Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 36
Filter
Add more filters

Country/Region as subject
Publication year range
1.
J Neurooncol ; 147(2): 247-260, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32140976

ABSTRACT

PURPOSE: Epstein Barr virus (EBV)-associated smooth muscle tumors (SMT) in the central nervous system are rare tumors. EBV-associated SMT mainly occur in patient with compromised immune status. We report on a case of a HIV positive patient, who developed multiple EBV-SMTs, intracranially and in the spine. We systematically review the literature on the topic. CASE REPORT: A 46 years old female with HIV was imaged for complaints of headaches for 2 years, when an intracranial lesion was found. The patient was followed with sequential MRI scans before an excision was performed 5 years later. Pathology revealed an EBV-associated SMT. Multiple other lesions appearing in the brain and in the spine over years were treated by stereotactic radiosurgery or by surgery. At the time of this report, the patient is alive under HARRT treatment without recurrence. METHODS: A systematic PRISMA guided literature research was conducted on the topic reviewing multiple databases for EBV-associated SMT located in brain or spine. We identified 52 patients from the literature and performed a pooled analysis. RESULTS: All patients in this cohort except one were immuno-suppressed from HIV, post-transplant therapy or because of CIS. Female predominance and a median age of 35 years was identified as was frequent multifocality. Therapeutic strategies varied but were mostly multidisciplinary with surgery. CONCLUSION: Based on our results, EBV-associated SMT should be included in the differential diagnosis of intracranial lesions mimicking meningiomas in immuno-suppressed patients. Stereotactic radiosurgery can be offered as an alternate treatment option for suitable lesions. Long-term surveillance via MRI scanning is recommended for follow up.


Subject(s)
Central Nervous System Neoplasms/physiopathology , Epstein-Barr Virus Infections/complications , Herpesvirus 4, Human/isolation & purification , Smooth Muscle Tumor/pathology , Epstein-Barr Virus Infections/virology , Female , Humans , Middle Aged , Prognosis , Radiosurgery , Smooth Muscle Tumor/etiology , Smooth Muscle Tumor/surgery
2.
AJNR Am J Neuroradiol ; 41(6): 1120-1125, 2020 06.
Article in English | MEDLINE | ID: mdl-32439645

ABSTRACT

BACKGROUND AND PURPOSE: Total spine MRIs are requested by the emergency department when focused imaging can not be ordered on the basis of history or clinical findings. However, their efficacy is not known. We assessed the following: 1) major radiologic and clinical outcomes of total spine MR imaging performed by the emergency department, and 2) whether the presence of a high-risk clinical profile and/or neurologic findings impacts the clinical outcomes. MATERIALS AND METHODS: Total spine MRIs requested by the emergency department during a 28-month period were evaluated for major radiologic (cord compression, cauda equina compression, and other significant findings) and major clinical outcomes (hospital admission during the visit followed by an operation, radiation therapy, or intravenous antibiotics or steroids). Associations between a high-risk clinical profile (cancer, infection, coagulopathy) and/or the presence of neurologic findings and outcomes were assessed. RESULTS: After we excluded trauma or nondiagnostic studies, 321/2047 (15.7%) MRIs ordered during study period were total spine MR imaging; 117/321 (36.4%) had major radiologic and 60/321 (18.6%) had major clinical outcomes (34/60 in <24 hours); and 58/117(49.6%) with major radiologic outcome were treated compared with 2/205 (1.0%) without (OR = 99, P < .001). The presence of both a high-risk clinical profile and neurologic findings concurrently in a patient (142/321) increased the likelihood of major clinical outcomes during the same visit (OR = 3.1, P < .001) and in <24-hours (OR = 2.6, P = .01) compared with those with either a high-risk clinical profile or neurologic findings alone (179/321). CONCLUSIONS: Total spine MR imaging ordered by our emergency department has a high radiologic and significant clinical yield. When a high-risk clinical profile and neurologic findings are both present in a patient, they should be prioritized for emergent total spine MR imaging, given the increased likelihood of clinical impact.


Subject(s)
Magnetic Resonance Imaging/methods , Spinal Cord Diseases/diagnostic imaging , Spinal Cord/diagnostic imaging , Spine/diagnostic imaging , Academic Medical Centers , Aged , Aged, 80 and over , Emergency Service, Hospital , Female , Humans , Magnetic Resonance Imaging/statistics & numerical data , Male , Middle Aged
3.
AJNR Am J Neuroradiol ; 41(1): 115-121, 2020 01.
Article in English | MEDLINE | ID: mdl-31924604

