Biomedical subjects

S Heiland

Publications and source records attributed to S Heiland.

At least 19 recordsLinked to original sources

PubMed2006

3.0 Tesla contrast-enhanced MR angiography of carotid artery stents: in vitro measurements as compared with 1.5 Tesla.

BACKGROUND AND PURPOSE: To assess the appearance of carotid artery stents at 3.0 Tesla contrast enhanced magnetic resonance angiography (CE-MRA) as compared with 1.5 Tesla. METHODS: 19 stents (GUIDANT Acculink, GUIDANT Dynalink, BOSTON SCIENTIFIC SMART Neuroform, GUIDANT Omnilink, EV3 Protege, BOSTON SCIENTIFIC Carotid Wallstent, ABBOTT Xact) of different materials (nitinol, stainless steal, cobalt alloy) and different sizes (4.0 mm-10.0 mm) were investigated regarding their appearance on CE-MRA at 3.0 Tesla and at 1.5 Tesla. For each stent artificial lumen narrowing (ALN) was calculated based on a pixel-by-pixel profile of the contrast-to-noise-ratio giving an objective indicator for the size of the evaluable stent diameter. RESULTS: Only in two stents (Omnilink 7.0 mm, Omnilink 10.0 mm) was ALN higher at 3.0 Tesla relative to 1.5 Tesla. In all other stents ALN at 3.0 Tesla was the same or even lower as compared with 1.5 Tesla. In contrast to the ferromagnetic stents where ALN was typically higher than 85%, in most of the nitinol stents (Acculink, Dynalink, Neuroform, Protege) ALN was below 35%. In the Xact stents ALN was generally 100% at 1.5 Tesla and ranged between 31.8% and 100% at 3.0 Tesla. CONCLUSION: CE-MRA after carotid artery stenting is considerably impaired by ALN both at 1.5 Tesla and at 3.0 Tesla. Nevertheless, CE-MRA is well suited for the examination of carotid artery stents made of nitinol at both field strengths. Stent manufacturers should be aware of potential artifacts caused by their stents during noninvasive diagnostic methods such as CE-MRA.

Alloys↗

PubMed2005

[Pseudonormalization of diffusion weighted images: magnetic resonance imaging in an animal model (C6-glioma)].

PURPOSE: Previous studies on intracranial tumors indicate that a high apparent diffusion coefficient (ADC) is due to low cellularity and that lower values indicate a dense, highly cellular tumor. Diffusion is affected by three major factors: cell density, existence and distribution of vasogenic edema, and hypoxic tissue. Therefore, we studied the characteristics of diffusion-weighted magnetic resonance imaging (DWI) in a rat brain C6 glioma during tumor progression. MATERIALS AND METHODS: In male Wistar rats, C6 gliomas were implanted in the caudoputamen. At day 9, 11, 13 and 15 after tumor inoculation, conventional DWI was performed on a 2.35 Tesla small bore MRI unit (Biospec 24/40, BRUKER Medizintechnik, Ettlingen, Germany). RESULTS: On conventional T2-weighted and contrast-enhanced T1-weighted images, all tumors could well be delineated from the surrounding brain tissue and showed significant progression. On DWI, the tumors were isointense or slightly hypointense compared to the surrounding brain. On the ADC maps, the tumors could be well visualized due to increasing ADC values from day 9 to 15. The mean ADC of brain tumor tissue was 0.76 +/- 0.4 x 10 ( - 3) mm (2)/s at day 9 and 0.91 +/- 0.03 x 10 ( - 3) mm (2)/s at day 15. The mean ADC of the normal contralateral caudoputamen was 0.59 +/- 0.007 x 10 ( - 3)mm (2)/s. CONCLUSION: T2 prolongation and increased water diffusion can be balanced on DWI in C6 gliomas, resulting in isointensity on DWI (T2 shine-through washout phenomenon). ADC maps are indispensable for the correct interpretation of tumor tissue diffusion behavior.

Animals↗

PubMed2004

Active deep brain stimulation during MRI: a feasibility study.

The goal of this study was to evaluate the feasibility of active deep brain stimulation (DBS) during the application of standard clinical sequences for functional MRI (fMRI) in phantom measurements. During active DBS, we investigated induced voltage, temperature at the electrode tips and lead, forces on the electrode and lead, consequences of defective leads and loose connections, proper operation of the neurostimulator, and image quality. Sequences for diffusion- and perfusion-weighted imaging, fMRI, and morphologic MRI were used. The DBS electrode and lead were placed in a NaCl solution-filled phantom. The results indicate that there are severe potential hazards for patients. Strong heating, high induced voltage, and even sparking at defects in the connecting cable could be observed. However, it was demonstrated that under certain conditions, safe MR examinations during active DBS are feasible. Certain safety precautions are recommended in this report.

