C-arm C-arm Computed Tomography Research Articles

Improved Precision and Safety of Supra-Tentorial Intracranial Hematoma Puncture Using C-Arm CT Four-Dimensional Navigation.

BACKGROUND Spontaneous intracerebral hemorrhage has a high fatality rate within the initial month after onset. This study determined the safety and therapeutic efficacy of minimally invasive puncture for supra-tentorial intracranial hematoma under C-arm computed tomography (CT) 4-dimensional navigation. MATERIAL AND METHODS We retrospectively analyzed 64 patients with supra-tentorial cerebral hemorrhage from June 2020 to May 2023; 31 patients were assigned to the study group (C-arm CT navigation puncture) and 33 patients were in the control group (conventional CT-guided puncture). The analysis focused on assessment of puncture error, postoperative complication rate, and the Glasgow Outcome Scale (GOS) and National Institute of Health Stroke Scale (NIHSS) scores 30 and 90 days after surgery. RESULTS C-arm CT navigation puncture had improved precision, with significantly reduced transverse (3.17±1.75 mm) and longitudinal (1.83±1.21 mm) deviations, compared with the control group (7.88±1.74 mm and 5.50±1.84 mm, respectively; P<0.05). The overall postoperative complication rate was significantly lower in the study group than in the control group (12.90% vs 36.36%, P<0.05). The mean GOS score was higher in the study group than in the control group 30 and 90 days postoperatively (3.42±0.96 and 3.97±0.95 vs 2.94±0.79 and 3.46±0.90, respectively; P<0.05), while the mean NIHSS score was lower in the study group than in the control group 30 and 90 days postoperatively (10.58±6.52 and 5.97±4.55 vs 14.42±8.13 and 9.55±8.31, respectively; P<0.05). CONCLUSIONS Supra-tentorial intracranial hematoma puncture under C-arm CT 4-dimensional navigation is accurate, safe, and beneficial.

Carbon nanotube-based multiple source C-arm CT system: feasibility study with prototype system.

To extend the field of view while reducing dimensions of the C-arm, we propose a carbon nanotube (CNT)-based C-arm computed tomography (CT) system with multiple X-ray sources. A prototype system was developed using three CNT X-ray sources, enabling a feasibility study. Geometry calibration and image reconstruction were performed to improve the quality of image acquisition. However, the geometry of the prototype system led to projection truncation for each source and an overlap region of object area covered by each source in the two-dimensional Radon space, necessitating specific corrective measures. We addressed these problems by implementing truncation correction and applying weighting techniques to the overlap region during the image reconstruction phase. Furthermore, to enable image reconstruction with a scan angle less than 360°, we designed a weighting function to solve data redundancy caused by the short scan angle. The accuracy of the geometry calibration method was evaluated via computer simulations. We also quantified the improvements in reconstructed image quality using mean-squared error and structural similarity. Moreover, detector lag correction was applied to address the afterglow observed in the experimental data obtained from the prototype system. Our evaluation of image quality involved comparing reconstructed images obtained with and without incorporating the geometry calibration results and images with and without lag correction. The outcomes of our simulation study and experimental investigation demonstrated the efficacy of our proposed geometry calibration, image reconstruction method, and lag correction in reducing image artifacts.

Three-dimensional laser combined with C-arm computed tomography-assisted puncture of intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) is the deadliest subtype of stroke, with a 30-day case fatality rate of approximately 40%. Timely and accurate treatment is essential to facilitate recovery. The introduction of stereotactic instruments and navigation systems has greatly improved the accuracy of surgical treatment. In this study, we explored the application and effects of a three-dimensional (3D) laser combined with C-arm computed tomography (CT) on ICH puncture. According to the principle of randomness, 118 patients with ICH were divided into control and experimental groups. The control group was treated with CT-guided puncture, and the experimental group was treated with 3D laser combined with C-arm CT puncture. The hematoma clearance rates at 3, 5, and 7 days after surgery and the prognosis at 1, 3, and 6 months after surgery were compared between the two groups. The hematoma clearance rates of the group using 3D laser combined with C-arm CT at 3, 5, and 7 days after surgery were significantly higher than those of the control group, and the difference was statistically significant (p < 0.05). One month postoperatively, the daily living ability (ADL) grading and recovery of the patients in the test group was significantly better than those of the control group (p < 0.05), but there was no statistically significant difference in ADL 3 and 6 months after surgery (p > 0.05). 3D laser combined with C-arm CT puncture has the advantages of real-time guidance, accurate positioning, and simple operation. It is an effective minimally invasive surgical method that is easy to master.

