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A novel Laser Navigation System reduces radiation exposure and improves accuracy and workflow of CT-guided spinal interventions: A prospective, randomized, controlled, clinical trial in comparison to conventional freehand puncture Carsten Moser a,∗ , Jan Becker a,1 , Martin Deli b,2 , Martin Busch a,3 , Marc Boehme b,4 , Dietrich H.W. Groenemeyer a,4 a Groenemeyer Institute for Microtherapy, Faculty for Radiology and Microtherapy, University Witten/Herdecke, Universitaetsstrasse 142, 44799 Bochum, Germany b amedo Smart Tracking Solutions GmbH, Universitaetsstrasse 142, 44799 Bochum, Germany
a r t i c l e
i n f o
Article history: Received 9 July 2012 Received in revised form 12 October 2012 Accepted 26 October 2012 Keywords: Navigation CT-guided intervention Spinal injection Microtherapy Needle guidance Drug delivery
a b s t r a c t Purpose: Phantom model evaluation and prospective randomized clinical trial to assess the clinical feasibility and benefit of using a novel Laser Navigation System (LNS) in CT-guided epidural and perineural injections in comparison to the conventional freehand procedure. Methods: The LNS guided puncture technique was compared to the standard CT-guided freehand treatment using a phantom model and a randomized clinical trial. Spinal injections were administered by an experienced interventional team to evaluate needle placement accuracy, treatment time and radiation exposure. Results: In the LNS group of the phantom model study, the needle entrance point accuracy of 0.5 mm (freehand 3.1 mm), needle target point accuracy of 2.0 mm (freehand 3.5 mm), number of control CT slices of 1.4 (freehand 2.7) and needle placement time of 5 min 4 s (freehand: 9 min 18 s) showed significant improvements compared to freehand in 60 punctures. In the clinical trial the LNS group achieved needle entrance point accuracy of 1.3 mm (freehand 4.6 mm), needle angulation accuracy of 0.4◦ (freehand 2.3◦ ), number of control CT slices of 1.1 (freehand 1.8) and needle placement time of 6 min 54 s (freehand 9 min 00 s), showing significant improvements compared to freehand in a total of 58 CT-guided interventions. Conclusion: The LNS group showed significantly improved results in both study designs. Both the phantom model evaluation and the clinical trial of spinal injections showed feasibility and efficacy of using the novel LNS. Even an experienced interventional team worked with it more precise, faster and with reduced radiation exposure. © 2012 Elsevier Ireland Ltd. All rights reserved.
1. Introduction Low back pain (LBP) is the most frequent musculoskeletal complaint worldwide affecting all age groups. Health care systems are
∗ Corresponding author. Tel.: +49 1733771731/234 9780 165; fax: +49 234 9780 166/234 9780 156. E-mail addresses:
[email protected],
[email protected] (C. Moser),
[email protected] (J. Becker),
[email protected] (M. Deli),
[email protected] (M. Busch),
[email protected] (M. Boehme),
[email protected] (D.H.W. Groenemeyer). 1 Tel.: +49 234 9780 152. 2 Tel.: +49 174 3338925. 3 Tel.: +49 234 9780129. 4 Tel.: +49 1733771731.
