Executive performance is related to regional gray matter volume in healthy older individuals.

Individual differences in executive functioning and brain morphology are considerable. In this study, we investigated their interrelation in a large sample of healthy older individuals. Digit span, trail-making, and Stroop tasks were used to assess different executive subfunctions in 367 nondemented community-dwelling individuals (50-81 years). Task performance was analyzed relative to brain structure using voxel-based morphometry, corrected for age and sex. Improved task performance was associated with increased local gray matter volume in task-specific patterns that showed partial, but not complete overlap with known task-specific functional imaging patterns. While all three tasks showed associations with prefrontal gray matter volume as expected for executive functioning, the strongest overlap between the three tasks was found in insular cortex, suggesting that it has a previously underestimated role for executive functions. The association between the insular cortex and executive functioning was corroborated using stereological region-of-interest measurement of insular volume in a subgroup of 93 subjects. Quantitatively, the volume of the single most strongly related region explained 2.4 ± 1.1% of the variance in executive performance over and above the variance explained by age, which amounted to 7.4 ± 4.1%. The age-independent peak associations between executive performance and gray matter described here occurred in regions that were also strongly affected by age-related gray matter atrophy, consistent with the hypothesis that age-related regional brain volume loss and age-related cognitive changes are linked.

Denosumab: a potential new and innovative treatment option for aneurysmal bone cysts.

INTRODUCTION: Aneurysmal bone cysts (ABCs) are expansive and destructive lesions positive for osteoclast markers, resembling benign giant cell tumors (GCTs). Treatment options include surgical resection, curettage and cavity filling, embolization, injection of fibrosing agents, or radiotherapy. Particularly in children and adolescents with spinal ABCs, these options may be unsatisfactory, and innovative forms of treatment are needed. Denosumab is a human monoclonal antibody that inhibits osteoclast function by blocking the cytokine receptor activator of the nuclear factor-kappa B ligand. Satisfactory results with denosumab in treating GCTs and immunohistochemical similarities suggest that it may also have positive effects on ABCs. METHODS AND RESULTS: This report is the first description of the therapeutic use of denosumab in two patients with spinal ABCs. Two boys (aged 8 and 11) had recurrent ABCs at C5 after surgery with intralesional tumor resection. Treatment options were discussed by the interdisciplinary tumor board. Arterial embolization was attempted, but failed due to an absence of appropriate afferent arteries. After the families had received extensive information and provided written consent, denosumab therapy was initiated as an individualized treatment, despite the absence as yet of scientific evidence. After the start of denosumab therapy, both patients recovered from pain and neurologic symptoms significantly and are now in a healthy condition with no severe side effects. Magnetic resonance imaging check-ups after 2 or 4 months of denosumab treatment, respectively, showed tumor regression in both patients. DISCUSSION: Longer follow-up and clinical studies are warranted to establish the value of denosumab in the treatment of ABCs.

Changes in knee cartilage T2 values over 24 months in subjects with and without risk factors for knee osteoarthritis and their association with focal knee lesions at baseline: data from the osteoarthritis initiative.

PURPOSE: To examine the changes in knee cartilage T2 values over 24 months in subjects with and without risk factors for knee osteoarthritis (OA) and their association with focal knee lesions at baseline. MATERIALS AND METHODS: Forty-one subjects without and 101 subjects with OA risk factors (such as history of knee injury or surgery) were selected from the Osteoarthritis Initiative database (age: 45-55 years, no radiographic OA in the right knee). Baseline magnetic resonance imaging (MRI) of the right knee were assessed for prevalence and grade of focal knee lesions. Right knee cartilage T2 measurements were performed in five compartments (patella, medial/lateral femur/tibia) at baseline and at 24-month follow-up. RESULTS: Compared to subjects without OA risk factors, those with OA risk factors showed no significant differences in baseline prevalence and grade of focal knee lesions (P > .05), but had significantly higher T2 values in the medial femur compartment at both timepoints (P < 0.05). T2 values averaged over all five compartments increased significantly over 24 months in both groups, but differences in T2 increase between the groups were not significant. Subjects with cartilage lesions showed significantly higher T2 values compared to subjects without cartilage lesions at both timepoints, but no accelerated T2 increase over 24 months (P > 0.05). CONCLUSION: Cartilage T2 values significantly increased over 24 months in subjects with and without OA risk factors, but neither the presence of OA risk factors nor the presence of cartilage lesions at baseline were associated with these T2 increases.

