Validity of the Bern Score as a Surrogate Marker of Clinical Severity in Patients with Spontaneous Intracranial Hypotension.

BACKGROUND AND PURPOSE: The Bern score is a quantitative scale characterizing brain MR imaging changes in spontaneous intracranial hypotension. Higher scores are associated with more abnormalities on brain MR imaging, raising the question of whether the score can serve as a measure of disease severity. However, the relationship between clinical symptom severity and the Bern score has not been evaluated. Our purpose was to assess correlations between Bern scores and clinical headache severity in spontaneous intracranial hypotension. MATERIALS AND METHODS: This study was a single-center, retrospective cohort of patients satisfying the International Classification of Headache Disorders-3 criteria for spontaneous intracranial hypotension. Fifty-seven patients who completed a pretreatment headache severity questionnaire (Headache Impact Test-6) and had pretreatment brain MR imaging evidence of spontaneous intracranial hypotension were included. Pearson correlation coefficients (ρ) for the Headache Impact Test-6 and Bern scores were calculated. Receiver operating characteristic curves were used to assess the ability of Bern scores to discriminate among categories of headache severity. RESULTS: We found low correlations between clinical headache severity and Bern scores (ρ = 0.139; 95% CI, -0.127-0.385). Subgroup analyses examining the timing of brain MR imaging, symptom duration, and prior epidural blood patch showed negligible-to-weak correlations in all subgroups. Receiver operating characteristic analysis found that the Bern score poorly discriminated subjects with greater headache severity from those with lower severity. CONCLUSIONS: Pretreatment Bern scores show a low correlation with headache severity in patients with spontaneous intracranial hypotension. This finding suggests that brain imaging findings as reflected by Bern scores may not reliably reflect clinical severity and should not replace clinical metrics for outcome assessment.

Resisted Inspiration Improves Visualization of CSF-Venous Fistulas in Spontaneous Intracranial Hypotension.

BACKGROUND AND PURPOSE: CSF-venous fistulas are an important cause of spontaneous intracranial hypotension but are challenging to detect. A newly described technique known as resisted inspiration has been found to augment the CSF-venous pressure gradient and was hypothesized to be of potential use in CSF-venous fistula detection but has not yet been investigated in patients with spontaneous intracranial hypotension. The purpose of this investigation was to determine whether resisted inspiration results in improved visibility of CSF-venous fistulas on CT myelography in patients with spontaneous intracranial hypotension. MATERIALS AND METHODS: A retrospective cohort of patients underwent CT myelography from November 2022 to January 2023. Patients with an observed or suspected CSF-venous fistula identified during CT myelography using standard maximum suspended inspiration were immediately rescanned using resisted inspiration and the Valsalva maneuver. The visibility of the CSF-venous fistula among these 3 respiratory phases was compared, and changes in venous drainage patterns between phases were assessed. RESULTS: Eight patients with confirmed CSF-venous fistulas who underwent CT myelography using the 3-phase respiratory protocol were included. Visibility of the CSF-venous fistula was greatest during resisted inspiration in 5/8 (63%) of cases. Visibility was optimal with the Valsalva maneuver and maximum suspended inspiration in 1 case each, and it was equivalent in all respiratory phases in 1 case. In 2/8 (25%) cases, the pattern of venous drainage shifted between respiratory phases. CONCLUSIONS: In patients with spontaneous intracranial hypotension, resisted inspiration improved visualization of CSF-venous fistulas in most, but not all, cases. Further investigation is needed to determine the impact of this technique on the overall diagnostic yield of myelography in this condition.

Efficacy of Epidural Blood Patching or Surgery in Spontaneous Intracranial Hypotension: A Systematic Review and Evidence Map.