stained by enormous costs generated through the treatments of an ever increasing amount of patients [1,2]. Treatment options include either non-operative or interventional/surgical procedures (depending on etiology and severity). Several studies have shown favourable improvement in patient assessed pain and disability scores with conservative care such as exercise therapy, chiropractic manipulation and pharmacological interventions. More severe cases may benefit from therapeutic injections or spine surgery [3–6]. Percutaneous epidural or perineural steroid injections have been extensively investigated the past years. Along with the use of low-dose mixtures of local anesthetics, saline, autologous antiinflammatory cytokines the steroid injection is current standard treatment for LBP. To successfully perform injections, precise needle placement and -guidance is essential for accurate drug
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Please cite this article in press as: Moser C, et al. A novel Laser Navigation System reduces radiation exposure and improves accuracy and workflow of CT-guided spinal interventions: A prospective, randomized, controlled, clinical trial in comparison to conventional freehand puncture. Eur J Radiol (2012), http://dx.doi.org/10.1016/j.ejrad.2012.10.028
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delivery [7]. Missing the intended target and injecting into surrounding structures increases the risk of tendon tears, soft tissue atrophy, skin atrophy, depigmentation, and injury to adjacent structures [6]. Image guiding techniques are proven to be beneficial for safety and effectiveness of spinal interventions. However navigation and guidance systems have been studied and utilized primarily for radiation therapy, brachytherapy or neurosurgery; they are rarely used for spinal punctures or other percutaneous interventions [4,8–10]. Many physicians inject steroids and local anesthetics in their own practice. Current guidelines recommend imaging guidance including the use of a contrast agent to visualize the procedure and deliver the drug to the targeted area [3,4]. Image-guided therapeutic injections are usually performed using computed tomography (CT), fluoroscopy, ultrasound and most recently, magnetic resonance imaging (MRI). CT provides high spatial resolution and superior 3-dimensional anatomic details at a good bone to soft tissue contrast and is claimed to be more accurate than fluoroscopy in locating anatomic landmarks. However, lacking real-time visualization, the needle puncture is often performed freehand in an iterative way and usually requires several CT control slices for each case. This results in increased radiation exposure and prolonged procedure time. Intermittent low dose CT fluoroscopy had been described to reduce the radiation dose to the patient and the total procedure time compared to conventional CT [11,12]. Nevertheless, physicians are exposed to radiation when using CT fluoroscopy. Previous studies have established a correlation between the time and radiation exposure of a freehand CT-guided injection and the level of experience of an interventional team [9,13–15]. Needle guidance systems are aiming at higher accuracy with fewer complications, shorter treatment times and lower radiation exposures compared to freehand punctures. Different positioning devices are available including laser alignment systems, optical or electromagnetic tracked navigation systems, stereotactic systems, and fixed needle holders [9,16–18]. Multiple studies have shown the advantages of computerassisted navigation systems but deficiencies such as increased handling and set-up times have prohibited the spread of one particular navigation system [15,18,19]. So far laser alignment systems for CT-guided interventions require manual incision angle alignment. No laser-based needle guidance system showed both the entry point on the patient’s skin and guided the incision angle alignment automatically. The objective is the assessment of the feasibility and benefit of the novel LNS in a first clinical study. This study compares LNS guided epidural and perineural lumbar injection procedures to the conventional freehand procedure.
needle trajectory follows the ray of the laser beam. Correct positioning is apparent when the needle was inserted at the laser target point keeping the laser beam at the distal end of the needle. 2.2. CT imaging In phantom model and clinical study CT imaging was performed with a single slice CT (Tomoscan, Philips Medical Systems, Eindhoven, Netherlands) applying a low dose protocol of fixed CT parameters (0.45 mm × 0.45 mm × 5 mm, 120 kV, 20 mA, 2 s/rotation, 1 slice/rotation, 5 mm table increment). An average number of 4 scans is needed for planning and needle control of a single needle epidural injection in our institution. By using this specific institutional low dose protocol on that particular CT scanner the effective radiation doses for male patients on average are 0.4 mSv and 0.6 mSv for female patients (calculated with CT-Expo software [20], Version 1.7.1). Lower values can be achieved with different (new) CT-scanners [21]. 2.3. Phantom model An anthropomorphic plastic model of the lumbar spine that was embedded in polyurethane foam with latex coating and clearly delineated osseous elements of the spine was used to assess the applicability, precision and feasibility of using the LNS. Texture and resolution of the phantom were subjectively comparable to those of tissues in vivo. The phantom was placed on the CT table corresponding to a prone position for a patient. Images were transferred to the LNS to plan axial epidural and perineural punctures. 