Synthetic interpolated DSA for radiation exposure reduction via gamma variate contrast flow modeling: a retrospective cohort study.

BACKGROUND: Digital subtraction angiography (DSA) yields high cumulative radiation dosages (RD) delivered to patients. We present a temporal interpolation of low frame rate angiograms as a method to reduce cumulative RDs. METHODS: Patients undergoing interventional evaluation and treatment of cerebrovascular vasospasm following subarachnoid hemorrhage were retrospectively identified. DSAs containing pre- and post-intervention runs capturing the full arterial, capillary, and venous phases with at least 16 frames each were selected. Frame rate reduction (FRR) of the original DSAs was performed to 50%, 66%, and 75% of the original frame rate. Missing frames were regenerated by sampling a gamma variate model (GVM) fit to the contrast response curves to the reduced data. A formal reader study was performed to assess the diagnostic accuracy of the "synthetic" studies (sDSA) compared to the original DSA. RESULTS: Thirty-eight studies met inclusion criteria (average RD 1,361.9 mGy). Seven were excluded for differing views, magnifications, or motion. GVMs fit to 50%, 66%, and 75% FRR studies demonstrated average voxel errors of 2.0 ± 2.5% (mean ± standard deviation), 6.5 ± 1.5%, and 27 ± 2%, respectively for anteroposterior projections, 2.0 ± 2.2%, 15.0 ± 3.1%, and 14.8 ± 13.0% for lateral projections, respectively. Reconstructions took 0.51 s/study. Reader studies demonstrated an average rating of 12.8 (95% CI 12.3-13.3) for 75% FRR, 12.7 (12.2-13.2) for 66% FRR and 12.0 (11.5-12.5) for 50% FRR using Subjective Image Grading Scale. Kendall's coefficient of concordance resulted in W = 0.506. CONCLUSION: FRR by 75% combined with GVM reconstruction does not compromise diagnostic quality for the assessment of cerebral vasculature. RELEVANCE STATEMENT: Using this novel algorithm, it is possible to reduce the frame rate of DSA by as much as 75%, with a proportional reduction in radiation exposure, without degrading imaging quality. KEY POINTS: • DSA delivers some of the highest doses of radiation to patients. • Frame rate reduction (FRR) was combined with bolus tracking to interpolate intermediate frames. • This technique provided a 75% FRR with preservation of diagnostic utility as graded by a formal reader study for cerebral angiography performed for the evaluation of cerebral vasospasm. • This approach can be applied to other types of angiography studies.

Combined evaluation of blood flow and tissue perfusion in diabetic feet by intra-arterial dynamic 4DCT imaging.

Critical limb ischemia is associated with high mortality and major amputations. Intra-arterial digital subtraction angiography (IADSA) has been the reference standard but has some shortcomings including the two-dimensional projection and the lack of tissue perfusion information. The aim of this exploratory study is to examine four-dimensional computed tomography (4DCT) angiography and perfusion imaging using low-volume intra-arterial contrast injections for an improved anatomic and hemodynamic assessment in patients with foot ulcers. Three patients underwent a low-volume (2 mL) intra-arterial contrast-enhanced 4DCT examination combined with a diagnostic IADSA. An automated assessment of blood flow and tissue perfusion from the 4DCT data was performed. Vascular structures and corresponding blood flows were successfully assessed and correlated well with the IADSA results. Perfusion values of the affected tissue were significantly higher compared to the unaffected tissue. The proposed 4DCT protocol combined with the minimal usage of contrast agent (2 mL) provides superior images compared to IADSA as three phases (arterial, perfusion, and venous) are captured. The obtained parameters could allow for an improved diagnosis of critical limb ischemia as both the proximal vasculature and the extent of the perfusion deficit in the microvasculature can be assessed.Relevance statementIntra-arterial 4DCT allows for assessing three phases (arterial, perfusion and venous) using minimal contrast (2 mL). This method could lead to an improved diagnosis of critical limb ischemia as both proximal vasculature and the extent of the perfusion deficit are assessed.Trial registrationISRCTN, ISRCTN95737449. Registered 14 March 2023-retrospectively registered, https://www.isrctn.com/ISRCTN95737449 Key points• Three phases (arterial, perfusion, and venous) are obtained from 2 mL intra-arterial 4DCT.• The obtained hemodynamic parameters correlated well with the IADSA findings.• 4DCT surpassed IADSA in terms of assessment of venous blood flow and inflammatory hyperperfusion.• The assessment of tissue perfusion could lead to optimizing the revascularization strategy.

Inferior Vena Cava Stenosis Following Orthotopic Liver Transplantation: Differentiating Points from False Positives.