Cone-Beam CT–Guided Chemoembolization in Patients with Complete Response after Previous Chemoembolization but Subsequent Elevated α-Fetoprotein without Overt Hepatocellular Carcinoma

PurposeTo evaluate the performance of C-arm computed tomography (CT)–guided chemoembolization in patients with hepatocellular carcinoma (HCC) with serum α-fetoprotein (AFP) level > 20 ng/mL but with no overt tumor on CT and/or magnetic resonance imaging. Materials and MethodsFrom May 2010 to May 2017, 34 patients with HCC (25 men and 9 women; mean age, 59.7 y) who had elevated serum AFP levels (> 20 ng/mL) but no overt tumor on 6-mo imaging studies and had shown complete response (CR) after previous chemoembolization underwent C-arm CT–guided conventional chemoembolization. Three radiologists retrospectively reviewed the imaging studies (preprocedural images, C-arm CT scans, and follow-up images) in consensus, and clinical data including AFP levels were retrospectively obtained. Tumor detection by C-arm CT and treatment response after chemoembolization were assessed. ResultsHCC was imaged at the time of chemoembolization in 24 of 34 patients (70.6%). C-arm CT detected tumors in 25 patients (73.5%); 23 detections were true positives, 2 were false positives, and 1 was a false negative (diaphragm metastasis). Among the 23 patients with true-positive results, the first follow-up enhanced imaging studies showed CR (n = 17), partial response (n = 1), progressive disease (n = 4), and indeterminate status (n = 1; treated by percutaneous ethanol injection). ConclusionsC-arm CT–guided chemoembolization may help to detect and treat recurrent tumors in patients who have shown CR after previous chemoembolization but subsequently, during follow-up surveillance, had serum AFP levels > 20 ng/mL without an overt tumor evident on imaging studies.

Yttrium-90 Radioembolization of the Right Inferior Phrenic Artery in 20 Patients with Hepatocellular Carcinoma

PurposeTo address the feasibility of infusion of yttrium-90 (90Y) glass microspheres directly through the right inferior phrenic artery (RIPA). Materials and MethodsFrom November 2015 to May 2017, 20 patients underwent 90Y radioembolization through the RIPA. When the systemic-to-pulmonary shunt was demonstrated on C-arm computed tomography (CT) of the RIPA, prophylactic embolization by polyvinyl alcohol (PVA) particles was performed prior to infusion of 90Y glass microspheres. Follow-up CT scans were retrospectively reviewed for pulmonary complications. Tumor response was determined by the modified Response Evaluation Criteria in Solid Tumors. ResultsNine (45%) patients had systemic-to-pulmonary shunts on C-arm CT images of the RIPA. The feeder of the systemic-to-pulmonary shunt was the azygoesophageal branch (n = 7) and the anterior branch (n = 2). The mean activity of 90Y glass microspheres infused into the RIPA was 0.49 GBq (range, 0.19–1.55 GBq). No patient had symptomatic radiation pneumonitis or cutaneous complications during follow-up. Seven patients had focal atelectasis (n = 5), focal ground-glass opacity (n = 2), and/or a small amount of pleural effusion (n = 2) on follow-up image. Best tumor response fed by the RIPA was complete response (n = 4), partial response (n = 9), stable disease (n = 2), progressive disease (n = 4), and unevaluable (n = 1). ConclusionThe administration of 90Y glass microspheres through the RIPA may be safe after embolization of a systemic-to-pulmonary shunt identified on C-arm CT.

