MATERIALS AND METHODS: The diagnostic criteria are based on results of brain and spine imaging, clinical manifestations, results of lumbar puncture, and response to epidural blood patching. The diagnostic criteria include criterion A, the demonstration of extrathecal CSF on spinal imaging. If criterion A is not met, criterion B, which is cranial MR imaging findings of spontaneous intracranial hypotension, follows, with at least one of the following: 1) low opening pressure, 2) spinal meningeal diverticulum, or 3) improvement of symptoms after epidural blood patch. If criteria A and B are not met, there is criterion C, the presence of all of the following or at least 2 of the following if typical orthostatic headaches are present: 1) low opening pressure, 2) spinal meningeal diverticulum, and 3) improvement of symptoms after epidural blood patch. These criteria were applied to a group of 107 consecutive patients evaluated for spontaneous spinal CSF leaks and intracranial hypotension.

RESULTS: The diagnosis was confirmed in 94 patients, with use of criterion A in 78 patients, criterion B in 11 patients, and criterion C in 5 patients.

CONCLUSIONS:A new diagnostic scheme is presented reflecting the wide spectrum of clinical and radiographic manifestations of spontaneous spinal CSF leaks and intracranial hypotension.

MATERIALS AND METHODS:We retrospectively reviewed CT and MR images in 6 patients (2 men and 4 women), aged 18 to 51 years, with SFT proved on histologic examination located in and around the orbit. All patients underwent CT (including dual-phase CT in 3), and MR imaging was obtained in 3. We evaluated the imaging findings with emphasis on the location, size, margin, internal architecture, and pattern of enhancement of the lesion.

RESULTS:All 6 lesions were found as a solitary, well-defined mass, ranging in size from 18 to 30 mm (mean, 24 mm). Three were located in the postseptal orbit, 2 in the lacrimal sac, and 1 on the lower eyelid. Compared with the cerebral cortex, all 3 lesions examined by MR imaging showed homogeneous isointense signal intensity on T1-weighted images and heterogeneous mixed isointense and hyperintense signal intensity on T2-weighted images. On visual inspection, all 6 lesions showed marked homogeneous (n = 4) or heterogeneous (n = 2) enhancement on postcontrast CT and MR images. In 3 patients examined with dual-phase CT, all lesions demonstrated rapid enhancement with early washout of contrast material.

CONCLUSION:SFT might be included in the differential diagnosis of soft tissue masses in the orbit, if one sees a markedly enhancing mass showing the similar characteristics to those of the internal carotid artery on postcontrast CT or MR images.

MATERIALS AND METHODS: Three images of BB-MR imaging per plaque were obtained from 70 consecutive patients who underwent carotid endarterectomy (CEA) to generate T1- and T2-weighted images. To evaluate the relative signal intensity (rSI) of plaque components and the relationship between histologic findings and symptoms, we prepared sections at 2-mm intervals from 34 intact plaques. We then calculated the relative overall signal intensity (roSI) of 70 plaques to assess the relationship between MR signal intensity and plaque hardness and symptoms.

RESULTS: The characteristics of rSI values on T1- and T2-weighted images of fibrous cap (FC), fibrosis, calcification, myxomatous tissue, lipid core (LC) with intraplaque hemorrhage (IPH), and LC without IPH differed. Symptomatic plaques were associated with FC disruption (P < .001) and LC with IPH (P < .05). The roSI on T1-weighted images was significantly higher for soft than nonsoft plaques. When the roSI cutoff value was set at 1.25 (mean of the roSI), soft plaques were diagnosed with 79.4% sensitivity and 84.4% specificity. The roSI was also significantly higher for symptomatic than for asymptomatic plaques. Soft and nonsoft plaques as well as symptomatic and asymptomatic plaques did not significantly differ on T2-weighted images.

CONCLUSION: BB-MR imaging can diagnose plaque components and predict plaque hardness. This procedure provides useful information for planning therapeutic strategies of carotid atherosclerosis.

MATERIALS AND METHODS: Eight patients with transient ischemic attacks who underwent carotid CTA and "en bloc" endarterectomy were enrolled in a prospective study. An ex vivo micro-CT study of each endarterectomy specimen was obtained, followed by histologic examination. A systematic comparison of CTA images with histologic sections and micro-CT images was performed to determine the CT attenuation associated with each component of the atherosclerotic plaques. A computer algorithm was subsequently developed that automatically identifies the components of the carotid atherosclerotic plaques, based on the density of each pixel. A neuroradiologist's reading of this computer analysis was compared with the interpretation of the histologic slides by a pathologist with respect to the types and characteristics of the carotid plaques.