Orthotopic liver transplantation has become the treatment of choice for patients with end-stage liver disease. Various early or delayed vascular complications, including arterial pseudoaneurysm, thrombosis, or stenosis, and venous stenosis or occlusion, may lead to graft failure. Early detection and prompt management of such complications are essential to achieve successful transplantation and prevent the need for retransplantation. This report presents differentiating points, using computed tomography and digital subtraction angiography findings and measurement of pressure gradient across the stenotic lesion, that require immediate intervention in patients with inferior vena cava stenosis after orthotopic liver transplantation.

Initial Experience Using Digital Variance Angiography in Context of Prostatic Artery Embolization in Comparison with Digital Subtraction Angiography.

RATIONALE AND OBJECTIVES: In previous clinical studies digital variance angiography (DVA) provided higher contrast-to-noise ratio (CNR) and better image quality in lower extremity angiography than digital subtraction angiography (DSA). Our aim was to investigate whether DVA has similar quality reserve in prostatic artery embolization (PAE). The secondary aim was to explore the potential advantages of the color-coded DVA (ccDVA) technology in PAE. MATERIAL AND METHODS: This retrospective study evaluated 108 angiographic acquisitions from 30 patients (mean ± SD age 68.0 ± 8.9, range 41-87) undergoing PAE between May and October 2020. DSA and DVA images were generated from the same unsubtracted acquisition, and their CNR was calculated. Visual evaluation of DVA and DSA image quality was performed by four experienced interventional radiologists in a randomized, blinded manner. The diagnostic value of DSA and ccDVA images was also evaluated using clinically relevant criteria (visibility of small [< 2.5 mm] and large arteries [> 2.5 mm], feeding arteries and tissue blush) in a paired comparison. Data were analysed by the Wilcoxon signed rank test or the binomial test, the interrater agreement was determined by the Kendall W or Fleiss Kappa analysis. RESULTS: DVA provided 4.11 times higher median CNR than DSA (IQR: 1.72). The visual score of DVA images (4.40 ± 0.05) was significantly higher than that of DSA (3.39 ± 0.07, p < 0.001). The Kendall W analysis showed moderate but significant agreement (WDVA = 0.38, WDSA = 0.53). The preference of ccDVA images was significantly higher in all criteria (63-89%) with an interrater agreement of 58-79%. The Fleiss Kappa range was 0.02-0.18, significant in all criteria except large vessels. CONCLUSION: Our data show that DVA provides higher CNR and better image quality in PAE. This quality reserve might be used for dose management (reduction of radiation dose and contrast agent volume), and ccDVA technology has also a high potential to assist PAE interventions in the future.

The value of transcranial Doppler sonography and digital subtraction angiography in evaluating collateral circulation in ischemic stroke and its correlation with prognosis / 中国医师进修杂志

Objective:To explore the value of transcranial Doppler sonography (TCD) and digital subtraction angiography (DSA) in evaluating collateral circulation in ischemic stroke (IS) and its correlation with prognosis.Methods:The 350 IS patients admitted to Shaoxing People′s Hospital from January 2017 to December 2020 were selected as the research objects. According to the results of DSA, they were divided into collateral circulation group and non-collateral circulation group. According to the prognosis, they were divided into good prognosis group and poor prognosis group. The consistency between the evaluation results of collateral circulation on IS of TCD and DSA was analyzed, and its correlation with prognosis was analyzed.Results:The DSA results showed that among 350 patients, 118 had no collateral circulation and 232 had collateral circulation, including 130 cases of grade 1 collateral circulation and 102 cases of grade 2 collateral circulation. TCD results showed that there were 117 cases without collateral circulation and 233 cases with collateral circulation, including 131 cases with grade 1 collateral circulation and 102 cases with grade 2 collateral circulation. The consistency test showed that the evaluation results of TCD on collateral circulation was highly consistent with the gold standard DSA ( Kappa>0.9, P<0.05). Repeated measures analysis of variance showed that time-point effects, inter-group effects, time-point and inter-group interaction effects can significantly affect the changes in modified Rankin scale(mRS) scores ( P<0.05); and the mRS scores in the collateral circulation group were less than those in the non-collateral circulation group at admission the hospital, discharge of the hospital and 3 months after discharge the hospital: (1.89 ± 0.82) scores vs. (2.98 ± 0.98) scores, (1.13 ± 0.53) scores vs. (2.45 ± 0.80) scores, (0.50 ± 0.45) scores vs. (1.86 ± 0.80) scores, there were statistical differences ( P<0.05). The collateral circulation rate in the good prognosis group was higher than that in the poor prognosis group: 78.95%(150/190) vs. 47.50%(76/160), there was statistical difference ( P<0.05). Conclusions:The evaluation value of TCD for IS collateral circulation is high, and collateral circulation is closely related to prognosis.