Abstract No. 535 90Y radioembolization of the right inferior phrenic artery in 20 patients with hepatocellular carcinoma

To address the feasibility and safety of infusion of 90Y glass microspheres directly through the right inferior phrenic artery (RIPA). From November 2015 to May 2017, 20 patients underwent 90Y radioembolization through the RIPA. When the systemic-to-pulmonary shunt was demonstrated on C-arm computed tomography (CT) of the RIPA, prophylactic embolization by polyvinyl alcohol (PVA) particles was performed prior to infusion of 90Y glass microspheres. Follow-up medical records and CT scan were retrospectively reviewed for tumor response and possible complications. Nine (45%) patients had systemic-to-pulmonary shunts on C-arm CT images of the RIPA. The feeder of systemic-to-pulmonary shunt was the azygoesophageal branch (n = 7) and the anterior branch (n = 2). The mean activity of 90Y glass microspheres infused into the RIPA was 0.49 GBq (range, 0.19-1.55 GBq). No patient had radiation pneumonitis or cutaneous complications during follow-up. Seven patients had focal atelectasis (n = 5), focal ground glass opacity (n = 2), and/or small amount of pleural effusion (n = 2) on follow-up image. Tumor response fed by the RIPA was complete response (n = 5), partial response (n = 8), stable disease (n = 4), and progressive disease (n = 3). The administration of 90Y glass microspheres through the RIPA is safe after embolization of a systemic-to-pulmonary shunt identified on C-arm CT.

Percutaneous nephrolithotripsy: C-arm CT with 3D virtual navigation in non-dilated renal collecting systems.

We aimed to evaluate the clinical superiority of using C-arm computed tomography (CT) to establish percutaneous nephrolithotripsy (PCNL) access for patients with non-dilated renal collecting systems. From May 2014 to May 2015, 33 patients underwent C-arm CT-guided puncture to establish PCNL access after failed attempts of ultrasonography-guided nephrostomy. Technical success, procedure details, radiation exposure, complications, and stone-free rate were recorded. The technical success rate was 97% (32/33) with a mean puncture score of 4.5/5. Mean puncture, dilation, and fragmentation times were 17.9±6.0, 12.6±3.9, and 33.1±8.8 minutes, respectively. Mean radiation exposure was 4.8±2.1 mSv without serious complications. Stone-free rate was 93.8%. C-arm CT is a useful tool to establish PCNL access, particularly in cases of upper pole access or complicated anatomy.

Clinical comparative analysis of percutaneous gastrostomy guided by different imaging techniques

Objective To investigate the clinical characteristics of percutaneous gastrostomy guided by different imaging techniques, in an effort to inform selection of imaging guidance. Methods A retrospective analysis was conducted on the clinical data of 277 patients who underwent percutaneous gastrostomy at Affiliated Tumor Hospital of Zhengzhou University from January 2014 to December 2016. The patients were divided into three groups according to the imaging techniques used, i. e. group A guided by fluoroscopy of digital subtraction angiography (DSA), group B by C-arm computed tomography (CT), and group C by CT throughout the process. The technical success rate, complication rate, operation time and patient's radiation dose were compared among the three groups. Results There was no significant difference in technical success rate(93.8% vs. 97.3% vs. 100%, χ2=2.797, P=0.247) and complication rate(10.0% vs. 11.3% vs. 20.0%, χ2=1.343, P=0.511) among the 3 groups, but the operation time[(25.57±5.99)min vs.(29.01±6.63)min vs. (45.47±8.98)min, χ2=27.977, P<0.001] and patient's radiation[(27.30±19.27)mGy vs. (145.07±106.08)mGy vs. (2 590.26±1 088.22)mGy, χ2=204.444, P<0.001] dose were significantly different (χ2=87.977, P<0.001; χ2=204.444, P<0.001), with group A and B lower than group C (P<0.001) and group A lower than group B (P≤0.001). Conclusions DSA fluoroscopic guidance should be the first choice for percutaneous gastrostomy, but before the operation, abdominal CT scan should be performed to exclude such situations as hypertrophy of left lobe of liver, and colon in front of the stomach.If the DSA machine is equipped with C-arm CT function, the surgery can also be directly guided by C-arm CT.Complete CT guidance can be used as a supplement in the case of failure by both DSA fluoroscopy and C-arm CT guidance. Key words: Gastrostomy; Fluoroscopy; C-arm computed tomography; X-ray computed tomography

Reduced-dose C-arm computed tomography applications at a pediatric institution.

