Navigational Tools for Interventional Radiology and Interventional Oncology Applications

Electromagnetic navigation system for computed tomography-guided synchronous percutaneous lung biopsy and microwave ablation of pulmonary nodules: a prospective, single-center, single-arm clinical study

BACKGROUND

The purpose of this study was to clinically evaluate the safety and effectiveness of the electromagnetic navigation (EMN) system designed for computed tomography (CT)-guided synchronous percutaneous lung biopsy and microwave ablation (MWA) of pulmonary nodules.

METHODS

This prospective, single-center, single-arm clinical cohort study was conducted in Beijing Hospital from March 2023 to May 2023. Patients who underwent CT-guided synchronous percutaneous lung biopsy and MWA via the EMN system were prospectively enrolled in our study. All the interventional procedures were performed by the same interventional radiologist. The technical success rate, the technical efficacy rates of biopsy and MWA were assessed as the primary outcomes. Preoperative, intraoperative, and postoperative variables were also recorded and analyzed for each patient.

RESULTS

A total of 48 patients were enrolled in the study. The technical success rate was 100%. The technical efficacy rate of biopsy was 95.8% (46/48), and the technical efficacy rate of WMA was 100% (48/48) with no recurrence during follow-up. The total and subpleural needle trajectory length and distance error were 8.3 ± 2.6 cm, 3.6 ± 1.6 cm, and 1.84 ± 1.08 mm, respectively. The median numbers of needle adjustments and CT acquisitions were 1 (range 1-3) and 3 (range 3-5), respectively. The time to reach the target and procedure time were 4.4 ± 1.7 and 19.7 ± 5.2 min, respectively. The dose length product was 748.8 ± 221.8 mGy*cm. The median postoperative hospital stay was 1 (range 1-7) days. No major complications (grade ≥3) occurred and only seven minor complications (14.6%) occurred, including six cases of pneumothorax and one case of hemoptysis. The radiologists achieved high satisfaction scores after surgery.

CONCLUSION

The EMN system is feasible, safe and effective for CT-guided synchronous percutaneous lung biopsy and MWA of pulmonary nodules.

Augmented Reality Navigation System (SIRIO) for Neuroprotection in Vertebral Tumoral Ablation

(1) This study evaluates the impact of the CT-guided SIRIO augmented reality navigation system on the procedural efficacy and clinical outcomes of neuroprotection in vertebral thermal ablation (RTA) for primary and metastatic bone tumors. (2) Methods: A retrospective non-randomized analysis of 28 vertebral RTA procedures was conducted, comparing 12 SIRIO-assisted and 16 non-SIRIO-assisted procedures. The primary outcomes included dose-length product (DLP) and epidural dissection time. The secondary outcomes included technical success, complication rates, and pain scores at procedural time (VAS Time 0) and three months post-procedure (VAS Time 1). The statistical analyses included t-tests, Mann-Whitney U tests, and multiple regression. (3) Results: SIRIO-assisted procedures significantly reduced DLP (307.42 mGycm vs. 460.31 mGycm, p = 2.23 × 10-8) and procedural epidural dissection time (13.48 min vs. 32.26 min, p = 2.61 × 10-12) compared to non-SIRIO-assisted procedures. Multiple regression confirmed these reductions were significant (DLP: β = -162.38, p < 0.001; time: β = -18.25, p < 0.001). Pain scores (VAS Time 1) did not differ significantly between groups, and tumor type did not significantly influence outcomes. (4) Conclusions: The SIRIO system enhances neuroprotection efficacy and safety, reducing radiation dose and procedural time during spine tumoral ablation while maintaining consistent pain management outcomes.

Smart goggles augmented reality CT-US fusion compared to conventional fusion navigation for percutaneous needle insertion

PURPOSE

Targeting accuracy determines outcomes for percutaneous needle interventions. Augmented reality (AR) in IR may improve procedural guidance and facilitate access to complex locations. This study aimed to evaluate percutaneous needle placement accuracy using a goggle-based AR system compared to an ultrasound (US)-based fusion navigation system.

METHODS

Six interventional radiologists performed 24 independent needle placements in an anthropomorphic phantom (CIRS 057A) in four needle guidance cohorts (n = 6 each): (1) US-based fusion, (2) goggle-based AR with stereoscopically projected anatomy (AR-overlay), (3) goggle AR without the projection (AR-plain), and (4) CT-guided freehand. US-based fusion included US/CT registration with electromagnetic (EM) needle, transducer, and patient tracking. For AR-overlay, US, EM-tracked needle, stereoscopic anatomical structures and targets were superimposed over the phantom. Needle placement accuracy (distance from needle tip to target center), placement time (from skin puncture to final position), and procedure time (time to completion) were measured.

