Semi-automatic computed tomography angiography quantification assessment is an alternative method to digital subtraction angiography in intracranial stenosis: a multicenter study.

Background: The recent randomized controlled trials studying intracranial atherosclerotic stenosis (ICAS) have used digital subtraction angiography (DSA) to quantify stenosis and enroll patients. However, some disadvantages of DSA such as invasive features, contrast agent overuse, and X-ray radiation overexposure, were not considered in these studies. This study aimed to explore whether computed tomography angiography (CTA) with semi-automatic analysis could be an alternative method to DSA in quantifying the absolute stenotic degree in clinical trials. Methods: Patients with 50-99% ICAS were consecutively screened, prospectively enrolled, and underwent CTA and DSA between March 2021 and December 2021 at 6 centers. This study was registered at www.chictr.org.cn (ChiCTR2100052925). The absolute stenotic degree of ICAS on CTA with semi-automatic analysis was calculated by several protocols using minimal/maximum/mean diameters of stenosis and reference site from a semi-automatic analysis software. Intraclass correlation coefficient (ICC) was used to evaluate the reliabilities of quantifying stenotic degree on CTA. The optimal protocol for quantifying ICAS on CTA was explored. The agreements of quantifying ICAS in calcified or non-calcified lesions and 50-69% or 70-99% stenosis on CTA and DSA were assessed. Results: A total of 191 participants (58.8±10.7 years; 148 men) with 202 lesions were enrolled. The optimal protocol for quantifying ICAS on CTA was calculated as (1 - the minimal diameter of stenosis/the mean diameter of reference) × 100% for its highest agreement with DSA [ICC, 0.955, 95% confidence interval (CI): 0.944-0.966, P<0.001]. Among the 202 lesions, 80.2% (162/202) exhibited severe stenosis on DSA. The accuracy of CTA in detecting severe ICAS was excellent (sensitivity =95.1%, positive predictive value =98.1%). The agreements between DSA and CTA in non-calcified lesions (ICC, 0.960 vs. 0.849) and severe stenosis (ICC, 0.918 vs. 0.841) were higher than those in calcified lesions and moderate stenosis. Conclusions: CTA with semi-automatic analysis demonstrated an excellent agreement with DSA in quantifying ICAS, making it promising to replace DSA for the measurement of absolute stenotic degree in clinical trials.

Diagnostic performance of computed tomography-digital subtraction angiography and conventional magnetic resonance imaging for evaluating the vascularity of osseous spinal tumors.

BACKGROUND AND PURPOSE: Patients with hypervascular spinal tumors may have severe blood loss during tumor resection, which increases the risks of perioperative morbidity and mortality. However, the preoperative evaluation of tumor vascularity may be challenging; moreover, the reliability of the data obtained in conventional preoperative noninvasive imaging is debatable. In this study, we compared conventional magnetic resonance imaging (MRI) and subtraction computed tomography angiography (CTA) in terms of their performance in vascularity evaluation. The catheter digital subtraction angiography (DSA) technique was used as a reference standard. METHODS: This study included 123 consecutive patients with spinal tumor who underwent subtraction CTA, catheter DSA, and subsequent surgery between October 2015 and October 2021. Data regarding qualitative and semiquantitative subtraction CTA parameters and conventional MRI signs were collected for comparison with tumor vascularity graded through catheter DSA. The diagnostic performance of qualitative CTA, quantitative CTA, and conventional MRI in assessing spinal tumor vascularity was analyzed. RESULTS: Qualitative subtraction CTA was the best noninvasive imaging modality in terms of diagnostic performance (area under the receiver operating characteristic curve [AUROC], 0.95). Quantitative CTA was relatively inferior (AUROC, 0.87). MRI results had low reliability (AUROC, 0.51 to 0.59). Intratumoral hemorrhage and prominent foraminal venous plexus were found to be the specific signs for hypervascularity (specificity 93.2%). CONCLUSIONS: Qualitative subtraction CTA offers the highest diagnostic value in evaluating spinal tumor vascularity, compared to quantitative CTA and MRI. Although conventional MRI may not be a reliable approach, certain MRI signs may have high specificity, which may be crucial for assessing spinal tumor vascularity.

