Intraprocedural Cone-beam Computed Tomography Research Articles

Fluoroscopy-Guided Percutaneous Transthoracic Needle Lung Biopsy with the Aid of Planning Cone-Beam CT: Diagnostic Accuracy and Complications.

Background: Fluoroscopy-guided PTNB for fluoroscopy-identifiable lung lesions has been suggested as a useful method for the pathological diagnosis of lung lesions; however, it is lacking in accuracy and safety compared to CT-guided PTNB. Thus, we aimed to investigate the diagnostic accuracy and complications of fluoroscopy-guided percutaneous transthoracic needle biopsy (PTNB) with the aid of pre-procedural planning cone-beam computed tomography (CBCT) in order to take advantage of their respective strengths. Methods: A total of 255 fluoroscopy-guided PTNBs with the aid of planning CBCT were performed. Pre-procedural planning CBCT was conducted to calculate the shortest length from the skin puncture site to the margin of the target lesion for the needle trajectory. No intra-procedural CBCT was performed. The diagnostic performance of fluoroscopy-guided PTNB with the aid of planning CBCT was calculated. The prognostic factors for diagnostic failures and complications were evaluated using logistic regression analysis. Results: The accuracy, sensitivity, specificity, PPV, and NPV were 97.3%, 88.0%, 90.9%, 100%, and 62.5%, respectively. There were 29 diagnostic failures (11.8%), and the multivariable analysis showed that a longer lesion depth on CBCT and a shorter specimen length were each associated with diagnostic failure (p = 0.010 and 0.012, respectively). Complications occurred in 34 PTNBs (13.3%). The multivariable analysis showed that an increased total number of biopsies per lesion, a longer length of lung aeration via needle insertion, a smaller lesion size on CT imaging (≤20 mm), and the presence of an air bronchogram were associated with the occurrence of complications (p = 0.027, <0.001, 0.003, and 0.020, respectively). Conclusions: Excellent diagnostic accuracy was obtained by fluoroscopy-guided PTNB with the aid of planning CBCT. Compared to that of CT- or CBCT-guided PTNB, the procedure-related complication rate was acceptably low, but the radiation dose to patients could be potentially reduced.

Cone-beam CT-based Navigation With Augmented Fluoroscopy of the Airways for Image-guided Bronchoscopic Biopsy of Peripheral Pulmonary Nodules: A Prospective Clinical Study.

Cone-beam computed tomography (CBCT) and augmented fluoroscopy (AF), in which intraprocedural CBCT data is fused with fluoroscopy, have been utilized as a novel image-guidance technique for biopsy of peripheral pulmonary lesions. The aim of this clinical study is to determine the safety and diagnostic performance of CBCT-guided bronchoscopy with advanced software tools for procedural planning and navigational guidance with AF of the airways for biopsy of peripheral pulmonary nodules. Fifty-two consecutive subjects were prospectively enrolled in the AIRWAZE study (December 2018 to October 2019). Image-guided bronchoscopic biopsy procedures were performed under general anesthesia with specific ventilation protocols in a hybrid operating room equipped with a ceiling-mounted C-arm system. Procedural planning and image-guided bronchoscopy with CBCT and AF were performed using the Airwaze investigational device. A total of 58 pulmonary lesions with a median size of 19.0mm (range 7 to 48mm) were biopsied. The overall diagnostic yield at index procedure was 87.9% (95% CI: 77.1%-94.0%). No severe adverse events related to CBCT-guided bronchoscopy, such as pneumothorax, bleeding, or respiratory failure, were observed. CBCT-guided bronchoscopic biopsy with augmented fluoroscopic views of the airways and target lesion for navigational guidance is technically feasible and safe. Three-dimensional image-guided navigation biopsy is associated with high navigational success and a high diagnostic yield for peripheral pulmonary nodules.