Physical activity is associated with magnetic resonance imaging-based knee cartilage T2 measurements in asymptomatic subjects with and those without osteoarthritis risk factors.

OBJECTIVE: To evaluate the association of exercise and knee-bending activities with magnetic resonance imaging (MRI)-based knee cartilage T2 relaxation times and morphologic abnormalities in asymptomatic subjects from the Osteoarthritis Initiative, with or without osteoarthritis (OA) risk factors. METHODS: We studied 128 subjects with knee OA risk factors and 33 normal control subjects ages 45-55 years, with a body mass index of 18-27 kg/m(2) and no knee pain. Subjects were categorized according to exercise level, using the leisure activity component of the Physical Activity Scale for the Elderly, and by self-reported frequent knee-bending activities. Two radiologists graded the cartilage of the right knee on MR images, using the Whole-Organ MRI Score (WORMS). Cartilage was segmented, and compartment-specific T2 values were calculated. Differences between the exercise groups and knee-bending groups were determined using multiple linear and logistic regression models. RESULTS: Among subjects with risk factors for knee OA, light exercisers had lower T2 values compared with sedentary and moderate/strenuous exercisers. When the sexes were analyzed separately, female moderate/strenuous exercisers had higher T2 values compared with sedentary individuals and light exercisers. Subjects without risk factors displayed no significant differences in T2 values according to exercise level. However, frequent knee-bending activities were associated with higher T2 values in both subjects with OA risk factors and those without OA risk factors and with more severe cartilage lesions in the group with risk factors. CONCLUSION: In subjects at risk of knee OA, light exercise was associated with low T2 values, whereas moderate/strenuous exercise in women was associated with high T2 values. Higher T2 values and WORMS grades were also observed in frequent knee-benders, suggesting greater cartilage degeneration in these individuals.

Cartilage in anterior cruciate ligament-reconstructed knees: MR imaging T1{rho} and T2--initial experience with 1-year follow-up.

PURPOSE: To longitudinally evaluate cartilage matrix changes by using magnetic resonance (MR) imaging T1(ρ) (T1 relaxation time in rotating frame) and T2 quantification and to study the relationship between meniscal damage and cartilage degeneration in anterior cruciate ligament (ACL)-reconstructed knees. MATERIALS AND METHODS: This was an institutional review board-approved, HIPAA-compliant study. Informed consent was obtained. Twelve patients with acute ACL injuries were imaged with 3.0-T MR imaging at baseline (after injury and prior to ACL reconstruction) and 1 year after ACL reconstruction. Ten age-matched healthy subjects were studied as controls. Cartilage T1(ρ) and T2 were quantified in full thickness, superficial, and deep layers of defined subcompartments at baseline and follow-up in ACL-injured knees and were compared with measures acquired in matched regions of control knees. Meniscal lesions were graded by using modified subscores of the Whole-Organ Magnetic Resonance Imaging Score system. RESULTS: T1(ρ) values of the posterolateral tibial cartilage in ACL-injured knees were significantly elevated at baseline compared with T1(ρ)values of control knees and were not fully recovered at 1-year follow-up. T1(ρ) values of weight-bearing medial femorotibial cartilage in ACL-injured knees were significantly elevated at 1-year follow-up compared with those of control knees. No significant differences in T2 values between ACL-injured and control knees were found. Patients with lesions in the posterior horn of the medial meniscus showed a greater increase of T1(ρ) and T2 from baseline to follow-up in adjacent cartilage than patients without lesions in the medial meniscus. CONCLUSION: Quantitative MR imaging T1(ρ) and T2 enable detection of changes in the cartilage matrix of ACL-reconstructed knees as early as 1 year after ACL reconstruction.

Meniscal T1rho and T2 measured with 3.0T MRI increases directly after running a marathon.

PURPOSE: To prospectively evaluate changes in T1rho and T2 relaxation time in the meniscus using 3.0 T MRI in asymptomatic knees of marathon runners and to compare these findings with those of age-matched healthy subjects. MATERIAL AND METHODS: Thirteen marathon runners underwent 3.0 T MRI including T1rho and T2 mapping sequences before, 48-72 h after, and 3 months after competition. Ten controls were examined at baseline and after 3 months. All images were analyzed by two musculoskeletal radiologists identifying and grading cartilage, meniscal, ligamentous. and other knee abnormalities with WORMS scores. Meniscal segmentation was performed to generate T1rho and T2 maps in six compartments. RESULTS: No differences in morphological knee abnormalities were found before and after the marathon. However, all marathon runners showed a significant increase in T1rho and T2 values after competition in all meniscus compartments (p < 0.0001), which may indicate changes in the biochemical composition of meniscal tissue. While T2 values decreased after 3 months T1rho values remained at a high level, indicating persisting changes in the meniscal matrix composition after a marathon. CONCLUSION: T2 values in menisci have the potential to be used as biomarkers for identifying reversible meniscus matrix changes indicating potential tissue damage. T1rho values need further study, but may be a valuable marker for diagnosing early, degenerative changes in the menisci following exercise.