Advances in imaging studies of primary angiitis of the central nervous system / 中华神经科杂志

Primary angiitis of the central nervous system (PACNS) is a rare inflammatory disease of the central nervous system with unknown etiology affecting the brain and spinal cord. As the incidence of PACNS is low, the clinical manifestations are diverse, the cerebrospinal fluid examination lacks specificity, its diagnosis mainly depends on the "gold standard" pathological biopsy. However, due to the subjectivity of the sampling site, tissue staining and microscopic reading, some patients may be misdiagnosed. In addition, the potentially aggressive course of PACNS may reduce disability and mortality through appropriate immunosuppressive therapy, so the early diagnosis of PACNS is conducive to the prognosis of patients. Imaging examination is convenient, non-invasive, and can provide important information for the diagnosis and differential diagnosis of PACNS from various aspects. Therefore, it is very important to explore the imaging features of the disease. This paper reviews the current research status of imaging examination in PACNS and summarizes the different types of imaging findings in PACNS.

Quantitative analysis of digital subtraction angiography: the way to advanced reperfusion evaluation / 中华神经科杂志

Quantitative digital subtraction angiography (DSA) analysis can obtain pixel time density curves through changes in contrast agent concentration, and calculate the corresponding parameters of the contrast agent in the area of interest, achieving semi quantitative analysis of patient hemodynamic, used to evaluate the reperfusion status of intravascular therapy in patients with acute ischemic large vessel occlusion stroke. With the widespread application of artificial intelligence technology, especially deep learning algorithms in medical image processing, it is expected to further excavate the DSA images, which can comprehensively evaluate cerebral vascular diseases in multiple phases, angles, and directions.

Prognostic prediction value of quantitative digital subtraction angiography parameters after mechanical thrombectomy in patients with acute ischemic stroke with large vessel occlusion in the anterior circulation of different etiology / 中华神经科杂志

Objective:To explore the prognostic prediction value of quantitative digital subtraction angiography (DSA) parameters in patients with acute anterior circulation ischemic stroke undergoing mechanical thrombectomy, and whether the clinical values vary by stroke etiology.Methods:This study was a post hoc analysis of the Multicenter Prospective Captor Trial. Patients with acute anterior circulation large-vessel occlusion and successful recanalization from April 2018 to July 2019 were screened. Post-processing analysis was performed on the DSA imaging sequence after recanalization, and 4 regions of interest (ROI) were selected in the target vessel: ROI1 (the proximal of the internal carotid artery-C2 segment), ROI2 (the starting point of the internal carotid artery-C7 segment), ROI3 (the end of the middle cerebral artery-M1 segment), and ROI4 (the end of the middle cerebral artery-M2 segment). Time to peak (TTP) was defined as the time at contrast concentration of selected ROI reached its maximum. Relative TTP (rTTP) was calculated by subtracting the TTP of ROI1 from the TTP of distalis ROIs. Successful recanalization was defined as modified Thrombolysis In Cerebral Infarction (mTICI) grade≥2b. Favorable outcomes at 3 months were defined as the modified Rankin Scale score≤2. According to the modified Rankin Scale score, the patients were divided into good prognosis group and poor prognosis group. The differences in clinical characteristics, postoperative hemodynamic parameters, and other data were compared between patients with good and poor prognoses. Univariate and multivariate Logistic regression was used to analyze factors related to a good prognosis. Finally, the prognostic prediction value of hemodynamic parameters was analyzed in patients with different Trial of Org10172 in Acute Stroke Treatment etiological classifications.Results:A total of 245 patients were collected, of which 161 patients [age 69 (60, 76) years, 92 (57.1%) male] were finally included in the analysis, including 36 cases of large artery atherosclerosis (LAA) stroke, 76 cases of cardiogenic embolism (CE), and 49 cases of other causes of stroke. Seventy-one (44.1%) patients had favorable outcomes at 3 months. The post-operative hemodynamic analysis indicated that patients with favorable outcomes ( n=71) had a higher proportion of mTICI grade 3 [54/71 (76.1%) vs 41/90 (45.6%),χ 2=15.26, P<0.001] and lower rTTP 31 [means TTP ROI3-TTP ROI1;0.33 (0.23, 0.54) s vs 0.47 (0.31, 0.65) s, Z=-2.71, P=0.007] than patients with unfavorable outcomes ( n=90). The mTICI score and rTTP 31 were respectively included in multivariate Logistic regression models. It was shown that mTICI grade 3 (adjusted OR=5.97, 95% CI 2.49-14.27, P<0.001) and rTTP 31 (adjusted OR=0.24, 95% CI 0.06-0.99, P=0.048) were significantly associated with favorable outcomes, and the area under the receiver operating characteristic curve of the models had no statistically significant difference ( P=0.170). Subgroup analysis showed that rTTP 31 was significantly associated with the prognosis of patients with LAA stroke ( OR=0, 95% CI 0-0.25, P=0.014), while mTICI grade was associated with the prognosis of patients with CE ( OR=3.91, 95% CI 1.40-10.91, P=0.009) and other etiologies ( OR=7.35, 95% CI 1.92-28.14, P=0.004). Conclusions:In patients with acute anterior circulation ischemic stroke and successful recanalization, both mTICI score and rTTP 31 had significant predictive value for favorable outcomes at 3 months. Moreover, rTTP 31 was significantly associated with the prognosis of patients with LAA stroke, while mTICI score was significantly related to the prognosis of patients with CE and other causes of stroke.