Comparative diagnostic efficacy of cranial CT, CTA, and DSA in subarachnoid hemorrhage management: A systematic review and meta-analysis.

INTRODUCTION: Subarachnoid hemorrhage (SAH) is a critical medical condition associated with high morbidity and mortality rates. Timely and accurate diagnosis is crucial for optimal patient outcomes. Cranial computed tomography (CT), computed tomography angiography (CTA), and digital subtraction angiography (DSA) are commonly used imaging modalities for diagnosing SAH, but their comparative diagnostic efficacy remains debated. METHODS: A systematic review and meta-analysis was conducted to evaluate the diagnostic performance of cranial CT, CTA, and DSA in identifying SAH. PubMed, Google scholar, Cochrane Library databases were searched for relevant studies published up to January 2024. Pooled sensitivity, specificity, and the summary receiver operating characteristic (SROC) curve were calculated using Review Manager 5.4. RESULTS: A total of 31 studies involving 10,287 patients were included in the analysis. The pooled sensitivity of cranial CT for detecting SAH was 94.7 % (95 % Confidence Interval, CI) with a specificity of 98.3 % (95 % CI). CTA demonstrated a pooled sensitivity of 94.1 % (95 % CI) and specificity of 93.4 % (95 % CI). DSA showed a pooled sensitivity of 87.7 % (95 % CI) and specificity of 95.8 % (95 % CI). The SROC curve demonstrated discriminatory ability for all modalities. CONCLUSION: Cranial CT, CTA, and DSA are valuable imaging modalities for diagnosing SAH, with high sensitivity and specificity. Cranial CT serves as an initial screening tool, while CTA offers superior sensitivity in detecting aneurysmal SAH. DSA remains essential in specific clinical scenarios. Further prospective studies are needed to validate these findings and refine diagnostic guidelines for SAH.

Digital Subtraction Angiography of Cerebral Arteries: Influence of Cranial Dimensions on X-ray Tube Performance.

(1) Background. Digital subtraction angiography (DSA) is indispensable for diagnosing cerebral aneurysms due to its superior imaging precision. However, optimizing X-ray parameters is crucial for accurate diagnosis, with X-ray tube settings significantly influencing image quality. Understanding the relationship between skull dimensions and X-ray parameters is pivotal for tailoring imaging protocols to individual patients. (2) Methods. A retrospective analysis of DSA data from a single center was conducted, involving 251 patients. Cephalometric measurements and statistical analyses were performed to assess correlations between skull dimensions and X-ray tube parameters (voltage and current). (3) Results. The study revealed significant correlations between skull dimensions and X-ray tube parameters, highlighting the importance of considering individual anatomical variations. Gender-based differences in X-ray parameters were observed, emphasizing the need for personalized imaging protocols. (4) Conclusions. Personalized approaches to DSA imaging, integrating individual anatomical variations and gender-specific differences, are essential for optimizing diagnostic outcomes. While this study provides valuable insights, further research across multiple centers and diverse imaging equipment is warranted to validate these findings.

Cerebral Vasospasm After Burr Hole Evacuation of Chronic Subdural Hematoma.

Cerebral vasospasm is a frequent complication of subarachnoid hemorrhage. We report a case of chronic subdural hematoma complicated by cerebral vasospasm after burr hole evacuation. A 74-year-old woman underwent burr hole evacuation of a chronic subdural hematoma. She developed left hemiparesis and disturbance of consciousness on postoperative day 3. Magnetic resonance imaging showed a right parietal infarct and decreased cerebral blood flow signal in the right middle cerebral artery territory. Digital subtraction angiography showed multiple segmental narrowings of the right middle cerebral artery. Her neurological symptoms recovered with conservative treatment. Follow-up angiography showed improvement in the arterial narrowing, which finally led to a diagnosis of cerebral vasospasm. Cerebral vasospasm can occur after burr hole evacuation of chronic subdural hematoma. Magnetic resonance angiography is useful for determining the cause of postoperative neurological worsening in chronic subdural hematoma patients.

Role of Carotid Ultrasonography Combined with Monocyte/HDL Ratio in Internal Carotid Artery Stenosis.

