Interventional Neuroradiology Procedures Research Articles

Clinical diagnostic reference levels in neuroradiology based on clinical indication.

This study focuses on patient radiation exposure in interventional neuroradiology (INR) procedures, a field that has advanced significantly since its inception in the 1980s. INR employs minimally invasive techniques to treat complex cerebrovascular diseases in the head, neck, and spine. The study establishes diagnostic reference levels (DRLs) for three clinical indications (CIs): stroke (S), brain aneurysms (ANs), and brain arteriovenous malformation (AVM). Data from 209 adult patients were analyzed, and DRLs were determined in terms of various dosimetric and technical quantities. For stroke, the established DRLs median values were found to be 78Gycm2, 378mGy, 118mGy, 12min, 442 images, and 15 runs. Similarly, DRLs for brain AN are 85Gycm2, 611mGy, 95.5mGy, 19.5, 717 images, and 26 runs. For brain AVM, the DRL's are 180Gycm2, 1144mGy, 537mGy, 36min, 1375 images, and 31 runs. Notably, this study is unique in reporting DRLs for specific CIs within INR procedures, providing valuable insights for optimizing patient safety and radiation exposure management.

Image Quality and Radiation Dose of Conventional and Wide-Field High-Resolution Cone-Beam Computed Tomography for Cerebral Angiography: A Phantom Study.

There has been an increase in the use of interventional neuroradiology procedures because of their non-invasiveness compared to surgeries and the improved image quality of fluoroscopy, digital subtraction angiography, and rotational angiography. Although cone-beam computed tomography (CBCT) images are inferior to multi-detector CT images in terms of low-contrast detectability and lower radiation doses, CBCT scans are frequently performed because of their accessibility. This study aimed to evaluate the image quality and radiation dose of two different high-resolution CBCTs (HR CBCT): conventional (C-HR CBCT) and wide-field HR CBCT (W-HR CBCT). The modulation transfer function (MTF), noise power spectrum (NPS), and contrast-to-noise ratio (CNR) were used to evaluate the image quality. On comparing the MTF of C-HR CBCT with a 256 × 256 matrix and that of W-HR CBCT with a 384 × 384 matrix, the MTF of W-HR CBCT with the 384 × 384 matrix was larger. A comparison of the NPS and CNR of C-HR CBCT with a 256 × 256 matrix and W-HR CBCT with a 384 × 384 matrix showed that both values were comparable. The reference air kerma values were equal for C-HR CBCT and W-HR CBCT; however, the value of the kerma area product was 1.44 times higher for W-HR CBCT compared to C-HR CBCT. The W-HR CBCT allowed for improved spatial resolution while maintaining the image noise and low-contrast detectability by changing the number of image matrices from 256 × 256 to 384 × 384. Our study revealed the image characteristics and radiation dose of W-HR CBCT. Given its advantages of low-contrast detectability and wide-area imaging with high spatial resolution, W-HR CBCT may be useful in interventional neuroradiology for acute ischemic stroke.

Comparative verification of control methodology for robotic interventional neuroradiology procedures

PurposeThe use of robotics is emerging for performing interventional radiology procedures. Robots in interventional radiology are typically controlled using button presses and joystick movements. This study identified how different human–robot interfaces affect endovascular surgical performance using interventional radiology simulations.MethodsNine participants performed a navigation task on an interventional radiology simulator with three different human–computer interfaces. Using Simulation Open Framework Architecture we developed a simulation profile of vessels, catheters and guidewires. We designed and manufactured a bespoke haptic interventional radiology controller for robotic systems to control the simulation. Metrics including time taken for navigation, number of incorrect catheterisations, number of catheter and guidewire prolapses and forces applied to vessel walls were measured and used to characterise the interfaces. Finally, participants responded to a questionnaire to evaluate the perception of the controllers.ResultsTime taken for navigation, number of incorrect catheterisations and the number of catheter and guidewire prolapses, showed that the device-mimicking controller is better suited for controlling interventional neuroradiology procedures over joystick control approaches. Qualitative metrics also showed that interventional radiologists prefer a device-mimicking controller approach over a joystick approach.ConclusionOf the four metrics used to compare and contrast the human–robot interfaces, three conclusively showed that a device-mimicking controller was better suited for controlling interventional neuroradiology robotics.

