Counterpoint: Conventional Fluoroscopy-Guided Selective Cervical Nerve Root Block-A Safe, Effective, and Efficient Modality in the Hands of an Experienced Proceduralist.

BACKGROUND AND PURPOSE: The conventional fluoroscopy-guided (CF) selective cervical nerve root block (SCNRB) is being used commonly as a treatment for cervical radicular pain as well as a diagnostic tool. This study aimed to identify any major complications and determine the safety and clinical utility of CF-SCNRB performed in a university hospital and associated outpatient clinics. MATERIALS AND METHODS: Two-hundred fifty-four conventional fluoroscopy-guided selective cervical nerve root blocks were retrospectively identified from 2011 to 2018 using a radiology report search tool. Each procedure was performed by an experienced neuroradiologist performing spinal injections on a full-time basis in clinical practice. A 10-point pain scale was used for pre- and postprocedural pain-level assessment. Successful conventional, fluoroscopy-guided, selective cervical nerve root block was defined as a patient-reported pain scale reduction of at least 50% and/or alleviation of numbness or paresthesia at ≥2 weeks postinjection. All clinically important immediate and delayed complications were also recorded. RESULTS: Two-hundred fifty-four conventional fluoroscopy-guided selective cervical nerve root blocks were performed via an anterolateral approach with an average fluoroscopy time of 24.3 seconds for all cases. There were no aborted procedures and no major or permanent complications. There were 14 minor complications; 12 of these were periprocedural and resolved by the 2-week follow-up visit. One-hundred eighty-five patients (75.2%) reported pain improvement of >50% from baseline at 15 minutes postinjection. Overall, 172 patients (67.7%) reported >50% pain scale reduction or alleviation from paresthesia at least 2 weeks postinjection. CONCLUSIONS: Conventional fluoroscopy-guided selective cervical nerve root block is an efficacious, efficient, and safe outpatient procedure when performed by a skilled and experienced proceduralist.

Acute Toxic Leukoencephalopathy: Etiologies, Imaging Findings, and Outcomes in 101 Patients.

BACKGROUND AND PURPOSE: Prior studies regarding acute toxic leukoencephalopathy (ATL) are either small, or preliminary. Our aim was to evaluate etiologies of and differences in imaging severity and outcomes among various etiologies of ATL. MATERIALS AND METHODS: MRIs of patients with suspected ATL over 15 years were retrospectively reviewed; inclusion criteria were: MRI <3 weeks of presentation with both DWI and FLAIR. These were jointly graded by two neuroradiologists via a previously described score of severity. Clinical outcome was evaluated via both modified Rankin (mRS) and ATL outcome (ATLOS) scores, each being correlated with the DWI and FLAIR scores. Etiologic subgroups of n > 6 patients were statistically compared. RESULTS: Of 101 included patients, the 4 subgroups of n > 6 were the following: chemotherapy (n = 35), opiates (n = 19), acute hepatic encephalopathy (n = 14), and immunosuppressants (n = 11). Other causes (n = 22 total) notably included carbon monoxide (n = 3) metronidazole (n = 2), and uremia (n = 1). The mean DWI/FLAIR severity scores were 2.6/2.3, 3.3/3.3, 2.1/2.1 and 2.0/2.5 for chemotherapeutics, opiates, AHE and immunosuppressants, respectively, with significant differences in both imaging severity and outcome (P = .003-.032) among subgroups, particularly immunosuppressant versus chemotherapy-related ATL and immunosuppressants versus opiates (P = .004-.032) related ATL. DWI and FLAIR severity weakly correlated with outcome (ρ = 0.289-.349, P < .005) but correlated stronger in the chemotherapy (ρ = 0.460-.586, P < .010) and opiate (ρ =.472-.608, P < .05) subgroups, which had the worst outcomes. ATL clinically resolved in 36%, with severe outcomes in 23% (coma or death, 9/16 deaths from fludarabine). Notable laboratory results were elevated CSF myelin basic protein levels in 8/9 patients and serum blood urea nitrogen levels in 24/91. CONCLUSIONS: Clinical outcomes of ATL vary on the basis of etiology, being worse in chemotherapeutic- and opiate-related ATL. Uremia may be a predisposing or exacerbating factor.

Transforaminal Lumbar Puncture: An Alternative Technique in Patients with Challenging Access.