Added Value of Cone-Beam CT to Identify Arterial Supply during Genicular Artery Embolization for Knee Osteoarthritis

To evaluate if the addition of cone-beam computed tomography (CT) to digital subtraction angiography (DSA) improves the identification of the genicular arteries during genicular artery embolization (GAE) for knee pain secondary to osteoarthritis (OA). This single-center study retrospectively analyzed 222 patients who underwent GAE for painful knee OA between May 2018 and April 2022. Intraprocedural cone-beam CT and DSA images were reviewed independently by 2 sets of interventional radiologists. DSA was performed for all patients. Technically adequate cone-beam CT was available for 205 patients (92.3%). The presence of the genicular arteries identified by cone-beam CT and DSA was compared using Φ coefficients. Embolization targets identified by both cone-beam CT and DSA were evaluated against those identified by DSA alone. Genicular arteries with the highest concordance between cone-beam CT and DSA were the inferior lateral (196 vs 198; Φ= 0.3530; P < .0001), superior lateral (197 vs 200; Φ= 0.3060; P < .0001), and superior medial genicular (186 vs 161; Φ= 0.2836; P < .0001) arteries. Cone-beam CT demonstrated higher rates of detection of the inferior medial (195 vs 178; Φ= 0.04573; P= .5150) and median genicular arteries (200 vs 192; Φ= 0.04573; P= .5150). Meanwhile, genicular arteries less frequently identified by cone-beam CT were the descending genicular (197 vs 200; Φ=-0.03186; P= .6502), superior patellar (175 vs 184; Φ= 0.1332; P= .0569), and recurrent anterior tibial (156 vs 186; Φ= 0.01809; P= .7969) arteries. Cone-beam CT in combination with DSA identified 13.4% (372 vs 328) more targets compared to DSA alone. Based on the results of the current study, cone-beam CT serves as a valuable adjunct for visualizing the genicular arteries during GAE, and together with DSA, it identifies more potential embolization targets.

Empirical transarterial embolization in angiographically negative lower gastrointestinal bleeding using vessel tracking and 3D navigation tools: report of 2 patients

BackgroundRecently, an empiric Cone-beam Computed Tomography (CBCT)-guided transarterial embolization (TAE) technique has been investigated for lower gastrointestinal bleeding (LGIB). Although this empirical strategy reduced the rate of rebleeding in hemodynamically unstable patients compared to a ‘wait and see’ strategy, the specified technique is challenging and time-consuming.Case presentationWe present two methods to perform a prompt empiric TAE in LGIB when catheter angiography is negative. Based on the pre-procedural Computed Tomography Angiography bleeding site and using vessel detection and navigation software tools that are integrated in contemporary angiosuites, the culprit bleeding artery could be targeted with only one selective intraprocedural CBCT acquisition.ConclusionThe proposed techniques are promising to reduce procedure time and facilitate the implementation of empiric CBCT-guided TAE in clinical practice when angiography is negative.

Quantitative Automated Segmentation of Lipiodol Deposits on Cone-Beam CT Imaging Acquired during Transarterial Chemoembolization for Liver Tumors: A Deep Learning Approach

To show that a deep learning (DL)-based, automated model for Lipiodol (Guerbet Pharmaceuticals, Paris, France) segmentation on cone-beam computed tomography (CT) after conventional transarterial chemoembolization performs closer to the "ground truth segmentation" than a conventional thresholding-based model. This post hoc analysis included 36 patients with a diagnosis of hepatocellular carcinoma or other solid liver tumors who underwent conventional transarterial chemoembolization with an intraprocedural cone-beam CT. Semiautomatic segmentation of Lipiodol was obtained. Subsequently, a convolutional U-net model was used to output a binary mask that predicted Lipiodol deposition. A threshold value of signal intensity on cone-beam CT was used to obtain a Lipiodol mask for comparison. The dice similarity coefficient (DSC), mean squared error (MSE), center of mass (CM), and fractional volume ratios for both masks were obtained by comparing them to the ground truth (radiologist-segmented Lipiodol deposits) to obtain accuracy metrics for the 2 masks. These results were used to compare the model versus the threshold technique. For all metrics, the U-net outperformed the threshold technique: DSC (0.65 ± 0.17 vs 0.45 ± 0.22, P < .001) and MSE (125.53 ± 107.36 vs 185.98 ± 93.82, P= .005). The difference between the CM predicted and the actual CM was 15.31 mm ± 14.63 versus 31.34 mm ± 30.24 (P < .001), with lesser distance indicating higher accuracy. The fraction of volume present ([predicted Lipiodol volume]/[ground truth Lipiodol volume]) was 1.22 ± 0.84 versus 2.58 ± 3.52 (P= .048) for the current model's prediction and threshold technique, respectively. This study showed that a DL framework could detect Lipiodol in cone-beam CT imaging and was capable of outperforming the conventionally used thresholding technique over several metrics. Further optimization will allow for more accurate, quantitative predictions of Lipiodol depositions intraprocedurally.

