Predicting Histologic Grade of Meningiomas Using a Combined Model of Radiomic and Clinical Imaging Features from Preoperative MRI.

Meningiomas are common primary brain tumors, and their accurate preoperative grading is crucial for treatment planning. This study aimed to evaluate the value of radiomics and clinical imaging features in predicting the histologic grade of meningiomas from preoperative MRI. We retrospectively reviewed patients with intracranial meningiomas from two hospitals. Preoperative MRIs were analyzed for tumor and edema volumes, enhancement patterns, margins, and tumor-brain interfaces. Radiomics features were extracted, and machine learning models were employed to predict meningioma grades. A total of 212 patients were included. In the training group (Hospital 1), significant differences were observed between low-grade and high-grade meningiomas in terms of tumor volume (p = 0.012), edema volume (p = 0.004), enhancement (p = 0.001), margin (p < 0.001), and tumor-brain interface (p < 0.001). Five radiomics features were selected for model development. The prediction model for radiomics features demonstrated an average validation accuracy of 0.74, while the model for clinical imaging features showed an average validation accuracy of 0.69. When applied to external test data (Hospital 2), the radiomics model achieved an area under the receiver operating characteristics curve (AUC) of 0.72 and accuracy of 0.69, while the clinical imaging model achieved an AUC of 0.82 and accuracy of 0.81. An improved performance was obtained from the model constructed by combining radiomics and clinical imaging features. In the combined model, the AUC and accuracy for meningioma grading were 0.86 and 0.73, respectively. In conclusion, this study demonstrates the potential value of radiomics and clinical imaging features in predicting the histologic grade of meningiomas. The combination of both radiomics and clinical imaging features achieved the highest AUC among the models. Therefore, the combined model of radiomics and clinical imaging features may offer a more effective tool for predicting clinical outcomes in meningioma patients.

Superior cerebellar artery occlusion remaining after thrombectomy for acute basilar artery occlusion.

To investigate the incidence and impact of superior cerebellar artery (SCA) occlusion remaining after thrombectomy for acute basilar artery occlusion (BAO). We retrospectively analyzed data from 116 patients who underwent thrombectomy for BAO. The patency of SCA was assessed on final angiograms. Clinical and radiologic data of the patients were retrieved from a prospectively collected database and analyzed. All patients underwent pretreatment and follow-up DWI to detect new infarctions in SCA territory. Ten patients (8.6%) had SCA occlusions on final angiograms. Of these, two patients had bilateral occlusions. A new infarction with a diameter ranged from 4 to 11 mm in corresponding SCA territory occurred in 5 of 10 patients. No patients with SCA occlusions experienced symptomatic cerebellar hemorrhage or malignant cerebellar infarction. Nine of 12 SCA occlusions showed spontaneous recanalization on follow-up CT angiography. Four of 10 patients showed 90-day favorable outcome (mRS 0-3) and 90-day mortality occurred in one patient. SCA occlusions remaining after thrombectomy for acute BAO had a benign clinical course. Most of these lesions recanalized spontaneously. Our study suggests that attempts to recanalize remnant SCA occlusion may be unnecessary after basilar artery thrombectomy.

Preoperative prediction of Ki-67 and p53 status in meningioma using a multiparametric MRI-based clinical-radiomic model.

Purpose: To investigate the utility of preoperative multiparametric magnetic resonance imaging (mpMRI)-based clinical-radiomic analysis combined with machine learning (ML) algorithms in predicting the expression of the Ki-67 proliferative index and p53 tumor suppressor protein in patients with meningioma. Methods: This multicenter retrospective study included 483 and 93 patients from two centers. The Ki-67 index was classified into high (Ki-67≥5%) and low (Ki-67<5%)-expressed groups, and the p53 index was classified into positive (p53≥5%) and negative (p53<5%)-expressed groups. Clinical and radiological features were analyzed using univariate and multivariate statistical analyses. Six ML models were performed with different types of classifiers to predict Ki-67 and p53 status. Results: In the multivariate analysis, larger tumor volumes (p<0.001), irregular tumor margin (p<0.001), and unclear tumor-brain interface (p<0.001) were independently associated with a high Ki-67 status, whereas the presence of both necrosis (p=0.003) and the dural tail sign (p=0.026) were independently associated with a positive p53 status. A relatively better performance was yielded from the model constructed by combined clinical and radiological features. The area under the curve (AUC) and accuracy of high Ki-67 were 0.820 and 0.867 in the internal test, and 0.666 and 0.773 in the external test, respectively. Regarding p53 positivity, the AUC and accuracy were 0.858 and 0.857 in the internal test, and 0.684 and 0.718 in the external test. Conclusion: The present study developed clinical-radiomic ML models to non-invasively predict Ki-67 and p53 expression in meningioma using mpMRI features, and provides a novel non-invasive strategy for assessing cell proliferation.