BACKGROUND: Spontaneous intracranial hypotension is an important cause of treatable secondary headaches. Evidence on the efficacy of epidural blood patching and surgery for spontaneous intracranial hypotension has not been synthesized. PURPOSE: Our aim was to identify evidence clusters and knowledge gaps in the efficacy of treatments for spontaneous intracranial hypotension to prioritize future research. DATA SOURCES: We searched published English language articles on MEDLINE (Ovid), the Web of Science (Clarivate), and EMBASE (Elsevier) from inception until October 29, 2021. STUDY SELECTION: We reviewed experimental, observational, and systematic review studies assessing the efficacy of epidural blood patching or surgery in spontaneous intracranial hypotension. DATA ANALYSIS: One author performed data extraction, and a second verified it. Disagreements were resolved by consensus or adjudicated by a third author. DATA SYNTHESIS: One hundred thirty-nine studies were included (median, 14 participants; range, 3-298 participants). Most articles were published in the past decade. Most assessed epidural blood patching outcomes. No studies met level 1 evidence. Most were retrospective cohort or case series (92.1%, n = 128). A few compared the efficacy of different treatments (10.8%, n = 15). Most used objective methods for the diagnosis of spontaneous intracranial hypotension (62.3%, n = 86); however, 37.7% (n = 52) did not clearly meet the International Classification of Headache Disorders-3 criteria. CSF leak type was unclear in 77.7% (n = 108). Nearly all reported patient symptoms using unvalidated measures (84.9%, n = 118). Outcomes were rarely collected at uniform prespecified time points. LIMITATIONS: The investigation did not include transvenous embolization of CSF-to-venous fistulas. CONCLUSIONS: Evidence gaps demonstrate a need for prospective study designs, clinical trials, and comparative studies. We recommend using the International Classification of Headache Disorders-3 diagnostic criteria, explicit reporting of CSF leak subtype, inclusion of key procedural details, and using objective validated outcome measures collected at uniform time points.

Respiratory Phase Affects the Conspicuity of CSF-Venous Fistulas in Spontaneous Intracranial Hypotension.

Spinal CSF-venous fistulas are a cause of spontaneous intracranial hypotension that can be difficult to detect on imaging. We describe how the respiratory phase affects the visibility of CSF-venous fistulas during myelography.

Decubitus CT Myelography for Detecting Subtle CSF Leaks in Spontaneous Intracranial Hypotension.

Spontaneous intracranial hypotension is caused by spinal CSF leaks, but the site of the leak is not always detected on spinal imaging. We report on the additional value of decubitus positioning during CT myelography in enhancing the detection of subtle leaks.

Critical Assessment of Myelography Practices: A Call for Rational Guideline Revision.

BACKGROUND AND PURPOSE: Patient preparation for myelography and postprocedural monitoring varies widely between practices, despite published guidelines. Our aim was to examine the current practice variations in discontinuing reportedly seizure threshold-lowering medications before myelography and to assess the reported incidence of postmyelographic seizures. MATERIALS AND METHODS: An e-mail survey was sent to American Society of Neuroradiology members concerning the number of postmyelographic seizures experienced in the past 5 years, the presence of an institutional policy for discontinuing seizure threshold-lowering medications, and the type of myelographic contrast used. We compared the postmyelographic seizure frequency in the responses. RESULTS: Of 700 survey responses, 57% reported that they do not discontinue seizure threshold-lowering medications before myelography. Most (97%) indicated never having a patient experience a seizure following myelography. The number of postmyelographic seizures between those who discontinue seizure threshold-lowering medications and those who do not was not statistically significant (OR = 2.13; 95% CI, 0.91-4.98; P = .08). Most (95%) reported using nonionic hypo-osmolar agents. CONCLUSIONS: Survey results revealed widely variable practices for patient myelography preparation and postprocedural monitoring. We found no difference in reported seizures between those who discontinued seizure threshold-lowering medications and those who did not. In light of our findings, we propose that discontinuing reportedly seizure threshold-lowering medications is not warranted with the current nonionic water-soluble contrast agents and may be potentially harmful in some instances. This work supports revision of existing recommendations to withhold such medications before myelography.

Incidence of Inadvertent Dural Puncture During CT Fluoroscopy-Guided Interlaminar Epidural Corticosteroid Injections in the Cervical Spine: An Analysis of 974 Cases.