Reduced-dose C-arm computed tomography (CT) uses flat-panel detectors to acquire real-time 3-D images in the interventional radiology suite to assist with anatomical localization and procedure planning. To describe dose-reduction techniques for C-arm CT at a pediatric institution and to provide guidance for implementation. We conducted a 5-year retrospective study on procedures using an institution-specific reduced-dose protocol: 5 or 8s Dyna Rotation, 248/396 projection images/acquisition and 0.1-0.17 μGy/projection dose at the detector with 0.3/0.6/0.9-mm copper (Cu) filtration. We categorized cases by procedure type and average patient age and calculated C-arm CT and total dose area product (DAP). Two hundred twenty-two C-arm CT-guided procedures were performed with a dose-reduction protocol. The most common procedures were temporomandibular and sacroiliac joint injections (48.6%) and sclerotherapy (34.2%). C-arm CT was utilized in cases of difficult percutaneous access in less common applications such as cecostomy and gastrostomy placement, foreign body retrieval and thoracentesis. C-arm CT accounted for between 9.9% and 80.7% of the total procedural DAP. Dose-reducing techniques can preserve image quality for intervention while reducing radiation exposure to the child. This technology has multiple applications within pediatric interventional radiology and can be considered as an adjunctive imaging tool in a variety of procedures, particularly when percutaneous access is challenging despite routine fluoroscopic or ultrasound guidance.

C-arm computed tomography and volume perfusion computed tomography (VPCT)-based assessment of blood volume changes in hepatocellular carcinoma in prediction of midterm tumor response to transarterial chemoembolization: a single center retrospective trial.

BackgroundThis study aims to evaluate immediate changes in perfusion parameters in hepatocellular carcinoma (HCC) to transarterial chemoembolization (TACE) in C-arm computed tomography (CT) and volume perfusion CT (VPCT) and prediction of midterm tumor response.MethodsTwenty-five patients (median age 66, range 61 to 75 years) with 62 HCC lesions undergoing TACE received immediate pre- and post-interventional assessment by C-arm CT and VPCT. Cross-sectional imaging was analyzed at baseline and approximately 12 weeks after TACE according to modified RECIST criteria. Outcome was defined as objective response (OR, > 30 % reduction of viable tumor) or non-OR. Perfusion parameters were evaluated in C-arm CT [parenchymal blood volume (PBV)] and VPCT [blood volume (BV) and blood flow (BF)]. Ratios of perfusion parameters before and after TACE within the tumor and the non-affected liver parenchyma were calculated.ResultsCorrelation between tumor PBV and BV revealed a moderate correlation (rho = 0.45, p = 0.005). In non-affected liver parenchyma, a significant decrease in PBV was seen, compared to a significant increase in BF and BV. Perfusion ratios in HCC lesions were significantly (p < 0.05) increased in OR group compared to non-OR patients in C-arm CT and VPCT: PBV ratio (0.95 (0.06) to 0.67 (0.38), BV ratio 0.63 (0.34) to 0.15 (0.6), and BF ratio 0.6 (0.32) to 0.22 (0.51). Logistic regression including PBV and BF allowed prediction of OR (sensitivity 88 %/specificity of 83 %).ConclusionsPerfusion parameters acquired by C-arm CT and VPCT cannot simply be substituted by each other, but show similar capability in prediction of midterm tumor response.

Whole brain C-arm computed tomography parenchymal blood volume measurements.