Value of Latest-generation Cone-beam Computed Tomography for Post Lipiodol-embolization Imaging in Hepatic Transarterial Chemoembolization in Comparison with Multi-detector Computed Tomography

To evaluate image quality, radiation dose (phantom study) and tumor volumetry of intraprocedural cone-beam computed tomography (CBCT) compared to postprocedural multidetector computed tomography (MDCT) in patients undergoing hepatic conventional transarterial chemoembolization (cTACE). One hundred fourteen patients (64/50 female/male; mean age, 57 ± 14 years) who had undergone cTACE including intraprocedural-CBCT and postprocedural-MDCT were retrospectively enrolled. Subjective image quality (IQ) and suitability for assessing Lipiodol distribution were compared using 4-point Likert scales; additionally, lesion to liver contrast (LLC) and contrast-to-noise-ratio (CNR) were compared. Tumor volumes were measured semi-automatically and compared to magnetic resonance imaging (MRI). Effective doses were measured using an anthropomorphic phantom. The suitability of CBCT for assessing Lipiodol distribution during cTACE was comparable to MDCT (mean score, 3.2 ± 0.6) and CBCT (3.4 ± 1.0, p=0.29). Subjective overall IQ was rated with a mean score of 3.2 ± 0.7 (κ=0.66) in CBCT and 3.1 ± 0.4 (κ=0.57, p=0.15) in MDCT. Evaluation of LLC showed significant differences between CBCT and MDCT (mean scores 3.6 ± 1.2 and 2.6 ± 1.5, respectively). CNR analysis demonstrated comparable mean values for CBCT and MDCT (3.5 ± 1.3vs. 3.4 ± 1.8,p=0.31). No significant differences were found regarding tumor volumetry (mean volumes: CBCT, 27.0 ± 17.4 mm3; MDCT: 26.8 ± 16.0 mm3; p = 0.66) in comparison to T2-weighted MRI (25.9 ± 17.6 mm3). Effective doses were 3.2 ± 0.6 mSv (CBCT) and 2.5 ± 0.3 mSv (MDCT) (p < 0.001). No cTACE-related complications (bleeding, non-target embolization) were missed on intraprocedural CBCT in comparison to postprocedural MDCT. Latest-generation intraprocedural CBCT provides suitable assessment of Lipiodol distribution and similar image quality compared to MDCT while allowing for robust volumetric tumor measurements and immediate complication control by visualizing non-target embolization and hematoma. Therefore, it may improve patient safety and outcome as well as clinical workflow compared to postprocedural MDCT in hepatic cTACE in certain cases.

Prostatic Artery Embolization for Benign Prostatic Hyperplasia—A Primer for Interventional Radiologists

AbstractMale patients over 50 years with lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia (BPH) are potential candidates for prostatic artery embolization (PAE). PAE is not a perfect fit for all BPH patients. Careful pre- and postpostprocedural evaluation/consultation with correct selection of patients should be tailored on an individual basis. Evaluated parameters include the following: LUTS severity quantification with validated questionnaires as the international prostate symptom score (IPSS) and quality of life (QoL), erectile and ejaculatory evaluation with validated questionnaires, blood tests including full blood count, coagulation profile, renal function and total/free prostate-specific antigen (PSA), prostate volume measured by multiparametric magnetic resonance (mpMR) of the prostate and/or transrectal ultrasound, uroflowmetry measuring the peak urinary flowrate (Qmax), and postvoid residual urine (PVR). Correct arterial anatomy identification with either computed tomography (CT) angiography, MR angiography, or intraprocedural cone-beam CT (CBCT) are suggested for a confident procedure and avoiding potential complications. The minimally invasive nature of PAE with a faster recovery, preserving the sexual function, and comparable results to standard prostatic surgery make the procedure an attractive choice for many male patients suffering with this condition. Patients should be informed about the potential for higher retreatment rates and shorter duration of treatment effect when compared with standard prostatic surgery. In this comprehensive review, we provide an updated toolbox for all interventional radiologists interested in the PAE practice for patients with BPH. We explain how to evaluate patients during consultation before and after PAE, describe the preprocedural imaging required, explain the technique, and narrate how to optimize outcomes. Finally, we review the level of evidence of PAE for BPH.

Prospective Analysis of a Novel Endobronchial Augmented Fluoroscopic Navigation System for Diagnosis of Peripheral Pulmonary Lesions.