OBJECTIVE: The objective of this study is to determine the rate of inadvertent dural puncture during CT fluoroscopy-guided cervical interlaminar epidural corticosteroid injection. In addition, in a subanalysis, we aim to assess the rate of inadvertent dural puncture superior to C5-C6 occurring during interlaminar epidural corticosteroid injection using CT fluoroscopy guidance because such injections are not performed using conventional fluoroscopy. MATERIALS AND METHODS: Images obtained from consecutive CT fluoroscopy-guided cervical interlaminar epidural corticosteroid injections conducted from November 2009 to November 2015 were reviewed. The following information was recorded: the presence of inadvertent dural puncture, the level of the cervical interlaminar space, approach laterality (left or right), anteroposterior spinal canal diameter, and the presence of a trainee. Two-tailed Fisher exact tests were used for assessment of categoric variables, and t tests were used for continuous variables. RESULTS: A total of 974 cervical interlaminar epidural corticosteroid injections were identified in 728 patients. Inadvertent dural punctures were identified in association with 1.4% (14/974) of these injections; all punctures were recognized during the procedure. Needle placements were performed at every cervical level (C1-C2 through C7-T1). The highest rate of dural puncture (2.8%) occurred at C5-C6. No dural punctures occurred superior to C5-C6 (16.6% of cases). The complication rate was 0.4%. Only greater anteroposterior spinal canal diameter was associated with increased dural puncture rates (p = 0.049). CONCLUSION: CT fluoroscopy-guided cervical interlaminar epidural corticosteroid injections were performed at all levels throughout the cervical spine. A very low complication rate and a minimal rate of inadvertent dural puncture were noted, similar to previously reported rates for conventional fluoroscopy-guided injections limited to the lower cervical spine only.

Inadvertent Intrafacet Injection during Lumbar Interlaminar Epidural Steroid Injection: A Comparison of CT Fluoroscopic and Conventional Fluoroscopic Guidance.

BACKGROUND AND PURPOSE: Inadvertent intrafacet injection can occur during interlaminar epidural steroid injection, resulting in a false-positive loss of resistance and nontarget injection of medication. The purpose of this investigation was to compare the observed rates of this phenomenon during lumbar interlaminar epidural steroid injection performed by using conventional fluoroscopic and CT fluoroscopic guidance. MATERIALS AND METHODS: We retrospectively reviewed 349 lumbar interlaminar epidural steroid injections performed by using conventional fluoroscopy or CT fluoroscopic guidance to determine the observed rates of inadvertent intrafacet injection with each technique. Cases of inadvertent intrafacet injection were classified as either recognized or unrecognized by the proceduralist at the time of the procedure. Multivariate logistic regression was used to determine the independent effect of imaging guidance technique, age, and sex. RESULTS: The rate of inadvertent intrafacet injection was observed to be 7.5% in the CT fluoroscopic group and 0.75% in the conventional fluoroscopy group. All 16 cases identified from CT fluoroscopic procedures were recognized during the procedure; the single case identified from conventional fluoroscopy procedures was not recognized prospectively. The type of imaging guidance showed a statistically significant effect on the detection of the phenomenon (OR for conventional fluoroscopy versus CT fluoroscopy = 0.10, P = .03) that was independent of differences in age or sex. CONCLUSIONS: Inadvertent intrafacet injection is identified during CT fluoroscopic-guided interlaminar epidural steroid injection at a rate that is 10-fold greater than the same procedure performed under conventional fluoroscopy guidance.

CT Fluoroscopy-Guided Blood Patching of Ventral CSF Leaks by Direct Needle Placement in the Ventral Epidural Space Using a Transforaminal Approach.

BACKGROUND AND PURPOSE: Epidural blood patch treatment of spontaneous intracranial hypotension arising from ventral CSF leaks can be difficult secondary to challenges in achieving ventral spread of patching material. The purpose of this study was to determine the technical success rates and safety profile of direct needle placement into the ventral epidural space via a posterior transforaminal approach. MATERIALS AND METHODS: We retrospectively reviewed consecutive CT fluoroscopy-guided epidural blood patches from June 2013 through July 2015. Cases were included if a posterior transforaminal approach was taken to place the needle directly in the ventral epidural space. Rates of technical success (defined as contrast in the spinal canal ventral epidural space) and optimal epidurogram (defined as contrast spreading into or beyond the middle third of the spinal canal ventral epidural space) were determined. Factors influencing these rates were assessed. All complications, inadvertent intravascular injections, and intrathecal punctures were recorded. RESULTS: A total of 72 ventral epidural blood patches were identified; immediate technical success was achieved in 95.8% and an optimal epidurogram in 47.2%. Needle position within the spinal canal ventral epidural space was associated with obtaining an optimal epidurogram (P = .005). Inadvertent intravascular injection was identified in 29.3% of cases, but all were venous. There were no inadvertent intrathecal punctures or complications. CONCLUSIONS: Direct needle placement in the ventral epidural space via a transforaminal approach for treatment of ventral CSF leaks has an excellent technical success rate and safety profile. This technique can be considered as a treatment option in selected patients with ventral CSF leaks for whom traditional techniques are unsuccessful.