Preliminary exploration of endovascular treatment for cerebral infarction caused by middle cerebral artery stenosis with hypoperfusion in the blood supply area of the lenticulostriate artery / 中华神经科杂志

Objective:To evaluate the necessity, safety and efficacy of endovascular treatment for cerebral infarction caused by middle cerebral artery (MCA) stenosis with hypoperfusion in the blood supply area of the lenticulostriate artery.Methods:The clinical and surgical data of patients with MCA atherosclerotic disease who underwent endovascular treatment in the First Affiliated Hospital of Zhengzhou University from January 2014 to October 2021 were retrospectively analyzed. A total of 6 patients with cerebral infarction caused by MCA stenosis with hypoperfusion in the blood supply area of the lenticulostriate artery were selected. The preoperative and postoperative clinical imaging characteristics, perioperative complications and follow-up of these 6 patients were summarized and evaluated.Results:After the endovascular treatment, the imaging of the lenticulostriate artery in all the 6 patients was clearer than that before the operation, and the number of main trunks of the lenticulostriate artery shown by imaging in 2 patients was more than that before operation. The computer tomography perfusion of 6 patients after the endovascular treatment showed that perfusion in the supply area of the lenticulostriate artery was significantly improved compared with pre-operation. No stroke, transient ischemic attack (TIA) and death occurred during the perioperative period. The time of clinical follow-up was 360 (322, 495) days, and there were no stroke, TIA or death occurring in the corresponding artery. All the 6 patients underwent imaging follow-up, of which 3 patients underwent digital subtraction angiography and 3 underwent CT angiography. The lumen of the target vessels showed patency in all patients.Conclusions:With rigorous imaging evaluation, endovascular treatment may be safe and effective for cerebral infarction caused by MCA stenosis with hypoperfusion in the blood supply area of the lenticulostriate artery.

Clinical value of high-resolution vessel wall imaging and silent magnetic resonance angiography in re-examination after intracranial aneurysm embolization / 中华神经科杂志

Objective:To explore the clinical application of time of flight-magnetic resonance angiography (TOF-MRA), silent magnetic resonance angiography (SilenZ-MRA) and high-resolution vessel wall imaging (HR-VWI) in non-invasive evaluation of intracranial aneurysm after embolization.Methods:From February 2021 to February 2022, 39 patients, including 8 males and 31 females, who were 29-86 (54.50±11.80) years old and had received intracranial aneurysm embolization were collected in the Second Affiliated Hospital of Nanchang University. Kruskal-Wallis test was used to compare the image quality score and the evaluation results of lumen stenosis rate in the stent segments by TOF-MRA, SilenZ-MRA and HR-VWI. The diagnostic value of TOF-MRA, SilenZ-MRA and HR-VWI was analyzed by receiver operating characteristic (ROC) curve with DSA as the reference standard.Results:The image quality scores of TOF-MRA, SilenZ-MRA and HR-VWI were 2(1, 3), 4(3, 4) and 4(4, 4), respectively, with statistically significant difference ( H=80.78, P<0.05). The pairwise comparison results were as follows: TOF-MRA vs SilenZ-MRA, P<0.017; TOF-MRA vs HR-VWI, P<0.017; SilenZ-MRA vs HR-VWI, P>0.017. The lumen stenosis rates of stent segments measured by TOF-MRA, SilenZ-MRA, HR-VWI and DSA were 45.00% (29.60%, 61.05%), 17.60% (10.80%, 26.80%), 13.35% (8.90%, 15.95%) and 7.95% (4.80%, 11.25%), respectively, with statistically significant difference ( H=67.96, P<0.05). The results of comparison between TOF-MRA, SilenZ-MRA, HR-VWI and DSA were respectively as follows: TOF-MRA vs DSA, P<0.017; SilenZ-MRA vs DSA, P<0.017; HR-VWI vs DSA, P>0.017. DSA review showed that 12 (27.91%,12/43) aneurysms were not completely embolized, and 31 (72.09%, 31/43) aneurysms were completely embolized. The area under the curve of TOF-MRA, SilenZ-MRA and HR-VWI for evaluating the postoperative complete embolization of aneurysm was 0.75, 1.00 and 0.94, respectively, with statistically significant differences between TOF-MRA and HR-VWI ( Z=2.53, P<0.05) as well as between TOF-MRA and SilenZ-MRA ( Z=3.32, P<0.05). Conclusions:HR-VWI can clearly display the stent-segment lumen of the parent artery, and evaluate the stent-segment arterial wall and whether the stent-segment lumen is unobstructed or not. SilenZ-MRA is significantly superior to TOF-MRA in the evaluation of postoperative embolization status of aneurysms, and slightly superior to HR-VWI in tumor neck display. Combined application of HR-VWI and SilenZ-MRA has certain clinical significance for non-invasive evaluation of intracranial aneurysm after embolization.