Background:Navigational bronchoscopy has improved upon traditional bronchoscopy to identify suspicious pulmonary lesions, but wide variability exists in the diagnostic yield of various modalities. The aim of this study was to measure localization accuracy and diagnostic yield of a novel endobronchial augmented fluoroscopic navigation system (first-generation LungVision system) for peripheral pulmonary lesions (PPLs).Methods:This prospective single-center study included adults undergoing guided bronchoscopy to evaluate PPLs. Preprocedure computed tomography (CT) images were obtained, and planning software calculated a pathway to the lesion. A flexible bronchoscope was used to navigate along the pathway overlaid on the intraprocedural fluoroscopic image. When real-time display indicated the catheter tip had reached the lesion, cone-beam computed tomography (CBCT) was used to measure the actual location of the tip. Biopsy and rapid on-site cytopathologic evaluation were performed.Results:Fifty-one patients were included in the analysis. The median lesion diameter was 18.0 mm (range: 7.0 to 48.0 mm). Localization success was 96.1%. The average distance between lesion location as shown by LungVision augmented fluoroscopy and actual location measured by CBCT was 5.9 mm (range: 2.1 to 10.0 mm). Diagnostic yield at the index procedure was 78.4%. Diagnostic accuracy assessed at 12 months follow-up was 88.2%. Average CT-to-body divergence was 14.5 mm (range: 2.6 to 33.0 mm) from preprocedure CT to intraprocedural CBCT images.Conclusion:Augmented fluoroscopy for navigation and biopsy of PPLs with the LungVision system showed a high localization success rate and corresponding high diagnostic yield. Navigation and biopsy with real-time visualization can improve diagnostic yield for PPLs.

XperCT Sharpening Reconstruction for Cone-Beam Computed Tomography Guided Lung and Bone Interventions

AbstractC-arm cone-beam computed tomography (CBCT) is a valuable tool for three-dimensional navigation and mapping in the interventional radiology suite owing to its flexible gantry positioning, real-time three-dimensional volume acquisition, and reduced contrast and radiation use. Reports of CBCT-guided bone and lung interventions are relatively infrequent, however, possibly due in part to the lack of dedicated bone and lung reconstruction algorithms and concerns regarding insufficient lesion conspicuity. Two cases of an ad hoc intraprocedural CBCT sharpening reconstruction are presented in this article.

Feasibility of Yttrium-90 Radioembolization Dose Calculation Utilizing Intra-procedural Open Trajectory Cone Beam CT.

Dose calculation for transarterial radioembolization (TARE) with glass yttrium-90 (Y90) labeled microspheres is based on liver lobe and tumor volumes, currently measured from preprocedural MRI or CT. The variable time between MRI and radioembolization may not account for relevant tumor progression. Advances in cone beam computed tomography (CBCT) allow for intra-procedural assessment of these volumes that avoids this factor. Liver lobe and hepatocellular carcinoma tumor volume measurements and dose calculations using intra-procedural CBCT were compared to those using preprocedural MRI in order to determine feasibility. Retrospective analysis was performed in 20 patients with proven hepatocellular carcinoma (HCC) who underwent planning angiography with open trajectory CBCT acquisitions prior to radioembolization, and an MRI performed within 6 weeks prior to treatment planning. Liver lobe and tumor burden volumes were measured based on CBCT using embolization planning and guidance software and measured on preprocedural MRI using standard volume analysis software. Y90 doses were subsequently calculated using each measured volume. Comparisons of volume measurements and calculated Y90 doses between the two modalities were evaluated for significance using paired t tests. All target liver lobes and all tumors were completely depicted on CBCT. Mean liver lobe and tumor burden volumes measured on intra-procedural CBCT and preprocedural MRI showed no significant difference (p = 0.71). Mean calculated Y90 dose based on each modality showed no significant difference (p = 0.18). Lobar and tumor volume measurement with CBCT is a reliable alternative to measurement with preprocedural MRI. Utilization of CBCT 3D segmentation software during planning angiography may be useful to provide up-to-date volume measurements and dose calculations prior to radioembolization.

Computed Tomography for 4-Dimensional Angiography and Perfusion Imaging of the Prostate for Embolization Planning of Benign Prostatic Hyperplasia.