Accuracy of uncalibrated 2D digital subtraction angiography measurements on a novel biplane system compared to computed tomography angiography.

2D digital subtraction angiography (DSA) images are the gold standard for neuroradiological vascular assessment and the basis of interventional procedures such as mechanical thrombectomy and cerebral aneurysm coiling. However, length measurements in projected DSA images are affected by the distance between the x-ray source, the object, and the detector. Precise coordination between all integrated parts of a novel biplane system makes it possible to accurately measure DSA distances without manual calibration. The aim of this study was to compare vascular diameter measurements in uncalibrated DSA images with computed tomography angiography (CTA). Consecutive patients undergoing interventional neuroradiological procedures were retrospectively included. Vascular diameter measurements in the image isocenter and periphery were performed. These measurements were repeated in picture archiving and communication system (PACS) on DSA images and maximum intensity pixel (MIP) CTA images. Forty-two (42) consecutive patients with adequate DSA and CTA images were included in the final analysis. The correlation between vessel diameter measurements in the image isocenter (R2 = 0.81/0.85, p < 0.0001/p < 0.0001 [Reader1/Reader2]), periphery (R2 = 0.85/0.82, p < 0.0001/p < 0.0001 [Reader1/Reader2]), and all measurements combined (R2 = 0.87/0.87, p < 0.0001/p < 0.0001 [Reader1/Reader2]) on DSA and CTA were strong and statistically significant. The interclass correlation coefficient for measurements performed by two independent reviewers was strong (ICC = 0.96, 95% CI 0.92-0.98). The correlations between uncalibrated DSA measurements and CTA for vessel diameter were strong. In addition, there were strong correlations between these image types for repeated measurements in the image isocenter as well as image periphery for vessel diameter. Consequently, endovascular devices can be sized correctly without the need for pre-operative non-invasive imaging.

Comparison of neostigmine and sugammadex for hemodynamic parameters in neurointerventional anesthesia.

Hemodynamic stability is important during neurointerventional procedures. However, ICP or blood pressure may increase due to endotracheal extubation. The aim of this study was to compare the hemodynamic effects of sugammadex and neostigmine with atropine in neurointerventional procedures during emergence from anesthesia. Patients undergoing neurointerventional procedures were allocated to the sugammadex group (Group S) and the neostigmine group (Group N). Group S was administered IV 2 mg/kg sugammadex when a train-of-four (TOF) count of 2 was present, and Group N was administered neostigmine 50 mcg/kg with atropine 0.2 mg/kg at a TOF count of 2. We recorded heart rate, systolic blood pressure, diastolic blood pressure, mean blood pressure (MAP), and peripheral arterial oxygen saturation during administration of the reverse agent and at 2, 5, 10, 15, 30, 120 min, and 24 h thereafter. The primary outcome was blood pressure and heart rate change after the reversal agent was given. The secondary outcomes were systolic blood pressure variability standard deviation (a measure of the amount of variation or dispersion of a set of values), systolic blood pressure variability-successive variation (square root of the average squared difference between successive blood pressure measurements), nicardipine use, time-to-TOF ratio ≥0.9 after the administration of reversal agent, and time from the administration of the reversal agent to tracheal extubation. A total of 31 patients were randomized to sugammadex, and 30 patients were randomized to neostigmine. Except for anesthesia time, there were no significant differences in any of the clinical characteristics between the two groups. The results demonstrated that the increase in MAP from period A to B was significantly greater in Group N than in Group S (regression coefficient = -10, 95% confidence interval = -17.3 to -2.7, P = 0.007). The MAP level was significantly increased from period A to B in the neostigmine group (95.1 vs. 102.4 mm Hg, P = 0.015), but it was not altered in Group S. In contrast, the change in HR from periods A to B was not significantly different between groups. We suggest that sugammadex is a better option than neostigmine in interventional neuroradiological procedures due to the shorter extubation time and more stable hemodynamic change during emergence.