Imaging Signs in Spontaneous Intracranial Hypotension: Prevalence and Relationship to CSF Pressure.

BACKGROUND AND PURPOSE: Patients with spontaneous intracranial hypotension often exhibit low CSF pressure and changes on brain MR imaging and/or evidence of CSF leak on myelography. We investigated whether individual imaging signs of spontaneous intracranial hypotension correlate with measured CSF pressure and how frequently these 2 markers of spontaneous intracranial hypotension were concordant. MATERIALS AND METHODS: We performed a retrospective, cross-sectional study of 99 subjects with spontaneous intracranial hypotension. Prevalence of brain and myelographic imaging signs of spontaneous intracranial hypotension was recorded. CSF pressure among subjects with or without individual imaging signs was compared by using a 2-tailed t test and ANOVA. Concordance between low CSF pressure (≤6 cm H2O) and imaging was defined as the presence of the sign in a subject with low CSF pressure or absence of the sign when pressure was not low. RESULTS: Dural enhancement, brain sagging, and venous distension sign were present in 83%, 61%, and 75% of subjects, respectively, and myelographic evidence of CSF leak was seen in 55%. Marginal correlations between CSF pressure and brain sagging (P = .046) and the venous distension sign (P = .047) were found. Dural enhancement and myelographic evidence of leak were not significantly correlated with CSF pressure. Rates of concordance between imaging signs and low CSF pressure were generally low, ranging from 39% to 55%. CONCLUSIONS: Brain and myelographic signs of spontaneous intracranial hypotension correlate poorly with CSF pressure. These findings reinforce the need to base the diagnosis of spontaneous intracranial hypotension on multiple diagnostic criteria and suggest the presence of patient-specific variables that influence CSF pressure in these individuals.

The "Hyperdense Paraspinal Vein" Sign: A Marker of CSF-Venous Fistula.

CSF-venous fistula is a recently reported cause of spontaneous intracranial hypotension that may occur in the absence of myelographic evidence of CSF leak. Information about this entity is currently very limited, but it is of potential importance given the large percentage of cases of spontaneous intracranial hypotension associated with negative myelography findings. We report 3 additional cases of CSF-venous fistula and describe the "hyperdense paraspinal vein" sign, which may aid in its detection.

Incidence of Inadvertent Intravascular Injection during CT Fluoroscopy-Guided Epidural Steroid Injections.

BACKGROUND AND PURPOSE: Inadvertent intravascular injection during epidural steroid injection can result in complications and has been investigated previously with conventional fluoroscopy, but not CT fluoroscopy. The purpose of this study was to determine the incidence of intravascular injections recognized during CT fluoroscopy-guided epidural steroid injection. MATERIALS AND METHODS: We retrospectively reviewed 575 consecutive CT fluoroscopy-guided epidural steroid injections. Procedures were assessed to determine the incidence of intravascular injection. Cases positive for intravascular injection were classified on the basis of anatomic location, distance from the needle tip, washout pattern, and presence of combined epidural and vascular injection. Cases were also graded as either venous or arterial by using a 5-point scale. RESULTS: Intravascular injection was observed in 26% of cervical transforaminal epidural steroid injections (7/27), 9% of cervical interlaminar epidural steroid injections (4/47), 8% of lumbar transforaminal epidural steroid injections (22/275), and 2% of lumbar interlaminar epidural steroid injections (4/222). Vessels were most commonly identified close to the needle, but in 30% of cases, they were visualized in the anterior paraspinal soft tissues remote from the needle. Washout was most commonly delayed (86%), though rapid washout occurred in 14% of cases. Simultaneous epidural and vascular injections occurred in 32% of cases. Most visualized vessels were venous, but 2 cases were classified as probably arterial. CONCLUSIONS: Intravascular injections can be detected with CT fluoroscopy. The incidence in our study was similar to that in previous reports using conventional fluoroscopy. Technical factors such as the "double-tap" on CT fluoroscopy following contrast injection, assessment for discordance between injected and visualized contrast volume, and maintenance of an appropriate FOV facilitate the detection of such events.