60 injections were simulated on the phantom: 30 with LNS on one side of the phantom and 30 identical procedures using conventional freehand method on the other side (side randomly assigned). 2.4. Patient population and clinical trial In a prospective, randomized, clinical trial 29 patients with chronic LBP and radiculopathy were selected to be treated with CT-guided epidural or perineural steroid injections once with the conventional freehand method and once with the LNS supported method. A total of 58 injections were performed in patients suffering from pain for at least 6 consecutive weeks without vertebral fractures, coagulation impairment, known allergies against study medications, pregnancy or infections. To verify the diagnosis, anamnesis, clinical examination and MRI imaging of the lumbar spine were performed. Written informed consent was obtained from all patients. The study protocol had been approved by an independent ethics committee (IEC). 2.5. Intervention procedures
2. Material and methods 2.1. Laser Navigation System LNS (amedo Smart Tracking Solutions GmbH, Bochum, Germany) is a laser based guidance device for a combined use with any standard CT system. The LNS consists of a movable and rotatable laser unit on a 220◦ circular rail surrounding the patient table in front of the CT gantry, an image processing unit for the positioning of the laser and navigation software for the planning of the intervention (Fig. 1). The circular rail system is mounted at a fixed position relative to the gantry of the CT. The image processing unit enables puncture trajectory planning, and indicates needle incision depths and corresponding table position. The planning data are transferred to the mechanical system so that the laser positions automatically show the entrance point and incision angle. The
A well experienced interventional team (one physician and one CT operator) performed all treatments with fixed parameters including scanner, patient positioning (prone), CT low dose protocol and puncture needle. Each patient received two treatments without premedication. At a first appointment participants were randomly assigned by the use of sealed envelopes encoding the initial treatment method to the freehand technique (method A) or the LNS-assisted CT-guided injection (method B). Each treatment was followed by an injection using the other method. Needle position adjustments and number of control CT slices were exclusively conducted in accordance to individual medical needs. All punctures were carried out with a 22 gauge needle using 2.5 ml of Scandicain (1%) as local anesthetic. Before starting the drug injection (10 mg of Triamcinolone and 2 ml of saline solution), a final CT-scan was performed to document
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Fig. 1. The Laser Navigation System (laser unit; circular rail; image processing unit).
correct needle positioning using contrast agent (1 ml containing 150 mg iodine/ml). After injection all patients were observed for 30 min and monitored for adverse events. In method A (freehand) the physician planned the puncture trajectory. To determine the needle entrance point on the patient, the intervention team calculated the horizontal distance between the reference point previously marked on the patient and the ideal puncture trajectory as plotted on the screen. The needle entrance point was marked with a single-use hygienic pen before disinfecting and draping the patient in a sterile fashion. The physician iterated the needle to the target; controlling the position with CT control slices. Using method B (LNS), the needle path was planned with the LNS navigation software. The LNS transferred the planned entrance point and puncture trajectory via a laser beam on the patient’s skin. The physician introduced the needle at the highlighted entrance point and moved the needle inwards ensuring that the laser dot was continually visible on the distal end of the needle. By choosing a needle with an adequate length (needles had different lengths and same diameter) the procedure ensured even depth accuracy without needing further control CT slices.
between planning slice and realized slice position). Angle deviations were measured in the slice showing the needle entry point neglecting angular deviations in z-direction. The needle placement time [mm:ss] was extracted from the DICOM headers of the first planning-image up to the image of the needle at final position. Time to position or to remove the patient was not included. Total radiation exposure was directly proportional to the number of CT slices because one slice-fixed low dose CT parameters was used. Clinical parameters such as the VAS of pain or other patient recorded outcome measurements were not described in this study since all patients received both injection techniques during their treatment course. The data were displayed as arithmetic means, medians, quartiles, standard deviations, minimum and maximum values. After applying the Shapiro–Wilk test for normality, data were compared using either a paired t-test (non-rejection of the normality assumption) or a Wilcoxon signed-rank-test (rejection of the normality assumption). A p-value of or below 0.1 was considered to be significant concerning the normality test. For the paired t-test and the Wilcoxon signed-rank-test a p-value of or below 0.05 was considered to be significant. All analyses were conducted with the SAS statistical software (SAS Institute Inc., North Carolina, USA).