C-arm flat detector computed tomography (FDCT) parenchymal blood volume (PBV) imaging in the neuro-interventional suite is a new technique for which detailed whole brain measurements have not been previously reported. This study aims to create a catalogue of PBV measurements for various anatomical regions encompassing the whole brain, using a three-dimensional volume-of-interest (3D-VOI) analysis. We acquired and analysed 30 C-arm FDCT datasets from 26 patients with aneurysmal subarachnoid haemorrhage (SAH), as part of a prospective study comparing C-arm computed tomography (CT) PBV with magnetic resonance perfusion-weighted imaging (MR-PWI). We calculated the PBV values for various brain regions with an automated analysis, using 58 pre-defined atlas-based 3D-VOIs encompassing the whole brain. VOIs partially or completely overlapping regions of magnetic resonance diffusion weighted imaging (MR-DWI) abnormality or magnetic resonance cerebral blood flow (MR-CBF) asymmetry were excluded from the analysis. Of the 30 C-arm CT PBV datasets, 14 (54%; 12 patients) had areas of restricted diffusion, the majority of which were focal. The PBV values for the cerebral cortex and cerebral white matter were 4.01 ± 0.47 (mean ± SD) and 3.01 ± 0.39 ml per 100 ml. Lobar PBV values were: frontal lobe 4.2 ± 0.8, temporal lobe 4.2 ± 0.9, parietal lobe 3.9 ± 0.7 and occipital lobe 4.3 ± 0.8 ml/100 ml. The basal ganglia and brainstem PBV values were 3.4 ± 0.7 and 4.6 ± 0.6 ml/100 ml, respectively. Compared with the typical reference cerebral blood volume (CBV) values reported in the literature for Positron Emission Tomography (PET), the PBV values were relatively high for the white matter and relatively low for the cortical grey matter. The reported catalogue of PBV values for various brain regions would be useful to inform future studies and could be used in clinical practice, when interpreting PBV maps.

C-arm computed tomography parenchymal blood volume measurement in evaluation of hepatocellular carcinoma before transarterial chemoembolization with drug eluting beads.

BackgroundC-arm computed tomography (CT) guided intervention is an increasingly applied technique in transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). The aim of this study was to analyse the value of parenchymal blood volume (PBV) maps acquired during C-arm CT acquisition, for pre-treatment evaluation and planning of TACE in HCC patients.MethodsA total of 64 HCC lesions in 29 patients (median age, 73 years, range, 62–77 years) were included in this retrospective study. All patients received cross-sectional imaging (MRI or CT) prior to TACE and C-arm CT PBV measurement acquisition before performing TACE. Results of cross-sectional imaging regarding the number of HCC lesions and maximum diameter were compared to PBV–maps. Number of lesions and tumour feeding vessels detected in PBV-maps were compared to conventional angiography. Results of PBV were analysed concerning different tumour morphologies (pre-treated, encapsulated and diffuse).ResultsPre-interventional cross-sectional imaging and PBV maps showed an excellent agreement in lesion diameter (p = 0.88, MD = −0.28 mm) and number of detected lesions (κ = 1.0). Compared to conventional angiography, PBV maps showed an increased number of detected lesions (κ = 0.77, p = 0.001) and tumour feeding vessels (κ = 0.71, p < 0.0001). Diffuse HCC lesion revealed a significantly lower PBV compared to encapsulated lesions (p = 0.0001).ConclusionsC-arm CT acquired PBV measurements detect HCC tumours with a lesion detectability comparable to pre-interventional cross-sectional imaging. Furthermore, this technique facilitates TACE, allowing a more precise localization of HCC lesions and tumour feeding vessels compared to conventional angiography. Additionally, calculated PBV values enable a real time quantitative assessment of tumour perfusion.

Time-Resolved C-Arm Computed Tomographic Angiography Derived From Computed Tomographic Perfusion Acquisition: New Capability for One-Stop-Shop Acute Ischemic Stroke Treatment in the Angiosuite.