RESULTS

Mean needle placement accuracy using US-based fusion, AR-overlay, AR-plain, and freehand was 4.5 ± 1.7 mm, 7.0 ± 4.7 mm, 4.7 ± 1.7 mm, and 9.2 ± 5.8 mm, respectively. AR-plain demonstrated comparable accuracy to US-based fusion (p = 0.7) and AR-overlay (p = 0.06). Excluding two outliers, AR-overlay accuracy became 5.9 ± 2.6 mm. US-based fusion had the highest mean placement time (44.3 ± 27.7 s) compared to all navigation cohorts (p < 0.001). Longest procedure times were recorded with AR-overlay (34 ± 10.2 min) compared to AR-plain (22.7 ± 8.6 min, p = 0.09), US-based fusion (19.5 ± 5.6 min, p = 0.02), and freehand (14.8 ± 1.6 min, p = 0.002).

CONCLUSION

Goggle-based AR showed no difference in needle placement accuracy compared to the commercially available US-based fusion navigation platform. Differences in accuracy and procedure times were apparent with different display modes (with/without stereoscopic projections). The AR-based projection of the US and needle trajectory over the body may be a helpful tool to enhance visuospatial orientation. Thus, this study refines the potential role of AR for needle placements, which may serve as a catalyst for informed implementation of AR techniques in IR.

Innovations in Image-Guided Procedures: Unraveling Robot-Assisted Non-Hepatic Percutaneous Ablation

Interventional oncology is routinely tasked with the feat of tumor characterization or destruction, via image-guided biopsy and tumor ablation, which may pose difficulties due to challenging-to-reach structures, target complexity, and proximity to critical structures. Such procedures carry a risk-to-benefit ratio along with measurable radiation exposure. To streamline the complexity and inherent variability of these interventions, various systems, including table-, floor-, gantry-, and patient-mounted (semi-) automatic robotic aiming devices, have been developed to decrease human error and interoperator and intraoperator outcome variability. Their implementation in clinical practice holds promise for enhancing lesion targeting, increasing accuracy and technical success rates, reducing procedure duration and radiation exposure, enhancing standardization of the field, and ultimately improving patient outcomes. This narrative review collates evidence regarding robotic tools and their implementation in interventional oncology, focusing on clinical efficacy and safety for nonhepatic malignancies.

Quantitative differences in volumetric calculations for radiation dosimetry in segmental Y90 treatment planning using hybrid angiography-CT compared with anatomic segmentation

OBJECTIVE

To compare treatment volumes reconstructed from hybrid Angio-CT catheter-directed infusion imaging and Couinaud anatomic model as well as the implied differences in Y-90 radiation dosimetry.

METHODS

Patients who underwent transarterial radioembolization (TARE) using Y-90 glass microspheres with pretreatment CT or MRI imaging as well as intraprocedural angiography-CT (Angio-CT) were analysed. Treatment volumes were delineated using both tumoural angiosomes (derived from Angio-CT) and Couinaud anatomic landmarks. Segmental and lobar treatment volumes were calculated via semi-automated contouring software. Volume and dose differences were compared by the two-tailed Student t test or Wilcoxon signed-rank test. Factors affecting volume and dose differences were assessed via simple and/or multiple variable linear regression analysis.

RESULTS

From September 2018 to March 2021, 44 patients underwent 45 lobar treatments and 38 patients received 56 segmental treatments. All target liver lobes and all tumours were completely included within the field-of-view by Angio-CT. Tumour sizes ranged between 1.1 and 19.5 cm in diameter. Segmental volumes and treatment doses were significantly different between the Couinaud and Angio-CT volumetry methods (316 vs 404 mL, P < .0001 and 253 vs 212 Gy, P < .01, respectively). Watershed tumours were significantly correlated with underestimated volumes by the Couinaud anatomic model (P < .001). There was a significant linear relationship between tumour diameter and percent volume difference (R2 = 0.44, P < .0001). The Couinaud model overestimated volumes for large tumours that exhibited central hypovascularity/necrosis and for superselected peripheral tumours.

CONCLUSIONS

Angio-CT may confer advantages over the Couinaud anatomic model and enable more accurate, personalized dosimetry for TARE.

ADVANCES IN KNOWLEDGE

Angio-CT may confer advantages over traditional cross-sectional and cone-beam CT imaging for selective internal radiation therapy planning.