2.6. Assessment of outcome parameters and statistical evaluation
3. Results
Precision measurements were conducted with the Software JiveX (Visus Technology Transfer GmbH, Bochum, Germany). Needle entrance point accuracy was measured as difference between planned and achieved needle entrance point [mm], needle target point accuracy as difference between planned and achieved needle tip at target [mm] and needle angulation accuracy [degree] as difference between the planned and final angle of the puncture trajectory. Entrance point and target point accuracies were measured as the length of the vector in x-(horizontal deviation in slice), y-(vertical deviation in slice) and z-direction (deviation
3.1. No technical failures were observed during phantom study or clinical trial 3.1.1. Preclinical phantom study 60 punctures were successfully performed in the preclinical phantom study. After the planning CT-scan, the needle was placed in the designated epidural space or perineural area. The results of the t-tests and Wilcoxon signed-rank tests comparing accuracy, time and required CT slices of the conventional freehand method and LNS-guided punctures are summarized in Table 1. The
Please cite this article in press as: Moser C, et al. A novel Laser Navigation System reduces radiation exposure and improves accuracy and workflow of CT-guided spinal interventions: A prospective, randomized, controlled, clinical trial in comparison to conventional freehand puncture. Eur J Radiol (2012), http://dx.doi.org/10.1016/j.ejrad.2012.10.028
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Mean
(A) Accuracy measurements (A1) Needle entrance point accuracy XY [mm]* Freehand 30 3.1 LNS 30 0.5 30 2.6 Freehand – LNS (A2) Needle target point accuracy [mm]* Freehand 30 3.5 30 2.0 LNS 30 1.6 Freehand – LNS (B) Number of control CT slices** Freehand 30 2.7 30 1.4 LNS 30 1.3 Freehand – LNS (C) Needle placement time [mm:ss]*** Freehand 30 09:18 05:04 LNS 30 30 04:14 Freehand – LNS
SD
Min
25% Perc.
Median
75% Perc.
Max
2.0 0.7 1.9
0.0 0.0 −0.9
1.8 0.0 1.4
2.9 0.5 2.3
4.5 0.9 3.6
7.2 2.7 6.8
1.7 1.2 2.4
0.5 0.0 −3.1
2.3 0.9 0.1
3.7 1.9 1.4
4.7 2.9 2.8
7.1 3.8 7.1
1.3 0.7 1.3
1.0 1.0 −2.0
2.0 1.0 0.0
3.0 1.0 2.0
4.0 2.0 2.0
5.0 4.0 3.0
06:42 03:05 01:48
09:03 03:58 04:08
10:57 06:21 06:53
18:49 15:10 17:46
03:50 03:15 04:58
03:48 01:03 −08:52
Statistical comparison of assessed phantom study data for the comparison of freehand and LNS puncture technique. SD: standard deviation. * Normal distribution (Shapiro–Wilk test >0.1). Significance entrance point: paired t-test: p-value < 0.0001; Significance target point: paired t-test: p-value < 0.002. ** Non-normal distribution (Shapiro–Wilk test 0.1). Significance time: paired t-test: p-value < 0.0001.
LNS-guided punctures were significantly more accurate as measured by the mean deviation between the planned versus actual needle entrance and target point. The number of control slices and the needle placement time could be reduced significantly. 3.2. Clinical trial A total of 58 CT-guided injections were performed on 29 patients (20 males, 9 females). The mean age of the patients was 53 years (range 27–74), mean body mass index was 27.5 (range 21.3–40.6). In 19 patients the lumbar spine was treated at the L5/S1 level, 6 patients at L4/L5, and each 2 patients at L3/4 and L2/3 level. Substratification of the outcome parameters in correlation to the treated region revealed no statistically significant difference (each p > 0.05; data not shown). All patients received injections with both techniques. No post interventional complications occurred in either group. Overall puncture success rates (100%) were equal in both groups, statistically significant differences in the studied outcome parameters were determined: 3.2.1. Position accuracy LNS provided a needle entrance point accuracy (XYZ) of 1.3 ± 1.2 mm (mean ± SD, freehand: 4.6 ± 2.8 mm) and a needle angulation accuracy of 0.4 ± 0.5◦ (freehand: 2.3 ± 1.9◦ ). No needle bowing effects were seen. Statistical testing of the difference in both treatments was p < 0.0001 in the t-test indicating significance (Table 2A). 3.2.2. Radiation exposure The navigation system reduced the mean number of CT control slices from 1.8 ± 1.1 (freehand) to 1.1 ± 0.3 (LNS, p = 0.0004), an exposure reduction of more than 40% (Table 2B). Due to different reasons (e.g. patient movement, inability to rest for a longer time) in 13 of 29 patients in the freehand-group additional scans were necessary, but only in 3 of 29 patients of the LNS group. The physician was not present in the CT-room during CT scans. 3.2.3. Needle placement time The LNS planning process is performed before the intervention and takes no longer than the planning of a conventional freehand puncture. The total needle placement time of the LNS-guided puncture was 6:54 ± 1:22 min (mean value ± SD), while that of freehand technique was significantly longer (9:00 ± 3:40 min, p = 0.006).