Comparing Radiation Dose of Cerebral Angiography Using Conventional and High kV Techniques: A Retrospective Study on Intracranial Aneurysm Patients and a Phantom Study.

Evaluation of patient radiation dose after the implementation of a high kV technique during a cerebral angiographic procedure is an important issue. This study aimed to determine and compare the patient radiation dose of intracranial aneurysm patients undergoing cerebral angiography using the conventional and high kV techniques in a retrospective study and a phantom study. A total of 122 cases (61 cases with conventional technique and 61 cases with high kV technique) of intracranial aneurysm patients, who underwent cerebral angiographic procedure and met the inclusion criteria, were recruited. The radiation dose and the angiographic exposure parameters were reviewed retrospectively. The radiation dose in the phantom study was conducted using nanoDotTM optically stimulating luminescence (OSLD), which were placed on the scalp of the head phantom, the back of the neck, and the phantom skin at the position of the eyes. The standard cerebral angiographic procedure using the conventional and high kV techniques was performed following the standard protocol. The results showed that the high kV technique significantly reduced patient radiation dose and phantom skin dose. This study confirms that the implementation of a high kV technique in routine cerebral angiography for aneurysm diagnosis provides an effective reduction in radiation dose. Further investigation of radiation dose in other interventional neuroradiology procedures, particularly embolization procedure, should be performed.

The Complexity of Online Patient Education Materials About Interventional Neuroradiology Procedures Published by Major Academic Institutions.

Introduction Health literacy is an independent predictor of population health status and is directly related to the readability of available patient education material. The National Institutes of Health (NIH) and the American Medical Association have recommended that patient education materials (PEMs) be written between a fourth- and a sixth-grade education level. The authors assessed the readability of online PEMs about neurointerventional procedures that have been published by several academic institutions across the US. Methods Online PEMs regarding five common neurointerventional procedures, including mechanical thrombectomy for large vessel occlusion, cerebral diagnostic angiography, carotid artery stenting, endovascular aneurysm embolization, and epidural steroid injection collected from the websites of 20 top institutions in Neurology and Neurosurgery. The materials were assessed via five readability scales and then were statistically analyzed and compared to non-institutional education websites (Wikipedia.com and WebMD.com). Results None of the PEMs were written at or below the NIH's recommended 6th-grade reading level. The average educational level required to comprehend the texts across all institutions, as assessed by the readability scales, was 10-11th grade level. Some materials required a college-level education or higher. Material from non-institutional websites had significantly lower readability scores compared to the 20 institutions. Conclusions Current PEMs related to neurointerventional procedures are not written at or below the NIH's recommended fourth- to sixth-grade education level. Given the complexity of those procedures, significant attention should be pointed toward an improvement in the available online materials.

Measurement of Neutrophil Gelatinase-Associated Lipocalin (Ngal) Following Neuroradiological Procedure/s in Patients with Aneurysmal Subarachnoid Hemorrhage: A Preliminary Study.

Radiocontrast administration during interventional neuroradiology (INR) procedures for aneurysmal subarachnoid haemorrhage (aSAH) can add to renal insult. Serum creatinine (sCr) is a conventional marker of acute kidney injury (AKI). Serum neutrophil gelatinase-associated lipocalin (sNGAL) is a novel marker which is increasingly used to predict renal injury in susceptible patients. The primary aim of this study was to evaluate correlation between serum neutrophil gelatinase-associated lipocalin (NGAL) and sCr in aSAH patients undergoing therapeutic or diagnostic INR procedures. The secondary aim was to find the incidence of contrast-induced AKI and hemodynamic complications during the study period. All consenting aSAH patients (18-60 years, Modified Hunt and Hess grade 1-4) posted for INR procedures during the study time were included. Patients with history of chronic renal disease, recent contrast exposure, or renal insufficiency were excluded. Blood samples for sCr and sNGAL were obtained preprocedure and then at 1, 6, 24, and 48 h after contrast administration. Hourly urine output was noted. AKI was defined by KDIGO guidelines. Repeated measurement analysis of variance, Posthoc Bonferroni test and Pearson correlation coefficient test. Fifty patients, mean age 47.34 ± 9.31 years, were enrolled for the study. Majority (48; 96%) were Hunt and Hess (H and H) grade I-III. The mean volume of contrast administered was 123.2 ± 53.08 mL. The mean sNGAL and sCr values at pre-op, 1, 6, 24, and 48 h were 124.99 ± 64.58, 148.40 ± 77.90, 147.33 ± 76.00, 125.49 ± 64.44, and 116.38 ± 61.79 ng/mL and 0.629 ± 0.23, 0.624 ± 0.22, 0.612 ± 0.21, 0.632 ± 0.19, and 0.577 ± 0.22 mg/dL, respectively. There was a correlation in sCr and sNGAL value (P < 0.001) at all study time points. However, no specific pattern was seen. No patient developed any AKI or hemodynamic complications in first 48 h. There is a correlation between serum NGAL and sCr at individual time points. NGAL may represent a sensitive early biomarker of renal impairment after INR Procedures. There was no incidence of AKI after contrast administration in aSAH patients without predisposing renal risk factors.