RESULTS: There was a 72.6% agreement between CTA and histologic examination in carotid plaque characterization. CTA showed perfect concordance for calcifications. A significant overlap between densities associated with lipid-rich necrotic core, connective tissue, and hemorrhage limited the reliability of individual pixel readings to identify these components. However, CTA showed good correlation with histologic examination for large lipid cores ( = 0.796; P < .001) and large hemorrhages ( = 0.712; P = .102). CTA performed well in detecting ulcerations ( = 0.855) and in measuring the fibrous cap thickness (R² = 0.77; P < .001).

CONCLUSION: The composition of carotid atherosclerotic plaques determined by CTA reflects plaque composition defined by histologic examination.

MATERIALS AND METHODS: Three radiologists retrospectively and independently reviewed CE-MRA and conventional MR imaging in 27 patients with suspected paragangliomas. The overall image quality and the probability of paraganglioma were recorded. The results of each technique and their combination were analyzed for sensitivity and specificity. Receiver operating characteristic (ROC) analyses were performed by using histologic analysis, imaging, and/or clinical findings as the reference standard.

RESULTS: Forty-six lesions were found in 27 patients. In the assessment of paragangliomas, the combination of conventional MR imaging and CE-MRA was significantly superior to conventional MR imaging alone. Sensitivity and specificity respectively were the following: for CE-MRA, 100% and 94%; and for conventional MR imaging, 94% and 41%. The specificity of CE-MRA was significantly higher than that of conventional MR imaging (P = .004). There was good-to-excellent interobserver agreement for the paraganglioma probability with CE-MRA (nonweighted , 0.67–0.77), whereas there was fair-to-good interobserver agreement with conventional MR imaging (nonweighted , 0.50–0.65).

CONCLUSION: In combination with conventional MR imaging, CE-MRA yields an excellent diagnostic value for the assessment of head and neck paragangliomas; hence, the 2 techniques should be regarded as complementary.

MATERIALS AND METHODS: We retrospectively reviewed the imaging reports of patients during a 3-year period to identify those who had mandible fractures documented on dedicated facial bone CT scans. The incidence of unifocal fractures was determined, the unifocal fractures were further subcategorized, and any derangements of the temporomandibular joints were also evaluated.

RESULTS: One hundred two patients met the inclusion criteria. The incidence of unifocal mandible fractures was 42% (43/102). Three unifocal fracture patterns identified were the following: simple fractures (25/42, 58%), comminuted fractures (11/42, 26%), and fractures associated with condylar subluxations (7/42, 16%). Most fractures had none to mild displacement or distraction.

CONCLUSION: Unifocal mandible fractures occur with greater frequency than anticipated by most radiologists. This may be due to the somewhat dynamic nature of the mandibular "ring," which includes the temporomandibular joints, though joint derangements evident on CT occur in the minority of cases.

MATERIALS AND METHODS: Outpatient sinus CTs were evaluated for ORO in 500 consecutive patients (mean age, 46.9 years; 52.6% women). On a per-side basis (n = 1000), the presence of surgical changes, inflammatory sinus disease, and concha bullosa was determined by 2 neuroradiologists. Logistic regression was used to examine the association of ORO with these variables.

RESULTS: ORO was identified in 59 (11.8%) patients, bilateral in 27 (5.4%), and unilateral in 32 (6.4%). There were 343 of 1000 ethmoid sides that were diseased, and 66 (27.2%) showed ipsilateral ORO. In contrast, only 20 (3.0%) of 657 clear ethmoid sides showed ORO (P < .0001). ORO was significantly (P = .013) more common with previous surgery (18/75; 24.0%) than without (68/925; 7.4%). Ipsilateral concha bullosa was not associated with ORO. Of 32 patients with unilateral ORO, 5 (15.6%) had no ethmoid opacification or previous surgery, and 1 of these patients had an encephalocele causing the ORO. Finally, unilateral ORO was present in only 1 of 122 patients with completely clear sinuses (the encephalocele that was just mentioned).

CONCLUSION: ORO is distinctly uncommon without sinonasal inflammation or previous surgery. Isolated unilateral ORO raises suspicion for an underlying neoplasm or cephalocele and warrants further evaluation.

MATERIALS AND METHODS: Lesion localization, MR characteristics, lesion growth, and clinical management were reviewed in 52 patients diagnosed with an ILS between February 1991 and August 2007 in 2 referral centers. The number of ILSs and vestibulocochlear schwannomas in the cerebellopontine angle/internal auditory canal was compared to assess the prevalence.