The LNS-guided puncture process was more accurate than the conventional freehand method with reduced X-ray exposure and intervention time (Table 2C). 4. Discussion In this study, we evaluated a novel LNS to assist CT-guided spine interventions looking at the accuracy and usability of the system. A number of studies showed significant reduction of pain from LBP after spinal injection procedures. The accuracy of needle placement is critical for the success of the treatment. Only a few needle guidance systems for interventional procedures are available. However, these systems often need additional and time consuming registration and manual adjustments mostly for determination of the needle entrance point. Full threedimensional navigation systems based on optical, electromagnetic or robotic controlled tracking devices enable optimum real time visualization, but they require additional set-up and matching procedures of the imaging, hence this technology is not used in non-complex percutaneous interventions [9,16,18]. However, an improved procedure efficiency could improve overall clinic productivity. The LNS system we used was an automatically motorized and auto calibrated needle guidance system integrated in the existing clinical workflow. After data transfer from the CT workstation to LNS, image handling, image adjustments and treatment planning were simple. Error-prone process steps from the conventional method were omitted. The workflow was subjectively valued by the physician as user-friendly and intuitively. The integrated planning tool and the virtual trajectory on prior acquired planning image of the needle allow a precise needle placement. The improvement on accuracy of the needle entrance point and needle angulation was 3.3 mm and 1.9◦ in the clinical trial thus comparable with other needle guidance techniques. Jacobi et al. [22] and Pereles et al. [15] both described accuracy improvements using a manually operated laser guidance system in phantom models. They also established that accuracy correlates with experience of the physician and angulation of the intervention. In further clinical trials of using a movable laser guidance system or a patient-mounted navigated intervention system usefulness of laser guidance was reported [9]. Our study results are comparable to the data thus showing slightly higher improvements with regards to accuracy (Table 3).
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Table 2 Results of the clinical study. N
Mean
SD
(A) Accuracy measurements (A1) Needle entrance point accuracy XY [mm]* Freehand 29 4.2 LNS 29 1.1 29 3.1 Freehand – LNS (A2) Needle entrance point accuracy XYZ [mm]* Freehand 29 4.6 29 1.3 LNS 29 3.3 Freehand – LNS (A3) Needle angle deviation measurements XY [◦ ]* Freehand 29 2.3 29 0.4 LNS 29 1.9 Freehand – LNS (B) Number of control CT slices** . 1.8 Freehand 29 1.1 LNS 29 29 0.8 Freehand – LNS (C) Needle placement time [mm:ss]*** Freehand 29 09:00 06:54 LNS 29 Freehand – LNS 29 02:06
Min
25% Perc.
Median
75%-Perc.
Max
2.9 1.0 3.1
0.0 0.0 −1.8
1.8 0.5 0.5
3.6 0.9 2.7
6.3 1.8 5
11.7 4.1 11.7
2.8 1.2 3.0
0.0 0.0 −1.8
2.3 0.5 0.5
4.5 0.9 3.6
6.6 1.8 5.2
11.7 5.1 11.7
1.9 0.5 2.0
0.0 0.0 −1.4
0.5 0.0 0.0
2.1 0.2 1.4
3.6 1 3.6
6.7 1.4 6.7
1.1 0.3 1.2
1.0 1.0 −1.0
1.0 1.0 0.0
1.0 1.0 0.0
3.0 1.0 2.0
5.0 2.0 4.0
08:19 06:57 01:56
11:18 07:44 05:29
21:24 09:54 11:30
03:40 01:22 03:45
05:22 04:42 −03:20
06:03 05:51 −01:24
Statistical comparison of assessed clinical study data for the comparison of freehand and LNS puncture technique. SD: standard deviation. * Normal distribution (Shapiro–Wilk test >0.1). Significance entrance point (XY and XYZ) and angle deviation: paired t-test: p-value < 0.0001. ** Non-normal distribution (Shapiro–Wilk test 0.1). Significance time: paired t-test: p-value = 0.006.
