Value of non-contrast sequences in magnetic resonance angiography of hepatic arterial vasculature.

OBJECTIVE: To evaluate value of adding non-contrast MR angiographic sequence (In-Flow Inversion Recovery [IFIR]) to standard fat-suppressed T1-weighted postcontrast sequence (3D spoiled gradient echo [3D-GRE]) for evaluating hepatic arterial anatomy. METHODS: Retrospective evaluation of 30 consecutive patients undergoing multiphase liver MRI. Individual vessels for IFIR/3D-GRE sequences were evaluated by two blinded readers using a four-point scale. Statistical analysis was performed using the Wilcoxon signed-rank test for vessel conspicuity between IFIR/3D-GRE sequences. RESULTS: IFIR alone diagnostically imaged 8.1% of vessels, 3D-GRE alone 25.8%, 55.8% by both 3D-GRE/IFIR, and 10.3% of vessels by neither. Two patients with variant vascular anatomy were visualized with both sequences. Addition of IFIR to 3D-GRE resulted in statistically significant increase in arterial visualization (p<0.001), 10% relative increase in identified vessels, and 3-5 mi increase in acquisition time for total scan time of 30-35 min. CONCLUSIONS: IFIR may be a useful adjunct to 3D-GRE in hepatic angiography without adding considerably to scan time. 10% more hepatic arteries were seen when combining information from IFIR/3D-GRE vs. 3D-GRE alone.

Vestibular dysfunction in patients with chronic pain or underlying neurologic disorders.

CONTEXT: Individuals with vestibular dysfunction are at increased risk for falling. In addition, vestibular dysfunction is associated with chronic pain, which could present a serious public health concern as approximately 43% of US adults have chronic pain. OBJECTIVE: To assess the incidence of vestibular dysfunction in patients receiving medication for chronic, noncancer pain or other underlying neurologic disorders and to determine associated follow-up therapeutic and diagnostic recommendations. METHODS: The authors conducted a retrospective medical record review of consecutive patients who were treated in their private neuroscience practice with medications for chronic pain or underlying neurologic disorders in 2011. All patients underwent a series of tests using videonystagmography for the assessment of vestibular function. Test results and recommendations for therapy and additional testing were obtained. RESULTS: Medical records of 124 patients (78 women, 46 men) were reviewed. Vestibular deficits were detected in 83 patients (66.9%). Patient ages ranged from 29 through 72 years, with a mean age of 50.7 years for women and 52.5 years for men. Physician-recommended therapy and follow-up testing were as follows: 32 patients (38.6%), neurologic examination and possible magnetic resonance (MR) imaging or computed tomography (CT) of the brain; 26 patients (31.3%), vestibular rehabilitation therapy only; 22 patients (26.5%), vestibular and related balance-function rehabilitation therapy, further neurologic examination, and possible MR imaging or CT; 2 patients (2.4%), balance-function rehabilitation therapy and specialized internal auditory canal high-magnification MR imaging or CT to assess for acoustic neuroma; and 1 patient (1.2%), specialized internal auditory canal high-magnification MR imaging or CT to evaluate for possible intracanalicular acoustic neuroma. CONCLUSION: Patients being treated with medications for chronic, noncancer pain or other underlying neurologic disorders may have a higher-than-average incidence of vestibular dysfunction. Baseline assessment and monitoring of the vestibular apparatus may be indicated for these patients.

Scoliosis rates in symptomatic patients as demonstrated with weight-bearing or supine MR imaging.

CONTEXT: In the United States an estimated 6 million persons are affected by scoliosis, which is characterized by a 3-dimensional deformity of the spine that involves a curvature in the sagittal, frontal, and transverse planes. OBJECTIVE: To determine the rates of scoliosis in patients with spine-related pain unassociated with cancer, as demonstrated by magnetic resonance (MR) images obtained with patients in either a weight-bearing or a supine position. METHODS: The authors conducted a retrospective review of MR images obtained during a 2-year period in patients referred because of symptoms of radiculopathy or other spine-related pain unassociated with cancer and unresolved after conservative treatment. Images were obtained either with the patient supine or with the patient in a weight-bearing, seated position, and all images were reviewed by a neuroimaging physician. Scoliosis was assessed according to the Cobb angle method. RESULTS: A total of 1982 MR images from 1486 patients were reviewed. Of those, 986 images in 761 patients were obtained with a low-field-strength (0.3-T) MR imager with the patient supine, and 996 images in 725 patients were obtained with a mid-field-strength (0.6-T) MR imager with the patient in a weight-bearing, seated position. Scoliosis (dextroscoliosis, levoscoliosis, or both) was identified in 958 MR images (48.3%), of which 779 (78.2%) were obtained with patients in a weight-bearing position and 179 (18.2%) were obtained with patients in a supine position. CONCLUSION: The scoliosis rate was lower in the supine MR imaging group than in the weight-bearing MR imaging group. Scoliosis rates may be affected by the position in which the patient is examined, with the possibility that the weight-bearing position differentially exposes scoliosis, compared with the supine position.

Magnetic resonance angiography of the circle of Willis in patients with symptomatic intracranial neuropathology: medicare LCD L25367(R4).

Patients with symptomatic intracranial neuropathology such as atherosclerotic occlusive disease or unruptured aneurysms face high risks for morbidity and mortality. Magnetic resonance angiography of the circle of Willis is an important tool used to detect and diagnose intracranial neuropathology; however, recent changes to the Medicare local coverage determinations for this procedure threaten to compromise the physician's ability to deliver this current standard of care. Physicians can assume an important role in advocating for this lifesaving procedure on behalf of this vulnerable patient population.

