Search

BACKGROUND AND PURPOSE: Normal pressure hydrocephalus is characterized by systolic peaks of raised intracranial pressure, possibly due to a reduced compliance of the spinal CSF spaces. This concept of a reduced spinal CSF buffer function may be reflected by a low cervical CSF outflow from the cranium. The aim of this study was to investigate craniospinal CSF flow rates by phase-contrast MR imaging in patients with normal pressure hydrocephalus. MATERIALS AND METHODS: A total of 42 participants were included in this prospective study, consisting of 3 study groups: 1) 10 patients with normal pressure hydrocephalus (mean age, 74 [SD, 6] years, with proved normal pressure hydrocephalus according to current scientific criteria); 2) eighteen age-matched healthy controls (mean age, 71 [SD, 5] years); and 3) fourteen young healthy controls (mean age, 21 [SD, 2] years, for investigation of age-related effects). Axial phase-contrast MR imaging was performed, and the maximal systolic CSF and total arterial blood flow rates were measured at the level of the upper second cervical vertebra and compared among all study groups (2-sample unpaired t test). RESULTS: The maximal systolic CSF flow rate was significantly decreased in patients with normal pressure hydrocephalus compared with age-matched and young healthy controls (53 [SD, 40] mL/m; 329 [SD, 175] mL/m; 472 [SD, 194] mL/m; each P .05). CONCLUSIONS: The reduced maximal systolic craniospinal CSF flow rate in patients with normal pressure hydrocephalus may be reflective of a reduced compliance of the spinal CSF spaces and an ineffective spinal CSF buffer function. Systolic craniospinal CSF flow rates are an easily obtainable MR imaging–based measure that may support the diagnosis of normal pressure hydrocephalus.

Objectives The aim of this study was to investigate diagnostic accuracy and impact on patient management of an ultrafast (4:33 minutes/5 sequences) brain magnetic resonance imaging (MRI) protocol for the detection of intracranial pathologies in acute neurological emergencies. Materials and methods Four hundred forty-nine consecutive emergency patients with acute nontraumatic neurological symptoms were evaluated for this institutional review board-approved prospective single-center trial. Sixty patients (30 female, 30 male; mean age, 61 years) with negative head CT were included and underwent emergency brain MRI at 3 T subsequent to CT. MRI included the ultrafast protocol (ultrafast-MRI; sag T1 GRE, ax T2 TSE, ax T2 TSE Flair, ax T2* EPI-GRE, ax DWI SS-EPI; TA, 5 minutes) and an equivalent standard-length protocol (TA, 15 minutes) as reference standard. Two blinded board-certified neuroradiologists independently analyzed the MRI with regard to image quality (1, nondiagnostic; 2, substantial artifacts; 3, satisfactory; 4, minor artifacts; 5, no artifacts) and intracranial pathologies. Sensitivity and specificity for the detection of intracranial pathologies were calculated accordingly. Results Ninety-three additional intracranial lesions (acute ischemia, n = 21; intracranial hemorrhage/microbleeds, n = 27; edema, n = 2; white matter lesion, n = 38; chronic infarction, n = 3; others, n = 2) were detected by ultrafast-MRI, whereas 101 additional intracranial lesions were detected by the standard-length protocol (acute ischemia, n = 24; intracranial hemorrhage/microbleeds, n = 32; edema, n = 2; white matter lesion, n = 38; chronic infarction, n = 3; others, n = 2). Image quality was equivalent to the standard-length protocol. Ultrafast-MRI demonstrated high diagnostic accuracy (sensitivity, 0.939 [0.881-0.972]; specificity, 1.000 [0.895-1.000]) for the detection of intracranial pathologies. MRI led to a change in patient management in 10% compared with the initial CT. Conclusions Ultrafast-MRI enables time-optimized diagnostic workup in acute neurological emergencies at high sensitivity and specificity compared with a standard-length protocol, with direct impact on patient management. Ultrafast MRI protocols are a powerful tool in the emergency setting and may be implemented on various scanner types based on the optimization of individual acquisition parameters.