The intervention time was significantly reduced by 2 min on average; the maximum reduction was 11:30 min. For better comparison between both treatment procedures, we conducted this study using identical conditions following the same application flow. Because the LNS is adjusted in a fixed defined position to the CT gantry no registration procedure is required. Further time savings can be realized with LNS because this method allows for immediate disinfection and sterile covering after the patient is positioned on the patient table. Using the freehand method the sterile covering is applied after determination of the needle entrance point. The unavoidable disadvantage of CT-guided interventions is the radiation exposure for patients. For perineural/epidural injections of the lumbar spine 4–10 standard CT slices are used for iterating the needle to the target. Low-dose CT-protocols have been described as dose reduction and saving features, however image quality and morphological information was also lowered. Therefore tailored CT protocols with different radiation doses are recommended. Reviewing the literature only few studies present radiation data. Manchikanti et al. [23] evaluated different radiation exposures in interventional pain management on 1156 patients, observing reduced radiation time with increasing experience of the physician. Time of radiation exposure by fluoroscopy was reduced in lumbar facet joint nerve blocks from 11.7 s (physician < 2
years’ experience) down to 5.7 s (physician > 5 years’ experience). Proschek et al. [18] showed a significant reduction of radiation time (−32.7%) compared to standard procedures using a real time image guidance system for fluoroscopy procedures. However, especially with regards to the set-up of the system, a longer procedure time was required. Our clinical trial factored the number of CT slices per procedure instead of measuring exposure time. The number of control slices was reduced by 42.1%. This new navigation system for CT-guided interventions has some limitations. An unavoidable inherent weakness in this kind of study is in the inability to blind the physician which could potentially result in unintentional bias. The device cannot account for respiratory movements, patient motions or in-organ shifts when applied to soft tissue interventions. These movements can be critical for LNS as well as for the freehand method. Breath hold systems or vacuum mattresses allow for more precise control. Trajectory assistance systems including the LNS visualize needle insertion points and angles but do not provide information about the instrument tip position as an expensive and time-intensive electromagnetic tracking device could. In conclusion, LNS-guided injections proved to be feasible and accurate. The use of the LNS could lower radiation exposure, needle placement accuracy and treatment time for several percutaneous interventions not only for the experienced interventionists but
Table 3 Comparison of clinical trials with guidance systems.
Jacobi et al. (1998) Pereles et al.b [15] Brabrand et al. [19] Yang et al. [9] LNS-Phantom Study LNS-Clinical Study
Na
Needle entrance point accuracy [mm]
Needle target point accuracy [mm]
FH
LG
FH
LG
160 180 67 16 60 58
2.70
1.70 10.58
5.01
3.52
4.60 1.96
3.14 4.61
0.52 1.28
Needle angulation deviation [◦ ] FH
LG
1.80 3.60 2.28
0.40
LG: laser guidance; FH: free hand procedure. a Overall number of patients/punctures. b Porcine and bovine phantom study.