Interlaminar lumbar puncture and cervical puncture may not be ideal in all circumstances. Recently, we have used a transforaminal approach in selected situations. Between May 2016 and December 2017, twenty-six transforaminal lumbar punctures were performed in 9 patients (25 CT-guided, 1 fluoroscopy-guided). Seven had spinal muscular atrophy and were referred for intrathecal nusinersen administration. In 2, CT myelography was performed via transforaminal lumbar puncture. The lumbar posterior elements were completely fused in 8, and there was an overlying abscess in 1. The L1-2 level was used in 2; the L2-3 level, in 10; the L3-4 level, in 12; and the L4-5 level, in 2 procedures. Post-lumbar puncture headache was observed on 4 occasions, which resolved without blood patching. One patient felt heat and pain at the injection site that resolved spontaneously within hours. One patient had radicular pain that resolved with conservative treatment. Transforaminal lumbar puncture may become an effective alternative to classic interlaminar lumbar puncture or cervical puncture.

Susceptible vessel sign: identification of arterial occlusion and clinical implications in acute ischaemic stroke.

AIM: To determine the accuracy of the susceptible vessel sign (SVS) in the detection of arterial occlusion and its clinical implication in acute ischaemic stroke. MATERIALS AND METHODS: Consecutive ischaemic stroke patients who underwent magnetic resonance imaging (MRI) with susceptibility-weighted imaging (SWI) within 24 hours of symptom onset or time last-seen-well were included. Two independent neuroradiologists reviewed the SWI for evidence of the SVS. Admission stroke severity was determined by the National Institute of Health Stroke Scale (NIHSS) scores, and poor clinical outcome was defined by a 3-months modified Rankin scale (mRS) score >2. RESULTS: The SVS was identified in 26 (12%) of 213 patients with substantial inter-reviewer agreement. The SVS had 99% specificity, 88% negative predictive value (NPV), 51% sensitivity, and 92% positive predictive value (PPV) for detection of acute arterial occlusions. In consecutive stroke patients, the presence of SVS was associated with higher admission NIHSS scores (median 9 versus 3, p<0.001), arterial occlusion (92% versus 12%, p<0.001), larger infarct volume (162±180 ml versus 25±48 ml, p=0.001), and higher rate of poor clinical outcome at 3-months follow-up (58% versus 25%, p=0.001). In the subset of patients with acute arterial occlusion (n=47), the SVS was associated with higher admission NIHSS scores (median of 10 versus 3, p=0.038) and larger infarct volumes (173±184 ml versus 76±112 ml, p=0.034). CONCLUSIONS: The SVS is a highly specific sign of occlusive arterial thrombus, and is associated with larger infarct volume and more severe presentation in a series of consecutive stroke patients, as well as in the subgroup of patients with acute arterial occlusion.

Utility and Significance of Gadolinium-Based Contrast Enhancement in Posterior Reversible Encephalopathy Syndrome.

BACKGROUND AND PURPOSE: Posterior reversible encephalopathy syndrome is a clinicoradiologic syndrome. Literature regarding associated factors and the prognostic significance of contrast enhancement in posterior reversible encephalopathy syndrome is sparse. This study set out to evaluate an association between the presence of enhancement in posterior reversible encephalopathy syndrome and various clinical factors in a large series of patients with this syndrome. MATERIALS AND METHODS: From an MR imaging report search that yielded 176 patients with clinically confirmed posterior reversible encephalopathy syndrome between 1997 and 2014, we identified 135 patients who had received gadolinium-based contrast. The presenting symptoms, etiology, clinical follow-up, and maximum systolic and diastolic blood pressures within 1 day of MR imaging were recorded. MRIs were reviewed for parenchymal hemorrhage, MR imaging severity, and the presence and pattern of contrast enhancement. Statistical analyses evaluated a correlation between any clinical features and the presence or pattern of enhancement. RESULTS: Of 135 included patients (67.4% females; age range, 7-82 years), 59 (43.7%) had contrast enhancement on T1-weighted MR imaging, the most common pattern being leptomeningeal (n = 24, 17.8%) or leptomeningeal plus cortical (n = 21, 15.6%). Clinical outcomes were available in 96 patients. No significant association was found between the presence or pattern of enhancement and any of the variables, including sex, age, symptom, MR imaging severity, blood pressure, or outcome (all P > .05 after Bonferroni correction). CONCLUSIONS: The presence or pattern of enhancement in posterior reversible encephalopathy syndrome is not associated with any of the tested variables. However, an association was found between MR imaging severity and clinical outcome.

Intensity of MRI Gadolinium Enhancement in Cerebral Adrenoleukodystrophy: A Biomarker for Inflammation and Predictor of Outcome following Transplantation in Higher Risk Patients.