RESULTS: ILSs most frequently originate intracochlearly, are hyperintense on unenhanced T1-weighted images, enhance strongly after gadolinium administration, and are sharply circumscribed and hypointense on thin heavily T2-weighted 3D images. The scala tympani is more frequently or more extensively involved than the scala vestibuli. Follow-up MR imaging, available in 27 patients, showed growth in 59% of subjects. Growth was seen from the scala tympani into the scala vestibuli and from the scala vestibuli to the saccule and vice versa. Twelve lesions were resected, and the diagnosis of ILS histopathologically confirmed.

CONCLUSION: ILSs can account for up to 10% of all vestibulocochlear schwannomas in centers specializing in temporal bone imaging, grow in more than 50%, and are most frequently found intracochlearly, often anteriorly between the basal and second turn. Cochlear ILSs most often originate in the scala tympani and only later grow into the scala vestibuli. Growth can occur from the cochlea into the vestibule or vice versa through the anatomic open connection between the perilymphatic spaces in the scala vestibuli and around the saccule.

MATERIALS AND METHODS: Of 142 patients with VS treated with radiosurgery, we selected patients who were followed at least 3 times during a minimum of 32 months with a T1-weighted gadolinium-enhanced high-resolution 3D MR imaging examination identical to the pretreatment MR imaging. Forty-five patients were identified with a mean follow-up of 50 months (range, 32–78 months). Pre- and posttreatment tumor volumes were calculated by using BrainSCAN software by manually contouring tumors on each MR imaging study. Volume changes of >13% were defined as events.

RESULTS: At last follow-up MR imaging, volumes were smaller in 37 (82.2%) of the 45 patients. Eleven (29.7%) of these 37 tumors showed transient swelling preceding regression, with a median time to regression of 34 months (range, 20–55 months). Seven (15.6%) of the 45 tumors had volume progression compared with the tumor on pretreatment MR imaging studies. Of these 7 tumors, 3, however, had volume regression compared with the preceding MR imaging study, and in 4, volume progression was ongoing. One tumor remained the same.

CONCLUSIONS: Tumor-volume measurements by standardized T1-weighted gadolinium-enhanced high-resolution 3D MR imaging follow-up protocols revealed good local control of VS after radiosurgery. The first-follow-up MR imaging at 2 years and the second at 5 years postradiosurgery differentiated transient progression from ongoing progression and may prevent unnecessary therapeutic interventions.

Materials and METHODS: There were 21 patients with FM and 27 HC who underwent conventional structural MR imaging and additional 2D-chemical shift imaging (CSI) MR-spectroscopy sequences. For the 2D-CSI spectroscopy, larger volumes of interest (VOIs) were centered at the level of the basal ganglia and the supraventricular white matter. Within these larger areas, 16 smaller voxels were placed in a number of regions previously implicated in pain processing. N-acetylaspartate (NAA)/creatine(Cr), choline (Cho)/Cr and NAA/Cho ratios were calculated for each voxel. Subjects underwent clinical and experimental pain assessment.

RESULTS: Mean metabolite ratios and ratio variability for each region were analyzed by using repeated-measures analysis of variance (ANOVA). Correlations between clinical symptoms and metabolite ratios were assessed. Cho/Cr variability in the right dorsolateral prefrontal cortex (DLPFC) was significantly different in the 2 groups; a significant correlation between Cho/Cr in this location and clinical pain was present in the FM group. Evoked pain threshold correlated significantly with NAA/Cho ratios in the left insula and left basal ganglia.

CONCLUSION: Our data suggest that there are baseline differences in the variability of brain metabolite relative concentrations between patients with FM and HC, especially in the right DLPFC. Furthermore, there are significant correlations between metabolite ratios and clinical and experimental pain parameters in patients with FM.

MATERIALS AND METHODS: Fifteen patients with unilateral internal carotid stenosis (≥70%) underwent brain perfusional VCT (PVCT) 5 days before and 1 week after the stent-placement procedure. CBF and mean transit time (MTT) values were measured.

RESULTS: Decreased CBF and increased MTT values were observed in the cerebral areas supplied by the stenotic artery as compared with the areas supplied by the contralateral patent artery (P < .001). A significant normalization of the perfusion parameters was observed after the stent-placement procedure (mean pretreatment MTT value, 5.3 ± 0.2; mean posttreatment MTT value, 4.3 ± 0.18, P < .001; mean pretreatment CBF value, 41.2 mL/s ± 2.1; mean posttreatment CBF value, 47.9 mL/s ± 2.9, P < .001).