Severe hemorrhagic complications in acute necrotizing pancreatitis: a retrospective single-center study / 中华肝胆外科杂志

Objective:To study the clinical features in patients with acute necrotizing pancreatitis (ANP) complicated by hemorrhage, and to analyze the treatments and their outcomes.Methods:The clinical data of 44 ANP patients with hemorrhage managed at the Department of Pancreas Center, the First Affiliated Hospital of Nanjing Medical University from September 2015 to December 2020 were retrospectively analyzed. There were 34 males and 10 females, aged (48.9±12.2) years old. Clinical data were collected on the bleeding sites, bleeding interventions, and treatment outcomes. Follow-up visits were made by outpatients visits or telephone.Results:Of the 44 patients with bleeding, 8 had gastrointestinal bleeding, 31 had intra-abdominal bleeding, and the remaining 5 had mixed bleeding sites. The median interval from onset of ANP to development of hemorrhage was 30.5(20.8, 40.3) d. For the 13 patients with gastrointestinal bleeding and mixed sites of bleeding: 4 patients were successfully treated by endoscopically for upper gastrointestinal ulcers, 5 patients were successfully treated by endovascular embolization using digital subtraction angiography (DSA) to detect the sites of bleeding, and 4 patients were successfully treated by surgery. For the 31 patients with intra-abdominal hemorrhage: 24 underwent DSA. For the 7 patients who did not undergo DSA, 3 who were hemodynamically stable were treated conservatively, 2 underwent immediate open surgery to stop bleeding within 24 h after surgical debridement of infected pancreatic necrosis, 1 did not undergo DSA because the family members decided to abandon further treatment, and 1 died while preparing for DSA. For the 29 patients who underwent DSA, vascular abnormalities were found in 69.0%(20/29), with splenic artery hemorrhage being the most common. In the 44 patients with bleeding: 29.5%(13/44) were examined by endoscopy, and 4 were successfully stopped by endoscopic treatment; 65.9%(29/44) patients were examined by DSA, and 15 patients were successfully treated by intravascular embolization; 14 patients (31.9%) were treated by open surgery and 11 patients were successfully stopped. The mortality rate was 47.7%(21/44), of which 5 patients died from hemorrhagic shock complicated by multiple organ dysfunction syndrome (MODS) and 16 patients died from sepsis complicated by MODS. The mortality rate of 55.6%(20/36) in patients with intra-abdominal and mixed sites of bleeding was significantly higher than that of the 12.5%(1/8) in patients with gastrointestinal bleeding ( P=0.048). None of the 23 surviving patients developed recurrence of intra-abdominal and/or gastrointestinal bleeding on follow-up. Conclusion:Major bleeding commonly occurred about 1 month after ANP and it was associated with a higher in-hospital mortality rate. DSA, endoscopy, and open surgery were effective means to achieve hemostasis.

Comparison of 3D-arterial spin labeling and digital subtraction angiography in the diagnosis of occlusion and collateral circulation in patients with acute ischemic stroke / 中国医师杂志