ABSTRACT

BACKGROUND AND PURPOSE: Unilateral decreased/nonvisualization of a transverse dural sinus on MRV poses a diagnostic dilemma when gadolinium administration is contraindicated. We determined the frequency of unilateral decreased/nonvisualization of the transverse dural sinus and the performance of pregadolinium MR imaging sequences in diagnosing transverse sinus thrombosis in the presence of unilateral decreased/nonvisualization on phase-contrast MRV. MATERIALS AND METHODS: We conducted a retrospective review of consecutive 3D phase-contrast MRV (VENC, 30 cm/s) and routine brain imaging (noncontrast sagittal T1, axial T2, FLAIR, DWI, GRE, and postgadolinium 3D-MPRAGE images) performed during a 3-year period for a total of 208 patients. Nonvisualization of a transverse dural sinus was defined as ≥50% nonvisualization of the transverse sinus caliber versus the contralateral side on MRV. Noncontrast imaging findings were considered abnormal when hyperintense signal was present on T2, FLAIR, T1, and DWI, and there were T2* blooming artifacts on GRE and DWI. Postgadolinium 3D-MPRAGE was used to confirm the diagnosis of transverse sinus thrombosis. RESULTS: Nonvisualization of a transverse dural sinus was observed in 72/208 (34.6%) patients on MRV; 56/72 (77.8%) were without transverse sinus thrombosis, and 16/72 (22.2%) patients had transverse dural sinus thrombosis. Nonvisualization of a transverse dural sinus was seen in 56/192 (29.2%) patients without transverse sinus thrombosis and 16/16 (100%) with transverse sinus thrombosis. Abnormal findings on DWI (transverse sinus hyperintense signal or T2* blooming artifact) are 93.8% sensitive and 100.0% specific for transverse sinus thrombosis. Other noncontrast MR imaging sequences ranged from 56.3%-68.8% sensitive and 91.1%-100.0% specific. CONCLUSIONS: Nonvisualization of a transverse dural sinus is a frequent phenomenon on phase-contrast MRV. DWI can be effectively used to exclude sinus thrombosis when nonvisualization of a transverse dural sinus is a diagnostic conundrum on phase-contrast MRV and contrast-enhanced studies are contraindicated.


Subject(s)
Image Interpretation, Computer-Assisted/methods , Lateral Sinus Thrombosis/diagnostic imaging , Magnetic Resonance Imaging/methods , Neuroimaging/methods , Transverse Sinuses/diagnostic imaging , Adolescent , Adult , Aged , Aged, 80 and over , Contrast Media , Female , Gadolinium , Humans , Imaging, Three-Dimensional/methods , Male , Middle Aged , Retrospective Studies , Young Adult
4.
AJNR Am J Neuroradiol ; 40(3): 558-561, 2019 03.
Article in English | MEDLINE | ID: mdl-30765381

ABSTRACT

BACKGROUND AND PURPOSE: No MR imaging measurement criteria are available for the diagnosis of optic nerve atrophy. We determined a threshold optic nerve area on MR imaging that predicts a clinical diagnosis of optic nerve atrophy and assessed the relationship between optic nerve area and retinal nerve fiber layer thickness measured by optical coherence tomography, an ancillary test used to evaluate optic nerve disorders. MATERIALS AND METHODS: We evaluated 26 patients with suspected optic nerve atrophy (8 with unilateral, 13 with bilateral and 5 with suspected but not demonstrable optic nerve atrophy) who had both orbital MR imaging and optical coherence tomography examinations. Forty-five patients without optic nerve atrophy served as controls. Coronal inversion recovery images were used to measure optic nerve area on MR imaging. Retinal nerve fiber layer thickness was determined by optical coherence tomography. Individual eyes were treated separately; however, bootstrapping was used to account for clustering when appropriate. Correlation coefficients were used to evaluate relationships; receiver operating characteristic curves, to investigate predictive accuracy. RESULTS: There was a significant difference in optic nerve area between patients' affected eyes with optic nerve atrophy (mean, 3.09 ± 1.09 mm2), patients' unaffected eyes (mean, 5.27 ± 1.39 mm2; P = .008), and control eyes (mean, 6.27 ± 2.64 mm2; P < .001). Optic nerve area ≤ 4.0 mm2 had a sensitivity of 0.85 and a specificity of 0.83 in predicting the diagnosis of optic nerve atrophy. A significant relationship was found between optic nerve area and retinal nerve fiber layer thickness (r = 0.68, P < .001). CONCLUSIONS: MR imaging-measured optic nerve area ≤ 4.0 mm2 has moderately high sensitivity and specificity for predicting optic nerve atrophy, making it a potential diagnostic tool for radiologists.