The aim of this study was to evaluate the feasibility of a computed tomography (CT) protocol enabling the visualization of the prostatic artery (PA) before prostatic artery embolization (PAE) in benign prostatic hyperplasia, which provides quantitative perfusion information of the prostate gland. In this institutional review board-approved study, 22 consecutive patients (mean age, 67 ± 7 years) who were planned to undergo PAE underwent a dynamic CT scan of the pelvis (scan range, 22.4 cm; cycle time, 1.5 seconds; scan time, 44 seconds; 25 scan cycles; 70 kVp; 100 mAs) after the administration of 70 mL of iodinated contrast media (flow rate, 6 mL/s; 10 seconds' delay). Image postprocessing consisted of a spatiotemporal, frequency-depending multiband filtering technique with noise reduction, motion correction, resulting in (1) time-resolved, temporal maximum intensity projection (MIP) images from fusion of multiple arterial time points; (2) 4-dimensional (4D) CT angiography images after bone and calcium plaque removal; and (3) parametric perfusion maps of the prostate. Intraprocedural cone-beam CT was performed with a microcatheter in the PA. In both modalities, the contrast-to-noise ratio of the right internal iliac artery or the PA was calculated, respectively. Visibility of the PA was scored using a Likert scale (score 1 = not seen, to score 4 = intraprostatic PA branches seen). Quantitative perfusion analysis of the dynamic pelvic CT included calculation of the blood flow, blood volume, mean transit time, and flow extraction product. The average volume CT dose index and dose length product of CT was 35.7 ± 6.8 mGy and 737.4 ± 146.3 mGy·cm, respectively. Contrast-to-noise ratio of the pelvic vessels on temporal MIP images and cone-beam CT were 45 ± 19 and 69 ± 27, respectively (P < 0.01). The mean visibility score of the PA was 3.6 ± 0.6 for 4D-CT angiography and 3.97 ± 0.2 for cone-beam CT (P < 0.001). The PA was visualized in 100% of 4D-CT angiography examinations, with one PA being visible only proximally. Prostate CT perfusion analysis showed blood flow, blood volume, mean transit time, and flow extraction product values of 27.9 ± 12.5 mL/100 mL/min, 2.0 ± 0.8 mL/100 mL, 4.5 ± 0.5 second, and 12.6 ± 5.4 mL/100 mL/min, respectively, for the whole prostate gland. About half the patients showed a pronounced difference between the lobes. We introduced a CT protocol for PAE planning providing excellent visualization of the PA on temporal MIP images and 4D-CT angiography at a reasonable dose and low contrast volume. In addition, quantitative perfusion information is available, which might be useful for outcome prediction after embolization.

Safety margin of embolized area can reduce local recurrence of hepatocellular carcinoma after superselective transarterial chemoembolization.

Background/AimsWe aimed to determine the relationship between the safety margin of an embolized area and local tumor recurrence (LTR) of patients with hepatocellular carcinoma (HCC) who underwent superselective transarterial chemoembolization (TACE).MethodsThe medical records of 77 HCC patients with 109 HCC nodules who underwent superselective TACE were retrospectively analyzed for LTR. Univariate and multivariate analyses were performed for 16 potential factors using Cox proportional hazard regression. Iodized oil deposition on cone-beam computed tomography (CBCT) imaging was divided into three grades: A=complete tumor staining and complete circumferential safety margin, B=complete tumor staining but incomplete safety margin, C=incomplete tumor staining. The effect of a safety margin on LTR was evaluated by comparison between grade A and B group.ResultsUnivariate and multivariate analyses revealed that grade A iodized oil deposition and portal vein visualization were the only two independent significant factors of LTR (P<0.001 and P=0.029, respectively). The 12- and 24-month LTR rates of tumors for grade A (n=62), grade B (n=30), and grade C (n=17) were 16% vs. 41% vs. 100% and 16% vs. 61% vs. 100%, respectively (P<0.001). The tumors in the grade A group had a 75% risk reduction in LTR (odds ratio, 0.25; 95% confidence interval, 0.10 to 0.64; P=0.004) compared to the grade B group.ConclusionsLTR was significantly lower when a greater degree of iodized oil deposition occurred with a complete circumferential safety margin. In superselective TACE, the safety margin of the embolized areas using intraprocedural CBCT affected LTR in HCC patients.

Plug-Assisted Retrograde Transvenous Obliteration for the Treatment of Gastric Varices: The Role of Intra-Procedural Cone-Beam Computed Tomography.