Navigation and Robotics in Interventional Oncology: Current Status and Future Roadmap

Interventional oncology (IO) is the field of Interventional Radiology that provides minimally invasive procedures under imaging guidance for the diagnosis and treatment of malignant tumors. Sophisticated devices can be utilized to increase standardization, accuracy, outcomes, and "repeatability" in performing percutaneous Interventional Oncology techniques. These technologies can reduce variability, reduce human error, and outperform human hand-to-eye coordination and spatial relations, thus potentially normalizing an otherwise broad diversity of IO techniques, impacting simulation, training, navigation, outcomes, and performance, as well as verification of desired minimum ablation margin or other measures of successful procedures. Stereotactic navigation and robotic systems may yield specific advantages, such as the potential to reduce procedure duration and ionizing radiation exposure during the procedure and, at the same time, increase accuracy. Enhanced accuracy, in turn, is linked to improved outcomes in many clinical scenarios. The present review focuses on the current role of percutaneous navigation systems and robotics in diagnostic and therapeutic Interventional Oncology procedures. The currently available alternatives are presented, including their potential impact on clinical practice as reflected in the peer-reviewed medical literature. A review of such data may inform wiser investment of time and resources toward the most impactful IR/IO applications of robotics and navigation to both standardize and address unmet clinical needs.

Evaluation of the Access Cube Patient-Mounted Navigation System for CT-Guided Percutaneous Needle Placement-A Phantom Study

Free-hand computed tomography (CT)-guided interventions are common in interventional radiology. Their accuracy and technical success are highly dependent on the skill and experience of the performing interventionalist. This study evaluates a new, patient-mounted navigation device, which aims to facilitate percutaneous interventions-the Access Cube (AC). Sixty punctures were performed on 2 phantoms (rigid vs nonrigid) comparing the Free-Hand Method (FHM) to the AC on measures of accuracy, time, and the need for intraprocedural scans. Using the AC, punctures were significantly more accurate (3.8 mm ± 1.3 mm vs FHM 6.7 mm ± 4.5 mm, P = .004), significantly faster (263.1 s ± 84.4 s vs FHM 411.2 s ± 141.0 s, P < .001) and needed significantly fewer intraprocedural scans (1.4 ± 0.6 vs FHM 2.8 ± 0.4, P < .001). The AC may enable interventionalists to perform faster and more accurate punctures in a clinical setting.

Image Fusion Technology in Interventional Radiology

Image fusion technology aims to improve patient outcomes for image-guided interventions by leveraging the strengths of multimodality imaging datasets. This most commonly involves the overlay or co-display of advanced cross-sectional imaging permitting freedom of device placement via conventional image guidance such as ultrasound, fluoroscopy, and computed tomography. This can allow the interventionalist to target and treat lesions that would otherwise be difficult or impossible to visualize and access using conventional imaging guidance. Furthermore, the use of image fusion can allow for procedures traditionally performed with cross-sectional imaging to be performed under ultrasound or fluoroscopy, by importing the data from preacquired cross-sectional imaging into the interventional procedure. This manuscript provides an overview of image fusion technologies used for interventional radiology (IR) guidance, with an emphasis on technical considerations.

CT Navigation for Percutaneous Needle Placement: How I Do It

CT navigation (CTN) has recently been developed to combine many of the advantages of conventional CT and CT-fluoroscopic guidance for needle placement. CTN systems display real-time needle position superimposed on a CT dataset. This is accomplished by placing electromagnetic (EM) or optical transmitters/sensors on the patient and needle, combined with fiducials placed within the scan field to superimpose a known needle location onto a CT dataset. Advantages of CTN include real-time needle tracking using a contemporaneous CT dataset with the patient in the treatment position, reduced radiation to the physician, facilitation of procedures outside the gantry plane, fewer helical scans during needle placement, and needle guidance based on diagnostic-quality CT datasets. Limitations include the display of a virtual (vs actual) needle position, which can be inaccurate if the needle bends, the fiducial moves, or patient movement occurs between scans, and limitations in anatomical regions with a high degree of motion such as the lung bases. This review summarizes recently introduced CTN technologies in comparison to historical methods of CT needle guidance. A "How I do it" section follows, which describes how CT navigation has been integrated into the study center for both routine and challenging procedures, and includes step-by-step explanations, technical tips, and pitfalls.

Bone biopsies guided by augmented reality: a pilot study

PURPOSE

To test the technical feasibility of an augmented reality (AR) navigation system to guide bone biopsies.