CONCLUSIONS: PVCT is a useful technique for the assessment of the hemodynamic modifications in patients with severe carotid stenosis. The quantitative evaluation of cerebral perfusion makes it a reliable tool for the follow-up of patients who undergo CAS.

MATERIALS AND METHODS: We identified 27 patients (13 men and 14 women; age range, 22–72 years) who developed PRES after SOT. Features noted included SOT subtype, incidence and timing of PRES, infection and rejection, mean arterial pressure (MAP), and toxicity brain edema.

RESULTS: PRES developed in 21 (0.49%) of 4222 patients who underwent transplantation within the study period (no significant difference among SOT subtypes). Transplantation was performed in 5 patients before the study period, and 1 patient underwent transplantation elsewhere. In consideration of all 27 patients, PRES typically developed in the first 2 months in patients who had SOT of the liver (9 of 10 patients) and was associated with cytomegalovirus (CMV), mild rejection, or systemic bacterial infection. PRES also typically developed after 1 year in patients who had SOT of the kidney (8 of 9 patients) and was associated with moderate rejection or bacterial infection. Toxicity MAP was significantly lower (P < .001) in liver transplants (average MAP, 104.8 ± 16 mm Hg) compared with that in kidney transplants (average MAP, 143 ± 20 mm Hg). Toxicity brain edema was significantly greater (P < .001) in patients who had liver transplants and developed PRES compared with patients who had undergone kidney transplants despite severe hypertension in those who had the kidney transplants.

CONCLUSION: Patients who had undergone SOTs have a similar low incidence of developing PRES. Differences between those who have had liver and kidney transplants included time after transplant, toxicity MAP, and PRES vasogenic edema noted at presentation. In patients who have undergone kidney transplants, severely elevated MAP was associated with reduced, not greater, brain edema.

MATERIALS AND METHODS: First-time patients with MCA stroke who presented <3 hours from symptom onset and were evaluated by noncontrast CT/CTA/CT perfusion, had confirmed acute nonlacunar MCA infarct on diffusion-weighted MR imaging (DWI) within 7 days, and had follow-up angiography were included. Patients were excluded for persistent MCA occlusion or stenosis. Two raters through consensus assigned an ASPECTS on the noncontrast CT, CTA source images, and the section-selective (2 x 12 mm coverage) CT perfusion CBV maps. ASPECTS on follow-up DWI served as the reference standard. For each CT technique, the detection rates of regional infarction, the mean ASPECTS, and the linear correlation to final ASPECTS were determined and compared. P values <.05 were considered significant.

RESULTS: Twenty-eight patients satisfied the criteria with DWI performed at a mean of 50.3 hours (range, 22–125 hours) post-CT imaging. Of 280 ASPECTS regions, 100 were infarcted on DWI. The accuracy of noncontrast CT, CTA source images, and CT perfusion CBV for detecting regional infarct was 80.0%, 84.3%, and 96.8%, respectively (P < .0001). The mean ASPECTSs of noncontrast CT, CTA source images, CT perfusion CBV, and DWI were 8.4 ± 1.8, 8.0 ± 1.8, 6.8 ± 1.9, and 6.5 ± 1.8, respectively. The mean noncontrast CT and CTA source image ASPECTS was different from that of DWI (P < .05). Correlation of noncontrast CT, CTA source images, and CT perfusion CBV ASPECTS with final ASPECTS was r² = 0.34, r² = 0.42, and r² = 0.91, respectively.

CONCLUSION: In a retrospective cohort of MCA infarcts imaged <3 hours from stroke onset, ASPECTS was most accurately determined on CT perfusion CBV maps.

MATERIALS AND METHODS: During the 4-year study period, a total of 60 patients (36 men and 24 women) had an incidental DWI-defined infarction without overt clinical symptoms suggestive of a stroke or a transient ischemic attack. All of the MR images were obtained by using a similar protocol on 2 identical 1.5T whole-body scanners. The patient's vascular risk factors, as well as the presence of white matter lesions (WMLs) on MR imaging and atheromatous changes on MR angiography, were assessed retrospectively. The incidental DWI-defined infarcts were also characterized in terms of their lateralization, lobe, and specific location.