Patellar cartilage: T2 values and morphologic abnormalities at 3.0-T MR imaging in relation to physical activity in asymptomatic subjects from the osteoarthritis initiative.

PURPOSE: To study the interrelationship between patella cartilage T2 relaxation time, other knee abnormalities, and physical activity levels in asymptomatic subjects from the Osteoarthritis Initiative (OAI) incidence cohort. MATERIALS AND METHODS: The study had institutional review board approval and was HIPAA compliant. One hundred twenty subjects from the OAI without knee pain (age, 45-55 years) and with risk factors for knee osteoarthritis (OA) were studied by using knee radiographs, 3.0-T knee magnetic resonance (MR) images (including intermediate-weighted fast spin-echo and T2 mapping sequences), and the Physical Activity Scale for the Elderly. MR images of the right knee were assessed by two musculoskeletal radiologists for the presence and grade of abnormalities. Segmentation of the patella cartilage was performed, and T2 maps were generated. Statistical significance was determined by using analysis of variance, chi(2) analysis, correlation coefficient tests, the Cohen kappa, and a multiple linear regression model. RESULTS: Cartilage lesions were found in 95 (79.0%) of 120 knees, and meniscal lesions were found in 54 (45%) of 120 knees. A significant correlation between patella cartilage T2 values and the severity and grade of cartilage (P = .0025) and meniscus (P = .0067) lesions was demonstrated. Subjects with high activity levels had significantly higher prevalence and grade of abnormalities and higher T2 values (48.7 msec +/-4.35 vs 45.8 msec +/-3.93; P < .001) than did subjects with low activity levels. CONCLUSION: Middle-aged asymptomatic individuals with risk factors for knee OA had a high prevalence of cartilage and meniscus knee lesions. Physically active individuals had more knee abnormalities and higher patellar T2 values. Additional studies will be needed to determine causality.

Isotropic 3-dimensional fast spin echo imaging versus standard 2-dimensional imaging at 3.0 T of the knee: artificial cartilage and meniscal lesions in a porcine model.

PURPOSE: To compare different fat-saturated (FS) 3-dimensional (3D) intermediate-weighted (IM-w) fast spin echo (FSE) sequences with a standard FS 2-dimensional (2D) IM-w FSE sequence using a porcine in vitro model with artificially created cartilage and meniscus lesions. METHODS: Using a ceramic scalpel, cartilage lesions with different depths and sizes were created in porcine knee specimens at the patella as well as the medial and lateral femoral and tibial cartilage. In addition, lateral and medial meniscal lesions were produced. Magnetic resonance imaging was performed at 3.0 T in sagittal plane using an 8-channel knee coil. A standard FS 2D IM-w FSE sequence and 3 newly developed isotropic 3D FSE sequences: (i) non-FS echo train length (ETL): 78, (ii) FS ETL: 44, and (iii) FS ETL: 44, were used. The images were independently analyzed by 4 radiologists concerning image quality (1 = optimal image quality, 4 = substantially limited quality) and absence or presence of lesions using a 5-level confidence score (1 = definite no presence of abnormality, 5 = definite presence of abnormality). Radiologists were also asked to measure diameter and categorize the depth of cartilage lesions using a modified Noyes classification. Average scores for image quality, confidence of diagnosis, and sensitivity, specificity, and accuracy were calculated. In addition, contrast-to-noise ratios were calculated. RESULTS: Image quality was significantly (P < 0.05) lower on the 3D FSE images than on the 2D FSE images [3D (i): 1.6 (SD, 0.43); 3D (ii): 2.35 (SD, 0.7); 3D (iii): 2.35 (SD, 0.5); 2D: 1.3 (SD, 0.35)]. No significant differences in diagnostic performance were found between 3D (i) and 2D FSE sequences. However, 16% fewer lesions were correctly detected with the 3D (ii) and (iii) sequences. Sensitivity was highest for the 2D sequence, and specificity was highest for the 3D (i) sequence. Confidence scores were higher for the 3D (i) sequence than for the 2D sequence. A significant increase (P < 0.05) in correctly measured cartilage lesions size and depth was found for the 3D (i) sequence over the standard 2D FSE sequence. CONCLUSIONS: Although the 3D FSE sequence performed better in depiction and characterization of cartilage abnormalities than the standard 2D FSE sequence, we currently do not recommend to use it as substitute. For the diagnosis of meniscal defects, however, no significant improvement was found.

