CSF Flow Studies Research Articles

Neurotoxicity of intra-CSF liposomal cytarabine (DepoCyt) administered for the treatment of leptomeningeal metastases: a retrospective case series

Treatment of leptomeningeal metastasis (LMD) remains challenging due to advanced systemic disease at presentation and limited treatment options. All patients underwent standard pre-treatment LMD evaluation including CSF assessment (cytology or flow cytometry), brain and spine MR imaging, and radioisotope CSF flow study. DepoCyt (liposomal cytarabine) was administered intraventricularly (n = 80) or intralumbar (n = 40) at 50 mg every 2 weeks × 4 and then every 4 weeks × 6 in responding patients. Dexamethasone (4 mg orally twice per day × 5 days) was co-administered with each DepoCyt treatment. Patients were seen with each DepoCyt treatment and assessed for toxicity. 120 adult patients [median age 51 years (range 33-68)] with LMD were treated with DepoCyt. DepoCyt Common Toxicity Criteria ≥ Grade 3 neurotoxicity was seen in 60 cycles (11.5 %) in 28 patients (23.3 %). Toxicity included bacterial meningitis (3.75 % of ventricular treatments: 0 % of lumbar treatments); chemical meningitis (17.5:15 %); communicating hydrocephalus (3.75:5 %); conus medullaris/cauda equina syndrome (5:5 %); decreased visual acuity (5:2.5 %); encephalopathy (5:5 %); leukoencephalopathy (7.5:2.5 %); myelopathy (2.5:2.5 %); radiculopathy (1.25:5 %); and seizures (1.25:2.5 %). Distribution of toxicity was similar regardless of route of administration (ventricular vs. lumbar). Toxicities were transient in 34 episodes (57 %) and permanent in 26 (43 %). There were no treatment-related deaths however 20 treatment-related toxicities (32.2 %) required hospitalization. In this retrospective case series, DepoCyt is generally well tolerated however a subset of patients (12.5 %) not easily identified pre-treatment, develop serious treatment-related neurological complications that may be persistent and impact quality of life.

Chiari malformation associated with craniosynostosis

Chiari malformation (CM) Type I is frequently associated with craniosynostosis. Optimal management of CM in patients with craniosynostosis is not well-established. The goal of this study was to report on a series of pediatric patients with both craniosynostosis and CM and discuss their management. The authors searched the medical records of 383 consecutive patients treated for craniosynostosis at a single institution over a 15-year period to identify those with CM. They recorded demographic data as well as surgical treatment and outcomes for these patients. When MR imaging was performed, cerebellar tonsillar descent was recorded and any other associated findings, such as hydrocephalus or spinal syringes, were noted. A total of 29 patients with both CM and craniosynostosis were identified. Of these cases, 28% had associated occipital venous abnormalities, 45% were syndromic, and 52% also had hydrocephalus. Chiari malformation was more likely to be present in those patients with isolated lambdoid synostosis (55%), multisuture synostosis (35%), and pansynostosis (80%), compared with patients with coronal synostosis (6%) or sagittal synostosis (3%). All patients underwent surgical repair of craniosynostosis: 16 had craniosynostosis repair as well as CM decompression, and 13 patients did not undergo CM decompression. Of the 7 patients in whom craniosynostosis repair alone was performed, 5 had decreased tonsillar ectopia postoperatively and 5 had improved CSF flow studies postoperatively. Both patients with a spinal syrinx had imaging-documented syrinx regression after craniosynostosis repair. In 12 patients in whom CM was diagnosed after primary craniosynostosis repair, 5 had multiple cranial vault expansions and evidence of elevated intracranial pressure. In 5 cases, de novo CM development was documented following craniosynostosis repair at a mean of 3.5 years after surgery. Chiari malformation is frequently seen in patients with both multi- and single-suture lambdoid craniosynostosis. Chiari malformation, and even a spinal cord syrinx, will occasionally resolve following craniofacial repair. De novo development of CM after craniosynostosis repair is not unusual.