Body Temperature↗

PubMed2003

Differentiation of multiple sclerosis plaques, subacute cerebral ischaemic infarcts, focal vasogenic oedema and lesions of subcortical arteriosclerotic encephalopathy using magnetisation transfer measurements.

Although multiple sclerosis (MS) plaques, subacute cerebral ischaemic infarcts, focal vasogenic brain oedema, and subcortical arteriosclerotic encephalopathy (SAE) often have typical radiological patterns, they are sometimes difficult to distinguish from each other. Our aim was to determine whether they can be differentiated by magnetisation transfer (MT) measurements. We measured MT ratios (MTR) in ten patients with plaques of MS, 11 with subacute ischaemic infarcts, 12 with focal vasogenic oedema, and ten with lesions of SAE and compared the mean MTRs statistically. The MTR of normal white matter was 47.3%; the lowest MTR was found in plaques of MS (mean 26.4%). With the exception of vasogenic oedema and subacute cerebral ischaemic infarcts the mean MTRs were significantly different between all groups. MT measurements can provide additional information for the differentiation of these conditions, but we could not distinguish vasogenic oedema from subacute cerebral ischaemic infarcts.

Adult↗

PubMed2003

Changes in peptidyl-prolyl cis/trans isomerase activity and FK506 binding protein expression following neuroprotection by FK506 in the ischemic rat brain.

FK506 is an immunosuppressant also showing neuroprotection following cerebral ischemia. FK506 binds to intracellular proteins (FKBP) which have a wide range of functions but have in common the peptidyl-prolyl cis/trans isomerase activity. Following transient focal ischemia, we have analyzed the expression of FKBP12, 52 and 65 and the total FKBP enzyme activity. Furthermore, we have investigated the effect of FK506 on signal transduction in neurons and perfusion changes in the infarct area. After 90 min of transient middle cerebral artery occlusion in male rats the expression of FKBP12, 52 and 65 was analyzed by Western blot in FK506-treated and control animals and the peptidyl-prolyl cis/trans isomerase activity was determined. Magnetic resonance imaging was used to measure tissue perfusion, development of vasogenic edema and infarct size. To investigate the neuronal stress signal cascade, activating transcription factor 2 (ATF-2), Fas-ligand (Fas-L) and c-Jun expression and phosphorylation were analyzed by immunohistochemistry. FK506 decreased the cerebral infarct volume by 53% and reduced the cytotoxic edema. The total FKBP enzymatic activity in the infarct area was increased and blocked dose dependently by FK506. FKBP expression was selectively up-regulated by cerebral ischemia. FK506 treatment does not influence the expression patterns. c-Jun phosphorylation in neurons of the peri-infarct area and Fas-L expression was reduced by FK506 treatment whereas ATF-2 expression was preserved. Cerebral ischemic damage to the brain was reduced by FK506. It was shown for the first time that neuroprotection by FK506 also included the suppression of the cerebral peptidyl-prolyl cis/trans isomerase activity of FKBP in vivo whereas the expression levels of FKBP12, 52 and 65 following ischemia changed slightly and FK506 treatment does not suppress the expression patterns. However, changes of FKBP enzymatic activity result in suppression of the stress cell body response in the peri-infarct area as observed by suppression of c-Jun phosphorylation and Fas-L expression.

Activating Transcription Factors↗

PubMed2003

[Normal and abnormal water diffusion in the brain].

Diffusion magnetic resonance imaging (MRI) has become an important tool in the radiologic diagnosis of diseases of the brain as it measures molecular motion of water that characterizes the microstructure of tissues. Its most important clinical use to date is the early detection of cerebral ischemia by revealing the ischemic injury shortly after vessel occlusion and simultaneously providing therapy-relevant information on the tissue at risk. Furthermore, diffusion MRI is diagnostically promising in other diseases of the brain and is thus increasingly becoming part of routine clinical protocols in the diagnosis of tumors, inflammation, trauma, demyelination, dysmyelination and neurodegeneration. Although abnormalities of diffusion are generally not pathognomonic, diffusion MRI affords information about tissue changes for specific disorders that complements information obtained with standard MR techniques and frequently shows pathology earlier. In addition, diffusion MRI can be applied to plan, guide and follow-up biopsies or resective surgery. Particularly diffusion tensor imaging (DTI), which displays the orientation of white matter fibers, holds promise for improved surgical planning. Moreover, DTI can be used to detect changes in connectivity between functional brain areas. Therefore, DTI is highly relevant not only in advancing the knowledge of white matter diseases but also in stimulating research on normal brain development and brain aging.