Subject(s)
Magnetic Resonance Imaging/methods , Optic Atrophy/diagnostic imaging , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Optic Atrophy/pathology , Optic Nerve/diagnostic imaging , Optic Nerve/pathology , ROC Curve , Sensitivity and Specificity , Tomography, Optical Coherence/methods
5.
AJNR Am J Neuroradiol ; 39(7): 1267-1272, 2018 07.
Article in English | MEDLINE | ID: mdl-29748208

ABSTRACT

BACKGROUND AND PURPOSE: Currently no quantitative objective test exists to determine disease severity in a patient with Chiari I malformation. Our aim was to correlate disease severity in symptomatic patients with Chiari I malformation with cough-associated changes in CSF flow as measured with real-time MR imaging. MATERIALS AND METHODS: Thirteen symptomatic patients with Chiari I malformation (tonsillar herniation of ≥5 mm) were prospectively studied. A real-time, flow-sensitized pencil-beam MR imaging scan was used to measure CSF stroke volume during rest and immediately following coughing and relaxation periods (total scan time, 90 seconds). Multiple posterior fossa and craniocervical anatomic measurements were also obtained. Patients were classified into 2 groups by neurosurgeons blinded to MR imaging measurements: 1) nonspecific Chiari I malformation (5/13)-Chiari I malformation with nonspecific symptoms like non-cough-related or mild occasional cough-related headache, neck pain, dizziness, paresthesias, and/or trouble swallowing; 2) specific Chiari I malformation (8/13)-patients with Chiari I malformation with specific symptoms and/or objective findings like severe cough-related headache, myelopathy, syringomyelia, and muscle atrophy. The Spearman correlation was used to determine correlations between MR imaging measurements and disease severity, and both groups were also compared using a Mann-Whitney U test. RESULTS: There was a significant negative correlation between the percentage change in CSF stroke volume (resting to postcoughing) and Chiari I malformation disease severity (R = 0.59; P = .03). Mann-Whitney comparisons showed the percentage change in CSF stroke volume (resting to postcoughing) to be significantly different between patient groups (P = .04). No other CSF flow measurement or anatomic measure was significantly different between the groups. CONCLUSIONS: Our exploratory study suggests that assessment of CSF flow response to a coughing challenge has the potential to become a valuable objective noninvasive test for clinical assessment of disease severity in patients with Chiari I malformation.


Subject(s)
Arnold-Chiari Malformation/cerebrospinal fluid , Arnold-Chiari Malformation/diagnostic imaging , Cough/physiopathology , Magnetic Resonance Imaging/methods , Adult , Arnold-Chiari Malformation/complications , Cough/diagnostic imaging , Female , Humans , Male , Middle Aged
6.
AJNR Am J Neuroradiol ; 38(9): 1820-1825, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28684454

ABSTRACT

BACKGROUND AND PURPOSE: Acute C1-C2 fractures are difficult to detect on MR imaging due to a paucity of associated bone marrow edema. The purpose of this study was to determine the diagnostic utility of increased STIR signal in the posterior atlanto-occipital and atlantoaxial membrane complex (PAOAAM) in the detection of acute C1-C2 fractures on MR imaging. MATERIALS AND METHODS: Eighty-seven patients with C1-C2 fractures, 87 with no fractures, and 87 with other cervical fractures with acute injury who had both CT and MR imaging within 24 hours were included. All MR images were reviewed by 2 neuroradiologists for the presence of increased STIR signal in the PAOAAM and interspinous ligaments at other cervical levels. Sensitivity and specificity of increased signal within the PAOAAM for the presence of a C1-C2 fracture were assessed. RESULTS: Increased PAOAAM STIR signal was seen in 81/87 patients with C1-C2 fractures, 6/87 patients with no fractures, and 51/87 patients with other cervical fractures with 93.1% sensitivity versus those with no fractures, other cervical fractures, and all controls. Specificity was 93.1% versus those with no fractures, 41.4% versus those with other cervical fractures, and 67.2% versus all controls for the detection of acute C1-C2 fractures. Isolated increased PAOAAM STIR signal without increased signal in other cervical interspinous ligaments showed 89.7% sensitivity versus all controls. Specificity was 95.3% versus those with no fractures, 83.7% versus those with other cervical fractures, and 91.4% versus all controls. CONCLUSIONS: Increased PAOAAM signal on STIR is a highly sensitive indicator of an acute C1-C2 fracture on MR imaging. Furthermore, increased PAOAAM STIR signal as an isolated finding is highly specific for the presence of a C1-C2 fracture, making it a useful sign on MR imaging when CT is either unavailable or the findings are equivocal.


Subject(s)
Cervical Vertebrae/diagnostic imaging , Magnetic Resonance Imaging/methods , Spinal Fractures/diagnostic imaging , Adult , Atlanto-Axial Joint/injuries , Atlanto-Occipital Joint/diagnostic imaging , Atlanto-Occipital Joint/injuries , Cervical Vertebrae/injuries , Female , Humans , Male , Middle Aged , Neck , Sensitivity and Specificity , Young Adult , Zygapophyseal Joint/diagnostic imaging , Zygapophyseal Joint/injuries
7.
AJNR Am J Neuroradiol ; 37(5): 825-30, 2016 May.
Article in English | MEDLINE | ID: mdl-26705321