High-resolution magnetic resonance imaging of triangular fibrocartilage complex lesions in acute wrist trauma: image quality at different field strengths.

PURPOSE: The purposes of this study were to assess the diagnostic capacity of a new high-resolution imaging protocol for the wrist and triangular fibrocartilage complex (TFCC) lesions at 3.0 T and to compare it with our established 1.5-T protocol. MATERIALS AND METHODS: Twenty-one patients with an acute wrist trauma were examined at a 3.0-T imaging system and agreed to undergo an additional examination at 1.5 T. Magnetic resonance imaging was performed with 1.5-T (standard wrist coil) and 3.0-T (purpose-build phased-array coil) imaging system, using coronal T1-weighted turbo-spin-echo, proton density-weighted fat-saturated, and coronal and axial contrast-enhanced T1-weighted gradient-echo fat-saturated sequences, with reduced voxel size from 0.50 x 0.50 x 3.0 mm (1.5 T) to 0.20 x 0.20 x 1.5 mm (3.0 T). For qualitative analysis, 2 observers assessed in consensus delineation, image quality, and artifacts in anatomical landmarks (cartilage, TFCC, and TFCC lesion) and ranked them on a 5-point scale from 1 (nondiagnostic) to 5 (optimal). For quantitative analysis, measurements of the contrast-to-noise ratio were obtained between disk and surrounding tissue. RESULTS: All parts of the TFCC and TFCC lesions (n = 14) were seen significantly better at 3.0 T (mean [SD], 4.6 [0.5] vs 2.6 [1.2], P < 0.0001), with higher ranked overall image quality. In 3 cases, TFCC lesions were seen only at 3.0 T. Proton density-weighted fat-saturated sequence had significantly more artifacts at 3.0 T (2.5 [0.6] vs 1.9 [0.5], P < 0.001) in contrast to T1 sequences. Quantitative evaluation showed significantly higher contrast-to-noise ratio for 3.0 T (5.0 [1.1] vs 3.9 [0.9], P < 0.0001). CONCLUSION: Depiction of anatomy and pathology of the TFCC benefits significantly from 3.0-T imaging when higher signal-to-noise ratio is invested into improved spatial resolution. Especially small lesions of the disk were detected only or better at 3.0 T.

Three-Tesla magnetic resonance imaging of the wrist: diagnostic performance compared to 1.5-T.

PURPOSE: To assess the diagnostic capability of a new multi-contrast high-resolution imaging protocol for the wrist at 3 T and to compare it to our standard 1.5-T protocol. MATERIALS AND METHODS: In 10 volunteers, images were acquired at 1.5 T (standard surface coil) and 3 T (custom-made phased array coil; Gyroscan Intera; Philips Medical Systems, Best, the Netherlands). Imaging protocols consisted of coronal T1-weighted turbo spin-echo (TSE), coronal T2-weighted TSE, and proton density-weighted TSE fat-saturated (FS) sequences and sagittal T2-TSE and proton density-weighted TSE-FS sequences. Increased signal-to-noise ratio at 3 T was used to reduce measured voxel size from 0.50 x 0.50 x 3.0 mm (1.5 T) to 0.20 x 0.20 x 1.5 mm (3 T). Total examination time was approximately 25 minutes. To compare the diagnostic capability of both protocols, 4 observers assessed in consensus the visibility of 14 well-defined clinically important anatomical landmarks (origin and insertion of 6 intrinsic and extrinsic carpal ligaments, central portion of the triangular fibrocartilage complex, and ulna, triquetral, and radial attachments). Image quality and artifacts were ranked qualitatively on a 5-point scale. RESULTS: Of 140 detectable structures, 75 were detected at 1.5 T and 126 at 3 T. Overall image quality was significantly better at 3 T (3.8 vs 4.9, P = 0.002), whereas artifact score did not differ significantly (4.3 vs 4.5, P = 0.317). CONCLUSIONS: This is the result of investing the higher signal-to-noise ratio at 3 T into better spatial resolution; depiction of the normal anatomy of the wrist benefits significantly. Additional studies will need to be performed to determine if 3-T images will increase the accuracy of detecting abnormalities of these structures of the wrist.

