Image-Guided Spine Interventions for Pain: Ongoing Controversies.

An expanding array of image-guided spine interventions have the potential to provide immediate and effective pain relief. Innovations in spine intervention have proceeded rapidly, with clinical adoption of new techniques at times occurring before the development of bodies of evidence to establish efficacy. Although new spine interventions have been evaluated by clinical trials, acceptance of results has been hindered by controversies regarding trial methodology. This article explores controversial aspects of four categories of image-guided interventions for painful conditions: spine interventions for postdural puncture headache resulting from prior lumbar procedures, epidural steroid injections for cervical and lumbar radiculopathy, interventions for facet and sacroiliac joint pain, and vertebral augmentations for compression fractures. For each intervention, we summarize the available literature, with an emphasis on persistent controversies, and discuss how current areas of disagreement and challenge may shape future research and innovation. Despite the ongoing areas of debate regarding various aspects of these procedures, effective treatments continue to emerge and show promise for aiding relief of a range of debilitating conditions.

Comparison of the Prevalence of Ruptured and Unruptured Cerebral Aneurysms in a Poor Urban Minority Population.

BACKGROUND: Most ruptured cerebral aneurysms are small (<7 mm). Evidence suggests low rupture rates for such lesions (<1% per year). Population studies demonstrate a prevalence rate of 3.2%. This study simultaneously estimates the prevalence of aneurysms in a single geographic population while reporting the observed rate of aneurysmal subarachnoid hemorrhage (aSAH) in the same geographic region composed of a poor urban minority demographic. METHODS: This is an institutional review board-approved, Health Insurance Portability and Accountability Act of 1996-compliant retrospective study performed between 2005 and 2011 at a single center. Part 1 used the electronic medical record to identify all patients with a magnetic resonance angiography demonstrating a cerebral aneurysm. Part 2 used the electronic medical record to identify all patients from the same geographic area presenting with aSAH during the study period. RESULTS: A total of 11,160 subjects had a magnetic resonance angiography from the study area. In this group, 422 intradural cerebral aneurysms were incidentally discovered. Ninety-one percent were less than 10 mm (mean 5.49, standard deviation 4.6). Twenty-one percent were aneurysms of the anterior communicating artery complex. Fourteen percent were of posterior communicating artery origin. A total of 237 patients had aSAH. Ninety-two percent of the aneurysms were less than 10 mm (mean 6 mm, standard deviation 3.2 mm). Both groups were composed of poor urban minority patients. CONCLUSIONS: The observed annual rate of rupture of small anterior circulation aneurysms in this study was .06%-.15% per year. The extrapolated population prevalence of such aneurysms (4.0%-1.5%) may explain the observed rate of rupture of these small aneurysms in a poor urban minority population.

Radiation Dose and Procedure Time for 994 CT-guided Spine Pain Control Procedures.

BACKGROUND: Image guidance for spine pain control procedures, including epidural steroid injection, nerve root block, and facet block, can be performed with either computed tomography (CT) or conventional fluoroscopy. CT has the advantage of improved anatomic localization and use of air for contrast; however, there are concerns that CT leads to higher radiation dose and longer procedure time. OBJECTIVE: To evaluate procedure time and radiation dose for multiple types of spine pain control procedures performed under CT guidance. STUDY DESIGN: Retrospective evaluation. SETTING: Department of radiology in single academic medical center. METHODS: Institutional review board approval was obtained. We reviewed CT-guided spine procedures performed over a 12-month period from January 2012 to December 2012. Procedure type, procedure time, and dose-length product were recorded. Patient age and gender were recorded for each case; additionally, demographic and medical history data were obtained for a sub-group of patients. RESULTS: Nine hundred ninety-four studies (performed in 699 patients) were reviewed, including 585 epidural steroid injections, 228 nerve root blocks, and 90 facet blocks. For all studies, procedure time averaged 7:34 ± 5:05, and dose-length product averaged 75 mGy·cm ± 61. Additional medical history (available for 483 patients) revealed high rate of obesity (body mass index [BMI] = 30 ± 6.8, with 76% of patients overweight [BMI > 25] and 42% obese [BMI > 30]), and frequent medical comorbidities (including hypertension [n = 179], diabetes [n = 101], renal failure [n = 30], and heart failure [n = 17]). LIMITATIONS: This study was performed retrospectively, and limited to a single institution. CONCLUSION: These findings add to the growing evidence that CT guidance is a safe and effective technique for epidural steroid injection. These results further demonstrate that other spine intervention procedures, including nerve root block and facet block, can also be performed under CT guidance with short procedure time and reasonable levels of radiation exposure. This approach can be effectively used in a patient population with a high rate of obesity and medical comorbidities.