Natural history of Chiari malformation Type I following decision for conservative treatment

The natural history of the Chiari malformation Type I (CM-I) is incompletely understood. The authors report on the outcome of a large group of patients with CM-I that were initially selected for nonsurgical management. The authors identified 147 patients in whom CM-I was diagnosed on MR imaging, who were not offered surgery at the time of diagnosis, and in whom at least 1 year of clinical and MR imaging follow-up was available after the initial CM-I diagnosis. These patients were included in an outcome analysis. Patients were followed clinically and by MR imaging for a mean duration of 4.6 and 3.8 years, respectively. Of the 147 patients, 9 had new symptoms attributed to the CM-I during the follow-up interval. During this time, development of a spinal cord syrinx occurred in 8 patients; 5 of these patients had a prior diagnosis of a presyrinx state or a dilated central canal. Spontaneous resolution of a syrinx occurred in 3 patients. Multiple CSF flow studies were obtained in 74 patients. Of these patients, 23 had improvement in CSF flow, 39 had no change, and 12 showed worsening CSF flow at the foramen magnum. There was no significant change in the mean amount of cerebellar tonsillar herniation over the follow-up period. Fourteen patients underwent surgical treatment for CM-I. There were no differences in initial cerebellar tonsillar herniation or CSF flow at the foramen magnum in those who ultimately underwent surgery compared with those who did not. In patients with CM-Is that are selected for nonsurgical management, the natural history is usually benign, although spontaneous improvement and worsening are occasionally seen.

Neurotoxicity of intra-CSF liposomal cytarabine in the treatment of leptomeningeal metastases.

2062 Background: Treatment of leptomeningeal metastasis (LMD) remains challenging due to advanced systemic disease at presentation and limited treatment options. Methods: All patients underwent standard pre-treatment LMD assessment including CSF assessment (cytology or flow cytometry), brain and spine MR imaging, and radioisotope CSF flow study. Liposomal cytarabine was administered intraventricularly (n=80) or intralumbar (n=40) at 50mg every 2-weeks x4 and then every 4-weeks x6 in responding patients. Dexamethasone (4mg orally twice per day x5days) was co-administered with each liposomal cytarabine treatment. Patients were seen with each liposomal cytarabine treatment and assessed for toxicity. Results: 120 adult patients (median age 51 years [range 33-68]) with LMD were treated with liposomal cytarabine. Liposomal cytarabine Common Toxicity Criteria > Grade 3 neurotoxicity was seen in 62 cycles (11.9%) in 28 patients (23.3%). Toxicity included bacterial meningitis (3.75% ventricular: 0% lumbar); chemical meningitis (17.5%:15%); communicating hydrocephalus (3.75%: 5%); conus medullaris/cauda equina syndrome (5%:5%); decreased visual acuity (5%:2.5%); encephalopathy (5%: 5%); leukoencephalopathy (7.5%: 2.5%); myelopathy (2.5%: 2.5%); radiculopathy (1.25%: 5%); and seizures (1.25%: 2.5%). Distribution of toxicity was similar regardless of route of administration (ventricular vs. lumbar). Toxicities were transient in 38 episodes (61.3%) and permanent in 24 (38.7%; 17 patients). There were no treatment-related deaths however 20 treatment-related toxicities (32.2%) required hospitalization. Conclusions: Liposomal cytarabine is mostly well tolerated however a subset of patients (14%) not easily identified pre-treatment develop serious treatment-related neurological complications that may be persistent and impact quality of life.

Balanced steady-state free-precession MR imaging for measuring pulsatile motion of cerebellar tonsils during the cardiac cycle: a reliability study