Objective:To explore the diagnostic value of 3D-arterial spin labeling (ASL) and digital subtraction angiography (DSA) in the occlusion and collateral circulation (CC) of patients with acute ischemic stroke (AIS).Methods:From January 2019 to June 2020, 53 cases of AIS patients with middle cerebral artery (MCA) occlusion in Langfang Hospital of Traditional Chinese Medicine were selected as the research objects. All patients underwent DSA and 3D ASL examination. According to the gold standard of DSA, the diagnostic value of proximal intra-arterial signal (IAS) in 3D-ASL was observed, and the clinical value of distal IAS in the diagnosis of lateral CC was observed. Univariate and multivariate logistic regression were used to identify risk factors for poor outcome in AIS patients.Results:There were 31 cases with good collateral circulation judged by DSA. Taking DSA as the gold standard, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of digital IAS in diagnosing CC status were 93.55%, 81.82%, 87.88%, 90.00% and 88.68%, respectively. The National Institutes of Health Stroke Scale (NIHSS) score of patients with good CC assessed by 3D-ASL was lower than that of patients with poor CC at admission, and the good prognosis rate at discharge was higher than that of patients with poor CC, with statistically significant difference (all P<0.05). There was no significant difference in clinical data between patients with good CC and those with poor CC, such as gender, age, history of atrial fibrillation, hypertension, diabetes, smoking, drinking, onset to treatment time, treatment methods, etc (all P>0.05). Univariate and multivariate analysis showed that poor CC assessed by ASL was a risk factor for poor prognosis in AIS patients ( OR=5.897, P<0.05). Conclusions:The proximal and distal IAS of 3D-ASL can provide important diagnostic clues for detecting arterial occlusion and collateral perfusion in patients with AIS, and the detection of CC by ASL is of great value for prognosis.

Tantalum-specific contrast-to-noise ratio or conventional detector dose-driven exposure control in angiography: radiation dose and image quality evaluation in a porcine model.

BACKGROUND: The aim of this animal study was to compare the fluoroscopic image quality (IQ) and radiation dose between a tantalum (Ta)-specific contrast-to-noise ratio-driven exposure control (Ta-CEC) and a detector dose-driven exposure control (DEC) in abdominal angiography. METHODS: Nine angiography scenarios were created in seven anaesthetised pigs using Ta-based embolisation material during percutaneous liver and kidney intervention. Fluoroscopic images were acquired using three DEC protocols with different dose levels and Ta-CEC protocols with different IQ levels, sampled in small steps. Polymethyl-methacrylate and aluminium plates were used to simulate attenuation of three water equivalent thicknesses (WET). Three blinded readers evaluated the IQ of DEC and dose equivalent Ta images and selected the Ta-IQ equivalent image corresponding to the DEC image. RESULTS: Interobserver agreement for the IQ assessment was 0.43 for DEC, 0.56 for Ta-CEC and for the assessment of incident air kerma at the interventional reference point (Ka,r) for the Ta-IQ equivalent image 0.73. The average IQ of the dose equivalent Ta images was superior compared to the DEC images (p < 0.001) and also for every WET (26, 31, or 36 cm) and dose level (p ≤ 0.022). The average Ka,r for the Ta-IQ equivalent images was 59 ± 16% (mean ± standard deviation) lower compared to the DEC images (p < 0.001). CONCLUSIONS: Compared to DEC, Ta-CEC significantly improved the fluoroscopic depiction of Ta, while maintaining the Ka,r. Alternatively, the Ka,r can be significantly reduced by using Ta-CEC instead of DEC, while maintaining equivalent IQ.

Transradial Approach for Thoracolumbar Spinal Angiography and Tumor Embolization: Feasibility and Technical Considerations.

The transradial approach (TRA) is an effective and safe alternative to transfemoral access for diagnostic neuroangiography and craniocervical interventions. While the technical aspects of supraclavicular intervention are well-described, there are little data on the TRA for thoracolumbar angiography and intervention. The authors describe the feasibility of the TRA for preoperative thoracic tumor embolization, emphasizing technique, device selection, navigation, and catheterization of thoracolumbar segmental arteries. This approach extends the benefits of TRA to spinal interventional neuroradiology.

Center experience and other determinants of patient radiation exposure during prostatic artery embolization: a retrospective study in three Scandinavian centers.

OBJECTIVES: To evaluate the effects of center experience and a variety of patient- and procedure-related factors on patient radiation exposure during prostatic artery embolization (PAE) in three Scandinavian centers with different PAE protocols and levels of experience. Understanding factors that influence radiation exposure is crucial in effective patient selection and procedural planning. METHODS: Data were collected retrospectively for 352 consecutive PAE procedures from January 2015 to June 2020 at the three centers. Dose area product (DAP (Gy·cm2)) was selected as the primary outcome measure of radiation exposure. Multiple patient- and procedure-related explanatory variables were collected and correlated with the outcome variable. A multiple linear regression model was built to determine significant predictors of increased or decreased radiation exposure as reflected by DAP. RESULTS: There was considerable variation in DAP between the centers. Intended unilateral PAE (p = 0.03) and each 10 additional patients treated (p = 0.02) were significant predictors of decreased DAP. Conversely, increased patient body mass index (BMI, p < 0.001), fluoroscopy time (p < 0.001), and number of digital subtraction angiography (DSA) acquisitions (p < 0.001) were significant predictors of increased DAP. CONCLUSIONS: To minimize patient radiation exposure during PAE radiologists may, in collaboration with clinicians, consider unilateral embolization, pre-interventional CTA for procedure planning, using predominantly anteroposterior (AP) projections, and limiting the use of cone-beam CT (CBCT) and fluoroscopy. KEY POINTS: • Growing center experience and intended unilateral embolization decrease patient radiation exposure during prostatic artery embolization. • Patient BMI, fluoroscopy time, and number of DSA acquisitions are associated with increased DAP during procedures. • Large variation in radiation exposure between the centers may reflect the use of CTA before and CBCT during the procedure.