Blood-Brain Barrier↗

PubMed2002

Serial analysis of the apparent diffusion coefficient time course in human stroke.

Acute cerebral ischemic injury can be rapidly detected on diffusion-weighted images. The apparent diffusion coefficient (ADC) depends on the stage of cytotoxic edema and water content in the infarcted parenchyma. The purpose of this study is to determine the time course of ADC during the first days of ischemic stroke. These data should make it possible to distinguish between multiple stroke and a single progressive infarction. Eight patients with clinically diagnosed acute cerebral ischemia were examined by diffusion-weighted MRI from 2 to 20 h after onset of symptoms. Daily control scans were performed for up to 10 days. ADC values were analyzed from 55 MRI studies. Furthermore, ADC was measured in the tissue which showed a hyperintense signal at the first examination and in the contralateral tissue. White and gray matter were analyzed separately. Data were expressed as the ratio ADC (rADC) of lesion to control region of interest. All patients showed a uniform reduction in rADC from the first hours of stroke and decreasing to the 3rd day. The rADC increased again from the 4th day up to the point of pseudo-normalization on day 9. The gray matter showed a slightly faster increase than the white matter. rADC shows significant changes in the first days after stroke, following a rather uniform time course. Together with T2-weighted MRI this makes it possible to differentiate between hyperacute, acute, and chronic stroke. Furthermore, the age of an ischemia can be determined and multiple strokes can be distinguished from a single progressive stroke.

Aged↗

PubMed2002

[Functional magnetic resonance imaging: Physiological background, technical aspects and prerequisites for clinical use].

The advent of powerful gradient systems and ultrafast echo-planar imaging (EPI) offers the opportunity to use magnetic resonance imaging to measure and to localize brain function with high spatio-temporal resolution in clinically feasible scanning times. Functional magnetic resonance imaging (fMRI) opens up a new diagnostic field in radiology and neuroradiology with a change from pure morphological brain imaging to the measurement and visualization of brain function. Despite its successful application in neurosurgical, neurological, psychiatric, neuropediatric and pain patients fMRI has not yet reached the status of an established clinical diagnostic procedure. To this end special stimulation systems, standardized fMRI protocols and medically approved software, all dedicated to clinical application, are necessary. The training and teaching of doctors and radiographers will also be crucial for the progress of clinical fMRI. This paper gives an overview of the neurophysiological background, the technical requirements and the data processing strategies that are relevant for the clinical application of fMRI. Presurgical fMRI in patients with brain tumors is used as an example for the clinical relevance of the method.

Brain↗

PubMed2002

[Functional MRI procedures in the diagnosis of brain tumors: Perfusion- and diffusion-weighted imaging].

Despite the increased diagnostic accuracy of contrast material enhanced MR imaging, specification and grading of brain tumors are still only approximate at best: neither morphology, nor relaxation times or contrast material enhancement reliably predict tumor histology or tumor grade. As histology and tumor grade strongly influence which therapy concept is chosen, a more precise diagnosis is mandatory. With diffusion- and perfusion-weighted MR imaging (DWI, PWI) it is now possible to obtain important information regarding the cellular matrix and the relative regional cerebral blood volume (rrCBV) of brain tumors, which cannot be obtained with standard MR techniques. These dynamic-functional imaging techniques are very useful in the preoperative diagnosis of gliomas, lymphomas, and metastases, as well as in the differentiation of these neoplastic lesions from abscesses, atypical ischemic infarctions, and tumor-like manifestations of demyelinating disease. Additionally, they appear suitable for determining glioma grade and regions of active tumor growth which should be the target of stereotactic biopsy and therapy. After therapy these techniques are helpful to better assess the tumor response to therapy, possible therapy failure and therapy complications such as radiation necrosis.

Biopsy↗

PubMed2002

Neuroprotective effect of delayed moderate hypothermia after focal cerebral ischemia: an MRI study.