Assessment of the motion of the cerebellar tonsils is of interest in diseases affecting the CSF flow at the foramen magnum. Cardiac-gated balanced steady-state free-precession technique, which has recently been shown to demonstrate the pulsatile motion of neural structures, appears well suited to allow direct measurement of craniocaudal translation of cerebellar tonsils during the cardiac cycle. Our aim was to assess the intra-observer and inter-observer variability in the assessment of tonsillar motion utilizing this technique. We retrospectively identified 44 patients who had undergone MR imaging with cine TrueFISP sequence, as a part of CSF flow study. Two neuroradiologists independently assessed the images. The tonsillar pulsatility was subjectively characterized into none, minimal, and marked categories after review of the images on a cine loop. For patients with identifiable tonsillar motion, the maximal extent of translation of the inferior edge of the cerebellar tonsil was directly measured. Both readers repeated the measurements after a minimum interval of 2weeks. Intra- and inter-observer variability was characterized by calculating the kappa statistics. The intra-observer agreement for subjective assessment of tonsillar pulsatility was near perfect while the inter-observer agreement was substantial. A good intra- and inter-observer correlation was also seen for the objective measurements of the tonsillar motion. A good correlation was found between the subjective categorization of the tonsillar pulsatility and the objective measurements. Steady-state balanced free-precession MR imaging technique allows for a reproducible subjective and objective assessment of tonsillar pulsatility.

Head Injury Football

HISTORY: Senior QB comes to sideline in 2nd quarter stating "I think i had a concussion… I don't remember how the score became 10-3". Had played approximately 10-15 min after an injury where brought down and opponent then landed on his head. No LOC, (+) post traumatic and retrograde amnesia. Cannot remember particulars of game, able to recall opponent, color of jersey, prior opponent, but not prior game score. Anxious to return to play. No prior concussion in college PHYSICAL EXAMINATION: Alert, oriented X 3. no cervical spine tenderness. Full range of c-spine motion. normocephalic, non-traumatic, extra-ocular movements normal, Pupils equal, round, reactive to light, cranial nerves II-XII intact, tandem gait eyes open and closed normal. cerebellar exam otherwise normal. able to remember 2/5 words at 5 minutes, digit span backwards 3, months backwards delayed. DIFFERENTIAL DIAGNOSIS: Concussion, intracerebral bleed, cerivcal spine or skull fracture TEST AND RESULTS: treated as concussion. Removed from game and not returned to play. Followed closely and no deterioration or additional symptoms. Released to dorm upon returning to campus. Seen in follow up the following day and reported 1/10 headache. At approximately 30 hours post injury, phone call from father requesting CT scan. CT scan obtained; abnormal cystic structure in base of skull. Neurosurgical consult; MRI+/- contrast w/ CSF flow studies; prominent cisterna magna. Neuropsychological tests 48 hours post injury abnormal, repeat studies 96 hours post injury abnormal but flip-flop in deficits. FINAL WORKING DIAGNOSIS: Concussion, prominent cisterna magna (unrelated to trauma, likely congenital) TREATMENT AND OUTCOMES: Athlete returned to activity after discussion with athlete, parent, coach, neurosurgeon, neuropsychologist and athletic training staff. Gradual progression in activity; CV challenge, sport specific activity, light contact, full contact, full play withour restrictions. No additional sequelae.

Magnetic resonance imaging – unravelling the mystery

Magnetic resonance imaging – unravelling the mystery

Hydrocephalus in Persistent Vegetative State

Methods: 39 patients with hydrocephalic PVS were included in this study. W e analyzed the clinical outcome and prognosis according to clinical parameters, especially in relation to the shunt operation. Results: In 39 patients with hydrocephalic PVS, 26 underwent a shunt operation and 13 were treated conservatively. At the time of diagnosis of hydrocephalus in PVS, the mean Glasgow Coma Scale (GCS) and ventriculocranial ratio (VCR) were 5.31±0.85 and 0.24±0.05 in the conservative group, and 5.00±0.75 and 0.23±0.04 in the operative group. On the brain CT taken upon making the diagnosis of hydrocephalus, there were less cerebral infarctions (p=0.001) and more subarachnoid space (SAS) effacement (p=0.018) in the shunt operation group compared to the conservative group. After six months from an event causing PVS, the operative group showed an increased GCS score than the conservative group, a mean increase of 2.38±0.48 vs. 0.54± 0.14 (p=0.002), and a decreased VCR, with a decrease in VCR 0.07±0.03 vs. 0.01±0.01 (p=0.021) respectively. W ith regard to the outcome, according to GOS, the younger aged and post-traumatic patients showed a better prognosis, especially those younger than 60 years (p=0.016) and the operation did good in the highly selected group than those in conservative care (p=0.009). But CSF flow study grade was not significant prognostic factor. Conclusion: In hydrocephalic PVS patients, a better outcome and GOS may be anticipated in the case of highly selected patients of a younger age, less cerebral infarction and more SAS effacement preoperatively.