BACKGROUND AND PURPOSE: Outcomes following hematopoietic stem cell transplantation for higher risk childhood-onset cerebral adrenoleukodystrophy are variable. We explored whether a brain MR imaging gadolinium intensity scoring system improves prediction of neurologic outcome. MATERIALS AND METHODS: We developed a 4-point scale of gadolinium intensity relative to the choroid plexus: 0 = no enhancement; 1 = hypointense; 2 = isointense; 3 = hyperintense. The interobserver concordance of the scale was assessed on 30 randomly chosen studies. Scores were generated for 64 evaluable patients and compared with CSF chitotriosidase levels, a known inflammatory marker correlating with outcomes following transplantation. For 25 evaluable higher risk patients (Loes ≥10), the gadolinium intensity score was compared with longer term posttransplantation clinical change. RESULTS: The gadolinium intensity scoring system showed good interobserver reproducibility (κ = 0.72). Of 64 evaluable boys, the score positively correlated with average concomitant CSF chitotriosidase activity in nanograms/milliliter/hour: 0: 2717, n = 5; 1: 3218, n = 13; 2: 6497, n = 23; and 3: 12,030, n = 23 (P < .01). For 25 evaluable higher risk patients, more intense pretransplantation brain MR imaging gadolinium enhancement predicted greater average loss on the adrenoleukodystrophy neurologic function scale following transplantation: 0/1: adrenoleukodystrophy neurologic function scale score difference = 4.3, n = 7; 2/3: adrenoleukodystrophy neurologic function scale score difference = 10.4, n = 18 (P = .05). CONCLUSIONS: Gadolinium enhancement intensity on brain MR imaging can be scored simply and reproducibly for cerebral adrenoleukodystrophy. The enhancement score significantly correlates with chitotriosidase. In boys with higher risk cerebral disease (Loes ≥10), the enhancement score itself predicts neurologic outcome following treatment. Such data may help guide treatment decisions for clinicians and families.

Intramedullary spinal cord metastases: prognostic value of MRI and clinical features from a 13-year institutional case series.

BACKGROUND AND PURPOSE: In patients with intramedullary spinal cord metastases, the impact of MR imaging and clinical characteristics on survival has not been elucidated. Our aim was to identify MR imaging and clinical features with prognostic value among patients with intramedullary spinal cord metastases from a large retrospective series. MATERIALS AND METHODS: The relevant MR imaging examination and baseline clinical data for each patient from a consecutive group of patients with intramedullary spinal cord metastases had previously been reviewed by 2 neuroradiologists. Additional relevant clinical data were extracted. The influence of clinical and imaging characteristics on survival was assessed by Kaplan-Meier survival curves and log-rank tests for categoric characteristics. RESULTS: Forty-nine patients had 70 intramedullary spinal cord metastases; 10 (20%) of these patients had multiple metastases. From the date of diagnosis, median survival for all patients was 104 days (95% CI, 48-156 days). One clinical feature was associated with decreased median survival: lung or breast primary malignancy (57 days) compared with all other malignancy types (308 days; P < .001). Three MR imaging features were associated with decreased median survival: multiple intramedullary spinal cord metastases (53 versus 121 days, P = .022), greater longitudinal extent of cord T2 hyperintensity (if ≥3 segments, 111 days; if ≤2, 184 days; P = .018), and ancillary visualization of the primary tumor and/or non-CNS metastases (96 versus 316 days, P = .012). CONCLUSIONS: Spinal cord edema spanning multiple segments, the presence of multifocal intramedullary spinal cord metastases, and ancillary evidence for non-CNS metastases and/or the primary tumor are MR imaging features associated with decreased survival and should be specifically sought. Patients with either a lung or breast primary malignancy are expected to have decreased survival compared with other primary tumor types.

Intramedullary spinal cord metastases: visibility on PET and correlation with MRI features.

BACKGROUND AND PURPOSE: Studies systematically evaluating the detection of intramedullary spinal cord metastasis with PET are lacking. Our purpose was to evaluate the visibility of intramedullary spinal cord metastasis on PET in a single institutional series and to correlate PET and MR imaging features. MATERIALS AND METHODS: Patients were included if pretreatment MR imaging identifying an intramedullary spinal cord metastasis and an [(18)F] FDG-PET examination near the time of MR imaging were available. PET examinations were retrospectively reviewed, with reviewers blinded and then unblinded to the PET report and MR imaging findings. PET intramedullary spinal cord metastasis features were compared with and correlated with previously analyzed MR imaging lesion characteristics. Original clinical PET reports were reviewed. RESULTS: The final study sample was 10 PET examinations in 10 patients with 13 intramedullary spinal cord metastases. In 7 (70%) patients, retrospective blinded review demonstrated convincing evidence of 10 (77%) intramedullary spinal cord metastases. Three MR imaging features correlated with intramedullary spinal cord metastases being visible on PET compared with those nonvisible, respectively: larger lesion enhancement size: mean size: 32.1 mm versus 6.0 mm (P = .038); larger longitudinal extent of T2 signal abnormality: mean 5.6 versus 1.0 segments (P = .0081); and larger ratio of extent of T2 signal abnormality to contrast enhancement: 3.8 versus 1.0 (P = .0069). Intramedullary spinal cord metastasis was confidently reported clinically in 2 (20%) patients, accounting for 5 (38%) intramedullary spinal cord metastases. CONCLUSIONS: Most intramedullary spinal cord metastases can be detected on PET when performed near the time of pretreatment MR imaging. However, intramedullary spinal cord metastases may not be clinically reported on PET. Larger lesions with more edema are more likely to be visible. The spinal cord should be specifically and carefully assessed on PET for evidence of intramedullary spinal cord metastases to provide timely diagnosis.