RESULTS: A total of 16,206 consecutive brain MR images were done during the study period; the overall incidence of incidental infarcts was 0.37%. Most of these patients with an incidental infarct had vascular risk factors and WMLs on MR images. Most of these patients (80%) had a single lesion on DWI. A total of 88 lesions were identified; most were located in the white matter of the supratentorial brain, primarily in the frontoparietal lobes. There were also lesions involving the brain stem (n = 2). The lesions involving cerebrum were more commonly located in the right side (right to left = 52:34).

CONCLUSION: Small, DWI-defined acute brain infarctions can be found incidentally in an asymptomatic population; this finding may account, at least in part, for the pathogenesis of WMLs identified on MR imaging.

MATERIALS AND METHODS: Twenty-four amnestic patients with MCI were included. After 3 years, 46% had progressed to AD (n = 11; age, 72.7 ± 4.8 years; women/men, 8/3). For 13 patients (age, 72.4 ± 8.6 years; women/men, 10/3), the diagnosis remained MCI. Baseline MR imaging at 1.5T included a coronal heavily T1-weighted 3D gradient-echo sequence. Localized gray matter differences were assessed with VBM.

RESULTS: The converters had less gray matter volume in medial (including the hippocampus) and lateral temporal lobe, parietal lobe, and lateral temporal lobe structures. After correction for age, sex, total gray matter volume, and neuropsychological evaluation, left-sided atrophy remained statistically significant. Specifically, converters had more left parietal atrophy (angular gyrus and inferior parietal lobule) and left lateral temporal lobe atrophy (superior and middle temporal gyrus) than stable patients with MCI.

CONCLUSION: By studying 2 MCI populations, converters versus nonconverters, we found atrophy beyond the medial temporal lobe to be characteristic of patients with MCI who will progress to dementia. Atrophy of structures such as the left lateral temporal lobe and left parietal cortex may independently predict conversion.

MATERIALS AND METHODS: Data of 50 patients without intraparenchymal pathology and 10 acute stroke patients who underwent MR imaging including a T2 and T2* sequence with 3 echotimes were included. After calculation of T2*, T2', and T2 maps, the values of gray matter (GM) and white matter (WM) for each hemisphere were measured in 6 distinct regions of interest (ROIs).

RESULTS: There was a negative correlation between age and T2* values in the caudate nucleus (r = –0.34 Pearson correlation; P = .001) and lentiform nucleus (r = –0.67; P = .001) and a positive correlation in the occipital (r = 0.41; P = .001) and subcortical (r = 0.45; P = .001) WM. An age dependency for T2' values was only found for the caudate (r = –0.35; P = .001) and lentiform nucleus (r = –0.69; P = .001). T2' values in acute stroke were lower than normal in all patients with stroke.

CONCLUSION: Decrease in T2' and T2* values in GM and increase of T2* values in WM correlate with the progress of brain aging. Explanations for decreasing T2' and T2* values include iron deposition in the caudate and lentiform nucleus. In contrast to T2* values, there is no association of T2' values with the degree of leukoaraiosis. These age-dependent values can be used as a reference in neurovascular diseases and for the discussion of functional MR imaging data.

MATERIALS AND METHODS: TSE180° and hyperTSE images with parameters adapted for equal T2 contrast were acquired on a 3T whole-body system in 51 patients with 54 cerebral pathologies. Region-of-interest analysis was performed of signal intensities of pathologies, normal white and gray matter, CSF, and the SD of noise. Signal intensity-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) for healthy tissues and pathologies were determined. A qualitative rating concerning artifacts, lesion conspicuity, and image quality was performed by 2 experienced neuroradiologists.

RESULTS: HyperTSE sequences were equivalent to standard TSE180° sequences for the CNR of pathologies and of the contrast between gray and white matter. The SNR of gray and white matter and CSF were also the same. The CNRs of the pathologies in hyperTSE and TSE180° images were strongly correlated with each other (r = 0.93, P = .001). The visual rating of images revealed no significant differences between hyperTSE and TSE180°.

CONCLUSION: HyperTSE sequences proved to be qualitatively and quantitatively equivalent to TSE180° sequences in the detection of high- and low-signal-intensity lesions. They provide equal CNR of pathologies and of gray minus white matter and reduce the imaging restrictions of conventional TSE180° imposed by SAR limitations at 3T.

MATERIALS AND METHODS: Between January 2006 and September 2007, 298 patients with suggested ruptured intracranial aneurysm were referred for DSA, and in 98 patients, DSA was negative. Of these 98 patients, 28 had aneurysmal SAH, and in 23 of these additional 3DRA was performed in the same or in a repeat angiographic procedure.