BACKGROUND: Carotid duplex ultrasonography (DUS) is the primary screening tool for carotid artery stenosis, but has low reliability. MHR, which is the ratio of monocytes to high-density lipoprotein cholesterol (HDL-C), can be a marker for the degree and distribution of extracranial and intracranial atherosclerotic stenosis. OBJECTIVE: We determined the diagnostic value of DUS+MHR for internal carotid artery (ICA) stenosis. METHODS: We divided 273 hospitalized patients into non-stenosis (<50%) and ICA stenosis (≥50%) groups based on Digital Subtraction Angiography (DSA). We determined the peak systolic velocity (PSV) in the ICA on DUS, calculated the MHR, and investigated their relationship with ICA stenosis. RESULTS: On DSA, 34.1% (93/273) patients had moderate-to-severe ICA stenosis. DUS and DSA showed low concordance for detecting ICA stenosis (kappa = 0.390). With increasing age, the incidence of moderate-to-severe ICA stenosis increased. PSV, monocyte count, and MHR were significantly greater in the stenosis group than in the non-stenosis group (P < 0.001), while the HDL-C level was significantly lower (P = 0.001). PSV (OR: 1.020, 95% CI: 1.011-1.029, P < 0.001) and MHR (OR: 5.662, 95% CI: 1.945-16.482, P = 0.002) were independent risk factors for ICA stenosis. The area under the receiver operating characteristic curve of PSV+MHR (0.819) was significantly higher than that of PSV or MHR alone (77.42% sensitivity, P = 0.0207; 73.89% specificity, P = 0.0032). CONCLUSION: The combination of ICA PSV on DUS and MHR is better than PSV alone at identifying ICA stenosis and is well-suited to screen high-risk patients.

[Radiation Dose Reduction through the Optimization of Mask Images in Cerebral Angiography].

PURPOSE: To verify the effectiveness of optimizing the number of mask images in DSA for radiation dose reduction during cerebral angiography. METHODS: A total of 60 angiography sessions in 2 times for 30 patients performed by the same operator were included in this study. In order to compare the effects of optimization to change the injection delay time of DSA from 1 s to the shortest possible time, the number of mask images, the number of imaging frames, and radiation doses between sessions were compared and analyzed retrospectively. RESULTS: In one DSA run, the number of mask images was decreased from 6 (5-7) to 3 (2-3) frames (p<0.01)/57.1% (median [IQR]/reduction rate), the number of imaging frames was decreased from 34 (32-36) to 32 (29-34) frames (p<0.01)/7.9%, and the radiation dose was decreased from 33 (23-47) to 30 (21-40) mGy (p<0.01)/8.3%. In magnification angiography, the reductions rate was significantly increased. In one angiography session, the number of mask images was decreased from 45 (35-72) to 19 (16-34) frames (p<0.01)/54.6%, the number of imaging frames was decreased from 242 (199-385) to 211 (181-346) frames (p<0.01)/8.3%, the radiation dose of DSA was decreased from 295 (190-341) to 242 (167-305) mGy (p<0.01)/11.6%, and the total radiation dose was decreased from 369 (259-418) to 328 (248-394) mGy (p<0.01)/7.5%. CONCLUSION: Using the shortest possible injection delay time for the number of mask image optimization was an effective radiation dose reduction method.

Diagnosis and treatment strategies for vascular complications after kidney transplantation / 器官移植

With persistent progress in donor-recipient evaluation criteria, organ procurement and preservation regimens and surgical techniques, the incidence of vascular complication after kidney transplantation has been declined, whereas it is still one of the most severe surgical complications of kidney transplantation, which may lead to graft loss and recipient death, and seriously affect the efficacy of kidney transplantation. Therefore, the occurrence, clinical manifestations, diagnosis and treatment strategies of common vascular complications after kidney transplantation, including vascular stenosis, arterial dissection, pseudoaneurysm, vascular rupture and thrombosis were reviewed in this article. In combination with the incidence, diagnosis and treatment of vascular complications after kidney transplantation in the First Affiliated Hospital of Xi'an Jiaotong University, diagnosis and treatment strategies for common vascular complications after kidney transplantation were summarized, aiming to provide reference for clinical diagnosis and treatment of vascular complications after kidney transplantation, lower the incidence of vascular complications, and improve clinical efficacy of kidney transplantation and survival rate of recipients.