Multimodal imaging using cone beam C-arm computed tomography (CT) may shorten the delay from ictus to revascularization for acute ischemic stroke patients with a large vessel occlusion. Largely because of limited temporal resolution, reconstruction of time-resolved CT angiography (CTA) from these systems has not yielded satisfactory results. We evaluated the image quality and diagnostic value of time-resolved C-arm CTA reconstructed using novel image processing algorithms. Studies were done under an Institutional Review Board approved protocol. Postprocessing of data from 21 C-arm CT dynamic perfusion acquisitions from 17 patients with acute ischemic stroke were done to derive time-resolved C-arm CTA images. Two observers independently evaluated image quality and diagnostic content for each case. ICC and receiver-operating characteristic analysis were performed to evaluate interobserver agreement and diagnostic value of this novel imaging modality. Time-resolved C-arm CTA images were successfully generated from 20 data sets (95.2%, 20/21). Two observers agreed well that the image quality for large cerebral arteries was good but was more limited for small cerebral arteries (distal to M1, A1, and P1). receiver-operating characteristic curves demonstrated excellent diagnostic value for detecting large vessel occlusions (area under the curve=0.987-1). Time-resolved CTAs derived from C-arm CT perfusion acquisitions provide high quality images that allowed accurate diagnosis of large vessel occlusions. Although image quality of smaller arteries in this study was not optimal ongoing modifications of the postprocessing algorithm will likely remove this limitation. Adding time-resolved C-arm CTAs to the capabilities of the angiography suite further enhances its suitability as a one-stop shop for care for patients with acute ischemic stroke.

Use of C-Arm Cone Beam CT During Hepatic Radioembolization: Protocol Optimization for Extrahepatic Shunting and Parenchymal Enhancement.

PurposeTo optimize a C-arm computed tomography (CT) protocol for radioembolization (RE), specifically for extrahepatic shunting and parenchymal enhancement.Materials and MethodsA prospective development study was performed per IDEAL recommendations. A literature-based protocol was applied in patients with unresectable and chemorefractory liver malignancies undergoing an angiography before radioembolization. Contrast and scan settings were adjusted stepwise and repeatedly reviewed in a consensus meeting. Afterwards, two independent raters analyzed all scans. A third rater evaluated the SPECT/CT scans as a reference standard for extrahepatic shunting and lack of target segment perfusion.ResultsFifty scans were obtained in 29 procedures. The first protocol, using a 6 s delay and 10 s scan, showed insufficient parenchymal enhancement. In the second protocol, the delay was determined by timing parenchymal enhancement on DSA power injection (median 8 s, range 4–10 s): enhancement improved, but breathing artifacts increased (from 0 to 27 %). Since the third protocol with a 5 s scan decremented subjective image quality, the second protocol was deemed optimal. Median CNR (range) was 1.7 (0.6–3.2), 2.2 (−1.4–4.0), and 2.1 (−0.3–3.0) for protocol 1, 2, and 3 (p = 0.80). Delineation of perfused segments was possible in 57, 73, and 44 % of scans (p = 0.13). In all C-arm CTs combined, the negative predictive value was 95 % for extrahepatic shunting and 83 % for lack of target segment perfusion.ConclusionAn optimized C-arm CT protocol was developed that can be used to detect extrahepatic shunts and non-perfusion of target segments during RE.

Contrast-Enhanced C-arm Computed Tomography Imaging of Myocardial Infarction in the Interventional Suite.

Cardiac C-arm computed tomography (CT) uses a standard C-arm fluoroscopy system rotating around the patient to provide CT-like images during interventional procedures without moving the patient to a conventional CT scanner. We hypothesized that C-arm CT can be used to visualize and quantify the size of perfusion defects and late enhancement resulting from a myocardial infarction (MI) using contrast-enhanced techniques similar to previous CT and magnetic resonance imaging studies. A balloon occlusion followed by reperfusion in a coronary artery was used to study acute and subacute MI in 12 swine. Electrocardiographically gated C-arm CT images were acquired the day of infarct creation (n = 6) or 4 weeks after infarct creation (n = 6). The images were acquired immediately after contrast injection, then at 1 minute, and every 5 minutes up to 30 minutes with no additional contrast. The volume of the infarct as measured on C-arm CT was compared against pathology. The volume of acute MI, visualized as a combined region of hyperenhancement with a hypoenhanced core, correlated well with pathologic staining (concordance correlation, 0.89; P < 0.0001; mean [SD] difference, 0.67 [2.98]cm3). The volume of subacute MI, visualized as a region of hyperenhancement, correlated well with pathologic staining at imaging times 5 to 15 minutes after contrast injection (concordance correlation, 0.82; P < 0.001; mean difference, -0.64 [1.94]cm3). C-arm CT visualization of acute and subacute MI is possible in a porcine model, but improvement in the imaging technique is important before clinical use. Visualization of MI in the catheterization laboratory may be possible and could provide 3-dimensional images for guidance during interventional procedures.