CSF flow study in Chiari I malformation.

The aim of this prospective study was to define the role of cardiac gated phase-contrast ciné magnetic resonance imaging in deciding the therapeutic strategy in patients with Chiari I malformation. Twenty-one patients operated on between February 2000 and July 2002 were enrolled in the study. All patients underwent a detailed preoperative neurological examination. MRI of the craniovertebral junction and the whole spine was done, followed by cardiac gated phase contrast ciné magnetic resonance imaging. Signs and symptoms of syringomyelia were noted in 15 patients and cerebellar signs in 11 patients. Three of them had trigeminal nerve involvement, and 4 had ninth and tenth cranial nerve involvement. The sixth and accessory nerves were involved in 1 patient each. Preoperative CSF flow studies revealed obstructive flow both anteriorly and posteriorly in 6 patients and only posterior block in 15 patients. One patient investigated for failed foramen magnum decompression revealed obstruction to CSF flow ventrally. Foramen magnum decompression with duroplasty was done in all these cases. The patient who had a persistent ventral flow block underwent odontoidectomy. Patients were followed up for a maximum of 36 months, with a mean of 18 months. MRI CSF flow studies revealed established flow dorsally in all cases. Seventeen patients showed clinical improvement and 2 of them did not show any neurological changes. Two patients deteriorated following an initial period with a shunt. MRI CSF flow study is an effective tool for deciding the type of surgery to be performed and also for monitoring patients postoperatively.

IPO Reform

<i>BACKGROUND AND PURPOSE:</i> Differentiating between intracranial cysts or cyst-like structures and communicating or noncommunicating cysts is often not possible with cranial CT or nonfunctional MR imaging. We evaluated a retrospective ECG-gated fast imaging with steady-state precession (PSIF) MR sequence with optional cine mode to differentiate cystic masses from enlarged CSF spaces and to determine the accuracy of detecting communication between cysts and neighboring CSF spaces. <i>METHODS:</i> Fourteen patients with intracranial cystic masses underwent CSF flow studies with an ungated and a retrospective ECG-gated cine-mode PSIF sequence in addition to spin-echo imaging. Findings were evaluated retrospectively by using a five-point rating scale and without knowledge of clinical or other imaging findings. Results were compared with intraoperative findings or with results of intrathecal contrast studies. <i>RESULTS:</i> Eighteen arachnoid cysts and one enlarged cisterna magna were diagnosed. Improved differentiation between cysts and enlarged CSF spaces was obtained with cine-mode PSIF imaging in six lesions (six patients). Increased diagnostic certainty as to communication between cysts and CSF spaces was obtained in 18 cysts (13 patients). Diagnoses were verified by membranectomy in five lesions, by CT cisternography in five lesions, and indirectly by shunting in one cystic lesion. In one case, MR diagnosis was not confirmed by CT cisternography. <i>CONCLUSION:</i> Cine-mode MR imaging with a retrospective ECG-gated flow-sensitive PSIF sequence contributed to the certainty of communication between arachnoid cysts and neighboring CSF spaces with an accuracy of 90%, using surgical findings or intrathecal contrast studies as reference. Differentiation between intracranial cysts and enlargement of CSF spaces and other cystic masses was improved in 25% of cases.

The use of gated cine phase contrast and MR venography in achondroplasia.