Effect of the CT table strap on radiation exposure and image quality during cervical spine CT.

BACKGROUND AND PURPOSE: The CT table strap may impair shoulder lowering during cervical spine CT. The purpose of this investigation was to evaluate the effect of the CT table strap on radiation exposure and image quality during CT of the cervical spine. MATERIALS AND METHODS: Patients undergoing cervical spine CT were prospectively randomized to having the CT table strap placed around the torso and arms (control group) or around the torso only (intervention group). Radiation exposure, shoulder position, and image quality were evaluated. Potential confounders, including neck diameter and scan length, were also assessed. RESULTS: Fifty-eight patients were enrolled and randomized, and 51 subjects were included in the final study population. There was a 21% decrease in radiation exposure in the intervention group compared with the control group (mean dose-length product, 540 ± 152 versus 686 ± 200 mGy × cm, P = .005). Subjects in the intervention group achieved shoulder lowering of an average of >1 vertebral body lower than the control group (mean shoulder level, 7.7 ± 1.3 versus 6.5 ± 1.3, P = .001). Subjective image quality, determined by the lowest level of spinal cord visibility, was also better in the intervention group (mean cord visibility level, 6.9 ± 1.3 versus 5.9 ± 1.3, P = .006). No differences in neck diameter (P = .28) or scan length (P = .55) were observed between groups. CONCLUSIONS: The CT table strap inhibits shoulder lowering during CT of the cervical spine. Placement of the patient's arms outside the CT table strap results in decreased radiation exposure and increased image quality compared with patients whose arms are placed inside the strap.

Rebound intracranial hypertension: a complication of epidural blood patching for intracranial hypotension.

Rebound intracranial hypertension is a complication of epidural blood patching for treatment of intracranial hypotension characterized by increased intracranial pressure, resulting in potentially severe headache, nausea, and vomiting. Because the symptoms of rebound intracranial hypertension may bear some similarity to those of intracranial hypotension and literature reports of rebound intracranial hypertension are limited, it may be mistaken for refractory intracranial hypotension, leading to inappropriate management. This clinical report of 9 patients with confirmed rebound intracranial hypertension reviews the clinical characteristics of patients with this condition, emphasizing factors that can be helpful in discriminating rebound intracranial hypertension from refractory spontaneous intracranial hypotension, and discusses treatment.

High variability in radiologists' reporting practices for incidental thyroid nodules detected on CT and MRI.

BACKGROUND AND PURPOSE: There are no guidelines for reporting incidental thyroid nodules seen on CT and MR imaging. We evaluated radiologists' current reporting practices for incidental thyroid nodules detected on these imaging modalities. MATERIALS AND METHODS: Radiologists were surveyed regarding their reporting practices by using 14 scenarios of incidental thyroid nodules differing in size, patient demographics, and clinical history. Scenarios were evaluated for the following: 1) radiologists' most commonly selected response, and 2) the proportion of radiologists selecting that response (degree of agreement). These measures were used to determine how the patient scenario and characteristics of the radiologists affected variability in practice. RESULTS: One hundred fifty-three radiologists participated. In 8/14 scenarios, the most common response was to "recommend sonography." For the other scenarios, the most common response was to "report in only body of report." The overall mean agreement for the 14 scenarios was 53%, and agreement ranged from 36% to 75%. Smaller nodules had lower agreement: 43%-51% for 8-mm nodules compared with 64%-75% for 15-mm nodules. Agreement was poorest for the 10-mm nodule in a 60-year-old woman (36%) and for scenarios with additional history of lung cancer (39%) and multiple nodules (36%). There was no significant difference in reporting practices and agreement when radiologists were categorized by years of practice, practice type, and subspecialty (P > .55). CONCLUSIONS: The reporting practice for incidental thyroid nodules on CT or MR imaging is highly variable among radiologists, especially for patients with smaller nodules (≤10 mm) and patients with multiple nodules and a history of cancer. This variability highlights the need for practice guidelines.