Comparison of Effect of Dexmedetomidine Versus Lignocaine on Haemodynamic Response and Quality of ExtubationIn Patients Undergoing Interventional Neuroradiological Procedures: A Randomized Double-Blind Interventional Study

Background and Aims: Haemodynamic and airway responses during and after extubation may be precarious in neurosurgical patients. We aimed to compare the effects of dexmedetomidine versus lignocaine on haemodynamic response and quality of extubation in patients undergoing interventional neuroradiological procedures. Material and methods: This prospective study was conducted in a randomized double-blind manner on a total of 80 patients of either sex aged 20-50 yrs of ASA grades I, II &amp; III who were randomly allocated into two groups (40 in each group). In Group A inj. Dexmedetomidine 0.5mcg/kg i.v and in Group B - inj. Lignocaine 1.5mg/kg i.v was given as a single bolus in 10 ml normal saline, at the end of the procedure. Haemodynamic variables (HR, SBP, DBP, MAP) were recorded at extubation, 1, 3, 5, 10, and 15min after extubation. Quality of extubation, sedation score and side effects (bradycardia, hypotension, nausea &amp; vomiting) were also noted. Statistical analysis was performed by using the student-t-test and Chi-square test (significant p-value ≤ 0.05). Results: The SBP, DBP and MAP were significantly higher in group B than in group A at extubation, 1min, 3min, 5min, 10min and 15min post-extubation whereas the significant difference in HR was observed only at extubation and 1min post-extubation (Group B &gt; A). Dexmedetomidine produced a higher sedation score grade 2 (73.68%) than lignocaine (20.51%) with better quality of extubation and nonsignificant side effects. Conclusion: Dexmedetomidine administered 10 min before extubation effectively attenuates the haemodynamic and airway responses during extubation as compared to Lignocaine. Keywords: Dexmedetomidine, Lignocaine, Interventional, Extubation, Haemodynamic

Acute cerebrovascular events-fundamentals

Acute ischemic stroke and subarachnoid hemorrhage due to aruptured intracranial aneurysm are cerebrovascular emergencies, in which interventional neuroradiological therapeutic procedures play acrucial role. Profound knowledge about indication based on current guidelines and treatment approaches with their advantages and disadvantages are the basis of an evidence-based therapeutic decision. This article aims to provide an empirical overview for everyday practical situations.

Surgeon eye lens dose monitoring in interventional neuroradiology, cardiovascular and radiology procedures