We developed a MRI protocol using transverse (T2) and longitudinal (T1) mapping sequences to characterise lung structural changes in preterm infants with bronchopulmonary dysplasia (BPD). We prospectively enrolled 61 infants to perform 3-Tesla MRI of the lung in quiet sleep. Statistical analysis was performed using logistic Group Lasso regression and logistic regression. Increased lung T2 relaxation time and decreased lung T1 relaxation time indicated BPD yielding an area under the curve (AUC) of 0.80. Results were confirmed in an independent study cohort (AUC 0.75) and mirrored by lung function testing, indicating the high potential for MRI in future BPD diagnostics.Trial registrationDRKS00004600.

Background Magnetic field therapy is a popular approach to pain therapy, but scientific evidence on treatment effects or even effects on sensory and pain perception in healthy controls is scarce. Methods In the present randomized, placebo-controlled study, we investigated the influence of static magnetic field exposure on sensory (touch) and pain (pinprick, pressure and heat) perception. Eighteen healthy volunteers (age: 23 ± 2 years, nine women) underwent three 10-min static magnetic field exposures using field strengths of 0 T (placebo), 1.5 T and 3 T within clinical MR scanners in randomized order on three separate days. Participants were blinded to magnetic field strength. Experimental sensory and pain testing was performed immediately before and after each magnetic field exposure. Results There was no significant effect of field strength on the assessed experimental sensory and pain testing parameters (mechanical detection threshold, pinprick threshold, pressure pain threshold, heat pain threshold and suprathreshold heat pain rating). Conclusion We found no evidence that a 10-min 1.5 T or 3 T static magnetic field exposure affects experimental sensory or pain perception in young healthy volunteers. Significance We used clinical MR scanners to investigate the effect of magnetic fields on pain perception. Using a rigorous, straightforward, placebo-controlled design, no effect of static magnetic fields on human experimental pain perception was detected. This provides a base for a more systematic investigation of magnetic field effects on pain.

To establish an optimized ultralow-dose digital pulsed fluoroscopy (FP) protocol for upper gastrointestinal tract examinations and to investigate the radiation dose and image quality. An Alderson-Rando-Phantom with 60 thermoluminescent dosimeters was used for dose measurements to systematically evaluate the dose–area product (DAP) and organ doses of the optimized FP protocol with the following acquisition parameters: 86.7 kV; 77 mA; 0.9 mm3, automatic image noise and contrast adaption. Subjective image quality, depiction of contrast agent and image noise (5-point Likert scale; 5 = excellent) were assessed in 41 patients, who underwent contrast-enhanced FP with the aforementioned optimized protocol by two radiologists in consensus. A conventional digital radiograph (DR) acquisition protocol served as the reference standard for radiation dose and image quality analyses. Phantom measurements revealed a general dose reduction of approximately 96% per image for the FP protocol as compared to the DR standard. DAP could be reduced by 97%. Significant dose reductions were also found for organ doses, both in the direct and scattered radiation beam with negligible orbital (FP 5.6 × 10−3 vs. DR 0.11; p = 0.02) and gonadal dose exposure (female FP 2.4 × 10−3 vs. DR 0.05; male FP 8 × 10−4 vs. DR 0.03; p ≤ 0.0004). FP provided diagnostic image quality in all patients, although reading scores were significantly lower for all evaluated parameters as compared to the DR standard (p