ABSTRACT

BACKGROUND AND PURPOSE: Invasive pressure studies have suggested that CSF flow across the foramen magnum may transiently decrease after coughing in patients with symptomatic Chiari I malformation. The purpose of this exploratory study was to demonstrate this phenomenon noninvasively by assessing CSF flow response to coughing in symptomatic patients with Chiari I malformation by using MR pencil beam imaging and to compare the response with that in healthy participants. MATERIALS AND METHODS: Eight symptomatic patients with Chiari I malformation and 6 healthy participants were studied by using MR pencil beam imaging with a temporal resolution of ∼50 ms. Patients and healthy participants were scanned for 90 seconds (without cardiac gating) to continuously record cardiac cycle-related CSF flow waveforms in real-time during resting, coughing, and postcoughing periods. CSF flow waveform amplitude, CSF stroke volume, and CSF flow rate (CSF Flow Rate = CSF Stroke Volume × Heart Rate) in the resting and immediate postcoughing periods were determined and compared between patients and healthy participants. RESULTS: There was no significant difference in CSF flow waveform amplitude, CSF stroke volume, and the CSF flow rate between patients with Chiari I malformation and healthy participants during rest. However, immediately after coughing, a significant decrease in CSF flow waveform amplitude (P < .001), CSF stroke volume (P = .001), and CSF flow rate (P = .001) was observed in patients with Chiari I malformation but not in the healthy participants. CONCLUSIONS: Real-time MR imaging noninvasively showed a transient decrease in CSF flow across the foramen magnum after coughing in symptomatic patients with Chiari I malformation, a phenomenon not seen in healthy participants. Our results provide preliminary evidence that the physiology-based imaging method used here has the potential to be an objective clinical test to differentiate symptomatic from asymptomatic patients with Chiari I malformation.


Subject(s)
Arnold-Chiari Malformation/diagnostic imaging , Cerebrospinal Fluid/diagnostic imaging , Cough/diagnostic imaging , Foramen Magnum/diagnostic imaging , Magnetic Resonance Imaging/methods , Adult , Arnold-Chiari Malformation/cerebrospinal fluid , Arnold-Chiari Malformation/physiopathology , Cough/cerebrospinal fluid , Female , Humans , Male , Middle Aged
8.
J Am Geriatr Soc ; 48(5): 467-72, 2000 May.
Article in English | MEDLINE | ID: mdl-10811537

ABSTRACT

OBJECTIVE: We studied the relationship between the use of estrogen replacement therapy (ERT) and cerebral magnetic resonance imaging (MRI) abnormalities among older women. DESIGN: A population-based prospective study (Cardiovascular Health Study). SETTING: Four regions in the United States. PARTICIPANTS: A total of 2133 (62.9% of the eligible) women aged 65 to 95 years (mean age 74.8), on whom MRI was performed in 1992-1994. MEASUREMENTS: Presence of global brain atrophy, white matter changes, small infarct-like lesion (ILL) (<3 mm), MRI infarcts (> or =3 mm, mostly small and asymptomatic), and cognitive function as measured by Mini-Mental State Exam (MMSE), and by ERT use (current/past/never), adjusted for a number of socioeconomic, lifestyle, and reproductive covariates. RESULTS: Current use of ERT was reported by 15% and past use by another 23% of participants; 35% of all women had MRI infarcts. The prevalence of MRI infarcts did not differ in current or past users from those who had never used ERT (nonusers). Bifrontal distance, the largest distance between frontal horns, and the size of ventricles were larger among current ERT users compared to past users or nonusers (P (trend) = .01), adjusted for all other covariates, but no dose-response relationship to current or past ERT use was found. Duration of estrogen use was not associated with any atrophy measure. Cortical atrophy measure, sulcal widening, or white matter disease did not differ significantly by ERT use or duration of use. Central measures of atrophy, bifrontal distance, and ventricular size were significantly associated with cognition as measured by MMSE. CONCLUSIONS: Current ERT users had much more clinically significant central atrophy than nonusers, but the implications remained unclear.


Subject(s)
Brain Infarction/epidemiology , Brain/pathology , Estrogen Replacement Therapy/adverse effects , Population Surveillance , Aged , Aged, 80 and over , Atrophy/chemically induced , Atrophy/epidemiology , Brain/drug effects , Brain Infarction/chemically induced , Female , Humans , Intelligence Tests , Life Style , Magnetic Resonance Imaging , Prevalence , Prospective Studies , Social Class , United States/epidemiology
9.
Ann Thorac Surg ; 63(1): 236-8, 1997 Jan.
Article in English | MEDLINE | ID: mdl-8993278

ABSTRACT

In the early postoperative period, it may be difficult to diagnose an infected implantable cardioverter-defibrillator system using anatomic imaging modalities such as computed tomography alone. We describe a case that illustrates the complementary physiologic role of indium-111-labeled leukocyte scintigraphy in identifying and defining the extent of early postoperative implantable cardioverter-defibrillator infection.