CT versus ultrasound guidance for percutaneous drainages in the pediatric population: an institutional review meant to limit radiation.

Computed tomography (CT)-guided percutaneous drainage is a minimally invasive procedure that allows for accurate diagnosis and therapy with minimal complications. The drawback is that CT guidance carries a significant amount of radiation exposure. CT-guided percutaneous drainages have been widely used in adults and have been gaining momentum within the pediatric population. Through a thorough review of our institution's (Montefiore Medical Center) CT-guided percutaneous drainages within our pediatric patients, we assessed the radiation exposure per study as well as which studies were deemed possible under ultrasound guidance as a possible alternative.

Comparison of CT and fluoroscopic guidance for lumbar puncture in an obese population with prior failed unguided attempt.

BACKGROUND AND PURPOSE: In the past 50 years, fluoroscopic guidance has been used to improve upon lumbar puncture (LP) technique that was unchanged for over a century. Recently, CT has seen increasing use as a guidance modality due to its ability to demonstrate soft tissue contrast and provide millimeter accuracy with needle targeting. This study compared procedure time and radiation dosages for fluoroscopic and CT guided LP. MATERIALS AND METHODS: This institutional review board and Health Insurance Portability and Accountability Act (HIPAA) compliant study was a retrospective review of a consecutive cohort referred for image guided LP. For CT, 45 patients aged 49 years (range 20-78, SD 14) with body mass index (BMI) values of 33 kg/m(2) (range 20-50, SD 12) were included. For fluoroscopy, 100 patients aged 47 years (range 18-88, SD 17) with BMI values of 29 kg/m(2) (range 15-56, SD 9) were included. CT procedure time was determined using picture archiving and communication system (PACS) image time stamps. Radiation dose was determined using the CT dose report and effective dose conversion factors. Fluoroscopic procedure time was determined from nursing. Fluoroscopic radiation dose was calculated from dose-area product (DAP) and fluoroscopy times, with effective dosage calculated using simulation software. RESULTS: For CT, procedure time average was 14 min (range 5-42, SD 8.5). Average dose-length product was 120 mGy×cm (range 39-211, SD 43) and average effective dose was 1.98 mSv (range 0.2-8.18, SD 4.4). For fluoroscopy, procedure time averaged 12 min (range 12-30, SD 6). Average DAP was 10 Gy×cm(2) (range 0.1-70, SD 11) and effective dose estimate averaged 2.9 mSv (range 0.9-9.4, SD 1.9). There were no unsuccessful taps or complications. CONCLUSIONS: Both fluoroscopic and CT guidance may be used to perform an LP in an obese population with a short procedure time and low radiation dose.

Impact of socioeconomic status on ionizing radiation exposure from medical imaging in children.

PURPOSE: To characterize cumulative radiation exposure from diagnostic imaging (CEDI) in pediatric patients and to investigate its relationship to patients' socioeconomic status and comorbid medical conditions. METHODS: A retrospective cohort study of >19,000 pediatric patients seen within the outpatient clinic system of an academic tertiary care urban medical center during the month of January 2006 was conducted to estimate CEDI from all procedures performed within 3 years of the index visit (until January 2009). Socioeconomic status was estimated from census tract geocoding. Comorbid medical conditions were identified from the electronic medical record. RESULTS: A total of 19,063 patients underwent imaging tests within the index month. The mean age was 8.9 ± 6.3 years. Most had private insurance (56%), with 36% receiving Medicaid and 8% private payers. Our population lived in census tracts in which 27 ± 16% of the population were below the federal poverty level with 62% living in areas in which 20% of residents were living below the poverty level. There were differences in CEDI (P < .0001) by age, insurance type, and percentage poverty in the census tract of residence but not among racial groups (P = .6508). The association between poverty and CEDI was generally explained by the 26 Elixhauser diagnoses, with the exception of rheumatoid arthritis. CONCLUSION: Patients living in areas of greater poverty were exposed over time to more radiation from diagnostic testing than those living in areas with lower percentages of residents living in poverty. This association was explained almost entirely by the presence of disease burden. No direct association was found between socioeconomic status and CEDI.