RESULTS: In 18 of 23 patients (78%), a ruptured small aneurysm was diagnosed on additional 3DRA. The location of 18 aneurysms was the anterior communicating artery (n = 11), the middle cerebral artery (n = 3), the posterior communicating artery (n = 2), the ophthalmic artery (n = 1), and the posterior inferior cerebellar artery (n = 1). Aneurysm size was 3 mm in 4, 2 mm in 9, and 1 mm in 5. Of 18 aneurysms, 9 were treated with coil placement; 7 with surgical clipping; and 2 were not treated.

CONCLUSION: In this study, 18 of 23 (78%) patients with negative findings on DSA had a small ruptured aneurysm when studied with 3DRA. These were most commonly located on the anterior communicating artery.

MATERIALS AND METHODS: Thirty-four adult patients with mild TBI with persistent symptoms were assessed for DAI by quantifying traumatic microhemorrhages detected on a conventional set of T2*-weighted gradient-echo images and by DTI measures of fractional anisotropy (FA) within a set of a priori regions of interest. FA values 2.5 SDs below the region average, based on a group of 26 healthy control adults, were coded as exhibiting DAI.

RESULTS: DTI measures revealed several predominant regions of damage including the anterior corona radiata (41% of the patients), uncinate fasciculus (29%), genu of the corpus callosum (21%), inferior longitudinal fasciculus (21%), and cingulum bundle (18%). The number of damaged white matter structures as quantified by DTI was significantly correlated with mean reaction time on a simple cognitive task (r = 0.49, P = .012). In contradistinction, the number of traumatic microhemorrhages was uncorrelated with reaction time (r = –0.08, P = .71).

CONCLUSION: Microstructural white matter lesions detected by DTI correlate with persistent cognitive deficits in mild TBI, even in populations in which conventional measures do not. DTI measures may thus contribute additional diagnostic information related to DAI.

MATERIALS AND METHODS: Three hundred fifty 3D datasets of 1 vascular tree of 350 patients with at least 1 intracranial aneurysm on the dataset were re-evaluated for the presence of additional aneurysms by 2 observers in consensus. Two other observers, blinded to the 3D images, re-evaluated DSA images of the same 350 vascular trees for these additional aneurysms. Results were compared.

RESULTS: In 350 3D datasets, 350 target aneurysms and 94 additional aneurysms were detected. The mean size of 94 additional aneurysms was 3.54 mm (median, 3; range, 0.5–17 mm). The proportion of aneurysms ≤3 mm was significantly higher in additional aneurysms (61 of 94, 65%) than in the target aneurysms (61 of 350, 17%) (², P < .0001). Of 94 additional aneurysms, 27 (29%) were missed on DSA by both observers. The mean size of the missed aneurysms was 1.94 mm (median, 2; range, 0.5–4 mm). The proportion of aneurysms ≤3 mm in missed additional aneurysms (26 of 27, 96%) was significantly higher than that in all additional aneurysms (61 of 94, 65%) (², P = .0035). The location of missed additional aneurysms was not different from the location of all additional aneurysms.

CONCLUSION: 3DRA depicts considerably more small (≤3 mm) additional aneurysms than DSA. In selected patients, accurate detection of these aneurysms may have consequences for the choice of treatment technique and for the frequency and duration of imaging follow-up.

MATERIALS AND METHODS: Ten patients with carotid or vertebral pseudoaneurysms treated with self-expanding or balloon-expandable covered stents were retrospectively reviewed after we obtained institutional review board approval. Distal protection devices were not used. All patients except 1 received anticoagulation therapy. Antiplatelet therapy was used in 8 of 10 patients. Follow-up was performed from 5 days to 25 months. Patients were followed with digital subtraction angiography, CT angiography (CTA), and/or sonography (US).

RESULTS: Pseudoaneurysm occlusion was obtained in all 10 patients. None of the pseudoaneurysms recanalized during the follow-up period. One patient had a distal embolization to the middle cerebral artery despite anticoagulation and antiplatelet therapy. One patient who did not receive any anticoagulation had stent occlusion at 4.5 months. Anticoagulation was stopped after 6 months in 2 patients with persistent stent patency and no neurologic complications for >1 year. Both US and CTA were useful for extracranial stent surveillance. CTA was helpful for intracranial stent surveillance.

CONCLUSION: In this small series, the use of covered stents allowed safe and effective treatment of pseudoaneurysms occurring in the cervical and cephalic segments of the carotid and vertebral arteries.