Comparative study of imaging at 3.0 T versus 1.5 T of the knee.

PURPOSE: The objectives of the study were to compare MR imaging at 1.5 and 3.0 T in the same patients concerning image quality and visualization of cartilage pathology and to assess diagnostic performance using arthroscopy as a standard of reference. MATERIALS AND METHODS: Twenty-six patients were identified retrospectively as having comparative 1.5 and 3.0 T MR studies of the knee within an average of 102 days. Standard protocols included T1-weighted and fat-saturated intermediate-weighted fast spin-echo sequences in three planes; sequence parameters had been adjusted to account for differences in relaxation at 3.0 T. Arthroscopy was performed in 19 patients. Four radiologists reviewed each study independently, scored image quality, and analyzed pathological findings. Sensitivities, specificities, and accuracies in diagnosing cartilage lesions were calculated in the 19 patients with arthroscopy, and differences between 1.5 and 3.0 T exams were compared using paired Student's t tests with a significance threshold of p < 0.05. RESULTS: Each radiologist scored the 3.0 T studies higher than those obtained at 1.5 T in visualizing anatomical structures and abnormalities (p < 0.05). Using arthroscopy as a standard of reference, diagnosis of cartilage abnormalities was improved at 3.0 T with higher sensitivity (75.7% versus 70.6%), accuracy (88.2% versus 86.4%), and correct grading of cartilage lesions (51.3% versus 42.9%). Diagnostic confidence scores were higher at 3.0 than 1.5 T (p < 0.05) and signal-to-noise ratio at 3.0 T was approximately twofold higher than at 1.5 T. CONCLUSION: MRI at 3.0 T improved visualization of anatomical structures and improved diagnostic confidence compared to 1.5 T. This resulted in significantly better sensitivity and grading of cartilage lesions at the knee.

Atrial fibrillation in stroke-free patients is associated with memory impairment and hippocampal atrophy.

AIMS: To determine whether atrial fibrillation (AF) in stroke-free patients is associated with impaired cognition and structural abnormalities of the brain. AF contributes to stroke and secondary cognitive decline. In the absence of manifest stroke, AF can activate coagulation and cause cerebral microembolism which could damage the brain. METHODS AND RESULTS: We cross-sectionally evaluated 122 stroke-free individuals with AF recruited locally within the German Competence Network on AF. As comparator, we recruited 563 individuals aged 37-84 years without AF from the same community. Subjects underwent 3 T magnetic resonance imaging to assess covert territorial brain infarction, white matter lesions, and brain volume measures. Subjects with evidence for stroke, dementia, or depression were excluded. Cognitive function was assessed by an extensive neuropsychological test battery covering the domains learning and memory, attention and executive functions, working memory, and visuospatial skills. Cognitive scores and radiographic measures were compared across individuals with and without AF by stepwise multiple regression models. Stroke-free individuals with AF performed significantly worse in tasks of learning and memory (ß = -0.115, P < 0.01) as well as attention and executive functions (ß = -0.105, P < 0.01) compared with subjects without AF. There was also a trend (P = 0.062) towards worse performance in learning and memory tasks in patients with chronic as compared with paroxysmal AF. Corresponding to the memory impairment, hippocampal volume was reduced in patients with AF. Other radiographic measures did not differ between groups. CONCLUSION: Even in the absence of manifest stroke, AF is a risk factor for cognitive impairment and hippocampal atrophy. Therefore, cognition and measures of structural brain integrity should be considered in the evaluation of novel treatments for AF.

High resolution 3.0 Tesla MR imaging findings in patients with bilateral Madelung's deformity.