PurposeThis study investigated the radiation dose to surgeon eye lens for single procedure and normalised to exposure parameters for eight selected neuroradiology, cardiovascular and radiology interventional procedures. MethodsThe procedures investigated were diagnostic study, Arteriovenous Malformations treatment (AVM) and aneurysm embolization for neuroradiology procedures, Coronary Angiography and Percutaneous Transluminal Coronary Angioplasty (CA-PTCA), Pacemaker and Implantable Cardioverter-Defibrillator implantation (PM-ICD), Endovascular Aortic Repair (EVAR) and Fenestrated Endovascular Aortic Repair (FEVAR) for cardiovascular and electrophysiology procedures. CT-guided lung biopsy was also monitored.All procedures were performed with table-mounted and ceiling-suspended shields (0.5 mm lead equivalent thickness), except for FEVAR and PM-ICD where only a table mounted shield was present, and CT-guided lung biopsy where no shield was used. Dose assessment was performed using a dosemeter positioned close to the most exposed eye of the surgeon, outside the protective eyewear. ResultsThe surgeon most exposed eye lens median Hp(3) equivalent dose for a single procedure, without protective eyewear contribution, was 18 μSv for neuroradiology diagnostic study, 62 μSv for AVM, 38 μSv for aneurysm embolization, 33 μSv for CA-PTCA, 39 μSv for PM-ICD, 49 μSv for EVAR, 2500 μSv for FEVAR, 153 μSv for CT-guided lung biopsy. ConclusionsIn interventional procedures, the 20 mSv/year dose limit for surgeon eye lens exposure might be exceeded if shields or protective eyewear are not used.Surgeon eye lens doses, normalised to single procedures and to exposure parameters, are a valuable tool for determining appropriate radiation protection measures and dedicated eye lens dosemeter assignment.

Discordance in tests used to detect inhibition of the P2Y12 receptor in patients undergoing interventional neuroradiology procedures.

Clopidogrel is an inhibitor of the P2Y12 platelet receptor but testing to demonstrate a drug effect is controversial since there are often discordant results between different tests methods. Samples from patients taking clopidogrel prior to intracranial flow-diversion procedures were tested using light transmission aggregometry (LTA), whole blood impedance aggregometry (WBIA) and the VerifyNow device (VND). Samples were classified as concordant if all test results were either responsive (inhibition) or resistant. Discordant results were separated using the VND into those with a responsive versus a resistant test result. Samples from 96 patients were studied. Concordance for all three tests was seen in 53/96 (55%) of samples, of which 41 (43%) were responsive and 12 (12%) were resistant. Discordance was observed in 43 samples (45%), 37 (28%) of which were caused by responsive VND and either a resistant WBIA or LTA and 6 (7%) of which were caused by a resistant VND but a responsive test result using either WBIA or LTA. These two discordant groups differed in both platelet count and hematocrit, but no such difference was present between the two concordant groups. Discordance in P2Y12 inhibition testing may be partly explained by sample platelet count and hematocrit.

Fosaprepitant Does Not Interfere With Commonly Used Intraoperative Neuromonitoring Modalities Under General Anesthesia: A Preliminary Study.

Fosaprepitant [Emend®], a neurokinin type-1 [NK-1] receptor antagonist, is a highly effective for the prophylaxis of postoperative nausea and vomiting [PONV] after general anesthesia; it is particularly effective in patients undergoing neurosurgical procedures. Based on the widespread distribution of NK-1 receptors in the central and peripheral nervous systems, we sought to determine whether fosaprepitant administration would interfere with commonly used intraoperative neurophysiologic monitoring modalities during general anesthesia. Eleven patients having propofol-based general anesthesia for interventional neuroradiology procedures were administered 150mg fosaprepitant intravenously after baseline electroencephalogram [EEG], transcranial motor evoked potential [TcMEP], and somatosensory evoked potential [SSEP] recordings were obtained. Recordings of these neuromonitoring modalities at 30, 60, and 90 min after fosaprepitant administration were compared to baseline. Fosaprepitant did not have a significant effect on SSEP/TcMEP amplitudes or latencies, or on TcMEP morphology. There were also no changes in EEG voltage, frequency, or symmetry. Fosaprepitant does not appear to markedly interfere with SSEP, TcMEP, or EEG neuromonitoring modalities during propofol-based general anesthesia.

Flat Detector CT with Cerebral Pooled Blood Volume Perfusion in the Angiography Suite: From Diagnostics to Treatment Monitoring.