ObjectiveTo investigate the technical and clinical outcomes of plug-assisted retrograde transvenous obliteration (PARTO) for the treatment of gastric varices (GV) and to evaluate the role of intra-procedural cone-beam computed tomography (CBCT) performed during PARTO to confirm its technical success.Materials and MethodsFrom January 2016 to December 2016, 17 patients with GV who had undergone PARTO were retrospectively evaluated. When the proximal part of the afferent vein was identified on a fluoroscopy, non-contrast CBCT images were obtained. In patients with incomplete embolization of GV, an additional injection of gelatin sponges was performed. Follow-up data from contrast-enhanced CT and upper intestinal endoscopy, as well as clinical and laboratory data were collected.ResultsPlug-assisted retrograde transvenous obliteration procedures were technically successful in all 17 patients. Complete embolization of GV was detected on CBCT images in 15 patients; whereas, incomplete embolization was detected in two. Complete embolization of GV was then achieved after an additional injection of gelatin sponges in these two patients as demonstrated on the 2nd CBCT image. The mean follow-up period after PARTO was 193 days (range, 73–383 days). A follow-up CT obtained 2–4 months after PARTO demonstrated marked shrinkage or complete obliteration of GV and portosystemic shunts in all 17 patients. There were no cases of variceal bleeding during the follow-up.ConclusionPlug-assisted retrograde transvenous obliteration is technically and clinically effective for the treatment of GV. In addition, intra-procedural CBCT can be an adjunct tool to fluoroscopy, because it can provide an immediate and accurate evaluation of the technical success of PARTO.

Comparison of Image Quality and Diagnostic Performance of Cone-Beam CT during Drug-Eluting Embolic Transarterial Chemoembolization and Multidetector CT in the Detection of Hepatocellular Carcinoma

To compare image quality and diagnostic performance of cone-beam computed tomography (CT) and multidetector CT in the detection of hypervascular hepatocellular carcinoma (HCC) in patients with cirrhosis undergoing transarterial chemoembolization with drug-eluting embolic agents. Fifty-five consecutive patients referred for chemoembolization of hypervascular HCC were prospectively enrolled. Imaging included preprocedural multidetector CT within 1 month before planned treatment, intraprocedural cone-beam CT, and 1-month follow-up multidetector CT. Analysis of image quality was performed with calculations of lesion-to-liver contrast-to-noise ratio (LLCNR) and lesion-to-liver signal-to-noise-ratio (LLSNR). One-month follow-up multidetector CT was considered the reference standard for the detection of HCC nodules. Median LLCNR values were 3.94 (95% confidence interval [CI], 3.06-5.05) for preprocedural multidetector CT and 6.90 (95% CI, 5.17-7.77) for intraprocedural cone-beam CT (P < .0001). Median LLSNR values were 11.53 (95% CI, 9.51-12.44) for preprocedural multidetector CT and 9.36 (95% CI, 8.12-10.39) for intraprocedural cone-beam CT (P < .0104). Preprocedural multidetector CT detected 115 hypervascular nodules with typical HCC behavior, and cone-beam CT detected 15 additional hypervascular nodules that were also visible on 1-month follow-up multidetector CT. Cone-beam CT has a significantly higher diagnostic performance compared with preprocedural multidetector CT in the detection of HCCs and can influence management of patients with cirrhosis by identifying particularly aggressive tumors.