The impact of socioeconomic status and comorbid medical conditions on ionizing radiation exposure from diagnostic medical imaging in adults.

PURPOSE: The aim of this study was to characterize cumulative exposure to ionizing radiation from diagnostic imaging (CEDI) in adult patients and investigate its relationship to a patient's socioeconomic status and comorbid medical conditions. METHODS: A retrospective cohort study was conducted of 54,015 patients seen within the outpatient clinic system of an academic, tertiary care, urban medical center during the month of January 2006, estimating the CEDI from all procedures performed within 3 years of the index visit (until January 2009). Socioeconomic status was estimated from census tract geocoding. Comorbid medical conditions were identified from the electronic medical record. RESULTS: A total of 9,537 adult patients were seen within the index month and underwent imaging tests. Eighty percent were living in areas with >10% poverty. Thirty-six percent of men and 43% of women had diagnoses from the Elixhauser list. Mean CEDI values were 10 ± 19.09 mSv for those from areas with >10% poverty and 8.9 ± 22.42 mSv for those living in areas with <10% poverty. Poverty and comorbidities covaried. Estimated CEDI within groups of patients with the same comorbidity was not associated with socioeconomic status. CONCLUSION: At this institution, there is a high prevalence of patients living in poverty. Those living in poverty are at higher risk for comorbid conditions that are associated with increased CEDI. However, controlling for comorbidity, socioeconomic status was no longer predictive of CEDI.

Bilateral internal carotid artery dissection in the postpartum period.

BACKGROUND: Bilateral internal carotid artery dissection is a rare event associated with pregnancy, especially in a patient without any predisposing risk factors. CASE: A 34-year-old woman presented with postpartum unilateral weakness, headaches, and blurry vision 14 days after vaginal delivery. Radiologic imaging revealed bilateral cervical internal carotid artery dissections and cerebral infarctions. She was treated with anticoagulation and showed radiographic and clinical improvement. CONCLUSION: The pathophysiology of cervical artery dissection appears multifactorial, with evidence suggesting environmental and genetic contributions. Intimal injury related to the Valsalva maneuver during labor as well as hemodynamic and hormonal changes related to pregnancy are presumed causes of peripartum spontaneous carotid artery dissection. Antithrombotic therapy for at least 3 to 6 months after dissection and follow-up neuroimaging are suggested.

Radiofrequency ablation of advanced head and neck cancer.

OBJECTIVE: To determine if the application of radiofrequency ablation to advanced head and neck cancer (HNC) would result in local control of the tumor. DESIGN: Radiofrequency ablation was applied to advanced head and neck malignant tumors in the participants of this nonrandomized controlled trial. SETTING: Academic tertiary care medical center. PARTICIPANTS: Twenty-one participants with recurrent and/or unresectable HNC who failed treatment with surgery, radiation, and/or chemotherapy were selected for the trial. Patients deemed appropriate for curative standard radiation or surgery were not accepted as participants. INTERVENTION: Radiofrequency ablation was applied to head and neck tumors under general anesthesia and computed tomographic scan guidance. MAIN OUTCOME MEASURES: The primary end point was local control. Computed tomographic scan tumor measurements were used to assess response by standard response evaluation criteria in solid tumors (RECIST) guidelines. Secondary outcome measures included survival and quality of life. RESULTS: Eight of 13 participants had stable disease after intervention. Median survival was 127 days, and an improvement in University of Washington quality-of-life scores was noted. Adverse outcomes included 1 death due to carotid hemorrhage and 2 strokes. CONCLUSION: Radiofrequency ablation is a palliative treatment alternative that shows promise in addressing the challenges of local control and quality of life in patients with incurable HNC who have failed standard curative treatment.

External validation of the New Orleans Criteria (NOC), the Canadian CT Head Rule (CCHR) and the National Emergency X-Radiography Utilization Study II (NEXUS II) for CT scanning in pediatric patients with minor head injury in a non-trauma center.

