"Giant" arachnoid granulations just like CSF?: NOT!!

"Giant" AGs (>1 cm) are uncommon and can be misdiagnosed as venous sinus pathology such as a neoplasm or thrombosis. Seventeen patients with a total of 19 venous sinus AGs of >1 cm were collected from contributing authors. MR imaging was available for all AGs; CT, for 5/19; and DSA, for 7/19. Intra-AG fluid was compared with CSF in subarachnoid spaces. Nonfluid AG tissue was compared with gray matter. Diagnosis was based on imaging findings. Fluid within giant AGs did not follow CSF signal intensity on at least 1 MR image in nearly 80% (15/19) of AGs. Nine of these 15 AGs had CSF-incongruent signal intensity on ≥2 MR images. CSF-incongruent signal intensity was seen in 8/8 AGs on FLAIR, 7/10 on precontrast T1WI, 13/19 on T2WI, and 8/14 on contrast-enhanced T1WI. Nonfluid signal intensity was present in 18/19 AGs and varied from absent/hypointense (intra-AG flow voids) to gray matter isointense (stromal tissue).

Emerging impact of CTA/perfusion CT on acute stroke thrombolysis in a community hospital.

Our objective was to retrospectively review the emerging role of CT, CTA, and perfusion CT (pCT) in the hyperacute stroke population of a community hospital. We reviewed 50 consecutive patients' records and imaging studies, who were treated with thrombolytic therapy within 6 h of symptom onset. Multidetector CT, CTA, and pCT studies were evaluated. Subsequent CT, magnetic resonance, or angiographic studies when available were correlated. Patients' clinical data at admission and outcomes at discharge were evaluated. Complications were tabulated. Of the 50 patients treated with thrombolytics, 37 had CT/CTA/pCT, the others non-contrast CT only. CT blood volume defect was present in a total of 14 patients, presaging permanent infarct in all. Arterial clot was seen in 28/37 CTAs (carotid "T" 6, MCA 16, vertebrobasilar 6). Viable penumbra was shown in 20/37; rescued penumbra was depicted after treatment in 14. 39 patients were treated with intravenous, nine with intra-arterial, two with both forms of thrombolysis. Modified Rankin score showed clinical improvement in 58%, three patients had complete recovery. Subsequent bleed was shown in two (4%), symptomatic in one (2%). Two patients died. Our experience suggests advanced CT is more sensitive to ischemia than routine CT, that salvageable penumbra can be identified, and that triage of patients with acute stroke for thrombolysis with CT/CTA/pCT is more robust than routine CT alone, and may improve outcomes in the community hospital setting.

Brown-Séquard syndrome secondary to spontaneous bleed from postradiation cavernous angiomas.

SUMMARY: The spontaneous occurrence of acute Brown-Séquard syndrome is an extremely rare event, with most reported cases being secondary to spontaneous epidural hematomas and spinal cord ischemia. We report a rare case of Brown-Séquard syndrome from spontaneous intraspinal hemorrhage in a patient with multiple cavernous angiomas in the spinal cord secondary to craniospinal radiation in childhood. Postulated mechanisms leading to the condition include postradiation molecular changes and venous occlusion.

Effects of diagnostic information, per se, on patient outcomes in acute radiculopathy and low back pain.

BACKGROUND AND PURPOSE: We conducted a prospective randomized study of patients with acute low back pain and/or radiculopathy to assess the effect of knowledge of diagnostic findings on clinical outcome. The practice of ordering spinal imaging, perhaps unintentionally, includes a large number of patients for whom the imaging test is performed for purposes of reassurance or because of patient expectations. If this rationale is valid, one would expect to see a measurable effect from diagnostic information, per se. MATERIALS AND METHODS: A total of 246 patients with acute (<3 weeks) low back pain (LBP) and/or radiculopathy (150 LBP and 96 radiculopathy patients) were recruited. Patients were randomized using a stratified block design with equal allocation to either the unblinded group (MR imaging results provided within 48 hours) or the blinded group (both patient and physician blinded to MR imaging results.) After the initial MR imaging, patients followed 6 weeks of conservative management. Roland function, visual pain analog, absenteeism, Short Form (SF)-36 Health Status Survey, self-efficacy scores, and Fear Avoidance Questionnaire were completed at presentation; 2, 4, 6, and 8 weeks; and 6, 12, and 24 months. Improvement of Roland score by 50% or more and patient satisfaction assessed by Cherkin symptom satisfaction measure were considered a positive outcome. RESULTS: Clinical outcome at 6 weeks was similar for unblinded and blinded patients. Self-efficacy, fear avoidance beliefs, and the SF-36 subscales were similar over time for blinded and unblinded patients, except for the general health subscale on the SF-36. General health of the blinded group improved more than for the unblinded group (P = .008). CONCLUSIONS: Patient knowledge of imaging findings do not alter outcome and are associated with a lesser sense of well-being.