World federation of interventional and therapeutic neuroradiology (WFITN) federation assembly neurointerventional surgery safety checklist.

Over the last 10 years, there has been a rise in neurointerventional case complexity, device variety and physician distractions. Even among experienced physicians, this trend challenges our memory and concentration, making it more difficult to remember safety principles and their implications. Checklists are regarded by some as a redundant exercise that wastes time, or as an attack on physician autonomy. However, given the increasing case and disease complexity along with the number of distractions, it is even more important now to have a compelling reminder of safety principles that preserve habits that are susceptible to being overlooked because they seem mundane. Most hospitals have mandated a pre-procedure neurointerventional time-out checklist, but often it ends up being done in a cursory fashion for the primary purpose of 'checking off boxes'. There may be value in iterating the checklist to further emphasize safety and communication. The Federation Assembly of the World Federation of Interventional and Therapeutic Neuroradiology (WFITN) decided to construct a checklist for neurointerventional cases based on a review of the literature and insights from an expert panel.

Secular trends and determinants of influenza vaccination uptake among patients with cardiovascular disease in Korea: Analysis using a nationwide database.

Background: Influenza vaccination reduces cardiovascular events in patients with cardiovascular disease (CVD). Identifying the factors that affect influenza vaccination uptake can help improve the prognosis in patients with CVD. This study aimed to evaluate the secular trends of influenza vaccination uptake and factors associated with lack of vaccination in individuals with CVD. Materials and methods: We analyzed the annual trends and factors associated with influenza vaccination among 3,264 patients with CVD, included from the Korea National Health and Nutrition Examination Survey which reflect the health and nutritional status of the nationwide population of Korea conducted between 2007/2008 and 2018/2019. We used a stratified, multistage sampling method. Results: The influenza vaccination rate was greater in patients with CVD (53-74%) than in those without CVD (28-40%). Multivariable logistic regression analysis showed that age <50 years [odds ratio (OR), 16.22; 95% confidence interval (CI), 7.72-34.07], 50-64 years (OR, 6.71; 95% CI, 4.37-10.28), male sex (OR, 1.45; 95% CI, 1.14-1.65), and asthma (OR, 0.45; 95% CI, 0.22-0.92) were independently associated with a lack of influenza vaccination. Among patients aged <65 years, smoking (OR, 2.30; 95% CI, 1.31-4.04), college graduation status (OR, 1.81; 95% CI, 1.16-2.82), and hypertension (OR, 0.70; 95% CI, 0.51-0.95) were independently associated with influenza vaccination. For individuals aged 65years, there was no significant determinant of lack of vaccination. Conclusion: In patients with CVD, a continuous increase in the secular trend of influenza vaccination was demonstrated in Korea. Young age, male sex, and non-asthma status were independently associated with lack of influenza vaccination uptake.

Clinical outcomes of rescue stenting for failed endovascular thrombectomy: a multicenter prospective registry.