BACKGROUND AND PURPOSE: In contrast to early hypothermia, the effects of delayed hypothermia in focal cerebral ischemia have not been widely addressed. We examined the influence of delayed hypothermia on secondary ischemic injury, MRI lesion size, and neurological outcome after transient focal cerebral ischemia in a rat model. METHODS: Rats (n=30) were subjected to transient middle cerebral artery occlusion (MCAO, 120 minutes) by use of the intraluminal filament model. Animals of the treatment group (n=12) were exposed to whole-body hypothermia of 33 degrees C for 5 hours starting 3 hours after MCAO, whereas the control group (n=18) was kept at 37 degrees C throughout the whole experiment. The normothermia- and hypothermia-treated animals were investigated daily by using the Menzies neurological score. Serial MRI was performed 1, 3, and 6 hours after MCAO and on days 1, 2, 3, and 5. After the final MRI scan, the rats were euthanized, and brain slices were stained by 2,3,5-triphenyltetrazolium chloride. RESULTS: Delayed hypothermia resulted in a significant increase of survival rate and a significant improvement of the Menzies score. Moreover, a significant decrease in the extent of hyperintense volumes in T2-weighted scans and a reduction of cerebral edema as calculated from T2-weighted scans throughout the examination period were obvious. The extent of cerebral infarct volume and cerebral brain edema examined by MRI was consistent with 2,3,5-triphenyltetrazolium chloride staining. CONCLUSIONS: Our results suggest that even delayed postischemic hypothermia can reduce the extent of infarct volume and brain edema after transient focal cerebral ischemia.

Animals↗

PubMed2001

Noise correction for the exact determination of apparent diffusion coefficients at low SNR.

Noise in MR image data increases the mean signal intensity of image regions due to the usually performed magnitude reconstruction. Diffusion-weighted imaging (DWI) is especially affected by high noise levels for several reasons, and a decreasing SNR at increasing diffusion weighting causes systematic errors when calculating apparent diffusion coefficients (ADCs). Two different methods are presented to correct biased signal intensities due to the presence of complex noise: 1) with Gaussian intensity distribution, and 2) with arbitrary intensity distribution. The performance of the correction schemes is demonstrated by numerical simulations and DWI measurements on two different MR systems with different noise characteristics. These experiments show that noise significantly influences the determination of ADCs. Applying the proposed correction schemes reduced the bias of the determined ADC to less than 10% of the bias without correction. Magn Reson Med 45:448-453, 2001.

Artifacts↗

PubMed2001

Diffusion-weighted imaging of the spine using radial k-space trajectories.

INTRODUCTION: Diffusion-weighted MR imaging (DWI) of the spine requires robust imaging methods, that are insensitive to susceptibility effects caused by the transition from bone to soft tissue and motion artifacts due to breathing, swallowing, and cardiac motion. The purpose of this study was to develop a robust imaging method suitable for DWI of the spine. METHODS AND SUBJECTS: A radial k-space spin echo sequence has been implemented, which is self-navigating because each acquisition line passes through the origin of k-space. Influence of cardiac motion and associated flow of cerebrospinal fluid is minimized by cardiac gating with a finger photoplethysmograph. The sequence has been tested on a 1.5T system. Diffusion-weighted images of six normal volunteers were acquired in the sagittal plane with 4 b values between 50 and 500 s mm(-2). Because of the symmetries of the cord, diffusion measurements in the head-foot (HF) or left-right (LR) directions were sufficient to measure the dominant effects of anisotropy. RESULTS: The apparent diffusion coefficients (ADCs) measured, respectively, in the LR and HF directions were (0.699+/-0.050)x10(-3) and (1.805+/-0.086)x10(-3) mm(2) s(-1) in the spinal cord, (1.588+/-0.082)x10(-3) and (1.528+/-0.052)x10(-3) mm(2) s(-1) in the intervertebral disks, and (0.346+/-0.047)x10(-3) and (0.306+/-0.035)x10(-3) mm(2) s(-1) in the vertebrae of the cervicothoracic spine. CONCLUSION: Diffusion-weighted spin echo sequences with radial trajectories in k-space provide a means of achieving robust, high quality diffusion-weighted imaging and measuring ADCs in the spine. The application of the diffusion-weighting gradients in different directions allows diffusion anisotropy to be measured.

Humans↗

PubMed2001

Does the "keyhole" technique improve spatial resolution in MRI perfusion measurements? A study in volunteers.