Subject(s)
Defibrillators, Implantable/adverse effects , Indium Radioisotopes , Staphylococcal Infections/diagnostic imaging , Surgical Wound Infection/diagnostic imaging , Aged , Female , Humans , Leukocytes , Radiography , Radionuclide Imaging , Surgical Wound Infection/microbiology , Time Factors
10.
AJNR Am J Neuroradiol ; 16(2): 389-400, 1995 Feb.
Article in English | MEDLINE | ID: mdl-7726089

ABSTRACT

PURPOSE: To analyze the characteristics of normal cerebrospinal fluid (CSF) flow waveforms and to relate them to the arterial input and venous output flow waveforms in healthy volunteers. METHODS: Cine phase-contrast MR was obtained in 17 volunteers. The temporal velocity information from the cervical pericord CSF spaces, basal cisterns, and aqueduct, as well as the internal carotid and vertebral arteries and internal jugular veins, were plotted as waveforms. The waveforms were analyzed for configurations, amplitudes, and temporal patterns. In four volunteers the reproducibility of the precord CSF flow waveforms was examined on different days. In three volunteers the effect of jugular venous compression on the precord and aqueductal CSF flow waveforms was also evaluated. RESULTS: (a) Distinct and reproducible configurational features were observed in the CSF flow waveforms. Jugular venous compression produced elevation of the disatolic slope of the precord waveforms. (b) The amplitudes were variable. Jugular venous compression reduced the precord CSF velocities. (c) The systolic temporal parameters were less variable and more reproducible than the diastolic temporal parameters. Jugular venous compression resulted in delay in the systolic parameters of the precord waveforms. (d) Craniocaudal and caudocranial postcord CSF flow occurred either simultaneous with or earlier than the precord CSF flow. Pericord CSF flow in either direction preceded that in the cisterns and in the aqueduct. (e) A significant temporal relationship was noted in the precord space between the time of the R wave to the maximum velocities and the arterial flow. CONCLUSION: CSF flow waveform analysis seems to be a reliable, reproducible, and sensitive method for assessing the CSF dynamics.


Subject(s)
Cerebrospinal Fluid/physiology , Magnetic Resonance Imaging , Adult , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Rheology
11.
AJNR Am J Neuroradiol ; 15(7): 1299-308, 1994 Aug.
Article in English | MEDLINE | ID: mdl-7976942

ABSTRACT

PURPOSE: To assess movement of the medulla, tonsils, and upper cervical cord as well as that of the posterior fossa cerebrospinal fluid pathways in both normal subjects and those with Chiari I malformations. METHODS: Nine healthy volunteers and eight patients with Chiari I malformations were examined with phase-contrast cine MR. With a region-of-interest cursor, the directions and intensities of the brain and cerebrospinal fluid were assessed and intensity-versus-time graphs generated. RESULTS: Cerebrospinal fluid flow patterns of the patients with Chiari I malformations were normal except for absence of valleculla flow. In addition, increased velocities (10 times normal) of the tonsils of all patients with Chiari I malformations together with posterior movement of the medulla (rather than the expected anterior movement seen in volunteers) occurred. CONCLUSIONS: Increased velocities of the tonsils may be the result of the carotid systolic pulse being delivered to a structure (the tonsil) without the normal surrounding cerebrospinal fluid, resulting in impact of the tonsils in the confined foramen magnum and a consequent caudocranial recoil. An alternative explanation would include the Bernoulli effect caused by the confined location of the tonsils. There may be a decrease in the peak tonsillar velocities after surgery.


Subject(s)
Arnold-Chiari Malformation/diagnosis , Cerebrospinal Fluid/physiology , Magnetic Resonance Imaging/methods , Adolescent , Arnold-Chiari Malformation/cerebrospinal fluid , Cerebellum/pathology , Cerebrospinal Fluid Pressure/physiology , Child , Cranial Fossa, Posterior , Female , Humans , Male , Medulla Oblongata/pathology , Reference Values , Spinal Cord/pathology
12.
J Child Neurol ; 16(3): 212-5, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11305689

ABSTRACT

Progeria, a rare genetic disorder, is characterized by severe growth failure, premature aging, and very early atherosclerosis with coronary artery and cerebrovascular disease. There has been no detailed description of progressive cerebrovascular changes in progeria or any attempted neurologic correlation of those changes. A 5-year-old boy developed signs of progeria at 4 months and hypertension at 4 years, treated with atenolol and dipyridamole. Left-sided seizures with a left hemiparesis occurred at 5 years. Magnetic resonance imaging (MRI) showed bilateral acute, subacute, and chronic cerebral infarctions. Magnetic resonance angiography disclosed severe stenosis of the left internal carotid artery. The child was also found to have an aortic valve vegetation and was anticoagulated. He subsequently developed right-sided seizures, and treatment with gabapentin was started. Later, severe stenosis also of the right internal carotid artery was found. MRI showed new left cerebral infarction. The child's neurologic symptoms almost certainly were caused by cerebral infarctions from progressive atherosclerosis of major intracranial vessels, but clinical-neuroradiologic correlations were imprecise. There were multiple cerebral infarctions of different ages, some asymptomatic, others ipsilateral to the child's neurologic findings. No therapy has halted progression of the child's cerebrovascular disease.