Atraumatic headache in US emergency departments: recent trends in CT/MRI utilisation and factors associated with severe intracranial pathology.

OBJECTIVES: To estimate recent trends in CT/MRI utilisation among patients seeking emergency care for atraumatic headache in the USA and to identify factors associated with a diagnosis of significant intracranial pathology (ICP) in these patients. DESIGN/SETTING/PARTICIPANTS: Data were obtained from the USA National Hospital Ambulatory Medical Care Survey of emergency department (ED) visits between 1998 and 2008. A cohort of atraumatic headache-related visits were identified using preassigned 'reason-for-visit' codes. Sample visits were weighted to provide national estimates. RESULTS: Between 1998 and 2008 the percentage of patients presenting to the ED with atraumatic headache who underwent imaging increased from 12.5% to 31.0% (p < 0.01) while the prevalence of ICP among those visits decreased from 10.1% to 3.5% (p < 0.05). The length of stay in the ED was 4.6 h (95% CI 4.4 to 4.8) for patients with headache who received imaging compared with 2.7 (95% CI 2.6 to 2.9) for those who did not. Of 18 factors evaluated in patients with headache, 10 were associated with a significantly increased odds of an ICP diagnosis: age ≥ 50 years, arrival by ambulance, triage immediacy <15 min, systolic blood pressure ≥ 160 mm Hg or diastolic blood pressure ≥ 100 mm Hg and disturbance in sensation, vision, speech or motor function including neurological weakness. CONCLUSIONS: The use of CT/MRI for evaluation of atraumatic headache increased dramatically in EDs in the USA between 1998 and 2008. The prevalence of ICP among patients who received CT/MRI declined concurrently, suggesting a role for clinical decision support to guide more judicious use of imaging.

Lumbar stenosis rates in symptomatic patients using weight-bearing and recumbent magnetic resonance imaging.

OBJECTIVE: The purpose of this study was to determine the rate of lumbar stenosis detected via magnetic resonance imaging (MRI) in patients with symptomatic foraminal stenosis, lateral recess stenosis, or central stenosis. METHODS: A retrospective review was performed on 1983 MRI scans from a 2-year period on 1486 symptomatic patients. Of these patients, 761 were scanned in the recumbent position using low-field (0.3 T, Airis II; Hitachi, Twinsburg, Ohio) MRI, and 725 were scanned in an upright sitting position using midfield (0.6 T) open Upright MRI (Fonar Corp, Melville, NY). In total, 986 serial scans (recumbent) and 997 serial scans (weight-bearing) were performed. RESULTS: Of scans performed in the recumbent position, stenoses were identified in 382 scans (38.8%), central stenosis in 119 scans (12%), lateral recess stenosis in 91 scans (9.2%), and foraminal stenosis in 327 scans (33.2%). Of scans performed in a weight-bearing position, stenoses were identified in 565 scans (56.7%), central stenosis in 136 scans (13.6%), lateral recess stenosis in 206 scans (20.7%), and foraminal stenosis in 524 scans (52.6%). CONCLUSIONS: The stenosis rates as indicated by MRI interpretation ranged between 38.5% (recumbent) and 56.7% (weight-bearing). These rates are higher than those reported in the medical literature for asymptomatic patients. Further study is needed to determine whether weight-bearing, compared with recumbent, MRI better informs the clinician in the diagnosis of spinal stenosis.

Loeys-Dietz syndrome: cardiovascular, neuroradiological and musculoskeletal imaging findings.

Loeys-Dietz syndrome (LDS) is an increasingly recognized autosomal-dominant connective tissue disorder with distinctive radiological manifestations, including arterial tortuosity/aneurysms, craniofacial malformations and skeletal abnormalities. LDS exhibits a more aggressive course than similar disorders, such as Marfan or the vascular subtype of Ehlers-Danlos syndrome, with morbidity and mortality typically resulting from complications of aortic/arterial dissections. Early diagnosis, short-interval follow-up imaging and prophylactic surgical intervention are essential in preventing catastrophic cardiovascular complications. This review focuses on the cardiovascular, neuroradiological and musculoskeletal imaging findings in this disorder and recommendations for follow-up imaging.

Lumbar disk protrusion rates of symptomatic patients using magnetic resonance imaging.

OBJECTIVE: The purpose of this study was to determine the rate of disk protrusions detected via magnetic resonance imaging (MRI) in patients symptomatic for spine pain, radiculopathy, or other spine-related pain. METHODS: A retrospective review of 1983 MRI scans was performed over a 2-year period on 1486 patients, each of whom was symptomatic for spine pain, radiculopathy, or other noncancer, spine-related pain. Of these patients, 761 were scanned in the recumbent position using low-field (0.3 T, Airis II, Hitachi, Twinsburg, Ohio) MRI, and 725 were scanned in an upright, sitting position using mid-field (0.6 T) open Upright MRI (Fonar, Melville, NY). In total, 986 serial scans were performed on patients in the recumbent position and 997 serial scans on patients in the weight-bearing position. RESULTS: One or more disk protrusions were identified in 73.3% of scans performed in the sitting position and in 50.1% of scans performed in the recumbent position. Most disk protrusions occurred at L5-S1 (52.3% and 29.8%), L4-L5 (42.6% and 26.7%), and L3-L4 (26.7% and 13.1%) in upright and recumbent positions, respectively. CONCLUSIONS: The disk protrusion rate in this group of patients ranged between 50.1% (recumbent) and 73.3% (weight-bearing). These rates are higher than rates reported in the medical literature for asymptomatic patients, a finding that supports the decision to further evaluate patients with persistent spine-related pain.