Diagnostic accuracy of computed tomography angiography (CTA) for diagnosing blunt cerebrovascular injury in trauma patients: a systematic review and meta-analysis.

OBJECTIVES: Previous literature showed that the diagnostic accuracy of computed tomographic angiography (CTA) is not equally comparable with that of the rarely used golden standard of digital subtraction angiography (DSA) for detecting blunt cerebrovascular injuries (BCVI) in trauma patients. However, advances in CTA technology may prove CTA to become equally accurate. This study investigated the diagnostic accuracy of CTA in detecting BCVI in comparison with DSA in trauma patients. METHODS: An electronic database search was performed in PubMed, EMBASE, and Cochrane Library. Summary estimates of sensitivity, specificity, positive and negative likelihood, diagnostic odds ratio, and 95% confidence intervals were determined using a bivariate random-effects model. RESULTS: Of the 3293 studies identified, 9 met the inclusion criteria. Pooled sensitivity was 64% (95% CI, 53-74%) and specificity 95% (95% CI, 87-99%) The estimated positive likelihood ratio was 11.8 (95%, 5.6-24.9), with a negative likelihood ratio of 0.38 (95%, 0.30-0.49) and a diagnostic odds ratio of 31 (95%, 17-56). CONCLUSION: CTA has reasonable specificity but low sensitivity when compared to DSA in diagnosing any BCVI. An increase in channels to 64 slices did not yield better sensitivity. There is a risk for underdiagnosis of BCVI when only using DSA to confirm CTA-positive cases, especially in those patients with low-grade injuries. KEY POINTS: • Low sensitivity and high specificity were seen in identifying BCVI with CTA as compared to DSA. • Increased CTA detector channels (≤ 64) did not lead to higher sensitivity when detecting BCVI. • The use of CTA instead of DSA may lead to underdiagnosis and, consequently, undertreatment of BCVI.

Development and validation of visual grading system for stenosis in intracranial atherosclerotic disease on time-of-flight magnetic resonance angiography.

OBJECTIVES: Although the overestimation problem of time-of-flight magnetic resonance angiography (TOF-MRA) applying the warfarin-aspirin symptomatic intracranial disease (WASID) method to assess intracranial arterial stenosis has often been suggested, no pertinent grading system for TOF-MRA has been developed. We aimed to develop and evaluate the performance of a visual grading system for intracranial arterial stenosis on TOF-MRA (MRAVICAST). METHODS: This single-center cohort study analyzed prospective observational registry data from a comprehensive stroke center between January 2014 and February 2020. Patients with confirmed stenosis of the intracranial large arteries who underwent confirmative digital subtraction angiography (DSA) were included; a 4-point grading system was developed based on physical characteristics of TOF-MRA. The overall diagnostic accuracies of MRAVICAST for each grade, interobserver reproducibility, and positive predictive values for > 50% and > 70% stenoses were evaluated. RESULTS: We analyzed 132 segments with intracranial atherosclerotic stenosis from 71 patients (34 men and 37 women; mean age, 61.0 ± 15.25 years; range, 21-89 years). The overall diagnostic accuracy of MRAVICAST (93.9%, 124/132) was higher than that of MRAWASID (50.8%, 67/132) for each grade. The degree of stenosis did not differ significantly between MRAVICAST and DSAWASID (p = .849). Regarding reproducibility, MRAVICAST demonstrated excellent interobserver agreement (ICC, 0.989; 95% CI, 0.979-0.999). The positive predictive values of MRAVICAST for the diagnosis of > 50% and > 70% stenoses were 97.3% and 100.0%, respectively. CONCLUSIONS: The new intuitive grading system accurately and reliably determined the degree of stenosis in intracranial arterial atherosclerosis patients. MRAVICAST could be a versatile alternative to MRAWASID for evaluating intracranial arterial stenosis. KEY POINTS: • In this retrospective diagnostic study (sample: 132 stenotic segments), the overall accuracy of the visual grading system (MRAVICAST) was 94%, and positive predictive value for > 50% stenosis was 97%. • In the era of medical treatment for intracranial atherosclerotic stenosis, MRAVICAST could be a versatile alternative method to MRAWASID for evaluating intracranial arterial stenosis.