Subject(s)
Carotid Stenosis/diagnosis , Cerebral Infarction/diagnosis , Epilepsies, Partial/diagnosis , Progeria/diagnosis , Brain/pathology , Carotid Artery, Internal/pathology , Carotid Stenosis/genetics , Cerebral Infarction/genetics , Epilepsies, Partial/genetics , Humans , Intracranial Arteriosclerosis/diagnosis , Intracranial Arteriosclerosis/genetics , Magnetic Resonance Angiography , Magnetic Resonance Imaging , Male , Progeria/genetics
13.
AJNR Am J Neuroradiol ; 35(7): 1325-9, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24676004

ABSTRACT

BACKGROUND AND PURPOSE: Fast spin-echo short τ inversion recovery sequences have been very useful for MR imaging-guided deep brain stimulation procedures in Parkinson disease. However, high-quality fast spin-echo imaging deposits significant heat, exceeding FDA-approved limits when patients already have undergone deep brain stimulation and need a second one or a routine brain MR imaging for neurologic indications. We have developed a STIR sequence with an ultra-low specific absorption rate that meets hardware limitations and produces adequate tissue contrast in cortical and subcortical brain tissues for deep brain stimulation recipients. MATERIALS AND METHODS: Thirteen patients with medically refractory Parkinson disease who qualified for deep brain stimulation were imaged at 1.5T with a fast spin-echo short τ inversion recovery sequence modified to meet conditional MR imaging hardware and specific absorption rate restrictions. Tissue contrast-to-noise ratios and implant localization were objectively and subjectively compared by 2 neuroradiologists, and image quality for surgical planning was assessed by a neurosurgeon for high and low specific absorption rate images. RESULTS: The mean contrast-to-noise ratio for cerebral tissues without including the contrast-to-noise ratio for ventricular fluid was 35 and 31 for high and low specific absorption rate images. Subjective ratings for low specific absorption rate tissue contrast in 77% of patients were identical to (and in a few cases higher than) those of high specific absorption rate contrast, while the neurosurgical coordinates for fusing the stereotactic atlas with low specific absorption rate MR imaging were equivalent to those of the high specific absorption rate for 69% of patients. CONCLUSIONS: Patients with Parkinson disease who have already had a deep brain stimulation face a risk of neural injury if routine, high specific absorption rate MR imaging is performed. Our modified fast spin-echo short τ inversion recovery sequence conforms to very conservative radiofrequency safety limits, while it maintains high tissue contrast for presurgical planning, postsurgical assessment, and radiologic evaluations with greater confidence for radiofrequency safety.


Subject(s)
Brain Injuries/etiology , Deep Brain Stimulation/adverse effects , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/adverse effects , Parkinson Disease/pathology , Radiation Injuries/etiology , Radiation Protection/methods , Aged , Brain Injuries/pathology , Brain Injuries/prevention & control , Deep Brain Stimulation/instrumentation , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Parkinson Disease/complications , Parkinson Disease/therapy , Radiation Dosage , Radiation Injuries/pathology , Radiation Injuries/prevention & control , Reproducibility of Results , Sensitivity and Specificity , Treatment Outcome
14.
Eur J Radiol ; 82(9): 1431-5, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23587902

ABSTRACT

PURPOSE: Iterative reconstruction has recently been revisited as a promising concept for substantial CT dose reduction. The purpose of this study was to assess the potential benefit of sinogram affirmed iterative reconstruction (SAFIRE) in head CT by comparing objective and subjective image quality at reduced tube current with standard dose filtered back projection (FBP). MATERIALS AND METHODS: Non-contrast reduced dose head CT (255 mAs, CTDIvol 47.8 mGy) was performed in thirty consecutive patients and reconstructed with SAFIRE and FBP. Images were assessed in terms of quantitative and qualitative image quality and compared with FBP of standard dose acquisitions (320 mAs, CTDI vol 59.7 mGy). RESULTS: In reduced dose CT examinations, use of SAFIRE versus FBP resulted in 47% increase in contrast-to-noise ratio (CNR) (2.49 vs. 1.69; p<0.0001). While reduction of tube current was associated with 13% decrease in CNR, quantitative degradation of image quality at lower dose was more than compensated through SAFIRE (2.49 vs. 1.96; p=0.0004). Objective measurements of image sharpness were comparable between FBP and SAFIRE reconstructions (575.9 ± 74.1 vs. 583.4 ± 74.7 change in HU/Pixel; p=0.28). Compared to standard dose FBP, subjective grading of noise as well as overall image quality scores were significantly improved when SAFIRE was used in reduced dose exams (1.3 vs. 1.6, p=0.006; 1.3 vs. 1.7, p=0.026). CONCLUSION: At 20% dose reduction, reconstruction of head CT by SAFIRE provides above standard objective and subjective image quality, suggesting potential for more vigorous dose savings in neuroradiology CT applications.