Foramen magnum and jugular foramen stenosis, well-known problems in achondroplasia, may result in brain stem compression and venous outflow obstruction, respectively. We studied a series of children with achondroplasia using gated cine phase contrast (PC) CSF flow studies to evaluate CSF dynamics across the foramen magnum and MR venography (MRV) to depict obstructed venous drainage. Ten patients (9 months to 11 years, mean 2.85 years) were referred for possible brain stem compression. MRI included routine sequences, cine PC with velocity encoding (VENC) = 5 cm/s, and MRV. Six patients, including the asymptomatic patient, had brain stem compression without tonsillar herniation; two had tonsillar herniation; and two had neither brain stem compression nor tonsillar herniation. Abnormal tonsillar movement was seen only with tonsillar herniation. MRV showed steno-occlusive disease of the internal jugular vein (IJV) in nine patients, sigmoid sinus in four, and absent or hypoplastic transverse sinus in seven. Veno-occlusive disease was not progressive. No patient had massive hydrocephalus, although larger ventricles were associated with more profuse venous collateral formation and more severe degrees of IJV stenosis. Three patients have undergone CSF diversion. MR imaging may be useful in defining the pathophysiology of brain stem compression and hydrocephalus in achondroplasia.

AIDS-related central nervous system lymphomas.

To evaluate combined radio-chemotherapy in patients with AIDS-related lymphomatous meningitis (LM) or primary central nervous system lymphoma (PCNSL). Eighteen men and 2 women with AIDS had cytologically documented LM. Fifteen patients had systemic non-Hodgkin's lymphoma with LM and 5 patients had PCNSL with CSF dissemination. Standardized pre-treatment evaluations included contrast cranial MRI, placement of an intraventricular reservoir, contrast spine MRI, ophthalmologic evaluation and 111Indium-DTPA CSF flow studies. Regions of bulky or symptomatic disease were treated with limited-field irradiation. Concurrent systemic chemotherapy was administered in 18 patients. All patients were scheduled to receive intraventricular methotrexate (MTX) according to a concentration x time (C x T) drug schedule. In cytologic or clinical failures, patients were treated with salvage therapy using intraventricular ara-C and in a similar manner, patients were treated with intraventricular thio-TEPA following cytologic relapse or clinical failure intraventricular following intraventricular ara-C. Sixty-seven patients (63 men; 4 women) with PCNSL underwent a standardized pre-treatment evaluation as in patients with LM and were treated according to 3 schedules. In the first group (n = 15), comfort care was offered. In the second group (n = 45), whole brain radiotherapy was administered. In the third group (n = 7), patients were treated with combined radio- and chemotherapy using systemic procarbazine, CCNU and vincristine (PCV-3). The third group was selected based on a Karnofsky performance status > or =60, no evidence of disseminated PCNSL, a CD4 count >200, no concurrent opportunistic infection and a patient's desire for aggressive therapy. In the LM patient group, 16 patients were evaluable as 4 patients subsequently withdrew consent for treatment. Median time to tumor progression/survival were as follows: not-treated (n = 4) 12 days/ month; treated non-responding (n = 6) 30 days/2 months; and treated responding (n = 10) 130 days/6 months. In the PCNSL patient group, median range survival were as follows: comfort care (n = 15) 1.5/0.5-3 months; whole brain radiotherapy (n = 45) 4/1.5-5 months; and combined radio-chemotherapy (n = 7) 13/10-18 months. Combined radio- and chemotherapy is appropriate for a small subset of patients with AIDS and either LM or PCNSL. This approach results in meaningful palliation not strikingly dissimilar from that seen in non-AIDS patients.

111Indium-diethylenetriamine pentaacetic acid cerebrospinal fluid flow studies predict distribution of intrathecally administered chemotherapy and outcome in patients with leptomeningeal metastases.