BACKGROUND: Head CT scans are considered the imaging modality of choice to screen patients with head trauma for neurocranial injuries; however, widespread CT imaging is not recommended and much research has been conducted to establish objective clinical predictors of intracranial injury (ICI) in order to optimize the use of neuroimaging in children with minor head trauma. OBJECTIVE: To evaluate whether a strict application of the New Orleans Criteria (NOC), Canadian CT Head Rule (CCHR) and National Emergency X-Radiography Utilization Study II (NEXUS II) in pediatric patients with head trauma presenting to a non-trauma center (level II) could reduce the number of cranial CT scans performed without missing clinically significant ICI. MATERIALS AND METHODS: We conducted an IRB-approved retrospective analysis of pediatric patients with head trauma who received a cranial CT scan between Jan. 1, 2001, and Sept. 1, 2008, and identified which patients would have required a scan based on the criteria of the above listed decision instruments. We then determined the sensitivities, specificities and negative predictive values of these aids. RESULTS: In our cohort of 2,101 patients, 92 (4.4%) had positive head CT findings. The sensitivities for the NOC, CCHR and NEXUS II were 96.7% (95%CI 93.1-100), 65.2% (95%CI 55.5-74.9) and 78.3% (95%CI 69.9-86.7), respectively, and their negative predictive values were 98.7%, 97.6% and 97.2%, respectively. In contrast, the specificities for these aids were 11.2% (95%CI 9.8-12.6), 64.2% (95%CI 62.1-66.3) and 34.2% (95%CI 32.1-36.3), respectively. Therefore, in our population it would have been possible to scan at least 10.9% fewer patients. CONCLUSIONS: The number of cranial CT scans conducted in our pediatric cohort with head trauma would have been reduced had any of the three clinical decision aids been applied. Therefore, we recommend that further validation and adoption of pediatric head CT decision aids in non-trauma centers be considered to ultimately increase patient safety while reducing medical expense.

Computed tomography-guided lumbar drain placement.

The authors describe a technique for lumbar drain placement using CT guidance. Midline or paramidline interlaminar approaches to the thecal sac can be used. The major advantage to CT guidance is direct visualization of the needle tip in relation to the thecal sac. This technical approach is a safe and rapid alternative to fluoroscopic guidance for the placement of lumbar drains in patients in whom standard lumbar drain placement techniques have failed.

Vertebral augmentation with a flexible curved needle: preliminary results in 17 consecutive patients.

This report details a trial demonstrating the viability of a blunt-tipped curved needle for use as a cement injection device for vertebral body augmentation. Between January and September 2007, 17 consecutive patients (eight men and nine women; average age, 76 years; age range, 52-97 years) underwent vertebral body augmentation with a blunt-tipped curved nitinol injection needle via a single pedicle to treat pain due to acute vertebral body compression fractures. All patients were successfully treated without complication. The results of the trial demonstrate that a curved blunt-tipped nitinol needle is a viable alternative to a rigid injection cannula when performing vertebral body augmentation with cement.

CT-guided radiofrequency ablation in the palliative treatment of recurrent advanced head and neck malignancies.

PURPOSE: To evaluate the safety and effectiveness of computed tomography (CT)-guided radiofrequency (RF) ablation in the palliative treatment of recurrent advanced head and neck cancers. MATERIALS AND METHODS: From November 2002 to January 2005, the authors identified 14 patients (median age, 61 years) with 14 recurrent advanced primary head and neck malignancies who underwent 27 CT-guided RF ablation applications during 20 sessions at their institution. RF ablation was performed in all patients with the intent of palliative therapy. Radiologic tumor response was assessed by using Response Evaluation Criteria in Solid Tumors. Patients were assessed clinically by means of University of Washington Head and Neck Quality of Life questionnaires. RESULTS: Technical success in tumor targeting and electrode deployment was 100%. University of Washington quality of life surveys completed by six of 14 patients (43%) showed an index increase by a median of 3.1 percentage points, with four of six patients (67%) demonstrating improvement. Three major complications (in 27 applications, 11%) occurred 7 days to 2 weeks after the procedure. These included stroke, carotid blowout leading to death, and threatened carotid blowout with subsequent stroke. Retrospective analysis of intraprocedural CT scans revealed that the retractable electrodes were within 1 cm of the carotid artery during ablation in these cases. CONCLUSIONS: RF ablation in patients with advanced head and neck malignancies is feasible and effective for palliation. CT-guidance provides accurate probe placement and electrode deployment. The energy level used and proximity of the ablation sphere to the carotid artery may predispose to vascular complications.