BACKGROUND: Mechanical thrombectomy (MT) is a primary endovascular modality for acute intracranial large vessel occlusion. However, further treatment, such as rescue stenting, is occasionally necessary for refractory cases. We aimed to investigate the efficacy and safety of rescue stenting in first-line MT failure and to identify the clinical factors affecting its clinical outcome. METHODS: A multicenter prospective registry was designed for this study. We enrolled consecutive patients who underwent rescue stenting for first-line MT failure. Endovascular details and outcomes, follow-up patency of the stented artery, and clinical outcomes were summarized and compared between the favorable and unfavorable outcome groups. RESULTS: A total of 78 patients were included. Intracranial atherosclerotic stenosis was the most common etiology for rescue stenting (97.4%). Seventy-seven patients (98.7%) were successfully recanalized by rescue stenting. A favorable outcome was observed in 66.7% of patients. Symptomatic intracranial hemorrhage and mortality were observed in 5.1% and 4.0% of patients, respectively. The stented artery was patent in 82.1% of patients on follow-up angiography. In a multivariable analysis, a patent stent on follow-up angiography was an independent factor for a favorable outcome (OR 87.6; 95% CI 4.77 to 1608.9; p=0.003). Postprocedural intravenous maintenance of glycoprotein IIb/IIIa inhibitor was significantly associated with the follow-up patency of the stented artery (OR 5.72; 95% CI 1.45 to 22.6; p=0.013). CONCLUSIONS: In this multicenter prospective registry, rescue stenting for first-line MT failure was effective and safe. For a favorable outcome, follow-up patency of the stented artery was important, which was significantly associated with postprocedural maintenance of glycoprotein IIb/IIIa inhibitors.

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

PURPOSE: To assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL). MATERIALS AND METHODS: Consecutive 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. RESULTS: Analysis 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. CONCLUSION: Various 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.

Differentiating Radiation Necrosis from Brain Tumor Using Hyperpolarized Carbon-13 MR Metabolic Imaging.

PURPOSE: Differentiation between radiation-induced necrosis and tumor recurrence is crucial to determine proper management strategies but continues to be one of the central challenges in neuro-oncology. We hypothesized that hyperpolarized 13C MRI, a unique technique to measure real-time in vivo metabolism, would distinguish radiation necrosis from tumor on the basis of cell-intrinsic metabolic differences. The purpose of this study was to explore the feasibility of using hyperpolarized [1-13C]pyruvate for differentiating radiation necrosis from brain tumors. PROCEDURES: Radiation necrosis was initiated by employing a CT-guided 80-Gy single-dose irradiation of a half cerebrum in mice (n = 7). Intracerebral tumor was modeled with two orthotopic mouse models: GL261 glioma (n = 6) and Lewis lung carcinoma (LLC) metastasis (n = 7). 13C 3D MR spectroscopic imaging data were acquired following hyperpolarized [1-13C]pyruvate injection approximately 89 and 14 days after treatment for irradiated and tumor-bearing mice, respectively. The ratio of lactate to pyruvate (Lac/Pyr), normalized lactate, and pyruvate in contrast-enhancing lesion was compared between the radiation-induced necrosis and brain tumors. Histopathological analysis was performed from resected brains. RESULTS: Conventional MRI exhibited typical radiographic features of radiation necrosis and brain tumor with large areas of contrast enhancement and T2 hyperintensity in all animals. Normalized lactate in radiation necrosis (0.10) was significantly lower than that in glioma (0.26, P = .004) and LLC metastatic tissue (0.25, P = .00007). Similarly, Lac/Pyr in radiation necrosis (0.18) was significantly lower than that in glioma (0.55, P = .00008) and LLC metastasis (0.46, P = .000008). These results were consistent with histological findings where tumor-bearing brains were highly cellular, while irradiated brains exhibited pathological markers consistent with reparative changes from radiation necrosis. CONCLUSION: Hyperpolarized 13C MR metabolic imaging of pyruvate is a noninvasive imaging method that differentiates between radiation necrosis and brain tumors, providing a groundwork for further clinical investigation and translation for the improved management of patients with brain tumors.

Association of pretreatment pontine infarction with extremely poor outcome after endovascular thrombectomy in acute basilar artery occlusion.

BACKGROUND: The association between pretreatment brain stem infarction and thrombectomy outcomes remains to be elucidated in patients with acute basilar artery occlusion (BAO). We aimed to assess the association between pretreatment pontine infarction and extremely poor outcome in patients who underwent endovascular thrombectomy due to acute BAO. METHODS: We retrospectively reviewed data from a stroke database to identify patients with acute BAO who underwent thrombectomy between January 2011 and August 2019. Patient characteristics, pretreatment diffusion-weighted imaging (DWI) data, and outcomes were evaluated. The largest infarct core was expressed as the percentage of infarct core area in each brain stem region on the DWI slice displaying the largest lesion. Extremely poor outcome was defined as a 90-day modified Rankin Scale score of 5 or 6. RESULTS: A total of 113 patients were included, 37 of whom had extremely poor outcome. Among the 15 patients with extensive pontine infarction (largest pontine infarct core of ≥70%), 93.3% had extremely poor outcome. Multivariate logistic regression analysis revealed that the following variables were independent predictors of extremely poor outcome: extensive pontine infarction (adjusted OR 22.494; 95% CI 2.335 to 216.689; p=0.007), posterior circulation ASPECTS on DWI (adjusted OR per 1-point decrease 1.744; 95% CI 1.197 to 2.541; p=0.004), age (adjusted OR per 1-year increase 1.067; 95% CI 1.009 to 1.128; p=0.023), and baseline NIHSS (adjusted OR per 1-point increase 1.105; 95% CI 1.004 to 1.216; p=0.040). CONCLUSION: Our results showed that a large pontine infarct core of ≥70% on pretreatment DWI was strongly associated with extremely poor outcome among patients treated with endovascular thrombectomy for acute BAO.