PURPOSE: Madelung deformity (MD) is a rare, normally painful abnormality of the wrist and forearm which characteristically begins in adolescence. Usually the deformity appears between the age of 8 and 14 years, often progressing from initially mild functional pain to fatigue and loss of strength and finally, reduced mobility. We present the MR-findings in three patients with bilateral MD, using a high-resolution imaging protocol adapted for 3.0 Tesla (3.0 T) examinations. MATERIALS AND METHODS: Wrist images of three patients were acquired at a 3.0 T Scanner (Gyroscan Intera, Philips Medical Systems, Best, The Netherlands), using a dedicated phased array coil. The imaging protocol consisted of coronal T1-weighted Turbo-spin-echo (T1w-TSE) and coronal and sagittal T2-weighted TSE sequences (T2w-TSE). RESULTS: MR-images of these three girls demonstrated severe volar bayonet configuration of the forearms with a dorsal prominence of the ulnar head, also a curved distal radial articular surface with increased ulnar angulation, due to a deceleration of growth in the ulnar portion of the distal epiphysis. The proximal carpal row showed pyramidal configuration. Also visible was a prominent short radiolunate ligament, the so called Vickers ligament, which originates from the ulnar border of the radius, inserts into the volar pole of the lunate and likely contributes to carpal pyramidalization. Furthermore, the images demonstrated an anomalous hypertrophied and elongated volar radiotriquetral ligament which, to our knowledge, has been described elsewhere only in another case. CONCLUSION: High resolution imaging at 3.0 T permitted a detailed analysis of the complex pathomorphology in patients with MD. Investing the better signal-to-noise ratio at higher field strengths into spatial resolution an excellent image quality could be obtained, depicting the Vickers ligament and the anomalous volar radiotriquetral ligament in this rare disease.

Microbiologic contamination of automatic injectors at MDCT: experimental and clinical investigations.

OBJECTIVE: It is mandatory to teach antiseptic skills to staff who use contrast agent injectors. The purpose of this study was to evaluate in an experimental setting and in clinical routine the risk of microbiologic contamination of the syringes of injectors used to administer contrast agent and saline solution for MDCT. MATERIALS AND METHODS: Microbiologic contamination of CT injector syringes over multiple uses for several injections was investigated in an experimental setup simulating the clinical setting. Each refill and injection operation was performed by the same technician, who processed a contrast agent for administration in a neighboring room as in clinical CT routine. Multiple administrations of nutritive medium and a chaser bolus were performed with the injection syringes. Simultaneously with each syringe replacement and filling operation, the filling and injection operation was simulated with a separate injection system under normal clinical conditions. Hygienic conditions in the CT department also were evaluated. For microbiologic analysis of devices and of palms of staff, imprints were obtained during clinical routine at the beginning of the study and at follow-up. Throughout the study, the staff participated in continuing education on hygienic behavior, such as hand disinfection and wearing of sterile gloves. In addition, clinical injector syringes were checked for microbiologic contamination. RESULTS: In the experimental setup, the first four samples of each simulation experiment were sterile, and the subsequent probes were found to be contaminated with typical dermal bacteria, such as staphylococci. In the CT department, contamination with skin and oral flora was found on surfaces of devices and on palms. No imprint of surfaces or palms was contaminated with nosocomial or fecal pathogens. CONCLUSION: Because even optimization of environments does not prevent contamination of syringes, multiple uses of syringes for more than one patient should be prohibited owing to the risk of septic complications.

Detection of asymptomatic cerebral microbleeds: a comparative study at 1.5 and 3.0 T.

RATIONALE AND OBJECTIVES: The magnitude of iron-induced susceptibility changes in gradient echo T2*-weighted magnet resonance imaging (T2* MRI) increases with the field strength and should increase the sensitivity for detection of cerebral microbleeds (CMBs) at 3.0 T. To test these hypotheses, we prospectively examined individuals with documented CMBs at 1.5 and 3.0 T. MATERIALS AND METHODS: Five hundred fifty elderly individuals, who participated in an interdisciplinary study of healthy aging, were examined at 3.0 T using T2* MRI sequences (repetition time [TR]/echo time [TE]/flip angle [FA] = 573 ms/16 ms/18 degrees ). Individuals positive for CMBs were asked to undergo an additional examination at 1.5 T (TR/TE/FA = 663 ms/23 ms/18 degrees ). Images were analyzed independently by two observers. CMBs were counted throughout the brain and were qualitatively analyzed comparing the degree of visible hypointensity on a 5-point scale from 1 (complete signal loss) to 5 (no detection) for both field strengths. Contrast-to-noise ratio of CMBs to surrounding brain tissue was calculated. RESULTS: At 3.0 T, CMBs were detected in 45 of 550 individuals; 25 agreed to an additional examination at 1.5 T. In this group (n = 25), a total of 53 CMBs were detected at 3.0 T, compared to 41 CMBs at 1.5 T. The mean contrast-to-noise ratio of CMBs was significantly increased at 3.0 T compared to 1.5 T (27.4 +/- 8.2 vs. 17.4 +/- 8.0; p < .001). On qualitative analysis, visibility of CMBs was ranked significantly higher at 3.0 T (1.3 +/- 0.4 vs. 2.9 +/- 1.1; p < .001). CONCLUSION: Evidence of past microbleeds may even be found in neurologically normal elderly individuals by MRI. Detection rate and visibility of CMBs benefit from the higher field strength, resulting in a significantly improved depiction of iron-containing brain structures (CMBs) at 3.0 T with potential clinical relevance.