RAPID aneurysm accurately measures aneurysm size on CT angiography compared to three-dimensional digital subtraction angiography.

BACKGROUND: Cerebral aneurysms are often identified and characterized on non-invasive CT Angiography (CTA) images, but digital subtraction angiography (DSA) is the gold standard for aneurysm evaluation. OBJECTIVE: We compared cerebral aneurysm size measurements as measured from CTA processed by a semi-automated artificial intelligence software program (RAPID Aneurysm) and three-dimensional rotational DSA (3D-DSA). METHODS: We performed a retrospective cohort study of consecutive patients with a cerebral aneurysm who underwent CTA and DSA with 3D reformations. CTA images were processed by RAPID Aneurysm to determine aneurysm height, width, and neck width. The reference standard was aneurysm measurements on 3D-DSA as measured by two neurointerventionalists. Both readers were blinded to RAPID Aneurysm measurements. Correlation and bias between these measurements were determined. RESULTS: Results from 50 patients with 50 aneurysms were compared. 32 patients (64%) were female. Median age was 65 (IQR: 56.25-71.75). 37 patients (74%) presented with ruptured aneurysms. The aneurysms represented a range of aneurysm sizes (1.9-33.3 mm; IQR 3.6-7.2 mm). RAPID Aneurysm size measurements showed excellent correlation and low bias (correlation, mean difference) when compared to the reference standard for aneurysm height (0.98, -0.9 mm), width (0.98, 0.1 mm), and neck width (0.94, 1.1 mm). The inter-reader comparison between the two neurointerventionalists was similarly excellent for aneurysm height (0.97, -0.4 mm), width (0.98, -0.2 mm), and neck width (0.89, 0.8 mm). CONCLUSION: RAPID Aneurysm measurement of cerebral aneurysm height, width, and neck width on CTA is strongly correlated to expert neurointerventionalist measurements on 3D-DSA.

Prediction of the mean transit time using machine learning models based on radiomics features from digital subtraction angiography in moyamoya disease or moyamoya syndrome-a development and validation model study.

Background: Digital subtraction angiography (DSA) is an important technique for diagnosis of moyamoya disease (MMD) or moyamoya syndrome (MMS), and computed tomography perfusion (CTP) is essential for assessing intracranial blood supply. The aim of this study was to assess whether radiomics features based on images of DSA could predict the mean transit time (MTT; outcome of CTP) using machine learning models. Methods: The DSA images and MTT values of adult patients with MMD or MMS, according to the diagnostic guidelines for MMD, as well as control cases, were retrospectively collected in the Guangdong Provincial People's Hospital between January 2018 and December 2020. A total of 93 features were extracted from the images of each case through 3-dimensional (3D) slicer. After features preprocessing and filtering, 3-4 features were selected by the least absolute shrinkage and selection operator (LASSO) regression algorithm. Prediction models were established using random forest (RF) and support vector machine (SVM) for MTT values. Single-factor receiver operating characteristic (ROC) curve analysis and partial-dependence (PD) profiles were conducted to investigate selected features and prediction models. Results: Our results showed that prediction models based on RF models had the best performance in frontal lobe {area under the curve (AUC) [95% confidence interval (CI)] =1.000 (1.000-1.000)], parietal lobe [AUC (95% CI) =1.000 (1.000-1.000)], and basal ganglia/thalamus [AUC (95% CI) =0.922 (0.797-1.000)] in the test set, whereas the SVM model performed the best in the temporal lobe [AUC (95% CI) =0.962 (0.876-1.000)] in the test set. The AUC values in the test set were greater than 0.9. The PD profiles showed good robustness and consistency. Conclusions: Prediction models based on radiomics features extracted from DSA images demonstrate excellent performance in predicting MTT in patients with MMD or MMS, which may provide guidance for future clinical practice.

A typically progressive dissection of the internal carotid artery with recurrent hiccups: A case report with continuous 2-year data recording.