C-arm flat-panel detector computed tomographic (CT) imaging in the angiography suite increasingly plays an important part during interventional neuroradiological procedures. In addition to conventional angiographic imaging of blood vessels, flat detector CT (FD CT) imaging allows simultaneous 3D visualization of parenchymal and vascular structures of the brain. Next to imaging of anatomical structures, it is also possible to perform FD CT perfusion imaging of the brain by means of cerebral blood volume (CBV) or pooled blood volume (PBV) mapping during steady state contrast administration. This enables more adequate decision making during interventional neuroradiological procedures, based on real-time insights into brain perfusion on the spot, obviating time consuming and often difficult transportation of the (anesthetized) patient to conventional cross-sectional imaging modalities. In this paper we review the literature about the nature of FD CT PBV mapping in patients and demonstrate its current use for diagnosis and treatment monitoring in interventional neuroradiology.

Evaluating the safety and efficacy of transradial approach for thrombectomy in posterior circulation stroke. A systematic literature review and meta-analysis.

Transradial access (TRA) is becoming more popular in neurointerventional radiology procedures and has been associated with reduced mortality, morbidity and access site complications. Guidelines state that TRA is a feasible option for posterior circulation thrombectomy however the evidence base is limited and no systematic literature review has yet been undertaken to evaluate its safety and efficacy. The Cochrane Library, PubMed, Web of Science, Scopus, TRIP and Embase databases were searched. Outcomes collected included TICI scores, puncture to recanalisation time, mRS scores at 90 days and access site complications. 291 records were identified and 31 full text articles were assessed for eligibility. Eight studies met the inclusion criteria and were meta-analysed. The rate of TICI 2b-3 was 94.7% (89.7-99.8% at 95% CI), TICI 3 was 67.9% (42.2-93.6% at 95% CI) and mRS 0-2 at 90 days was 49.8% (31.5-68.1% at 95% CI). Median puncture to reperfusion times were extracted from three studies as 24 (IQR 18-40), 24 (IQR 17.5-56.5) and 27 (IQR 24-33.5) minutes. No access site complications were reported. TICI 2b-3, TICI 3 and mRS scores were comparable to data for transfemoral access (TFA) from a large systematic review. Puncture to recanalisation times appeared lower than the TFA data but statistical comparison of this outcome was not possible. The use of TRA in posterior circulation thrombectomy is safe and effective with comparable results to TFA. Further research with a larger sample size is required to fully investigate the potential for shortened puncture to recanalisation times.

Evaluation of Peak Skin Doses and Lens Doses during Interventional Neuroradiology Using a Direct Measurement System.

In interventional neuroradiology (INR), the evaluation of the peak skin dose (PSD) and lens dose is important because the patient radiation dose increases in cases in which the procedure is more difficult and complex. This study evaluated the radiation doses during INR procedures using a direct measurement system. Radiation dose measurements during INR were performed in 332 patients with unruptured aneurysm (URAN), dural arteriovenous fistula (DAVF), and arteriovenous malformation (AVM). The PSD and bilateral lens doses were analyzed for each disease. The Pearson correlation test was used to determine whether the PSD and lens doses were linearly related to the reference air kerma (Ka,r). In all cases, the PSD and right and left lens doses were 2.36 ± 1.28 Gy, 114.2 ± 54.6 mGy, and 189.8 ± 160.3 mGy, respectively. The PSD and lens doses of the DAVF and AVM cases were significantly higher than those of the URAN case. The Pearson correlation test revealed statistically significant positive correlations between Ka,r and PSD, Ka,r and right lens dose, and Ka,r and left lens dose. The characteristics of radiation dose in INR were clarified. Owing to the concern of increased radiation doses exceeding the threshold values in DAVF and AVM cases, protection from radiation is required. Simple regression analysis revealed the possibility of precisely predicting PSD using Ka,r.

The practice of radiation protection in an interventional neuroradiology service.