C-arm flat detector computed tomography parenchymal blood volume imaging: the nature of parenchymal blood volume parameter and the feasibility of parenchymal blood volume imaging in aneurysmal subarachnoid haemorrhage patients.

C-arm flat detector computed tomography (FDCT) parenchymal blood volume (PBV) measurements allow assessment of cerebral haemodynamics in the neurointerventional suite. This paper explores the feasibility of C-arm computed tomography (CT) PBV imaging and the relationship between the C-arm CT PBV and the MR-PWI-derived cerebral blood volume (CBV) and cerebral blood flow (CBF) parameters in aneurysmal subarachnoid haemorrhage (SAH) patients developing delayed cerebral ischemia (DCI). Twenty-six patients with DCI following aneurysmal SAH underwent a research C-arm CT PBV scan using a biplane angiography system and contemporaneous MR-PWI scan as part of a prospective study. Quantitative whole-brain atlas-based volume-of-interest analysis in conjunction with Pearson correlation and Bland-Altman tests was performed to explore the agreement between C-arm CT PBV and MR-derived CBV and CBF measurements. All patients received medical management, while eight patients (31%) underwent selective intra-arterial chemical angioplasty. Colour-coded C-arm CT PBV maps were 91% sensitive and 100% specific in detecting the perfusion abnormalities. C-arm CT rPBV demonstrated good agreement and strong correlation with both MR-rCBV and MR-rCBF measurements; the agreement and correlation were stronger for MR-rCBF relative to MR-rCBV and improved for C-arm CT PBV versus the geometric mean of MR-rCBV and MR-rCBF. Analysis of weighted means showed that the C-arm CT PBV has a preferential blood flow weighting (≈ 60% blood flow and ≈ 40% blood volume weighting). C-arm CT PBV imaging is feasible in DCI following aneurysmal SAH. PBV is a composite perfusion parameter incorporating both blood flow and blood volume weightings. That PBV has preferential (≈ 60%) blood flow weighting is an important finding, which is of clinical significance when interpreting the C-arm CT PBV maps, particularly in the setting of acute brain ischemia.

Value of C-Arm Computed Tomography to Evaluate Stent Deployment During Femoro-Popliteal Revascularization

To compare the accuracy of C-arm computed tomography (CT) and digital subtraction angiography (DSA) in detecting incomplete stent expansion (ISE) after superficial femoral artery (SFA) stenting using intravascular ultrasound (IVUS) as a gold standard. Fifty patients with symptomatic SFA occlusive disease requiring angioplasty were prospectively included. Once technical success (<30 % residual stenosis) was obtained on post-procedural DSA, C-arm CT and IVUS were acquired. DSA and C-arm CT examinations were reviewed by 2 investigators and correlated with IVUS. C-arm CT image quality was rated on a four-point scale. Doppler ultrasound was performed at 1-year follow-up. The ankle-brachial index was 0.69 ± 0.10 and 0.99 ± 0.40, respectively, pre- and post-procedure. C-arm CT imaging quality was rated as good or excellent in 80%. In-stent minimal luminal diameter (MLD) was evaluated at 4.71 ± 0.7 mm on DSA, 3.39 ± 0.6 mm on IVUS, and 3.12 ± 0.9 mm on C-arm CT. Compared to IVUS, DSA demonstrated an overestimation of MLD (p = 0.0001), an underestimation of ISE (DSA = 18.8% ± 7.6; IVUS = 29.8% ± 9) (p < 0.0001), and a poor inter-technique intra-class correlation coefficient (ICC = 0.24). No difference was observed between IVUS and C-arm CT in ISE as calculated by diameter (29.8 ± 9 vs. 28.2 ± 12.5%, p = 0.5) and area (30.2 ± 8.4 vs. 33.3 ± 9.5%, p = 0.2). Inter-technique ICC between C-arm CT and IVUS was 0.72 [95%CI 0.49; 0.85] for MLA measurements. The inter-observer ICC for MLD and MLA measurements on C-arm CT were, respectively, estimated at 0.75 [95% CI 0.40, 0.89] and 0.77 [95% CI 0.43, 0.90)]. C-arm CT presents a better correlation with IVUS than DSA to determine lumen diameter and ISE immediately after percutaneous revascularization.