Patients with internal carotid artery dissection (ICAD) usually report headache, neck pain, Horner's syndrome, and ischemic stroke. Because the posterior cranial nerve is involved, some patients may show different forms of posterior cranial nerve paralysis. There have been no reports of patients with ICAD showing repeated hiccups. Here, to help clinicians identify ICAD early and gain a better understanding of the atypical manifestations of the disease, we report an atypical case of recurrent hiccup symptoms caused by ICAD.

Dynamic evaluation of unruptured intracranial aneurysms by 4D-CT angiography: comparison with digital subtraction angiography (DSA) and surgical findings.

BACKGROUND: This study was to prospectively investigate the feasibility of four-dimensional computed tomography angiography (4D-CTA) with electrocardiogram-gated (ECG) reconstruction for preoperative evaluation of morphological parameters, and compared with digital subtraction angiography (DSA). We also aimed to detect pulsation in unruptured intracranial aneurysms (UIAs) by using 4D-CTA, as a potential predicting factor of growth or rupture. MATERIALS: 64 patients with 64 UIAs underwent ECG-gated dynamic 4D-CTA imaging before treatment, of which 46 patients additionally underwent DSA. Original scanning data were reconstructed to produce 20 data sets of cardiac cycles with 5%-time intervals. The extent of agreement on UIAs morphological features assessed with 4D-CTA and DSA was estimated using the k coefficient of the Kappa test. The radiation doses were also calculated and compared between 4D-CTA and DSA. In the aneurysmal surgically treated in our institution, we were able to compare the surgical findings of the aneurysm wall with 4D-CTA images. We performed long-term follow-up on untreated patients. RESULTS: The morphological characteristics detected by 4D-CTA and DSA were consistent in aneurysm location (k = 1.0), shape (k = 0.76), maximum diameter (k = 0.94), aneurysm neck (k = 0.79) and proximity to parent and branch vessels (k = 0.85). 4D-CTA required lower radiation doses (0.32 ± 0.11 mSv) than DSA (0.84 ± 0.37 mSv, P < 0.001). Pulsation was detected in 26 of the 64 unruptured aneurysms, and all underwent neurosurgical clipping or interventional embolization. In aneurysms surgically treated in our hospital, we observed a significant correlation between 4D-CTA findings and surgical evaluation of the aneurysmal wall, in particular the irregular pulsations detected on 4D-CTA have demonstrated to correspond to dark-reddish thinner wall at surgery. CONCLUSIONS: In this proof-of-concept study, 4D-CTA provided real-time, non-invasive preoperative assessments of UIAs comparable to DSA. Moreover, optimal correlation between the irregular pulsation detected by 4D-CTA and the surgical findings support a possible role of this technique to identify aneurysms with a higher risk of rupture.

Peculiar Neurological Examination Secondary to Persistent Primitive Hypoglossal Artery.

A persistent primitive hypoglossal artery (PPHA) is an anatomical variant resulting in persistent carotid-vertebrobasilar anastomoses. This variant arises from the distal cervical segment of the internal carotid artery (ICA) between C1 and C3 and passes through an enlarged hypoglossal canal to join the basilar circulation. This case report describes a 60-year-old male with an acute ischemic event secondary to an occlusion in the right ICA and PPHA, resulting in a unique physical examination. Digital subtraction angiography (DSA) was utilized to visualize occlusion of the right common carotid artery with no residual right internal carotid artery or right vertebral artery filling. The patient's presenting symptoms yielded a unique neurological examination, making it difficult to localize a solitary lesion, which would account for the patient's acute presentation. In retrospect, with angiography revealing a right PPHA, his presentation fit more thoroughly with the clinical picture. With the increased utility of neuro-endovascular procedures, clinicians have a higher probability of encountering diverse angiographical findings. With this case report, we would like to familiarize practitioners with the presence of PPHA, present unique imaging findings involving typically isolated vascular territories, and stress the importance of clinical judgment when making decisions regarding stroke care.

A Case of Small Bowel Arteriovenous Malformation Diagnosed Using Multiphase CT Angiography and Digital Subtraction Angiography.