Whole-body MR imaging is increasingly utilised; although for lung dedicated sequences are often not included, the chest is typically imaged. Our objective was to determine the clinical utility of lung volumes derived from non-dedicated MRI sequences in the population-based KORA-FF4 cohort study. 400 subjects (56.4 ± 9.2 years, 57.6% males) underwent whole-body MRI including a coronal T1-DIXON-VIBE sequence in inspiration breath-hold, originally acquired for fat quantification. Based on MRI, lung volumes were derived using an automated framework and related to common predictors, pulmonary function tests (PFT; spirometry and pulmonary gas exchange, n = 214) and obstructive lung disease. MRI-based lung volume was 4.0 ± 1.1 L, which was 64.8 ± 14.9% of predicted total lung capacity (TLC) and 124.4 ± 27.9% of functional residual capacity. In multivariate analysis, it was positively associated with age, male, current smoking and height. Among PFT indices, MRI-based lung volume correlated best with TLC, alveolar volume and residual volume (RV; r = 0.57 each), while it was negatively correlated to FEV1/FVC (r = 0.36) and transfer factor for carbon monoxide (r = 0.16). Combining the strongest PFT parameters, RV and FEV1/FVC remained independently and incrementally associated with MRI-based lung volume (β = 0.50, p = 0.04 and β = – 0.02, p = 0.02, respectively) explaining 32% of the variability. For the identification of subjects with obstructive lung disease, height-indexed MRI-based lung volume yielded an AUC of 0.673–0.654. Lung volume derived from non-dedicated whole-body MRI is independently associated with RV and FEV1/FVC. Furthermore, its moderate accuracy for obstructive lung disease indicates that it may be a promising tool to assess pulmonary health in whole-body imaging when PFT is not available. • Although whole-body MRI often does not include dedicated lung sequences, lung volume can be automatically derived using dedicated segmentation algorithms • Lung volume derived from whole-body MRI correlates with typical predictors and risk factors of respiratory function including smoking and represents about 65% of total lung capacity and 125% of the functional residual capacity • Lung volume derived from whole-body MRI is independently associated with residual volume and the ratio of forced expiratory volume in 1 s to forced vital capacity and may allow detection of obstructive lung disease

The majority of the extremely premature infants are affected by the development of chronic lung disease, i.e. bronchopulmonary dysplasia (BPD). Driven by the exposure to mechanical ventilation and oxygen treatment after birth as well as pre- and postnatal infections, disease incidence steadily increases with improved survival rates (Rivera, L et al., Front. Pediatr., 2016). In order to possibly alleviate the debilitating and lifelong consequences especially of severe BPD, treatment of at-risk premature infants is needed as early as possible. Since BPD is diagnosed late in a premature neonate’s hospital stay, we used high-end protein screening in early plasma samples (n=30 infants, sampling day of life 1-7) to identify early biomarkers. Machine learning approaches were used to define a set of proteins associated with disease severity of later BPD. In particular, controls and mild BPD cases were separated well from moderate and severe cases by a characteristic protein signature together with the known risk factors gestational age, gender and early infections. The identified proteins were attributed to inflammation and cardiac strain as well as coagulation activation (extrinsic pathway), the latter mirroring tissue injury. The differential protein expression was driven by postnatal injury but not the degree of acute respiratory distress. Further associations of the protein signature was shown with imaging markers (lung MRI), i.e. indicators of interstitial remodeling and altered pulmonary blood flow. In conclusion, moderate and severe BPD can be separated from mild cases and controls by characteristic protein expression, allowing for early individualized treatment and monitoring.

Background Fluoroscopy is a frequently used examination in clinical routine without appropriate research evaluation latest hardware and software equipment. Purpose To evaluate the feasibility of low-dose pulsed video-fluoroscopic swallowing exams (pVFSE) to reduce dose exposure in patients with swallowing disorders compared to high-resolution radiograph examinations (hrVFSE) serving as standard of reference. Material and Methods A phantom study (Alderson-Rando Phantom, 60 thermoluminescent dosimeters [TLD]) was performed for dose measurements. Acquisition parameters were as follows: (i) pVFSE: 76.7 kV, 57 mA, 0.9 Cu mm, pulse rate/s 30; (ii) hrVFSE: 68.0 kV, 362 mA, 0.2 Cu mm, pictures 30/s. The dose area product (DAP) indicated by the detector system and the radiation dose derived from the TLD measurements were analyzed. In a patient study, image quality was assessed qualitatively (5-point Likert scale, 5 = hrVFSE; two independent readers) and quantitatively (SNR) in 35 patients who subsequently underwent contrast-enhanced pVFSE and hrVFSE. Results Phantom measurements showed a dose reduction per picture of factor 25 for pVFSE versus hrVFSE images (0.0025 mGy versus 0.062 mGy). The DAP (µGym2) was 28.0 versus 810.5 (pVFSE versus hrVFSE) for an average examination time of 30 s. Direct and scattered organ doses were significantly lower for pVFSE as compared to hrVFSE ( P Conclusion Pulsed VFSE is feasible, providing diagnostic image quality at a significant dose reduction as compared to hrVFSE.