Interventional neuroradiology procedures subject professionals who work in this area to high doses of ionizing radiation, and such exposure leads to a higher chance of occupational diseases related to this physical risk. Radiation protection practices aim to reduce the occurrence of such damage to the health of these workers. To identify how the practice of radiation protection occurs in a multidisciplinary team of an interventional neuroradiology service in the state of Santa Catarina, Brazil. A qualitative, exploratory, and descriptive research conducted with nine health professionals from the multidisciplinary team. Non-participant observation and a survey form were used as data collection techniques. For data analysis, descriptive analysis based on absolute and relative frequency and content analysis were used. Although some practices showed the use of radiation protection measures in practice, such as workers taking turns to perform procedures and continuous use of the lead apron as well as the mobile suspended protection, we found that most of the practices violate the principles of radiation protection. Among these inadequate radiological protection practices, the following aspects were observed: not wearing lead goggles, not using collimation to obtain the image, poor knowledge of the principles of radiation protection and biological effects of ionizing radiation, and non-use of an individual dosimeter. There was a lack of know-how of the multidisciplinary team working in interventional neuroradiology regarding the practice of radiation protection.

OD95 - Evaluation of radiation dose exposure for interventional and diagnostic neuroradiology procedures using a radiation dose index monitoring software

OD95 - Evaluation of radiation dose exposure for interventional and diagnostic neuroradiology procedures using a radiation dose index monitoring software

Monitoring Radiation Doses during Diagnostic and Therapeutic Neurointerventional Procedures: Multicenter Study for Establishment of Reference Levels.

PurposeTo assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL).Materials and MethodsConsecutive neurointerventional procedures, performed in 22 hospitals from December 2020 to June 2021, were retrospectively studied. We collected data from a sample of 429 diagnostic and 731 therapeutic procedures. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time (FT), and total number of image frames (NI) were obtained. RL were calculated as the 3rd quartiles of the distribution.ResultsAnalysis of 1160 procedures from 22 hospitals confirmed the large variability in patient dose for similar procedures. RLs in terms of DAP, CAK, FT, and NI were 101.6 Gy·cm2, 711.3 mGy, 13.3 minutes, and 637 frames for cerebral angiography, 199.9 Gy·cm2, 3,458.7 mGy, 57.3 minutes, and 1,000 frames for aneurysm coiling, 225.1 Gy·cm2, 1,590 mGy, 44.7 minutes, and 800 frames for stroke thrombolysis, 412.3 Gy·cm2, 4,447.8 mGy, 99.3 minutes, and 1,621.3 frames for arteriovenous malformation (AVM) embolization, respectively. For all procedures, the results were comparable to most of those already published. Statistical analysis showed male and presence of procedural complications were significant factors in aneurysmal coiling. Male, number of passages, and procedural combined technique were significant factors in stroke thrombolysis. In AVM embolization, a significantly higher radiation dose was found in the definitive endovascular cure group.ConclusionVarious RLs introduced in this study promote the optimization of patient doses in diagnostic and therapeutic interventional neuroradiology procedures. Proposed 3rd quartile DAP (Gy·cm2) values were 101.6 for diagnostic cerebral angiography, 199.9 for aneurysm coiling, 225.1 for stroke thrombolysis, and 412.3 for AVM embolization. Continual evolution of practices and technologies requires regular updates of RLs.

Common ground, different path: Ulnar artery access for interventional neurovascular procedures.

Recently, radial artery access has gained popularity for interventional neurovascular procedures due to patient comfort and fewer complications. However, there are instances where the radial artery approach is not feasible. In such cases, trans-ulnar artery access (TUA) can offer an alternate route. There is limited data regarding neuro-interventional procedures performed via this approach. This study aims to evaluate the feasibility and safety of trans-ulnar approach for a wide range of interventional neurovascular procedures. The data for all patients who underwent ulnar artery access for diagnostic or interventional neuroradiology procedures was retrospectively collected between September 2020 and March 2021. Patient demographics, procedural details, procedure success, and complications were recorded. During the study period, 23 patients underwent 24 trans-ulnar approach procedures. The mean age of patients was 50.1 ± 14.2 years. Fourteen diagnostic cerebral angiograms and ten interventional procedures were performed. All procedures were successfully completed via trans-ulnar approach without a switch to alternate access. No major access site complication was observed. Ulnar artery access is a safe and feasible option for neurovascular procedures. It can be effectively utilized for diagnostic cerebral angiography and a wide range of interventional procedures.