Influence of Age, BMI, Gender and Lumbar Level on T1ρ Magnetic Resonance Imaging of Lumbar Discs in Healthy Asymptomatic Adults.

PURPOSE: To assess the T1ρ range of lumbar intervertebral discs in healthy asymptomatic individuals at 1.5 T and to investigate the influence of age, body mass index (BMI), gender, and lumbar level on T1ρ relaxation. MATERIALS AND METHODS: In a prospective study, a total of 81 volunteers aged 20 - 80 years were included in this study and divided into three age groups (A: 20 - 39y; B: 40 - 59y; C: 60 - 80y). All of the volunteers underwent magnetic resonance imaging (MRI) at 1.5 T with acquisition of sagittal T1ρ images. The calculated T1ρ relaxation times were correlated with age, BMI, gender, and lumbar level relative to the total disc, the annulus fibrosus, and the nucleus pulposus. RESULTS: Age had a significant influence on T1ρ relaxation times at all lumbar levels, with increasing age being associated with reduced relaxation times. There was also a significant difference between age groups A vs. C and B vs. C (P = 0.0008 and P = 0.0149, respectively). No significant differences in T1ρ relaxation time were observed between men and women (P > 0.05). BMI showed a significant negative correlation with T1ρ relaxation times (P < 0.0001). Analysis of the lumbar level revealed a significant decrease in relaxation times from L1/2 to L5 / S1 (P = 0.0013). CONCLUSION: Increasing age correlated significantly with advanced lumbar disc degeneration in asymptomatic individuals, particularly in those aged 60 or older. Increasing BMI correlated significantly with increasing degeneration. The lower discs showed more degeneration than the upper ones. KEY POINTS: · Increasing age significantly reduces the T1ρ relaxation time in the intervertebral discs (P < 0.05). · Gender does not significantly influence T1ρ relaxation times (P > 0.05). · BMI shows a significant negative correlation with T1ρ relaxation times (P < 0.01). · Significantly shorter relaxation times in lower lumbar spine vs. upper lumbar spine (P < 0.01). CITATION FORMAT: · Gübitz R, Lange T, Gosheger G et al. Influence of Age, BMI, Gender and Lumbar Level on T1ρ Magnetic Resonance Imaging of Lumbar Discs in Healthy Asymptomatic Adults. Fortschr Röntgenstr 2018; 190: 144 - 151.

High-resolution magnetic resonance imaging of the temporomandibular joint: image quality at 1.5 and 3.0 Tesla in volunteers.

PURPOSE: To assess the image quality of a high-resolution imaging protocol for the temporomandibular joint (TMJ) at 3.0 T and to compare it with our standard 1.5 T protocol. MATERIALS AND METHODS: Fifteen volunteers without history of TMJ dysfunction underwent bilateral magnetic resonance imaging (MRI) of the TMJ with the jaw in closed and open position. MRI was performed with using a 1.5 T (standard TMJ coil) and 3.0 T (purpose build phased array coil) MR system (Gyroscan Intera 1.5 T and 3.0 T; Philips Medical Systems, Best, the Netherlands). Imaging protocols consisted of a parasagittal PDw-TSE sequence and a coronal PDw-TSE sequence in closed mouth position and a sagittal PDw-TSE sequence in open mouth position. Acquisition parameters were adjusted for 3.0 T and voxel size was reduced from 0.29 x 0.29 x 3.0 mm (1.5 T) to 0.15 x 0.15 x 1.5 mm (3.0 T). Total examination time (15 minutes) was similar for both systems. Two observers assessed in consensus delineation, image quality, and artifacts of anatomic landmarks (disk, bilaminar zone, capsular attachment, cortical bone) and ranked them qualitatively on a 5-point scale from 1 (optimal) to 5 (nondiagnostic). Disk position and motility was noted. For CNR analysis, signal intensity from disk and retrodiscal tissue was measured. RESULTS: Disk position and mobility was identical at both field strengths. All anatomic landmarks were visualized significantly better at 3.0 T. In particular, the capsular attachment was depicted in more detail. Overall image quality was ranked significantly higher at 3.0 T, whereas artifact score was similar. Quantitative evaluation showed significantly higher CNR for 3.0 T (10.23 vs. 8.08, P < 0.0001). CONCLUSION: Depiction of the normal anatomy of the TMJ benefits significantly when investing the higher SNR at 3.0 T into better spatial resolution. We anticipate that this advantage of 3.0 T MRI will also permit a more detailed analysis of capsular and disk pathology.