Small bowel arteriovenous malformation (AVM) is a rare vascular lesion, which should be considered in patients presenting with gastrointestinal bleeding, as it is a high-flow arterial lesion that can cause life-threatening bleeding. Although a primary endoscopic examination is performed in cases of suspected small bowel bleeding, the diagnosis of the causal lesion is sometimes difficult. We are presenting a case of small bowel AVM that could not be diagnosed endoscopically but was successfully detected using multiphase CT images with an appropriate protocol. The AVM diagnosis was confirmed using digital subtraction angiography. An endovascular coil is placed in the draining vein as a surgical resection marker. The AVM was resected successfully without any complications.

Anatomical information of the lenticulostriate arteries on high-resolution 3D-TOF MRA at 3 T: comparison with 3D-DSA.

PURPOSE: As the lenticulostriate arteries (LSAs) perfuse neurologically important areas, it is necessary to accurately assess the origin and number of the LSAs before surgery. Although three-dimensional time-of-flight MR angiography (3D-TOF MRA) is a non-invasive procedure, it requires high-resolution (HR) images to depict the LSAs with a small diameter. Therefore, we performed 3D-TOF MRA with the maximum HR (HR-MRA) using a 3 T scanner to examine whether a good depiction of the LSAs, equivalent to that of digital subtraction angiography (DSA), could be obtained. METHODS: Our study group comprised 16 consecutive patients who underwent HR-MRA and 3D-DSA. In both studies, we evaluated the localization of the origin from M1, M2, or A1 segments, their number of stems, and depiction. RESULTS: There was no significant difference in the visualization of the LSAs between HR-MRA and 3D-DSA (P values; M1, M2, and A1 = 0.39, 0.69, and 0.69, respectively), and both the number of stems and the localization of the origin of the LSAs corresponded between the two examinations. CONCLUSION: HR-MRA at 3 T can depict the LSA well. It reveals the number of the LSA stems and the LSA origin comparatively with DSA.

Hematoma Disguised as Cancer.

Hematomas are often associated with benign processes such as sport-related injuries, postsurgical complications, and medications such as blood thinners. Rarely, hematomas can occur spontaneously without any identifiable cause or recollection of an inciting event. Such events can lead to inaccurately diagnosing a patient, which could delay or alter treatment and worsen the patient's prognosis. This patient reported sudden-onset abdominal pain with radiation to her back and denied any recent medication use or trauma while at home. The case highlights the key radiographic findings of magnetic resonance imaging (MRI) and contrast-enhanced ultrasound to eventually confirm an obscure case of hepatocellular carcinoma and help guide management.

A dual-center validation of the PIRAMD scoring system for assessing the severity of ischemic Moyamoya disease.

Background: Prior Infarcts, Reactivity, and Angiography in Moyamoya Disease (PIRAMD) is a recently proposed imaging-based scoring system that incorporates the severity of disease and its impact on parenchymal hemodynamics in order to better support clinical management and evaluate response to intervention. In particular, PIRAMD may have merit in identifying symptomatic patients that may benefit most from revascularization. Our aim was to validate the PIRAMD scoring system. Methods: Patients with ischemic Moyamoya disease, who underwent catheter angiographic [modified Suzuki Score (mSS) and collateralization status], morphological MRI and a parenchymal hemodynamic evaluation with blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) at two transatlantic centers, were retrospectively included. The primary outcome was the presence of neurological symptoms. The diagnostic capacity of each PIRAMD feature alone was evaluated, as well as combined and the inter-institutional differences of each parameter were evaluated. Results: Seventy-two hemispheres of 38 patients were considered for analysis, of which 39 (54%) were classified as symptomatic. The presence of a prior infarct had the highest odds ratio [odds ratio (OR) =24; 95% CI: 6.7-87.2] for having neurological symptoms, followed by impaired CVR (OR =17; 95% CI: 5-62). No inter-institutional differences in the odds ratios or area under the curve (AUC) were found for any study parameter. The PIRAMD score had an AUC of 0.88 (95% CI: 0.80-0.96) with a similar AUC for the PIRAMD grading score. Conclusions: Our multicentric validation of the recently published PIRAMD scoring system was highly effective in rating the severity of ischemic Moyamoya disease with excellent inter-institutional agreement. Future studies should investigate the prognostic value of this novel imaging-based score in symptomatic patients with Moyamoya disease.