Optimal contrast concentration for CT-guided epidural steroid injections.

BACKGROUND AND PURPOSE: Contrast is used in CT-guided epidural steroid injections to ensure proper needle placement. Once injected, undiluted contrast often obscures the needle, hindering subsequent repositioning. The purpose of this investigation was to establish the optimal contrast dilution for CT-guided epidural steroid injections. MATERIALS AND METHODS: This investigation consisted of an initial phantom study, followed by a prospective, randomized, single-center trial assessing a range of contrast dilutions. In the phantom study, a phantom housing a chamber containing a 22-gauge needle and various dilutions of contrast was scanned, and images were evaluated for needle visibility. On the basis of these results, concentrations of 66, 100, 133, and 150 mg/mL iodine were selected for evaluation in a clinical study. Patients presenting for CT-guided epidural steroid injections were randomly assigned to a contrast dilution, and images from the procedure were evaluated by 2 readers blinded to the contrast assignment. Needle visibility was scored by use of a 5-point scale. RESULTS: In the phantom study, the needle was not visible at contrast concentrations of ≥133 mg/mL. In the clinical study, needle visibility was strongly associated with contrast concentration (P < .0001). Significant improvements in visibility were found in 66 mg/mL and 100 mg/mL compared with higher iodine concentrations; no difference was found comparing 66 mg/mL with 100 mg/mL iodine. Neither injection location (cervical versus lumbar) nor technique (interlaminar versus transforaminal) influenced visibility scores. CONCLUSIONS: For CT-guided epidural steroid injections, the optimal contrast concentration is 66-100 mg/mL iodine. Because these concentrations are not commercially available, proceduralists must dilute their contrast for such procedures.

CT-guided cervical transforaminal steroid injections: where should the needle tip be located?

BACKGROUND AND PURPOSE: The aim of CT-guided CTSI is to inject medication into the foraminal region where the nerve root is inflamed. The optimal location for needle placement and therapeutic delivery, however, remain uncertain. The purpose of this study was to investigate how needle positioning and angle of approach impact the transforaminal distribution of injectate. MATERIALS AND METHODS: We retrospectively reviewed fluoroscopic images from 90 CT-guided CTSI procedures for needle-tip location, needle angle, and contrast distribution. Needle-tip position was categorized as either foraminal zone, junctional, or extraforaminal. Distribution of contrast injected immediately before steroid administration was categorized as central epidural, intraforaminal, or extraforaminal in location. Needle-tip location and angle were correlated with contrast distribution. RESULTS: The needle tip was most commonly placed in the junctional position (36 cases, 40%), followed by foraminal (30 cases, 33%) and extraforaminal (24 cases, 27%) locations. Intraforaminal contrast distribution was highest when the needle location was foraminal (30/30, 100%) or junctional (35/36, 97%), compared with extraforaminal (7/24, 29%) (P value <.0001). There was no relationship between needle angle and contrast distribution. CONCLUSIONS: Needle-tip location at the outer edge of the neural foramen (junctional location) correlated well with intraforaminal distribution of contrast for CT-guided CTSI and compared favorably with injectate distribution following foraminal zone needle positioning. Junctional needle positioning may be preferred over the foraminal zone by some proceduralists. Extraforaminal needle positioning resulted in less favorable contrast distribution, which may significantly diminish the therapeutic efficacy of CTSI.

Spinal meningeal diverticula in spontaneous intracranial hypotension: analysis of prevalence and myelographic appearance.