Axially extended-volume C-arm CT using a reverse helical trajectory in the interventional room.

C-arm computed tomography (CT) is an innovative technique that enables a C-arm system to generate 3-D images from a set of 2-D X-ray projections. This technique can reduce treatment-related complications and may improve interventional efficacy and safety. However, state-of-the-art C-arm systems rely on a circular short scan for data acquisition, which limits coverage in the axial direction. This limitation was reported as a problem in hepatic vascular interventions. To solve this problem, as well as to further extend the value of C-arm CT, axially extended-volume C-arm CT is needed. For example, such an extension would enable imaging the full aorta, the peripheral arteries or the spine in the interventional room, which is currently not feasible. In this paper, we demonstrate that performing long object imaging using a reverse helix is feasible in the interventional room. This demonstration involved developing a novel calibration method, assessing geometric repeatability, implementing a reconstruction method that applies to real reverse helical data, and quantitatively evaluating image quality. Our results show that: 1) the reverse helical trajectory can be implemented and reliably repeated on a multiaxis C-arm system; and 2) a long volume can be reconstructed with satisfactory image quality using reverse helical data.

Probabilistic sparse matching for robust 3D/3D fusion in minimally invasive surgery.

Classical surgery is being overtaken by minimally invasive and transcatheter procedures. As there is no direct view or access to the affected anatomy, advanced imaging techniques such as 3D C-arm computed tomography (CT) and C-arm fluoroscopy are routinely used in clinical practice for intraoperative guidance. However, due to constraints regarding acquisition time and device configuration, intraoperative modalities have limited soft tissue image quality and reliable assessment of the cardiac anatomy typically requires contrast agent, which is harmful to the patient and requires complex acquisition protocols. We propose a probabilistic sparse matching approach to fuse high-quality preoperative CT images and nongated, noncontrast intraoperative C-arm CT images by utilizing robust machine learning and numerical optimization techniques. Thus, high-quality patient-specific models can be extracted from the preoperative CT and mapped to the intraoperative imaging environment to guide minimally invasive procedures. Extensive quantitative experiments on 95 clinical datasets demonstrate that our model-based fusion approach has an average execution time of 1.56 s, while the accuracy of 5.48 mm between the anchor anatomy in both images lies within expert user confidence intervals. In direct comparison with image-to-image registration based on an open-source state-of-the-art medical imaging library and a recently proposed quasi-global, knowledge-driven multi-modal fusion approach for thoracic-abdominal images, our model-based method exhibits superior performance in terms of registration accuracy and robustness with respect to both target anatomy and anchor anatomy alignment errors.

Percutaneous sclerotherapy of foot venous malformations: Evaluation of clinical response

To evaluate a single institutional experience with percutaneous sclerotherapy of venous malformations (VM) of the foot. Sixteen patients (mean age 14.6 years; range 6-27.3 years), who underwent 34 sclerotherapy procedures were retrospectively analysed. Technical success, Puig classification, VM size reduction, and the complication rate were evaluated. In procedures in which C-arm computed tomography (CT) was performed, the VM-to-skin surface distance was measured. Additionally, an e-mail-based questionnaire to evaluate the response to sclerotherapy was answered by the patients. Technical success was 97%. The mean number of procedures per patient was 2.1 (range 1-5). In all procedures, sodium tetradecyl sulphate foam was used. Appropriate follow-up was available for 29/33 procedures (88%). Post-procedural complications occurred after 6/29 procedures (21%), all of which were self-limited skin complications. C-arm CT was performed in 19/33 procedures (58%). The lesion-to-skin surface distance was significantly shorter in patients with skin post-procedural complications (p < 0.001). The e-mail-based questionnaire was completed by 13/16 patients (81%). Decrease in swelling, improvement of foot function and a significant decrease in pain (p = 0.003) was reported. No patient reported dis-improvement after sclerotherapy. Percutaneous sclerotherapy is an effective option for treating foot VMs. Skin complication rates are higher with shorter VM-to-skin surface distance.