Central neurocytoma: case report of an 81-year-old and histopathologic findings.

Central Neurocytomas are rare and usually benign tumors found primarily in the lateral ventricles of the brain. Central Neurocytomas are composed of uniform round cells exhibiting neuronal differentiation and are found almost exclusively in young adults between 15 and 60 years of age. The authors report the case of an 81-year-old man with a history of severe psychosis and depression, who presented with progressive confusion and ataxia likely unrelated to a central neurocytoma of his right lateral ventricle. The patient underwent a stereotactic biopsy of the lesion, followed by Gamma Knife radiosurgery. Histopathology showed immunohistological staining for synaptophysin, neuron specific enolase (NSE) and neuronal nuclear antigen (NeuN). A review of published literature on central neurocytomas revealed that this tumor occurs most frequently in young adults with a median age between 25 and 30 years. This pathology has never been reported in patients over the age of 80. Gamma Knife radiosurgery was successful in decreasing the tumor volume by 20% at the four month follow-up, but the fact that the patient died of unrelated occurrences in the elderly cannot be ruled out. Patients with central neurocytomas commonly present with obstructive hydrocephalus and immediate treatment may be necessary to tide over urgent situations.

Low back pain.

The communication between radiologists and their surgical colleagues is particularly important in the setting of back pain. This common disorder often does not have a definable cause, even when the imaging findings are abnormal. A shared understanding of the various causes of back pain, the appropriate terminology, and the needs of the surgeon is vital to proper patient treatment. Unfortunately, little standardization in the terminology for and management of back pain syndromes exists. This article elucidates the approaches to problems of back pain used in one clinical setting.

The syndrome of spontaneous intracranial hypotension.

The authors report four cases of headache and other symptomatology related to the syndrome of intracranial hypotension. They were seen in a routine clinical practice over the past 3 years. The clinical features, magnetic resonance imaging (MRI) findings, and follow-up of these patients are described. Review of the prior literature on the topic is also included. All four patients presented with orthostatic headache syndrome. Three of the four demonstrated diffuse leptomeningeal thickening and enhancement on MRI studies. One subsequently developed a subdural effusion. One patient demonstrated downward displacement of the posterior fossa initially, which resolved on follow-up MRI scanning. Possible pathophysiologies of the syndrome are discussed.

Fluid-attenuated inversion recovery (FLAIR): clinical prospectus of current and future applications.

A relative weakness of the traditional spin-echo technique, and particularly of the newer "FAST" or "TURBO" spin-echo sequences, has been diminished conspicuousness of lesions affecting the peripheral cortical mantle or those located in the periventricular region. This is a consequence of partial volume effects and high cerebrospinal fluid (CSF) signal adjacent to pathologic regions. Fluid-attenuated inversion recovery (FLAIR) is a magnetic resonance imaging (MRI) sequence that produces strong T2 weighting, suppresses the CSF signal, and minimizes contrast between gray matter and white matter. This effect produces images with significantly increased lesion-to-background CSF contrast and enhances the visibility of lesions as well as their detectability, particularly in the peripheral subcortical and periventricular regions. Applications are evolving, though preliminary reports highlight the superiority of FLAIR in the evaluation of infarction, multiple sclerosis, metastatic disease, tuberous sclerosis, and, possibly, subarachnoid hemorrhage. Early reports also address the application of FLAIR to imaging of the spinal cord. Modified versions of FLAIR are currently being developed; these modifications will further shorten acquisition times and eliminate pulsation artifacts. FLAIR may ultimately supplant conventional spin-echo imaging in routine MR screening of the brain.

Fluid-attenuated inversion recovery (FLAIR) for assessment of cerebral infarction. Initial clinical experience in 50 patients.