MATERIALS AND METHODS: Of 135 patients with a PcomA aneurysm treated with coils between January 1997 and December 2003, there were 21 patients with initial CN III dysfunction who were selected and reevaluated. There were 2 men and 19 women with a mean age of 54.9 years. In 17 patients, CN III palsy was associated with subarachnoid hemorrhage (SAH). Timing of treatment after onset of symptoms was 1 to 3 days in 5 patients, 4 to 14 days in 13, and more than 14 days in 3. Mean size of the aneurysm was 9 mm. Initial CN III palsy was complete in 15 patients and partial in 6. Mean follow-up after coiling was 3.7 years (range, 1–7 years).

RESULTS: Of 15 patients with initial complete CN III palsy, recovery was complete in 3 and partial in 10. In 2 patients, complete CN III palsy was unchanged. Of 6 patients with initial partial CN III palsy, recovery was complete in 5 and partial in 1. Initial partial CN III palsy was the only predictor of complete recovery at follow-up.

CONCLUSION: PcomA aneurysm-induced CN III palsy improves or cures after coiling in most patients. Complete recovery is more likely with initial partial dysfunction of the nerve.

MATERIALS AND METHODS: Results of coiling of 101 aneurysms treated with Nexus coils were compared with our results of coiling of 120 aneurysms with Guglielmi detachable coils (GDC 10) and 115 with Trufill coils treated between May 2003 and December 2004 with the same treatment protocol. Rate of complications, mean aneurysmal volume, packing attenuation, incomplete aneurysmal occlusion at 6 months, and rates of retreatment were compared.

RESULTS: Initial occlusion in aneurysms treated with Nexus coils was (near) complete in 97 aneurysms and incomplete in 4 aneurysms. There were no permanent procedural complications (0/95 patients, 0%; 97.5% CI, 0.0% to 3.3%). Mean aneurysmal volume was 180.2 mm³ (range, 5–1624 mm³). Mean packing was 19.4% (range, 7.5% to 38.9%). Six months’ angiographic follow-up in 87 of 101 aneurysms showed incomplete occlusion in 14 (16%), and 12 (14%) of those had additional coiling. Mean packing of 19.4% of Nexus coils was significantly lower than 22.9% for GDC 10 and 29.7% for Trufill coils. Other clinical results were not significantly different.

CONCLUSION: In this series, PGLA microfilament Nexus coils were safe to use with clinical results comparable with those of standard platinum coils. This study gives additional evidence of the lack of beneficial effect of PGLA addition to reduce the reopening rate of coiled intracranial aneurysms.

MATERIALS AND METHODS: In 16 patients with 17 large or giant (11–45 mm) unruptured ICA aneurysms presenting with dysfunction of cranial nerves (CN) II, III, IV, or VI, selective coil occlusion was performed. From a cohort of 39 patients with ICA aneurysms treated with ICA occlusion and long-term follow-up, we selected 31 patients with aneurysms presenting with cranial nerve dysfunction. Clinical recovery at follow-up from oculomotor dysfunction and visual symptoms was compared for both treatment modalities.

RESULTS: Of 17 aneurysms treated with selective coiling, symptoms of cranial nerve dysfunction resolved in 3, improved in 10, and remained unchanged in 4. In 9 of 17 patients, additional coiling during follow-up was required. Of 31 aneurysms treated with carotid artery occlusion, cranial nerve dysfunction resolved in 19, improved in 9, and remained unchanged in 3. These differences were not significant. There were no complications of treatment.

CONCLUSION: Recovery of ICA aneurysm-induced cranial nerve dysfunction occurs in most patients, both after ICA occlusion and after selective coiling. In patients who cannot tolerate ICA occlusion, selective aneurysmal occlusion with coils is a valuable alternative.

MATERIALS AND METHODS: Single-voxel point-resolved spectroscopy (PRESS) spectra from 85 patients with brain tumors and 469 control subjects were analyzed. Citrate seemed to be a likely candidate, and model spectra of citrate were added to the basis set of metabolites for automated processing with use of LCModel software. Absolute "apparent" concentrations of citrate and the Cramer-Rao lower bounds (CRLB), indicators for the reliability of detection, were determined.