Purpose The purpose of this study was to investigate intracranial pressure and associated hemo- and hydrodynamic parameters in patients with cerebral arteriovenous malformations AVMs. Methods Thirty consecutive patients with arteriovenous malformations (median age 38.7 years, 27/30 previously treated with radiosurgery) and 30 age- and gender-matched healthy controls were investigated on a 3.0 T MR scanner. Nidus volume was quantified on dynamic MR angiography. Total arterial cerebral blood flow (tCBF), venous outflow as well as aqueductal and craniospinal stroke volumes were obtained using velocity-encoded cine-phase contrast MRI. Intracranial volume change during the cardiac cycle was calculated and intracranial pressure (ICP) was derived from systolic intracranial volume change (ICVC) and pulse pressure gradient. Results TCBF was significantly higher in AVM patients as compared to healthy controls (median 799 vs. 692 mL/min, p = 0.007). There was a trend for venous flow to be increased in both the ipsilateral internal jugular vein (IJV, 282 vs. 225 mL/min, p = 0.16), and in the contralateral IJV (322 vs. 285 mL/min, p = 0.09), but not in secondary veins. There was no significant difference in median ICP between AVM patients and control subjects (6.9 vs. 8.6 mmHg, p = 0.30) and ICP did not correlate with nidus volume in AVM patients ( ρ = −0.06, p = 0.74). There was a significant positive correlation between tCBF and craniospinal CSF stroke volume ( ρ = 0.69, p = 0.02). Conclusions The elevated cerebral blood flow in patients with AVMs is drained through an increased flow in IJVs but not secondary veins. ICP is maintained within ranges of normal and does not correlate with nidus volume.

Background Idiopathic intracranial hypertension (IIH) in children is a rare condition of unknown etiology and various clinical presentations. The primary aim of this study was to evaluate if our pediatric IIH study group fulfilled the revised diagnostic criteria for IIH published in 2013, particularly with regard to clinical presentation and threshold value of an elevated lumbar puncture opening pressure. Additionally we investigated the potential utilization of MR-based and fundoscopic methods of estimating intracranial pressure for improved diagnosis. Patients and methods Clinical data were collected retrospectively from twelve pediatric patients diagnosed with IIH between 2008 and 2012 and revised diagnostic criteria were applied. Comparison with non-invasive methods for measuring intracranial pressure, MRI-based measurement (MR-ICP) and venous ophthalmodynamometry was performed. Results Only four of the twelve children (33%) fulfilled the revised diagnostic criteria for a definite diagnosis of IIH. Regarding noninvasive methods, MR-ICP (n = 6) showed a significantly higher mean of intracranial pressure compared to a healthy age- and sex-matched control group (p = 0.0043). Venous ophthalmodynamometry (n = 4) showed comparable results to invasive lumbar puncture. Conclusion The revised diagnostic criteria for IIH may be too strict especially in children without papilledema. MR-ICP and venous ophthalmodynamometry are promising complementary procedures for monitoring disease progression and response to treatment.

Purpose: To evaluate the intra- and inter-rater reliability of the quantification of blood and CSF flow rates by phase contrast MRI. Materials and Methods: Blood and CSF flows in the upper cervical region were imaged with velocity-encoded cine-phase contrast using 3T scanners from different manufacturers at two centers. Data of 6 subjects scanned in center A and of 5 subjects in center B were analyzed by six readers at two levels of training. Each data set was analyzed three times in a randomized order for a total of 33 data sets. Intra-class correlation coefficients (ICC) were calculated for the primary measurements of areas and flow rates through the main cervical arteries, veins and the CSF space, and for secondary parameters derived from the individual flow rates. Results: ICC ranged from 0.80 to 0.96 for the lumen area and from 0.97 to 0.99 for the volumetric flow rate. The ICC for the derived secondary measures ranged from 0.85 to 0.99. Differences due to operator level of training were not statistically significant. Conclusion: High intra- and inter-rater reliability of volumetric flow rate measurements is currently achievable across manufacturers and users' skill levels with a pulsatility based automated lumen segmentation. J. Magn. Reson. Imaging 2013;38:655–662. © 2013 Wiley Periodicals, Inc.