Bronchial arteriography CT combined with bronchoscopy in diagnosis of Dieulafoy′s disease (a report of 5 cases) / 中国医师杂志

Objective:To investigate the diagnostic value of bronchial arteriography CT (BA-ACT) combined with bronchoscopy (BS) in bronchial Dieulafoy′s disease (BDD), and the role of bronchial artery embolization (BAE) in the treatment of BDD.Methods:Retrospective analysis was made on the clinical data of 5 patients suspected of being BDD treated by BS in Guangzhou First People′s Hospital or Guangzhou Thoracic Hospital from January 2008 to January 2018 due to hemoptysis. Bronchial arteriography (BAG) and BA-ACT were performed during the operation of interventional embolization. BAG rotary acquisition data were post-processed according to BS findings, and BA-ACT reconstruction images of the diseased bronchi and bronchial arteries were obtained. BS reexamination and clinical follow-up observation were carried out after embolization to analyze the effect of embolization.Results:There were one BDD lesion for the five patients respectively, and the BAG lacked characteristic manifestations. Bronchoscopy revealed BDD foci to present as papillary (case 1-case 3), nodular (case 4), or lirellate (case 5) subbronchial submucosal protrusion lesions. On the BA-ACT reconstruction plot, the BDD lesions of papillary, nodular and carination manifested correspondingly as a bronchial artery branches locally " pointed arch" shaped (cases 1-case 4) or " bead-like" (case 5) fold and protruding toward the bronchial lumen. The BDD lesions of the cases 1-case 4 retraction and disappearance after one BAE were observed by BS examination, and no hemoptysis recurrence during the follow-up period (54-91 months). The ridge like BDD lesion of the case 5 remained unchanged after BAE, and hemoptysis recurred at 71 months after the first BAE; the uncollapsed foci were supplied by two collateral vessels that confirmed by second BAG and BA-ACT, and no hemoptysis for 71 months followed up after second BAE.Conclusions:BA-ACT combined with BS enables a locative and qualitative diagnosis of BDD, and BAE is a very effective treatment method for BDD.

Bilateral basal ganglia hemorrhage due to tentorial dural arteriovenous fistula: a case report and systematic literature review / 中华神经科杂志

Objective:To investigate the clinical characteristics of cerebral hemorrhage caused by tentorial dural arteriovenous fistula (TDAVF).Methods:An unusual TDAVF case admitted to the Department of Neurology, Qilu Hospital, Shandong University in March 2020, complicated with hypertension with successive bilateral basal ganglia hemorrhage in short term was reported. The characteristics of cerebral hemorrhage caused by TDAVF reported in the literature were summarized and analyzed.Results:Digital subtraction angiography (DSA) revealed that there was arteriovenous fistula in the tentorial foramen area of this patient (male, 33 years old), and the TDAVF was fed by the right meningohypophyseal trunk, bilateral middle meningeal artery and posterior cerebral artery. A shunted pouch was present in the tentorial foramen area, and retrograde reflux drainage was seen in the deep venous system, from the meningeal vein to superior sagittal sinus or sigmoid sinus. Transarterial embolization was performed and subsequently DSA showed obliteration of the fistula. This patient experienced no clinical decline or rehemorrhage during the 12 months follow-up period. Forty-one cases of TDAVF with hemorrhage of cerebral parenchyma which were reported before March 30, 2021 with detailed clinical and imaging data were summarized. The average age of onset of this group of patients was 57.2 years, and the ratio of male to female was about 3∶1. The hemorrhage was located in superior of the tentorium in 17 cases (41%), while in inferior of the tentorium in 24 cases (59%). Supratentorial intracerebral hemorrhage mainly occurred in occipital lobe and thalamus. DSA showed that the arteriovenous fistula was classified as Borden type Ⅲ or Cognard type Ⅳ in 36 cases (88%). Twenty-nine patients (71%) underwent a single surgical procedure, while 12 cases (29%) underwent combined surgical or other treatments. Overall, 37 patients (90%) achieved angiographically documented obliteration of the fistula and 39 patients (95%) experienced good or excellent outcomes.Conclusions:TDAVF often presents as cerebral parenchymal hemorrhage which is common in supratentorial region, but rare in basal ganglia region. The cause of cerebral hemorrhage in patients with hypertension may not be attributed to hypertension. Early diagnosis and intervention are of great significance to improve the prognosis of patients.