Pictorial Review of Mediastinal Masses with an Emphasis on Magnetic Resonance Imaging.

Magnetic resonance imaging (MRI) has become a crucial tool for evaluating mediastinal masses considering that several lesions that appear indeterminate on computed tomography and radiography can be differentiated on MRI. Using a three-compartment model to localize the mass and employing a basic knowledge of MRI, radiologists can easily diagnose mediastinal masses. Here, we review the use of MRI in evaluating mediastinal masses and present the images of various mediastinal masses categorized using the International Thymic Malignancy Interest Group's three-compartment classification system. These masses include thymic hyperplasia, thymic cyst, pericardial cyst, thymoma, mediastinal hemangioma, lymphoma, mature teratoma, bronchogenic cyst, esophageal duplication cyst, mediastinal thyroid carcinoma originating from ectopic thyroid tissue, mediastinal liposarcoma, mediastinal pancreatic pseudocyst, neurogenic tumor, meningocele, and plasmacytoma.

Creation of bladder assembloids mimicking tissue regeneration and cancer.

Current organoid models are limited by their inability to mimic mature organ architecture and associated tissue microenvironments1,2. Here we create multilayer bladder 'assembloids' by reconstituting tissue stem cells with stromal components to represent an organized architecture with an epithelium surrounding stroma and an outer muscle layer. These assembloids exhibit characteristics of mature adult bladders in cell composition and gene expression at the single-cell transcriptome level, and recapitulate in vivo tissue dynamics of regenerative responses to injury. We also develop malignant counterpart tumour assembloids to recapitulate the in vivo pathophysiological features of urothelial carcinoma. Using the genetically manipulated tumour-assembloid platform, we identify tumoural FOXA1, induced by stromal bone morphogenetic protein (BMP), as a master pioneer factor that drives enhancer reprogramming for the determination of tumour phenotype, suggesting the importance of the FOXA1-BMP-hedgehog signalling feedback axis between tumour and stroma in the control of tumour plasticity.

Incidentally detected sellar spine in a patient with Cushing's syndrome: a case report.

Sellar spine, a bony spur extending anteriorly from the dorsum sellae, is a very rare anatomical variant. Several hypotheses regarding its etiology have been proposed, including the strongly supported theory of a cephalic ossified notochordal remnant. Sellar spine is usually detected incidentally in patients who have no definite symptoms, but several cases have reportedly accompanied endocrinopathies such as precocious puberty, hypopituitarism, or galactorrhea/oligomenorrhea. However, no published reports have described sellar spine in a patient with Cushing's syndrome. We herein report a case of sellar spine detected during the evaluation of Cushing's disease in a 29-year-old woman who underwent inferior petrosal sinus sampling, computed tomography, magnetic resonance imaging, and exploratory surgery. There was no evidence of a pituitary microadenoma, but a sellar spine was present in the operative field. Thus, the sellar spine might have caused Cushing's syndrome in this case, although the exact mechanism is unknown.

Use of inkjet-printed single cells to quantify intratumoral heterogeneity.