BACKGROUND AND PURPOSE: Spinal meningeal diverticula have been implicated in the pathogenesis of spontaneous intracranial hypotension and have been proposed as both diagnostic features of and therapeutic targets for the condition. We compared the prevalence and myelographic appearance of spinal diverticula in patients with SIH and healthy controls. MATERIALS AND METHODS: Patients satisfying the ICHD-2 criteria for SIH were retrospectively identified. CT myelograms of 19 patients with SIH were compared with CT myelograms of 18 control patients. Images were reviewed by 2 blinded neuroradiologists. The prevalence, morphology (round versus multilobulated), size, and location (cervical, upper thoracic, lower thoracic, or lumbar) of spinal meningeal diverticula were analyzed. RESULTS: There was no difference in the proportion of patients with diverticula in the SIH group compared with the control group (68% versus 44%, P = .14) or in the mean number of diverticula per patient (6.3 versus 2.2, P = .099). No difference was seen in the morphology (P = .95) or size (P = .71) of diverticula between groups. There was a difference between groups that just reached statistical significance (P = .050) in the location of the diverticula along the spinal axis, but substantial overlap was seen between groups for all spinal locations. CONCLUSIONS: Despite the well-established association between spinal meningeal diverticula and SIH, we found no difference in the prevalence or myelographic appearance of diverticula in patients with SIH compared with controls. Further investigation into the role of diverticula in the diagnosis and treatment of SIH is necessary.

CT-guided lumbar nerve root injections: are we using the correct radiation dose settings?

BACKGROUND AND PURPOSE: Selecting a lower tube current for CT fluoroscopic spine injections is a method of radiation dose reduction. Ideally tube current should be tailored to the patient's body habitus, but a greater influence on tube current may be the proceduralist's personal preference. The purpose of this study was to compare tube current and fluoroscopy time of different proceduralists for lumbar spine CT-guided selective nerve root blocks, and to correlate image quality to patient diameter and tube current. MATERIALS AND METHODS: Eighty CT-guided SNRBs performed by 4 proceduralists were retrospectively reviewed for tube current and fluoroscopy time. Patient body habitus was evaluated by measuring anteroposterior diameters on scout images. Image quality was evaluated objectively and subjectively: noise was measured in the psoas muscle and images were graded on a 3-point scale. RESULTS: The mean tube current was 59 ± 20 mA and mean fluoroscopy time was 10.4 ± 7.5 seconds. The mean tube current between proceduralists differed by almost 2-fold, and there was greater than 2-fold difference in mean fluoroscopy time (P < .0001 and .01, respectively). Mean AP body size was 27 ± 5 cm. When categoric data of tube current and AP diameter were analyzed, only AP diameter was a statistically significant variable influencing image noise (P = .009). Twenty of 23 patients with AP diameter ≤30 cm had adequate to excellent image quality, even with lower tube current of ≤40 mA. CONCLUSIONS: Wide variability in tube current selection between proceduralists calls for a more objective method of selecting tube current to minimize radiation dose. Body size, measured by AP diameter, had the greatest influence on image quality. This could be used to identify patients for lower tube current selection.

CT fluoroscopy-guided cervical interlaminar steroid injections: safety, technique, and radiation dose parameters.

BACKGROUND AND PURPOSE: Cervical epidural steroid injections are approached with trepidation because of concerns over safety, including direct spinal cord injury. CT fluoroscopy is an alternative to conventional fluoroscopy that could potentially help reduce the risk of injury by providing improved localization of the needle tip. We sought to determine rates of technical success and risk of complications in our initial cohort of patients treated with cervical interlaminar ESI performed under CTF guidance. MATERIALS AND METHODS: In this retrospective case series, we reviewed procedural details and CTF images of 53 consecutive cervical interlaminar ESIs performed on 50 patients over a period of 8 months. Rates of technical success, incidence of complications, procedure times, and factors that influence radiation exposure were examined. RESULTS: No symptomatic procedural complications were observed. A single case of intrathecal contrast injection was observed, from which the patient was asymptomatic. The remaining injections were all technically successful. Injections were performed at every cervical level, as high as C1-C2. Total procedure times averaged less than 20 minutes. Average CT fluoroscopic time was 24 seconds and median tube current was 70 mA. CONCLUSIONS: CTF-guided cervical interlaminar ESI can be performed at all levels in the cervical spine with a low rate of procedural complications. Short total procedure times, CT-fluoroscopy times, and reduced tube current make this procedure a practical alternative to cervical ESI performed under conventional fluoroscopy.