Abnormal CSF flow can impair the distribution of intrathecally administered drugs. We examined the relationship between 111indium-diethylenetriamine pentaacetic acid (111In-DTPA) CSF flow studies and methotrexate levels in ventricular and lumbar CSF and correlated these findings with outcome in patients with leptomeningeal metastases (LM). Seven men and 10 women with LM (10 solid tumors, 6 lymphoma, 1 leukemia) received 12 mg methotrexate and 0.5 mCi 111In-DTPA by intra-Ommaya injection; images were obtained immediately and after 4, 24, and 48 hours. Ventricular and lumbar CSF methotrexate and radioactivity levels were measured 6 hours after injection. Thirteen patients had abnormal CSF flow studies, 9 with multiple sites of obstruction. CSF flow obstruction was observed at ventricular outlets in 13 patients, cerebral convexities in 9 and in the spine in 2. With one exception, all obstructions were explicable by tumor deposits on MRIs. For all patients, ventricular and lumbar methotrexate and radioactivity levels correlated closely. Three patients with a normal CSF flow study are alive at 15+, 7.5+, and 3.9+ months from treatment. Of 12 with abnormal CSF flow studies, 11 are dead a median of 2 months from diagnosis. Two patients had diffusely delayed flow studies and both developed methotrexate leukoencephalopathy. CSF flow studies using 111In-DTPA reliably predict distribution of intrathecal methotrexate. Abnormal flow studies correlate with structural abnormalities, are an unfavorable prognostic factor, and may predict intrathecal chemotherapy toxicity.

Radioisotope CSF flow studies in leptomeningeal metastases.

Leptomeningeal metastases is a frequent neuro-oncologic complication in patients with cancer. Radionuclide CSF flow studies provide a unique method of evaluating CSF compartments in patients with leptomeningeal metastases. Radionuclide CSF flow studies are performed by injecting (111)Indium-DTPA into either the ventricular or lumbar CSF compartment. (111)Indium-DTPA is entrained by CSF and flows through CSF compartments based on normal CSF physiology. Normal times to appearance of (111)Indium-DTPA following intraventricular injection in either adults or children are as follows: ventricles (median 1 minute); cisterna magna/basal cisterns (5); cervical (15); thoracic (20); and lumbar (30) spinal subarachnoid spaces; and sylvian cisterns (50). Normal times to appearance of (111)Indium-DTPA following intralumbar injection are as follows: lumbar (1); thoracic (22.5); cervical (32.5) spinal subarachnoid spaces; cisterna magna/basal cisterns (37.5); sylvian cisterns (65); ventricles (1,440); and cerebral convexities (1,440). In 30 consecutive patients, 47% of patients had documented compartmentalization of CSF by (111)Indium-DTPA CSF flow studies. 13% had base of brain obstruction of whom 50% responded with re-establishment of normal CSF flow and 33% had spinal subarachnoid space block of whom 40% following therapy had re-establishment of normal CSF flow. In 61 consecutive patients, 33% of patients had abnormal spinal CSF flow studies which better demonstrated interruption of CSF flow when compared to CT myelography and spine MR. In 40 patients, all with CSF block, 20 of whom responded to therapy with re-establishment of normal CSF flow as compared to 20 with refractory CSF block, significant differences were seen in median survival and cause of death favoring patients with normal or restored CSF flow. Radioisotope CSF flow studies in patients with leptomeningeal metastasis appear to have two practical uses. First, radioisotope CSF flow studies by documenting normal CSF flow predict for homogeneous distribution of intra-CSF chemotherapy. Secondly, in patients with CSF flow obstruction refractory to site of obstruction therapy, limited survival, rapid leptomeningeal disease progression and death due to progressive CNS disease is predicted.

Correlation Between Lumbo-Ventricular Perfusion and MRI-CSF Flow Studies in Idiopathic Normal Pressure Hydrocephalus

Background After the initial description of normal pressure hydrocephalus (NPH) and its clinical triad, there has been a continuous interest from clinicians and researchers to set different diagnostic criteria that would make the selection of candidates for shunt surgery easier and more precise. MethodS A preliminary group of 12 patients was given a diagnosis of idiopathic normal pressure hydrocephalus by clinical and radiologic criteria. Each patient underwent two different tests: a magnetic resonance imaging-cerebrospinal fluid (MRI-CSF) flow study and a lumbo-ventricular perfusion test. The purpose was to compare the correlation of the results obtained with these tests and the clinical results obtained after CSF diversion. Eleven patients were given shunts and one was managed with lumbar punctures. Results One year after treatment, 10 of the 12 patients had improved with good results. The MRI-CSF flow studies were reliable in six patients; there were five false negatives and one false positive. The lumbo-ventricular perfusion test showed reliability in nine patients; there were two false negatives and one false positive. In only three patients were the results of both of these tests in accordance with the outcome. Conclusions Even though there are few patients in this study so far, the data suggests that at the present time the most predictive guides for the diagnosis of NPH and its outcome after shunting are the clinical criteria and the radiological findings in computed tomography (CT) and/or MRI rather than lumbo-ventricular perfusion and CSF flow studies.