Intramedullary spinal cord metastases: MRI and relevant clinical features from a 13-year institutional case series.

BACKGROUND AND PURPOSE: Because intramedullary spinal cord metastasis is often a difficult diagnosis to make, our purpose was to perform a systematic review of the MR imaging and relevant baseline clinical features of intramedullary spinal cord metastases in a large series. MATERIALS AND METHODS: Consecutive patients with intramedullary spinal cord metastasis with available pretreatment digital MR imaging examinations were identified. The MR imaging examination(s) for each patient was reviewed by 2 neuroradiologists for various imaging characteristics. Relevant clinical data were obtained. RESULTS: Forty-nine patients had 70 intramedullary spinal cord metastases, with 10 (20%) having multiple intramedullary spinal cord metastases; 8% (4/49) were asymptomatic. Primary tumor diagnosis was preceded by intramedullary spinal cord metastasis presentation in 20% (10/49) and by intramedullary spinal cord metastasis diagnosis in 10% (5/49); 98% (63/64) of intramedullary spinal cord metastases enhanced. Cord edema was extensive: mean, 4.5 segments, 3.6-fold larger than enhancing lesion, and ≥3 segments in 54% (37/69). Intratumoral cystic change was seen in 3% (2/70) and hemorrhage in 1% (1/70); 59% (29/49) of reference MR imaging examinations displayed other CNS or spinal (non-spinal cord) metastases, and 59% (29/49) exhibited the primary tumor/non-CNS metastases, with 88% (43/49) displaying ≥1 finding and 31% (15/49) displaying both findings. Patients with solitary intramedullary spinal cord metastasis were less likely than those with multiple intramedullary spinal cord metastases to have other CNS or spinal (non-spinal cord) metastases on the reference MR imaging (20/39 [51%] versus 9/10 [90%], respectively; P = .0263). CONCLUSIONS: Lack of known primary malignancy or spinal cord symptoms should not discourage consideration of intramedullary spinal cord metastasis. Enhancement and extensive edema for lesion size (often ≥3 segments) are typical for intramedullary spinal cord metastasis. Presence of cystic change/hemorrhage makes intramedullary spinal cord metastasis unlikely. Evidence for other CNS or spinal (non-spinal cord) metastases and the primary tumor/non-CNS metastases are common. The prevalence of other CNS or spinal (non-spinal cord) metastases in those with multiple intramedullary spinal cord metastases is especially high.

Rim and flame signs: postgadolinium MRI findings specific for non-CNS intramedullary spinal cord metastases.

BACKGROUND AND PURPOSE: No highly specific MR imaging features distinguishing ISCMs from primary cord masses have been described. Our purpose was to retrospectively compare peripheral enhancement features on postgadolinium MR imaging of ISCMs with primary intramedullary cord masses. MATERIALS AND METHODS: A consecutive group of patients with firmly diagnosed ISCM (45 patients with 64 ISCMs) and a comparison group with consecutive pathologically proved primary intramedullary spinal cord masses (64 patients with 64 primary spinal cord masses: ependymoma, astrocytoma, hemangioblastoma, ganglioglioma, and cavernous malformation) were included. MR images were evaluated for 2 specific signs on postgadolinium images: a "rim" sign (more intense thin rim of peripheral enhancement around an enhancing lesion) and "flame" sign (ill-defined flame-shaped region of enhancement at the superior/inferior lesion margins). The frequency of rim and/or flame signs in ISCMs and primary cord masses was compared (χ2 test). For ISCMs, the maximal dimension of the enhancing lesion was correlated with the presence of rim or flame signs (t test). RESULTS: Rim and flame signs, alone and in combination, were seen more frequently in ISCMs than in primary cord masses (P<.0001 for each). Specificity and sensitivity, respectively, for diagnosing ISCMs among spinal cord masses on a per-patient basis were the following: rim sign, 97%, 47%; flame sign, 97%, 40%; at least 1 sign, 94%, 60%; and both signs concurrently, 100%, 27%. In the ISCM group, the presence of either a rim or flame sign correlated with a larger measured maximum enhancing lesion size (P=.0065 and P=.0012, respectively). CONCLUSIONS: The rim and flame signs are common in and specific for ISCM and are rare in primary spinal cord masses.