RESULTS: "Apparent" citrate was detected in 26 of 85 patients with CRLB of less than 25%. Diffuse intrinsic brain stem glioma (DIBSG) had the highest mean concentration (4.0 ± 1.1 mmol/kg in all subjects), and 8 of 12 patients had CRLB less than 25%. A significant reduction of citrate (P < .01) was observed in 6 DIBSGs that had follow-up MR spectroscopy studies after radiation therapy. "Apparent" citrate with CRLB less than 25% was detected in 5 of 22 medulloblastomas (mean citrate, 2.9 ± 2.2 mmol/kg), in 5 of 14 ependymomas (2.6 ± 1.8 mmol/kg), 5 of 14 astrocytomas (1.9 ± 1.2 mmol/kg), and 3 of 23 pilocytic astrocytomas (1.4 ± 1.1 mmol/kg). In control subjects older than 6 months, CRLB less than 25% was not observed, whereas CRLB less than 25% was observed in 39 of 194 subjects younger than 6 months,.

CONCLUSION: MR signal consistent with citrate was observed in pediatric brain tumors and in the developing brain of infants younger than 6 months.

MATERIALS AND METHODS: We performed a retrospective analysis of 48 patients with clinically complete cervical spine injury. Inclusion criteria were the clear documentation of the time of injury and MR imaging before surgical intervention within 72 hours of injury. The length of intramedullary spinal cord edema and hemorrhage was assessed. The correlation between time to imaging and lesion size was determined by multiple regression analysis. Short-interval follow-up MR imaging was also available for a few patients (n = 5), which allowed the direct visualization of changes in spinal cord edema.

RESULTS: MR imaging demonstrated cord edema in 100% of patients and cord hemorrhage in 67% of patients. The mean longitudinal length of cord edema was 10.3 ± 4.0 U, and the mean length of cord hemorrhage was 2.6 ± 2.0 U. Increased time to MR imaging correlated to increased spinal cord edema length (P = .002), even after accounting for the influence of other variables. A difference in time to MR imaging of 1.2 days corresponded to an average increase in cord edema by 1 full vertebral level. Hemorrhage length was not affected by time to imaging (P = .825). A temporal increase in the length of spinal cord edema was confirmed in patients with short-interval follow-up MR imaging (P = .003).

CONCLUSION: Spinal cord edema increases significantly during the early time period after injury, whereas intramedullary hemorrhage is comparatively static.

Materials and METHODS: A total of 105 block anesthetics were performed under fluoroscopic guidance in 47 consecutive patients with pure radiculopathy from a single confirmed level: 47 blocks were performed at the symptomatic level, and 58 were performed at the adjacent asymptomatic "control" level. Contrast and local anesthetics were injected, and spot radiographs were taken in all cases. We calculated the diagnostic value of the block anesthetics using concordance with the injected level. We analyzed the potential causes of false results using spot radiographs.

RESULTS: On the basis of a definition of a positive block as 70% pain relief, determined by receiver-operator characteristic (ROC) analysis, diagnostic lumbar selective nerve root block anesthetics had a sensitivity of 57%, a specificity of 86%, an accuracy of 73%, a positive predictive value of 77%, and a negative predictive value of 71%. False-negatives were due to the following causes identifiable on spot radiographs: insufficient infiltration, insufficient passage of the injectate, and intraepineural injections. On the other hand, false-positives resulted from overflow of the injectate from the injected asymptomatic level into either the epidural space or symptomatic level.

CONCLUSION: The accuracy of diagnostic lumbar selective nerve root blocks is only moderate. To improve the accuracy, great care should be taken to avoid inadequate blocks and overflow, and to precisely interpret spot radiographs.

MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for this Health Insurance Portability and Accountability Act–compliant study. Twenty control subjects without vascular malformation (6 men, 18–70 years of age) and 10 patients with AVMs (6 men, 20–74 years of age) underwent supra-aortic time-resolved and high-spatial-resolution CE-MRA at 3T. Large-field-of-view coronal acquisitions extending from the root of the aorta to the cranial vertex were obtained for both MRA techniques. Image quality was assessed by 2 specialized radiologists by using a 4-point scale. AVM characteristics and nidus size were evaluated by using both CE-MRA and CCA in all patients.

RESULTS: In patients, 96.6% (319/330) of arterial segments on high-spatial-resolution MRA and 87.7% (272/310) of arterial segments on time-resolved MRA were graded excellent/good. MRA showed 100% specificity for detecting feeding arteries and venous drainage (n = 8) and complete obliteration of the AVM in 2 cases (concordance with CCA). Nidus diameters measured by both MRA and CCA resulted in a very strong correlation (r = 0.99) with a mild overestimation by MRA (0.10 cm by using the Bland-Altman plot).

CONCLUSION: By combining highly temporally resolved and highly spatially resolved MRA at 3T as complementary studies, one can assess vascular anatomy and hemodynamics noninvasively in patients with AVM.