Quantification of intratumoral heterogeneity is essential for designing effective therapeutic strategies in the age of personalized medicine. In this study, we used a piezoelectric inkjet printer to enable analysis of intratumoral heterogeneity in a bladder cancer for the first time. Patient-derived tumor organoids were dissociated into single cell suspension and used as a bioink. The individual cells were precisely allocated into a microwell plate by drop-on-demand inkjet printing without any additive or treatment, followed by culturing into organoids for further analysis. The sizes and morphologies of the organoids were observed, so as the expression of proliferation and apoptotic markers. The tumor organoids also showed heterogeneous responses against chemotherapeutic agent. Further, we quantified mRNA expression levels of representative luminal and basal genes in both type of tumor organoids. These results verify the heterogeneous expression of various genes among individual organoids. This study demonstrates that the fully automated inkjet printing technique can be used as an effective tool to sort cells for evaluating intratumoral heterogeneity.

Outcomes of endovascular treatment in acute ischemic stroke patients with current malignancy.

BACKGROUND AND PURPOSES: The role of endovascular recanalization in the treatment of cancer patients with acute stroke remains elusive. Our study aimed to investigate the clinical and imaging outcomes of endovascular recanalization treatment in patients with acute large vessel occlusion stroke who had active cancer. METHODS: We retrospectively reviewed the data from our stroke registry from January 2011 to September 2016 which was collected prospectively. Acute stroke patients with large artery occlusion in the anterior circulation who had active cancer were identified. Baseline clinical characteristics and postprocedural and long-term clinicoradiological outcomes were evaluated. A good outcome was defined as a 90-day modified Rankin Scale score of 0 to 2. Outcomes were also compared with those of non-malignancy patients who had received endovascular therapy during the same period. RESULTS: A total of 378 ischemic stroke patients received endovascular treatment, of whom 27 (7.14 %) had current malignancy. In patients with current malignancy, a low baseline NIHSS score and male sex were associated with functional independency at 90 days. When comparing with non-malignancy patients, no significant differences in the proportions of patients with symptomatic intracranial hemorrhage (11.1% vs 16.2%, p = 0.60) and good functional outcome (37.0% vs 39.6%, p = 0.84) were found in the malignancy patients. CONCLUSION: Endovascular treatment might be a feasible therapeutic option for acute ischemic stroke patients with current malignancy when candidates are selected carefully because the outcomes were not differed. Future large-scale prospective studies are necessary.

Predictors and impact of hemorrhagic transformations after endovascular thrombectomy in patients with acute large vessel occlusions.

BACKGROUND: Predictors and impact of hemorrhagic transformation (HT) after thrombectomy remain to be elucidated. OBJECTIVE: To investigate the independent predictors and impact of each hemorrhagic infarction (HI) and parenchymal hematoma (PH) after thrombectomy in patients with acute stroke due to intracranial large vessel occlusion (LVO). MATERIALS AND METHODS: We retrospectively reviewed data from 400 patients with acute LVO who underwent thrombectomy. Logistic regression analyses were performed to determine independent predictors of HI and PH on post-treatment CT scans. Associations between HT and poor outcome (modified Rankin Scalescore ≥3) at 90 days were analyzed. RESULTS: HT was observed in 98 patients (62 HIs (15.5%) and 36 PHs (9%)). Independent predictors of HI were male sex, atrial fibrillation, and time from symptom onset to groin puncture. Hyperlipidemia (OR=0.221, 95% CI 0.064 to 0.767, P=0.017) and successful reperfusion (OR=0.246, 95% CI 0.093 to 0.651, P=0.005) were independently associated with a lower chance of PH, while hypertension (OR=2.260, 95% CI 1.014 to 5.035, P=0.046) and longer procedure duration (OR=1.046, 95% CI 1.016 to 1.077, P=0.003) were independently associated with a higher chance of PH. Only PH (OR=10.154, 95% CI 3.260 to 31.632, P<0.001) was an independent predictor of poor outcome. CONCLUSIONS: PH is independently associated with poor outcome, whereas HI does not predict outcome after thrombectomy in patients with acute LVO. Our findings suggest that rapid and successful reperfusion is essential to prevent PH in patients undergoing thrombectomy for acute LVO. In addition, our study suggests that hyperlipidemia is associated with a lower risk of PH in such patients.

Inflammatory mediator expression within retrieved clots in acute ischemic stroke.