Subject(s)
Algorithms , Brain Diseases/diagnosis , Craniocerebral Trauma/diagnostic imaging , Radiation Dosage , Radiation Protection/methods , Radiographic Image Enhancement/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Adult , Female , Humans , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity , Tomography, X-Ray Computed
15.
AJNR Am J Neuroradiol ; 34(9): 1857-62, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23620074

ABSTRACT

BACKGROUND AND PURPOSE: MR imaging is currently not used to evaluate CSF flow changes due to short-lasting physiological maneuvers. The purpose of this study was to evaluate the ability of MR imaging to assess the CSF flow response to a Valsalva maneuver in healthy participants. MATERIALS AND METHODS: A cardiac-gated fast cine-PC sequence with ≤15-second acquisition time was used to assess CSF flow in 8 healthy participants at the foramen magnum at rest, during, and immediately after a controlled Valsalva maneuver. CSF mean displacement volume VCSF during the cardiac cycle and CSF flow waveform App were determined. A work-in-progress real-time pencil-beam imaging method with temporal resolution ≤56 ms was used to scan 2 participants for 90 seconds during which resting, Valsalva, and post-Valsalva CSF flow, respiration, and HR were continuously recorded. Results were qualitatively compared with invasive craniospinal differential pressure measurements from the literature. RESULTS: Both methods showed 1) a decrease from baseline in VCSF and App during Valsalva and 2) an increase in VCSF and App immediately after Valsalva compared with values measured both at rest and during Valsalva. Whereas fast cine-PC produced a single CSF flow waveform that is an average over many cardiac cycles, pencil-beam imaging depicted waveforms for each heartbeat and was able to capture many dynamic features of CSF flow, including transients synchronized with the Valsalva maneuver. CONCLUSIONS: Both fast cine-PC and pencil-beam imaging demonstrated expected changes in CSF flow with Valsalva maneuver in healthy participants. The real-time capability of pencil-beam imaging may be necessary to detect Valsalva-related transient CSF flow obstruction in patients with pathologic conditions such as Chiari I malformation.


Subject(s)
Cerebrospinal Fluid/physiology , Foramen Magnum/physiology , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging, Cine/methods , Magnetic Resonance Imaging/methods , Valsalva Maneuver/physiology , Adult , Computer Simulation , Female , Foramen Magnum/anatomy & histology , Humans , Male , Models, Biological , Reproducibility of Results , Sensitivity and Specificity
16.
AJNR Am J Neuroradiol ; 32(4): 739-42, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21330393

ABSTRACT

The purpose of this study was to analyze the CSF flow in patients with Chiari I to determine differences between patients with and without CAH. Thirty patients with Chiari I malformation underwent cine-PC CSF flow imaging in the sagittal plane. CSF flow pulsations were analyzed by placing regions of interest in the anterior cervical subarachnoid space. Maximum CSF systolic (craniocaudal) and diastolic (caudocranial) velocities as well as the durations of CSF systole and diastole (measured in fractions of the cardiac cycle) were determined. In the region of interest just below the foramen magnum, patients with CAH had a significantly shorter CSF systole and longer diastole (P=.02). A CSF diastolic length of ≥0.75 of the cardiac cycle was 67% sensitive and 86% specific for CAH. Our results indicate that Cine-PC imaging can show differences in CSF flow patterns in patients with Chiari I with and without CAH.


Subject(s)
Arnold-Chiari Malformation , Cerebrovascular Circulation/physiology , Headache Disorders, Primary , Magnetic Resonance Imaging, Cine/methods , Adolescent , Adult , Arnold-Chiari Malformation/complications , Arnold-Chiari Malformation/pathology , Arnold-Chiari Malformation/physiopathology , Blood Flow Velocity/physiology , Child , Child, Preschool , Female , Foramen Magnum , Headache Disorders, Primary/etiology , Headache Disorders, Primary/pathology , Headache Disorders, Primary/physiopathology , Humans , Male , Middle Aged , Young Adult
17.
Neurology ; 74(1): 18-26, 2010 Jan 05.
Article in English | MEDLINE | ID: mdl-19940273