Improved stereo perception in coronary angiography using the X-ray tube as the viewpoint and validation with 3D printed models.

Coronary angiography (CAG) provides two-dimensional images, but a clinician who is experienced in percutaneous coronary interventions can use information from these images to interpret spatial depth and infer the three-dimensional (3D) locations of vessels. We hypothesized that CAG results were equivalent to the mirror image of a coronary artery perspective projection, and a stereo perception could be easily established when the viewpoint of the angiogram was the X-ray tube instead of the detector. To eliminate the influence of heartbeat and respiration, a 3D-printed a coronary artery model was constructed for analysis. The effects of gantry movements during digital subtraction angiography (DSA) on the image were used to identify factors that affected DSA image transformation. Then, based on these factors, DSA imaging was simulated using UG NX software with three methods: (i) a perspective projection with the detector as the viewpoint; (ii) a parallel projection; and (iii) a mirror image of the perspective projection with the X-ray tube as the viewpoint. Finally, the resulting 3D images were compared with the DSA image. Our mirror image of the coronary artery perspective projection that used the X-ray tube as the viewpoint fused precisely with the CAG results and provided exact simulations of all the effects of DSA gantry movements on the DSA image. CAG results were equivalent to the mirror image of coronary artery perspective projection, and the stereo perception was easily established using the X-ray tube as the viewpoint.

Intraoperative Augmented Reality in Microsurgery for Intracranial Arteriovenous Malformation: A Case Report and Literature Review.

BACKGROUND: Intracranial arteriovenous malformations (AVMs) are lesions containing complex vessels with a lack of buffering capillary architecture which might result in hemorrhagic cerebrovascular accidents (CVAs). Intraoperative navigation can improve resection rates and functional preservation in patients with lesions in eloquent areas, but current systems have limitations that can distract the operator. Augmented Reality (AR) surgical technology can reduce these distractions and provide real-time information regarding vascular morphology and location. METHODS: In this case report, an adult patient was admitted to the emergency department after a fall, and diagnostic imaging revealed a Spetzler-Martin grade I AVM in the right parietal region with evidence of rupture. The patient underwent a stereotactic microsurgical resection with assistance from augmented reality technology, which allowed for a hologram of the angioarchitecture to be projected onto the cortical surface, aiding in the recognition of the angiographic anatomy during surgery. RESULTS: The patient's postoperative recovery went smoothly. At 6-month follow-up, the patient had remained in stable condition, experiencing complete relief from his previous symptoms. The follow-up examination also revealed complete obliteration of the AVMs without any remaining pathological vascular structure. CONCLUSIONS: AR-assisted microsurgery makes both the dissection and resection steps safer and more delicate. As several innovations are occurring in AR technology today, it is likely that this novel technique will be increasingly adopted in both surgical applications and education. Although certain limitations exist, this technique may still become more efficient and precise as this novel technology its continues to develop further.

Successful Endovascular Treatment of a Traumatic Cervical Arteriovenous Fistula After a Carotid Paraganglioma Resection: A Case Report.

Traumatic cervical arteriovenous fistulas are rare, accounting for only 4% of all arteriovenous fistulas. They can be caused by penetrating, or rarely, blunt trauma, resulting in high-pressure arterial blood draining directly into a vein, decreasing distal perfusion. They are seldom reported as a complication of a carotid paraganglioma surgical resection. Historically, arteriovenous fistulas were treated initially conservatively, after that, surgically; nowadays, endovascular treatment, when feasible, is the preferred method as it offers advantages over surgery. This case report describes a rare traumatic cervical arteriovenous fistula that developed after a carotid paraganglioma resection and was successfully treated using coils and Onyx embolic agent via endovascular embolization. After successful embolization, the patient had a smooth recovery and remained stable. In conclusion, vascular injury seems to be the only constant in all acquired cervical arteriovenous fistulas independent of the trauma mechanism; and endovascular treatment, when feasible, is preferred over surgery as it offers superior advantages.