Objective: In this study we investigate the association between the expression of inflammatory mediators measured in clots retrieved by mechanical thrombectomy, stroke etiology, and the susceptibility vessel sign (SVS) on gradient-echo (GRE) MR imaging in acute ischemic stroke patients. Methods: We performed molecular analysis of intracranial clots retrieved by mechanical thrombectomy from 82 patients with acute stroke. Seventy-two of these patients underwent GRE imaging before endovascular therapy. We measured the relative expression of inflammatory mediators by performing the quantitative real-time polymerase chain reaction on the retrieved clots and assessed associations between the expression of inflammatory mediators and stroke subtypes as well as with GRE SVS. Results: Classifications of stroke etiology for the cohort were as follows: cardioembolism (51, 62.2%), large artery atherosclerosis (9, 11%), and undetermined etiology (22, 26.8%). Clots associated with large artery atherosclerosis showed significantly higher interleukin (IL)-1ß expression than clots from both cardioembolism and undetermined etiology (P = 0.008). A positive SVS was identified in 48 of 72 patients (66.7%) who had GRE imaging. IL-1ß, tumor necrosis factor-α, and matrix metalloproteinase-9 expressions were significantly higher in clots with a negative SVS than in those with a positive SVS (P = 0.010, 0.049, and 0.004, respectively). Interpretation: Expression of inflammatory mediators in intracranial clots differs significantly based on stroke etiology or presence or the absence of SVS on GRE imaging. This study suggests that molecular analysis of inflammatory mediators in retrieved clots is a promising tool for determining stroke mechanism in acute ischemic stroke patients.

Automatic Detection of Pectoral Muscle Region for Computer-Aided Diagnosis Using MIAS Mammograms.

The computer-aided detection (CAD) systems have been developed to help radiologists with the early detection of breast cancer. This system provides objective and accurate information to reduce the misdiagnosis of the disease. In mammography, the pectoral muscle region is used as an index to compare the symmetry between the left and right images in the mediolateral oblique (MLO) view. The pectoral muscle segmentation is necessary for the detection of microcalcification or mass because the pectoral muscle has a similar pixel intensity as that of lesions, which affects the results of automatic detection. In this study, the mammographic image analysis society database (MIAS, 322 cases) was used for detecting the pectoral muscle segmentation. The pectoral muscle was detected by using the morphological method and the random sample consensus (RANSAC) algorithm. We evaluated the detected pectoral muscle region and compared the manual segmentation with the automatic segmentation. The results showed 92.2% accuracy. We expect that the proposed method improves the detection accuracy of breast cancer lesions using a CAD system.

Patient Radiation Exposure During Diagnostic and Therapeutic Procedures for Intracranial Aneurysms: A Multicenter Study.

PURPOSE: To assess patient radiation doses during cerebral angiography and embolization of intracranial aneurysms across multi-centers and propose a diagnostic reference level (DRL). MATERIALS AND METHODS: We studied a sample of 490 diagnostic and 371 therapeutic procedures for intracranial aneurysms, which were performed at 23 hospitals in Korea in 2015. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time and total angiographic image frames were obtained and analyzed. RESULTS: Total mean DAP, CAK, fluoroscopy time, and total angiographic image frames were 106.2 ± 66.4 Gy-cm(2), 697.1 ± 473.7 mGy, 9.7 ± 6.5 minutes, 241.5 ± 116.6 frames for diagnostic procedures, 218.8 ± 164.3 Gy-cm(2), 3365.7 ± 2205.8 mGy, 51.5 ± 31.1 minutes, 443.5 ± 270.7 frames for therapeutic procedures, respectively. For diagnostic procedure, the third quartiles for DRLs were 144.2 Gy-cm(2) for DAP, 921.1 mGy for CAK, 12.2 minutes for fluoroscopy times and 286.5 for number of image frames, respectively. For therapeutic procedures, the third quartiles for DRLs were 271.0 Gy-cm(2) for DAP, 4471.3 mGy for CAK, 64.7 minutes for fluoroscopy times and 567.3 for number of image frames, respectively. On average, rotational angiography was used 1.5 ± 0.7 times/session (range, 0-4; n=490) for diagnostic procedures and 1.6 ± 1.2 times/session (range, 0-4; n=368) for therapeutic procedures, respectively. CONCLUSION: Radiation dose as measured by DAP, fluoroscopy time and image frames were lower in our patients compared to another study regarding cerebral angiography, and DAP was lower with fewer angiographic image frames for therapeutic procedures. Proposed DRLs can be used for quality assurance and patient safety in diagnostic and therapeutic procedures.