High-resolution magnetic resonance imaging (MRI) at 3.0 Tesla in the short-term follow-up of patients with proven cervical artery dissection.

PURPOSE: For the imaging evaluation of patients with suspected cervical artery dissection (CAD) in the last decade, magnetic resonance imaging (MRI) has become the first line imaging modality. However, CAD is a highly dynamic process with rapid changes over time. Aim of this study was to assess the short-term morphologic changes in patients with proven CAD by MRI within 2 weeks after the initial diagnosis using a multicontrast high-resolution noninvasive vessel wall imaging approach at 3.0 T. MATERIALS AND METHODS: Eighty-two patients with clinically suspected CAD were examined using a 3.0 T system (Gyroscan Intera, Philips). Imaging protocol consisted of 3-dimensional inflow MRA (repetition time [TR]/echo time [TE]/flip angle [FA] = 25 milliseconds/3.1 milliseconds/16 degrees, reconstructed voxel size 0.3 x 0.3 x 0.8 mm), black blood T1w 3-dimensional spoiled gradient echo (TR/TE/FA = 31 milliseconds/7.7 milliseconds/15 degrees, 0.3 x 0.3 x 1.0 mm), and fat suppressed T2w turbo spin echo (TSE) (TR/TE/echo train length = 3 heart beats/44 milliseconds/7, 0.3 x 0.3 x 2 mm). Three observers in consensus performed image analysis. Images were assessed with regard to presence and size of intramural hematoma, degree of stenosis, presence of intraluminal thrombus, development of pseudoaneurysm, and incidence of additional dissections. In 29 patients (35%) a dissection had initially been proven by direct visualization of an intramural hematoma. Twenty-one patients (72%; 7 male, 14 female; mean age 41.5 years) were available for follow-up studies leading to a total of 24 diseased cervical arteries being reevaluated 2 weeks later for prospective follow-up. RESULTS: Mean interval between initial study and follow-up was 14.2 days (range 7-30 days). Eighteen patients had presented with an acute CAD in 1 artery, 3 patients with an acute CAD in 2 arteries. At follow-up, degree of stenosis had increased in 2 arteries, remained unchanged in 13, and decreased in 5 arteries. Four initially occluded arteries were recanalized at follow-up. In 3 arteries a pseudoaneurysm had been visible in the initial study and remained unchanged at follow-up; in 1 artery a new pseudoaneurysm was observed. In 3 arteries, new dissections were identified during follow-up. CONCLUSION: High-resolution MRI of acute CAD at 3.0 T permits a refined cross-sectional and longitudinal analysis of the morphologic features of CAD. The increased signal-to-noise ratio at 3.0 T allows for a high spatial resolution permitting detailed analysis of the diseased vessel segment. An unequivocal distinction between intramural hematoma and thrombus was possible. Information could be gained with regard to recanalization, degree of stenosis, formation of pseudoaneurysm, and appearance of new dissections making short-term follow-up in pts with acute CAD recommendable. Further studies are needed to assess the relationship between short-term results and definite outcome.

Age- and gender-adjusted normative data for the German version of Rey's Auditory Verbal Learning Test from healthy subjects aged between 50 and 70 years.

Rey's Auditory Verbal Learning Test (AVLT) is widely used to evaluate dysfunctional episodic memory. The current study aimed to provide extended age- and gender-specific norms for the German AVLT for individuals older than 50 years. In 690 subjects, a comprehensive medical examination including a structural 3.0-tesla magnetic resonance imaging scan was administered, as well as extensive neuropsychological tests. After controlling for exclusion criteria, 407 subjects were included in the analysis. AVLT performance decreased with age, and women outperformed men. We present age- and gender-specific normative data for the German AVLT from subjects aged between 50 and 70 years.