BACKGROUND AND PURPOSE: Our aim was to evaluate fluid-attenuated inversion recovery (FLAIR) sequence in the diagnosis of cerebral infarction with MRI. METHODS: A retrospective review was undertaken of 50 consecutive MRI studies ordered for suspected cerebrovascular accident. All studies included FLAIR and rapid acquisition with relaxation enhancement (RARE) T2-weighted spin-echo sequences. The two sequences were compared independently by four observers at two different institutions. Detectability of lesions and image quality were scored. RESULTS: Overall, FLAIR sequences proved superior in 10 patients, detecting acute cortical infarcts missed with RARE spin-echo technique in five patients. In five additional patients, improved characterization of chronic infarction and improved detection of microangiopathic deep hemispheric changes were observed. One brain stem infarct was missed with the FLAIR sequence. CONCLUSIONS: FLAIR offers advantages in detection of acute infarcts affecting the cortical ribbon, is a useful, rapid adjunct to conventional T2-weighted spin-echo sequences, and has the potential to replace these in the future.

Interobserver and intraobserver variability in interpretation of lumbar disc abnormalities. A comparison of two nomenclatures.

STUDY DESIGN: A double-blind prospective study was used to measure interobserver and intraobserver variability when interpreting lumbar spine magnetic resonance imaging studies of disc abnormalities. OBJECTIVES: To evaluate reader consistency when interpreting disc extension beyond the interspace, and assess the effect of two distinct nomenclatures on reader consistency. SUMMARY OF BACKGROUND DATA: Interobserver and intraobserver variability in interpretation of lumbar disc abnormalities is an important consideration in analyzing the technical efficacy of an imaging modality. However, this has not been well measured (particularly for standardized nomenclature). METHODS: Magnetic resonance imaging studies of the lumbar spine performed prospectively in 98 asymptomatic volunteers, and an additional 27 selected studies from symptomatic patients, were read blindly by two experienced neuroradiologists, using two separate nomenclatures. Only the discs were evaluated (625 interspaces). Nomenclature I was normal, bulge, herniation. Nomenclature II was normal, bulge, protrusion, extrusion. Intraobserver and interobserver variation were measured with Kappa statistic analysis. RESULTS: Interobserver agreement was 80% for both nomenclatures with a Kappa statistic of 0.58. Intraobserver agreement was 86% for each reader, with a Kappa statistic of 0.71 and 0.69, respectively. The most common disagreement was for normal versus bulge. The next most common disagreement (5-6%) was for bulge versus herniation (or protrusion in Nomenclature II). Herniation was read in 23% of the asymptomatic subjects. Using Nomenclature II, protrusion was seen in 27% of these subjects. Extrusion was read in only two asymptomatic subjects. CONCLUSIONS: Experienced readers using standardized nomenclature showed moderate to substantial agreement with interpreting disc extension beyond the interspace on magnetic resonance imaging.

Spinal nomenclature.

There has been a proliferation of differing terms, even among practicing surgeons. A morphologically based nomenclature may be needed for radiologic purposes, whereas a more histopathologic terminology would be desirable for surgical descriptors. Whichever approach is undertaken, the true radiologic-surgical correlation of disc abnormalities within the spine is doomed to failure without agreement on some type of standard nomenclature. A review of the problem and potential solutions are suggested.

MRI of degenerative disease of the lumbar spine.

Low back pain (LBP) is one of the most common reasons that patients seek medical attention. Although acute LBP is generally a self-limiting condition, the estimated cost for this health care problem exceeds $8 billion annually. MR accurately depicts both the morphologic as well as biochemical sequelae of disc degeneration. Additionally, MR is superior in its ability to depict disease processes that can present in an indistinguishable fashion. Although multiple mechanisms have been proposed for the possible etiology of disc degeneration, it remains incompletely understood at this time. In addition to the unknown etiology of disc degeneration, the relationship between degenerative disc disease and LBP has not been firmly established. Substantial percentages of people without a history of LBP or sciatica have been shown to have abnormal imaging examinations. Mechanical compression of neural elements by disc herniation, as well as direct biochemical and inflammatory effects of the contents of the nucleus pulposus upon neural structures, have been proposed as possible sources of LBP. Due to the above, caution is urged before attributing a particular anatomic finding as the patient's source of low back pain.