Neonatal chronic lung disease, i.e. BPD determines long-term pulmonary and neurologic development. Early markers are urgently needed for timely diagnosis and personalized treatment. The prospective study determined structural and functional changes in the preterm lung at the time of diagnosis and identified early disease markers by proteome screening in plasma in the first week of life. 40 infants (27.7±2.09wks, 984±332g) were included for advanced MRI measurements (3-Tesla) and complemented by Infant Lung function testing (ILFT) in spontaneously breathing infants. Plasma samples were processed for proteomic screening by SOMAscan™. Key findings were confirmed in an independent study cohort (n=21 infants). Statistical analysis used penalized and Poisson regression analysis; for protein analysis confounder effects were subtracted by lasso regression. Statistical analysis confirmed a high correlation of MRI and lung function variables and identified a pattern characterizing changes in the lungs of preterm infants by T2- and T1-weighed image analysis and lung volume measurements as well as ILFT. Functional enrichment analysis showed overrepresentation of the GO categories 9immune function9, 9extracellular matrix9, 9cellular proliferation/migration9, 9organ development9 and 9angiogenesis9 in infants with BPD. One protein was identified as a potential biomarker. We identified a structural pattern characterizing BPD by advanced MRI confirmed by ILFT. The identified protein indicated BPD development in the first week of life enabling personalized treatment strategies.

Liegt ein Hydrozephalus vor, so ist das System aus Liquorproduktion, Liquorpassage und Liquorresorption aus dem Gleichgewicht geraten. Dies fuhrt dazu, dass sich Liquor im Bereich des zentralen Nervensystems aufstaut und dort eine Druckwirkung auf das Hirnparenchym ausubt. Als ursachliche Mechanismen fur einen Hydrozephalus kommen folgende 3 Prinzipien infrage: 1 eine Uberproduktion von Liquor, entsprechend einem Hydrocephalus hypersecretorius, 2 eine Passagestorung des Liquors, also eine Liquorflussbehinderung, entsprechend einem Hydrocephalus non communicans, sowie 3 eine verminderte Resorption von Liquor, entsprechend einem Hydrocephalus communicans oder malresorptivus.

The corpus callosum (CC) represents a key structure for hand motor development and is accessible to investigation by diffusion tensor magnetic resonance imaging (DTI) and transcranial magnetic stimulation (TMS). To identify quantifiable markers for motor development, we combined DTI with TMS.We examined groups of 11 healthy preschool-aged children, 10 healthy adolescents, and 10 healthy adults with both, DTI and TMS/ipsilateral silent period (iSP). DTI-values for fractional anisotropy (FA) were calculated for areas I to V of the CC. ISP-values for latency, duration, and extent of electromyography suppression were calculated.FA was significantly lower in areas II to IV of the CC in children as compared with adults (P0.05). In area III, where callosal motor fibers cross the CC, FA differed significantly between children and adolescents (P0.05). TMS parameters demonstrated significant age-related differences in duration and extent of iSP (P0.05). No significant differences were detected regarding latency of iSP.The maturation of callosal motor fiber connectivity seems to reflect the degree of interhemispheric inhibition between the motor cortices with anisotropy of callosal motor fibers being a potential marker for motor development.