ABSTRACT

BACKGROUND: Vitamin D deficiency has potential adverse effects on neurocognitive health and subcortical function. However, no studies have examined the association between vitamin D status, dementia, and cranial MRI indicators of cerebrovascular disease (CVD). METHODS: Cross-sectional investigation of 25-hydroxyvitamin D [25(OH)D], dementia, and MRI measures of CVD in elders receiving home care (aged 65-99 years) from 2003 to 2007. RESULTS: Among 318 participants, the mean age was 73.5 +/- 8.1 years, 231 (72.6%) were women, and 109 (34.3%) were black. 25(OH)D concentrations were deficient (<10 ng/mL) in 14.5% and insufficient (10-20 ng/mL) in 44.3% of participants. There were 76 participants (23.9%) with dementia, 41 of which were classified as probable AD. Mean 25(OH)D concentrations were lower in subjects with dementia (16.8 vs 20.0 ng/mL, p < 0.01). There was a higher prevalence of dementia among participants with 25(OH)D insufficiency (< or =20 ng/mL) (30.5% vs 14.5%, p < 0.01). 25(OH)D deficiency was associated with increased white matter hyperintensity volume (4.9 vs 2.9 mL, p < 0.01), grade (3.0 vs 2.2, p = 0.04), and prevalence of large vessel infarcts (10.1% vs 6.9%, p < 0.01). After adjustment for age, race, sex, body mass index, and education, 25(OH)D insufficiency (< or =20 ng/mL) was associated with more than twice the odds of all-cause dementia (odds ratio [OR] = 2.3, 95% confidence interval [CI] 1.2-4.2), Alzheimer disease (OR = 2.5, 95% CI 1.1-6.1), and stroke (with and without dementia symptoms) (OR = 2.0, 95% CI 1.0-4.0). CONCLUSIONS: Vitamin D insufficiency and deficiency was associated with all-cause dementia, Alzheimer disease, stroke (with and without dementia symptoms), and MRI indicators of cerebrovascular disease. These findings suggest a potential vasculoprotective role of vitamin D.


Subject(s)
Alzheimer Disease/etiology , Dementia/etiology , Stroke/etiology , Vitamin D Deficiency/complications , Vitamin D/analogs & derivatives , Aged , Aged, 80 and over , Body Mass Index , Confidence Intervals , Cross-Sectional Studies , Dementia/classification , Female , Humans , Logistic Models , Magnetic Resonance Imaging/methods , Male , Neurologic Examination/methods , Odds Ratio , Phlebotomy/methods , Retrospective Studies , Risk Factors , Temporal Lobe/pathology , Vitamin D/blood
19.
AJNR Am J Neuroradiol ; 29(8): 1564-5, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18499795

ABSTRACT

We present a unique variant of the middle turbinate that extends posteriorly through the choana to wrap around the posterior free edge of the nasal septum. The embryology and anatomy of the lateral nasal wall and the nasal septum are reviewed.


Subject(s)
Nasal Cavity/abnormalities , Nasal Cavity/diagnostic imaging , Nasopharyngeal Neoplasms/diagnostic imaging , Tomography, X-Ray Computed/methods , Adult , Diagnosis, Differential , False Positive Reactions , Humans , Male
20.
AJNR Am J Neuroradiol ; 29(4): 720-3, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18238842

ABSTRACT

BACKGROUND AND PURPOSE: Elevated protein levels have been reported in perilymph of patients with vestibular schwannoma. Fluid-attenuated inversion recovery (FLAIR) imaging is sensitive to high protein contents in fluids. The purpose of this study was to investigate if in patients with unilateral vestibular schwannoma, cochlear FLAIR signal intensity on the affected side is increased compared with the unaffected side and control subjects. MATERIALS AND METHODS: Fifteen patients with unilateral vestibular schwannoma and 25 age-matched control subjects (without a history of hearing loss) were retrospectively evaluated. All patients and controls had routine 5-mm FLAIR and T1- and T2-weighted imaging of the brain. The signal intensity of both cochleae was evaluated by placing a small region of interest on FLAIR images. The signal intensity of the brain stem was also determined by placing a second region of interest. A ratio of cochlear signal intensity to brain stem signal intensity (CIBI ratio) was determined. A t test was used to compare the CIBI ratios. RESULTS: In patients, the mean CIBI ratio of the affected side was 0.89 +/- 0.18, and that of the unaffected side was 0.57 +/- 0.12. In control subjects, it was 0.51 +/- 0.07. The CIBI ratio of the affected side was significantly higher compared with the unaffected side (P < .001) and compared with control subjects (P < .001). CONCLUSION: Patients with vestibular schwannoma have increased cochlear FLAIR signal intensity on the affected side compared with the unaffected side and healthy subjects.


Subject(s)
Cochlea/pathology , Magnetic Resonance Imaging , Neuroma, Acoustic/diagnosis , Perilymph/chemistry , Adult , Aged , Aged, 80 and over , Female , Humans , Image Processing, Computer-Assisted , Male , Middle Aged , Proteins/analysis
SELECTION OF CITATIONS
SEARCH DETAIL