Multimodality 3D Tumor Segmentation in HCC Patients Treated with TACE

To validate the concordance of a semiautomated multimodality lesion segmentation technique between contrast-enhanced magnetic resonance imaging (CE-MRI), cone-beam computed tomography (CBCT), and multidetector CT (MDCT) in patients with hepatocellular carcinoma (HCC) treated with transarterial chemoembolization (TACE). This retrospective analysis included 45 patients with unresectable HCC who underwent baseline CE-MRI within 1 month before the treatment, intraprocedural CBCT during conventional TACE, and MDCT within 24 hours after TACE. Fourteen patients were excluded because of atypical lesion morphology, portal vein invasion, or small lesion size which precluded sufficient lesion visualization. Thirty-one patients with a total of 40 target lesions were included into the analysis. A tumor segmentation software, based on non-Euclidean geometry and theory of radial basis functions, was used to allow for the segmentation of target lesions in 3D on all three modalities. The algorithm created image-based masks located in a 3D region whose center and size were defined by the user, yielding the nomenclature "semiautomatic". On the basis of that, tumor volumes on all three modalities were calculated and compared using a linear regression model (R(2) values). Residual plots were used to analyze drift and variance of the values. The mean value of tumor volumes was 18.72 ± 19.13 cm(3) (range, 0.41-59.16 cm(3)) on CE-MRI, 21.26 ± 21.99 cm(3) (range, 0.62-86.82 cm(3)) on CBCT, and 19.88 ± 20.88 cm(3) (range, 0.45-75.24 cm(3)) on MDCT. The average volumes of the tumor were not significantly different between CE-MRI and DP-CBCT, DP-CBCT and MDCT, MDCT and CE-MRI (P = .577, .770, and .794, respectively). A strong correlation between volumes on CE-MRI and CBCT, CBCT and MDCT, MDCT and CE-MRI was observed (R(2) = 0.974, 0.992 and 0.983, respectively). When plotting the residuals, no drift was observed for all methods showing deviations of no >10% of absolute volumes (in cm(3)). A semiautomated 3D segmentation of HCC lesions treated with TACE provides high volumetric concordance across all tested imaging modalities.

Three-dimensional Evaluation of Lipiodol Retention in HCC after Chemoembolization: A Quantitative Comparison between CBCT and MDCT

To evaluate the capability of cone-beam computed tomography (CBCT) acquired immediately after transcatheter arterial chemoembolization (TACE) in determining lipiodol retention quantitatively and volumetrically when compared to 1-day postprocedure unenhanced multidetector computed tomography (MDCT). From June to December 2012, 15 patients met the inclusion criteria of unresectable hepatocellular carcinoma (HCC) that was treated with conventional TACE (cTACE) and had intraprocedural CBCT and 1-day post-TACE MDCT. Four patients were excluded because the lipiodol was diffuse throughout the entire liver or lipiodol deposition was not clear on both CBCT and MDCT. Eleven patients with a total of 31 target lesions were included in the analysis. A quantitative three-dimensional software was used to assess complete, localized, and diffuse lipiodol deposition. Tumor volume, lipiodol volume in the tumor, percent lipiodol retention, and lipiodol enhancement in Hounsfield units (HU) were calculated and compared between CBCT and MDCT using two-tailed Student's t test and Bland-Altman plots. The mean value of tumor volume, lipiodol-deposited regions, calculated average percent lipiodol retention, and HU value of CBCT were not significantly different from those of MDCT (tumor volume: 9.37 ± 11.35 cm(3) vs 9.34 ± 11.44 cm(3), P = .991; lipiodol volume: 7.84 ± 9.34 cm(3) vs 7.84 ± 9.60 cm(3), P = .998; lipiodol retention: 89.3% ± 14.7% vs. 90.2% ± 14.9%, P = .811; HU value: 307.7 ± 160.1 HU vs. 257.2 ± 120.0 HU, P = .139). Bland-Altman plots showed only minimal difference and high agreement when comparing CBCT to MDCT. CBCT has a similar capability, intraprocedurally, to assess lipiodol deposition in three dimensions for patients with HCC treated with cTACE when compared to MDCT.

Comparison of Local Control in Transcatheter Arterial Chemoembolization of Hepatocellular Carcinoma ≤6 cm With or Without Intraprocedural Monitoring of the Embolized Area Using Cone-Beam Computed Tomography

This study was designed to compare technical success and local recurrence rates of transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) with/without monitoring of embolized areas using cone-beam computed tomography (CBCT). A total of 207 HCCs ≤6 cm were treated with superselective TACE using digital subtraction angiography (DSA) alone (DSA group, 98 tumors of 70 patients) or plus CBCT monitoring (CBCT group, 109 tumors of 79 patients). Technical success of TACE was classified into three grades according to 1-week CT; the tumor was embolized with a safety margin (5-mm wide for tumors <25 mm, and 10-mm wide for tumors 25≥ and ≤60 mm; grade A), without a margin in parts (grade B), or the entire tumor was not embolized (grade C). Technical success and local recurrence rates in the DSA and CBCT groups were compared. Local recurrence rates of grade A and B tumors were also compared. The grade A/B/C tumors in the DSA and CBCT groups were 64 (65.3%)/25 (25.5%)/9 (9.2%) and 95 (87.2%)/11 (10.1%)/3 (2.8%), respectively. Local recurrence developed in 46/158 (29.1%) grade A tumors and 24/36 (66.7%) grade B. There were significant differences in technical success between the DSA and CBCT groups (p < 0.001) and local recurrence rates between grade A and B tumors (p < 0.001). The 1-, 2-, and 3-year local recurrence rates in the DSA and CBCT groups were 33.3 and 22.3%, 41.3 and 26.8%, and 48 and 30.6%, respectively (p = 0.0217). Intraprocedural CBCT monitoring of embolized areas reduces the local tumor recurrence.