Background Careful patient selection is the prerequisite to raise transplant benefit. In lung transplant (LT) candidates, the effect of body mass index (BMI) on postoperative outcome remains controversial, possibly due to the inaccuracy of BMI in discriminating between fat and muscle mass. We therefore hypothesized that assessment of body composition by muscle mass measures is more accurate than by BMI regarding postoperative outcome. Methods All LT recipients from 2011 to 2014 were included and retrospectively analyzed. Lean psoas area (LPA) was assessed from pretransplant computed tomography scans, and associations with postoperative outcomes were investigated. Results Included were 103 consecutive LT recipients with a mean pre-LT BMI of 22.0 ± 4.0 kg/m 2 and a mean LPA of 22.3 ± 8.3 cm 2 . LPA was inversely associated with length of mechanical ventilation ( p = 0.03), requirement of tracheostomy ( p = 0.035), and length of stay in the intensive care unit ( p = 0.02), while controlling for underlying disease, BMI, sex, age, and procedure; in contrast, BMI was not ( p = 0.25, p = 0.54, and p = 0.42, respectively.). Multiple regression analysis revealed that the 6-minute walk distance at the end of pulmonary rehabilitation was significantly associated with LPA ( p = 0.02). Conclusions LPA can easily be assessed in LT candidates as part of pretransplant evaluation and was significantly associated with short-term outcome, whereas BMI was not. Assessment of LPA may provide additional information on body composition beyond BMI. However, the clinical utility has to be further evaluated.

Background/purpose Migraine is frequent in young adults and adolescents and often associated with neck muscle tension and pain. Common pathophysiological pathways, such as reciprocal cervico-trigeminal activation, are assumed. Tense areas within the neck muscles can be clinically observed many patients with migraine. The aim of this pilot case study was to visualize these tense areas via magnet resonance imaging (MRI). Methods Three young patients with migraine were examined by an experienced investigator. In all three patients tense areas in the trapezius muscles were palpated. These areas were marked by nitroglycerin capsules on the adjacent skin surface. Results The MRI showed focal signal alterations at the marked locations within the trapezius muscles. Conclusion Visualization of palpable tense areas by MRI may be usefully applied in the future to help elucidate the underlying pathophysiological processes of migraine.

The length of the cochlea can be determined with good precision using a 3D-curved multiplanar reconstruction analysis technique and linear reconstruction of the cochlea. The method is not time-consuming and can be applied during clinical routine.A preoperative prediction of the best cochlear implant electrode length can help reduce the risk of intraoperative cochlear trauma in patients who need to retain residual acoustic hearing for electric-acoustic stimulation or in patients with anatomical anomalies or malformations. The goal of this study was to evaluate the accuracy and reliability of length measurement of the cochlea after linear reconstruction using 3D-curved multiplanar reconstrucion analysis of high resolution computed tomography (CT) scans.Human cadaveric temporal bone specimens underwent cochlear implantation using custom-made electrodes with two radiopaque markers of a defined length before CTscans were made. Length measurement was performed by four readers and the results were compared to the true value. Inter-reader reliability was calculated. The time needed for analysis was recorded.The mean time needed for analysis of one specimen's radiologic data was 6.1 (± 3.4) min. The mean deviation of the length measurement from the true value was 0.8 (± 0.7) mm. Inter-reader reliability was excellent (0.76, p = 0.006).

To evaluate the intra- and inter-rater reliability of the quantification of blood and CSF flow rates by phase contrast MRI.Blood and CSF flows in the upper cervical region were imaged with velocity-encoded cine-phase contrast using 3T scanners from different manufacturers at two centers. Data of 6 subjects scanned in center A and of 5 subjects in center B were analyzed by six readers at two levels of training. Each data set was analyzed three times in a randomized order for a total of 33 data sets. Intra-class correlation coefficients (ICC) were calculated for the primary measurements of areas and flow rates through the main cervical arteries, veins and the CSF space, and for secondary parameters derived from the individual flow rates.ICC ranged from 0.80 to 0.96 for the lumen area and from 0.97 to 0.99 for the volumetric flow rate. The ICC for the derived secondary measures ranged from 0.85 to 0.99. Differences due to operator level of training were not statistically significant.High intra- and inter-rater reliability of volumetric flow rate measurements is currently achievable across manufacturers and users' skill levels with a pulsatility based automated lumen segmentation.