We examined the potential of the 'keyhole' technique to improve spatial resolution in perfusion-weighted MRI on whole-body imagers with standard gradient hardware. We examined 15 healthy volunteers. We acquired a high-resolution image with 256 phase-encoding steps before a bolus-tracking procedure. For the dynamic series we collected only 34 lines in the center of k-space. Data reconstruction was performed by both zero-filling and keyhole methods. The dynamic datasets, concentration-time curves calculated from user-defined regions and maps of the cerebrovascular parameters using both reconstruction methods were compared. Using keyhole series, anatomical structures could easily be defined which were not seen on the original dynamic series because of blurring due to ringing artefacts. Comparison of signal-time curves in large regions yielded no significant difference in signal loss during bolus passage. In the parameter maps truncation artefacts were significantly reduced using keyhole reconstruction. The keyhole method is appropriate for enhancing image quality in perfusion-weighted imaging on standard imagers without sacrificing time resolution or information about transitory susceptibility changes. However, it should be applied carefully, because the spatial resolution of the dynamic signal change and the cerebrovascular parameters is less than that afforded by the spatial resolution of the reconstructed images.

Brain↗

PubMed2001

Diffusion-weighted imaging of the brain: comparison of stimulated- and spin-echo echo-planar sequences.

We used a rat model of focal cerebral ischaemia to compare stimulated-echo (STE) and spin-echo (SE) echo planar (EPI) diffusion-weighted sequences as regards image quality and accuracy of calculation of apparent diffusion coefficients (ADC). Focal cerebral ischaemia was induced by endovascular occlusion of the middle cerebral artery in five rats. MRI was performed on a 2.35 tesla imager. For diffusion-weighted imaging (DWI) we used STE-EPI and SE-EPI with different diffusion times (delta) of 15, 30, 45, 60, 75 and 90 ms using values of b of 200, 300, 400, 500, 600 and 700 s/mm2. We assessed image quality, the signal-to-noise-ratio (SNR) and the accuracy of the ADC calculated from both sequences. Infarcts were delineated in all cases, independent of sequence type and delta. The image quality and SNR of the SE-EPI images were significantly better, with a higher SNR than STE-EPI images for short and intermediate values of delta. However, when delta reached 75 ms STE-EPI became superior to SE-EPI. ADC calculated from STE-EPI images were smaller than those from SE-EPI images for short and intermediate diffusion times, possibly because of the lower SNR of the former. We suggest that SE-EPI sequences be used for DWI of the brain, particularly on experimental systems and whole-body imagers with enhanced gradient hardware, where it is possible to run highly diffusion-weighted sequences (b > 500 s/mm2) with delta less than 50 ms. However, when using very long values of delta because of hardware restrictions or for measurement of restricted diffusion, STE sequences give better results.

Animals↗

PubMed2001

Comparison of CT with diffusion-weighted MRI in patients with hyperacute stroke.

Tissue changes in ischaemic stroke are detectable by diffusion-weighted MRI (DWI) within minutes of the onset of symptoms. However, in daily routine CT is still the preferred imaging modality for patients with acute stroke. Our purpose of this study was to determine how early and reliably ischaemic brain infarcts can be identified by CT and DWI. Three neuroradiologists, blinded to clinical signs but aware that they were dealing with stroke, analysed the CT and DWI of 31 patients with an acute ischaemic stroke. We calculated kappa-values to analyse inter-rater variability. The ratings were compared with follow-up studies showing the extent of the infarct. The combined assessment of all observers gave positive findings in 77.4% of all CT examinations, with kappa = 0.58. Areas of high signal were seen on all DWI studies by all observers (kappa = 1). Estimation of the extent of the infarct based on DWI yeilded kappa = 0.70 and that based on CT kappa = 0.39. DWI was much more reliable than CT in the detection of early ischaemic lesions and we believe that it should be used in acute ischaemic stroke before aggressive therapeutic intervention.

Aged↗

PubMed2001

[Magnetic resonance tomography for planning dental implantation].