Intraprocedural C-Arm Dual-Phase Cone-Beam CT: Can It Be Used to Predict Short-term Response to TACE with Drug-eluting Beads in Patients with Hepatocellular Carcinoma?

To investigate whether C-arm dual-phase cone-beam computed tomography (CT) performed during transcatheter arterial chemoembolization (TACE) with doxorubicin-eluting beads can help predict tumor response at 1-month follow-up in patients with hepatocellular carcinoma (HCC). This prospective study was compliant with HIPAA and approved by the institutional review board and animal care and use committee. Analysis was performed retrospectively on 50 targeted HCC lesions in 29 patients (16 men, 13 women; mean age, 61.9 years ± 10.7) treated with TACE with drug-eluting beads. Magnetic resonance (MR) imaging was performed at baseline and 1 month after TACE. Dual-phase cone-beam CT was performed before and after TACE. Tumor enhancement at dual-phase cone-beam CT in early arterial and delayed venous phases was assessed retrospectively with blinding to MR findings. Tumor response at MR imaging was assessed according to European Association for the Study of the Liver (EASL) guidelines. Two patients were excluded from analysis because dual-phase cone-beam CT scans were not interpretable. Logistic regression models for correlated data were used to compare changes in tumor enhancement between modalities. The radiation dose with dual-phase cone-beam CT was measured in one pig. At 1-month MR imaging follow-up, complete and/or partial tumor response was seen in 74% and 76% of lesions in the arterial and venous phases, respectively. Paired t tests used to compare images obtained before and after TACE showed a significant reduction in tumor enhancement with both modalities (P < .0001). The decrease in tumor enhancement seen with dual-phase cone-beam CT after TACE showed a linear correlation with MR findings. Estimated correlation coefficients were excellent for first (R = 0.89) and second (R = 0.82) phases. A significant relationship between tumor enhancement at cone-beam CT after TACE and complete and/or partial tumor response at MR imaging was found for arterial (odds ratio, 0.95; 95% confidence interval [CI]: 0.91, 0.99; P = .023) and venous (odds ratio, 0.96; 95% CI: 0.93, 0.99; P = .035) phases with the multivariate logistic regression model. Radiation dose for two dual-phase cone-beam CT scans was 3.08 mSv. Intraprocedural C-arm dual-phase cone-beam CT can be used immediately after TACE with doxorubicin-eluting beads to predict HCC tumor response at 1-month MR imaging follow-up.

Image integration of three-dimensional cone-beam computed tomography angiogram into electroanatomical mapping system to guide catheter ablation of atrial fibrillation

To evaluate the feasibility of integrating three-dimensional images created by intra-procedural cone-beam computed tomography (CBCT) into three-dimensional electroanatomical maps (EAM) and compare its accuracy with that of pre-procedural multi-slice CT (MSCT). In 24 patients with drug-refractory atrial fibrillation (AF), atriography using CBCT with pulmonary arterial contrast injection was performed at the beginning of the AF ablation procedure. Intra-procedural CBCT images and pre-procedural MSCT images were individually imported into the EAM system and compared their integration accuracy (point-to-surface distance) of each image and EAM just before ablation. The CBCT images were assessed qualitatively and quantitatively in comparison with MSCT images. All CBCT images were graded as optimal or useful in delineating the left atrium-pulmonary vein anatomy and were successfully integrated with the EAM. Overall, integration accuracy was similar for CBCT and MSCT. However, in 11 patients, the MSCT was performed 5 or more days prior to EAM, resulting in significantly shorter surface-to-point distance in CBCT than that in MSCT (P = 0.047). Radiation exposure with CBCT was significantly reduced compared with MSCT (P < 0.001). It is feasible to integrate CBCT image into EAM, and the integration is relatively accurate. Intra-procedural atriography by CBCT may replace pre-procedural MSCT as the imaging source for image integration.