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even more so for less experienced physicians. Further research is needed for the evaluation of the feasibility of other LNS-guided applications and angulated interventions. Acknowledgements We acknowledge Hedwig Wolski (Study Nurse) and the staff of the Groenemeyer Institute for Microtherapy, University Witten/Herdecke, Germany for their active support, and Dr. Silke Lange P-Wert, for the statistical evaluation of the study. References [1] Freburger JK, Holmes GM, Agans RP, et al. The rising prevalence of chronic low back pain. Archives of Internal Medicine 2009;169(3):251–8. [2] Manchikanti L, Singh V, Datta S, et al. Comprehensive review of epidemiology, scope, and impact of spinal pain. Pain Physician 2009;12(4):E35–70. [3] Airaksinen O, Brox JI, Cedraschi C, et al. European guidelines for the management of chronic nonspecific low back pain. European Spine Journal 2006;15(Suppl. 2):S192–300. Chapter 4. [4] Heran MK, Smith AD, Legiehn GM. Spinal injection procedures: a review of concepts, controversies, and complications. Radiologic Clinics of North America 2008;46(3):487–514, v–vi. [5] Peterson C, Hodler J. Evidence-based radiology (part 1): is there sufficient research to support the use of therapeutic injections for the spine and sacroiliac joints? Skeletal Radiology 2010;39(1):5–9. [6] Peterson C, Hodler J. Adverse events from diagnostic and therapeutic joint injections: a literature review. Skeletal Radiology 2011;40(1):5–12. [7] Groenemeyer D, Seibel R. Interventional Computed Tomography. Bochum: Blackwell Scientific Publications; 1990. [8] Bale R, Widmann G. Navigated CT-guided interventions. Minimally Invasive Therapy and Allied Technologies 2007;16(4):196–204. [9] Yang CL, Yang BD, Lin ML, et al. A patient-mount navigated intervention system for spinal diseases and its clinical trial on percutaneous pulsed radiofrequency stimulation of dorsal root ganglion. Spine (Phila Pa 1976) 2010;35(21):E1126–32.
[10] Schulz T, Rottger S, Bahner-Heyne EJ, et al. Comparison of two navigation systems for CT-guided interventions under special consideration of the ergonomic properties of the used systems. Rofo 2009;181(6):564–72. [11] Carlson SK, Bender CE, Classic KL, et al. Benefits and safety of CT fluoroscopy in interventional radiologic procedures. Radiology 2001;219(2):515–20. [12] Silverman SG, Tuncali K, Adams DF, et al. CT fluoroscopy-guided abdominal interventions: techniques, results, and radiation exposure. Radiology 1999;212(3):673–81. [13] Schmid G, Schmitz A, Borchardt D, et al. Effective dose of CT- and fluoroscopyguided perineural/epidural injections of the lumbar spine: a comparative study. Cardiovascular and Interventional Radiology 2006;29(1):84–91. [14] Tsalafoutas IA, Tsapaki V, Triantopoulou C, et al. CT-guided interventional procedures without CT fluoroscopy assistance: patient effective dose and absorbed dose considerations. American Journal of Roentgenology 2007;188(6):1479–84. [15] Pereles FS, Baker M, Baldwin R, et al. Accuracy of CT biopsy: laser guidance versus conventional freehand techniques. Academic Radiology 1998;5(11):766–70. [16] Bruners P, Penzkofer T, Nagel M, et al. Electromagnetic tracking for CT-guided spine interventions: phantom, ex-vivo and in-vivo results. European Radiology 2009;19(4):990–4. [17] Meier-Meitinger M, Nagel M, Kalender W, et al. Computer-assisted navigation system for interventional CT-guided procedures: results of phantom and clinical studies. Rofo 2008;180(4):310–7. [18] Proschek D, Kafchitsas K, Rauschmann MA, et al. Reduction of radiation dose during facet joint injection using the new image guidance system SabreSource: a prospective study in 60 patients. European Spine Journal 2009;18(4):546–53. [19] Brabrand K, Aalokken TM, Krombach GA, et al. Multicenter evaluation of a new laser guidance system for computed tomography intervention. Acta Radiologica 2004;45(3):308–12. [20] Stamm G, Nagel HD. CT-expo – a novel program for dose evaluation in CT. Rofo 2002;174(12):1570–6. [21] Artner J, Cakir B, Weckbach S, et al. Radiation dose reduction in CT-guided periradicular injections in lumbar spine: feasibility of a new institutional protocol for improved patient safety. Patient Safety in Surgery 2012;6(1):19. [22] Jacobi V, Thalhammer A, Kirchner J. Value of a laser guidance system for CT interventions: a phantom study. European Radiology 1999;9(1):137–40. [23] Manchikanti L, Cash KA, Moss TL, et al. Radiation exposure to the physician in interventional pain management. Pain Physician 2002;5(4):385–93.
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