Dynamic CSF flow study in the pathophysiology of syringomyelia associated with arachnoid cysts of the posterior fossa

A bstract Two patients with posterior fossa arachnoid cysts associated with syringomyelia are discussed adding to the five cases already reported in the literature. The formation and progression of syringomyelia secondary to a posterior fossa cyst and its possible pathophysiology by dynamic CSF flow studies using magnetic resonance (MR) imaging are discussed and reviewed.

MRI-Cine CSF Flow Studies as a Predictor of Outcome in Pediatric Chiari I Population

MRI-Cine CSF Flow Studies as a Predictor of Outcome in Pediatric Chiari I Population

MRI-Cine CSF Flow Studies as a Predictor of Outcome in Pediatric Chiari I Population

Bulsara, Ketan R. MD; Kureshi, Sohaib A. MD; Enterline, David S. MD; George, Timothy M. MD; Fuchs, Herbert E. MD, PhD

Quantification of low-velocity motion using a navigator-echo supported MR velocity-mapping technique: Application to intracranial dynamics in volunteers and patients with brain tumours

Gradient-echo pulse sequences with velocity-encoding gradients of 22.5–25 mT/m, were used for brainmotion and CSF-flow studies. To reduce motion artifacts, a phase-correction technique based on navigator echoes was evaluated. Three patients with right-sided parietal tumours were investigated; one astrocytoma grade III–IV, one astrocytoma grade I–II and one benign meningioma. In healthy volunteers, a maximal brain-tissue velocity of (0.94 ± 0.26) mm/s (mean ± 1SD) was observed, which is consistent with previously presented results. The phase correction was proven useful for reduction of artifacts due to external head movements in modulus and phase images, without loss of phase information related to internal motion. The tissue velocity within the astrocytomas was low during the entire cardiac cycle. An abnormally high rostral velocity component was, however, observed in the brain tissue frontal to the astrocytomas. In all patients, an abnormal CSF flow pattern was observed. The study of brain motion may provide further understanding of the effects of tumours and other pathological conditions in the brain. When considering intracranial motion as a source of error in diffusion/perfusion MRI, the present study suggests that a pathology can alter the properties of brain motion and CSF flow considerably, leading to a more complex impact on diffusion/perfusion images.

Prognostic significance of sup 111 Indium-DTPA CSF flow studies in leptomeningeal metastases

We assessed the clinical significance of interruption of CSF flow documented by radionuclide ventriculography (111Indium-DTPA CSF flow study) in patients with leptomeningeal metastases. Forty patients (25 men and 15 women) ranging in age from 6 to 70 years (median 38.5 years) with cytologically documented leptomeningeal metastases were demonstrated to have interruption of CSF flow by radionuclide ventriculography. All patients were treated with radiotherapy (30 Gy in 10 fractions) to the site of CSF obstruction after which intra-CSF chemotherapy (methotrexate or cytarabine followed by cytarabine or thio-TEPA if clinically indicated) was administered. Twenty patients (group 1) after radiotherapy to the site of CSF flow block demonstrated reestablishment of normal CSF flow. By contrast, 20 patients (group 2) treated in a similar manner had persistent CSF flow obstruction. All patients were treated with intraventricular chemotherapy. Median survival was 6 months in group 1 (range 3 to 15 months) compared with 1.75 months in group 2 (range 1 to 4 months) (p < 0.0001). Cause of death differed between groups with 20% of group 1 patients dying of progressive leptomeningeal disease compared with 70% of group 2 patients (p < 0.0006). In patients with leptomeningeal metastases and CSF flow obstruction, 111Indium-DTPA CSF flow studies predict patient survival and are useful in determining which patients would be candidates for intra-CSF chemotherapy administration.