PROBLEM: Three-dimensional imaging diagnostics are increasingly recommended before inserting dental implants in high-risk areas and in cases of severe alveolar atrophy. Since patients are exposed to considerable radiation with computed tomography (CT), the possibilities of employing magnetic resonance imaging (MRI) of the jaw as a diagnostic imaging method before inserting dental implants were examined. MATERIAL AND METHOD: Twelve patients and three volunteers were examined by MRI with T1-weighted, fat-suppressed sequences and conventional T1-weighted sequences. The patients wore a diagnostic splint including markers--in the form of capillaries filled with 0.025 x 10(-2) M gadolinium solution (1.5 mm in diameter)--in the planned implant's position and axis. RESULTS: The presentation of relevant anatomic structures and the three-dimensional accuracy of the markers were judged. Metal artefacts were evaluated in vitro. The MRI of the jaw and midface represents the mandibular canal, the maxillary sinus, and other decisive anatomic structures by detailed representation of the connective tissue surrounding the bone. Artefacts of metallic fillings reduce the image quality. CONCLUSION: Obtaining clinical findings and planning before inserting dental implants with the help of MRI can certainly be applied with toothless patients and facilitates three-dimensional planning by representing the exact location and angle of the drill tubes. Local restrictions result from metal extinction artefacts in jaws with teeth and in controls after having inserted titanium implants.

Adolescent↗

PubMed2001

How do concentration and dosage of the contrast agent affect the signal change in perfusion-weighted magnetic resonance imaging? A computer simulation.

In this study we investigated the effect of varying both concentration and dosage of an intravenously administered MR contrast agent on the concentration-time curve in brain tissue. Aside from injection time and injection rate, our model considers the distribution of transit-time between injection site and brain but it is independent from pulse rate, heart volume or other circulation parameters. The width of the transit-time distribution and the concentration-time course in the brain were computed according to indicator dilution theory. We found that increasing the dosage of the administered contrast agent raises the maximum concentration of the agent in the brain, particularly if the injection time is short. Increasing the concentration of the agent (at fixed dosage and injection rate) also increases maximum concentration in the brain capillaries, particularly if the injection time is long. This increase, however, is less than that achieved by raising the dosage.

Animals↗

PubMed2001

[Measurement of CSF flow in the spinal canal using MRI with an optimized MRI protocol: experimental and clinical studies].

PURPOSE: Measurement of the oscillating CSF flow in the spinal canal (SC) of healthy volunteers and in patients with post-traumatic syringomyelia (PTS) using an optimized MRI protocol as well as to determine whether stenosis induced velocity changes are detectable using MRI. METHODS: In 68 healthy volunteers quantitative studies of CSF flow in the cervical, thoracic, and lumbar regions were performed. First, an optimized sequence was developed and tested in 19 volunteers using four different flow-encoding velocities (4, 8, 12, 16 cm/s). Secondly, the optimized sequence was employed in 49 volunteers to measure the different CSF patterns in the cervical, thoracic, and lumbar spinal canals (CSC, TSC, LSC). Part three of the study, in which patients with PTS are being examined is still underway. We measured the maximum velocity (cm/s), the pixel area (mm2), and the stroke volume (ml/s). Using a flow model the velocities prior to and after compression with 5 different power levels were measured at the stenosis and at a distance of 70 cm. RESULTS: A total of 226 dynamic measurements have been performed--so far 76 in the first part (62 = 81.5% evaluable) and 150 in the second part--using the optimized sequence and optimal flow velocities. A flow-encoding sequence of 12 cm/s was found best in the CSC and one of 6 cm/s in the TSC and LSC. The maximum velocity in the CSC was 0.95 cm/s with the flow being directed caudal and 0.38 cm/s with the flow being directed cranial. In the TSC the values were 4.7 cm/s and 1.65 cm/s and in the LSC 0.96 cm/s and 0.59 cm/s. The highest velocities were found at the TSC, which has the smallest diameter compared to the CSC and LSC. In the 4 patients with PTS, the maximum velocities were between 0.09 cm/s and 0.97 cm/s with the flow being directed cranial and between 0.04 cm/s and 1.03 cm/s with the flow being directed caudal. The stroke volumina in the CSC were between 0.1 and 1.23 ml/s (mean: 0.48 ml/s) and 0.2 and 2.45 ml/s (mean: 0.66 ml/s) in the TSC and in the LSC 0.08 ml/s and 0.67 ml/s (mean: 0.29 ml/s). The results of the flow model studies showed an increase of velocity between 2.06 and 4.94 cm/s (mean: 3.31 cm/s) at the stenosis and 1.1 and 1.33 cm/s (mean: 1.23 cm/s) at a distance of 70 cm. CONCLUSION: Quantitative measurement of the oscillating CSF flow in the entire spinal canal (SC) is possible using an optimized MRI protocol as well as to detect stenosis induced velocity changes. Due to the high interindividual variability in the data of spinal CSF dynamics, further studies are necessary to collect normal data. The detection of movement of CSF in a post-traumatic spinal cord lesion may alter the therapeutic management.

Adult↗