METHODS

We enrolled patients subjected to percutaneous computed tomography (CT)-guided bone biopsy using a novel AR navigation system. Data from prospectively enrolled patients (AR group) were compared with data obtained retrospectively from previous standard CT-guided bone biopsies (control group). We evaluated the following: procedure duration, number of CT passes, patient's radiation dose (dose-length product), complications, and specimen adequacy. Technical success was defined as the ability to complete the procedure as planned, reaching the target center. Technical efficacy was assessed evaluating specimen adequacy.

RESULTS

Eight patients (4 males) aged 58 ± 24 years (mean ± standard deviation) were enrolled in the AR group and compared with 8 controls (4 males) aged 60 ± 15 years. No complications were observed. Procedure duration, number of CT passes, and radiation dose were 22 ± 5 min, 4 (median) [4, 6 interquartile range] and 1,034 ± 672 mGy*cm for the AR group and 23 ± 5 min, 9 [7.75, 11.25], and 1,954 ± 993 mGy*cm for controls, respectively. No significant differences were observed for procedure duration (p = 0.878). Conversely, number of CT passes and radiation doses were significantly lower for the AR group (p < 0.001 and p = 0.021, respectively). Technical success and technical efficacy were 100% for both groups.

CONCLUSIONS

This AR navigation system is safe, feasible, and effective; it can decrease radiation exposure and number of CT passes during bone biopsies without increasing duration time.

RELEVANCE STATEMENT

This augmented reality (AR) navigation system is a safe and feasible guidance for bone biopsies; it may ensure a decrease in the number of CT passes and patient's radiation dose.

KEY POINTS

• This AR navigation system is a safe guidance for bone biopsies. • It ensures decrease of number of CT passes and patient's radiation exposure. • Procedure duration was similar to that of standard CT-guided biopsy. • Technical success was 100% as in all patients the target was reached. • Technical efficacy was 100% as the specimen was adequate in all patients.

Transarterial Embolization and Percutaneous Ablation of Primary and Metastatic Soft Tissue Tumors

Soft tissue tumors (STTs) include a range of benign and malignant tumors originating from soft tissues. Transarterial and percutaneous therapies are image-guided and minimally invasive approaches for managing primary and metastatic STTs. The objective of this review is to discuss transarterial and percutaneous therapies by examining the current literature, including indications, patient selection, safety, and effectiveness. Transarterial therapies (e.g., transarterial bland embolization and transarterial chemoembolization) involve the delivery of either embolic or chemotherapeutic particles using a catheter into arteries feeding the tumor, resulting in localized tumor destruction. Percutaneous therapies (e.g., radiofrequency ablation, cryoablation, irreversible electroporation, laser ablation, and magnetic resonance-guided high-intensity focused ultrasound) involve the delivery of either hot or cold temperatures, electrical current, laser, or ultrasound to specifically target tumor cells. Both therapies have been shown to be safe and effective for reducing morbidity and local control of STTs, specifically in patients who are surgically inoperable or who are unresponsive to conventional therapies. Accurate diagnosis, staging, and histological subtype identification are crucial for treatment selection. A multidisciplinary approach, a thorough understanding of tissue anatomy and surrounding structures, as well as individualized strategies based on assessment are essential for optimal patient care.

Improving puncture accuracy in percutaneous CT-guided needle insertion with wireless inertial measurement unit: a phantom study

OBJECTIVES

A novel method applying inertial measurement units (IMUs) was developed to assist CT-guided puncture, which enables real-time displays of planned and actual needle trajectories. The method was compared with freehand and laser protractor-assisted methods.

METHODS

The phantom study was performed by three operators with 8, 2, and 0 years of experience in CT-guided procedure conducted five consecutive needle placements for three target groups using three methods (freehand, laser protractor-assisted, or IMU-assisted method). The endpoints included mediolateral angle error and caudocranial angle error of the first pass, the procedure time, the total number of needle passes, and the radiation dose.

RESULTS

There was a significant difference in the number of needle passes (IMU 1.2 ± 0.42, laser protractor 2.9 ± 1.6, freehand 3.6 ± 2.0 time, p < 0.001), the procedure time (IMU 3.0 ± 1.2, laser protractor 6.4 ± 2.9, freehand 6.2 ± 3.1 min, p < 0.001), the mediolateral angle error of the first pass (IMU 1.4 ± 1.2, laser protractor 1.6 ± 1.3, freehand 3.7 ± 2.5 degree, p < 0.001), the caudocranial angle error of the first pass (IMU 1.2 ± 1.2, laser protractor 5.3 ± 4.7, freehand 3.9 ± 3.1 degree, p < 0.001), and the radiation dose (IMU 250.5 ± 74.1, laser protractor 484.6 ± 260.2, freehand 561.4 ± 339.8 mGy-cm, p < 0.001) among three CT-guided needle insertion methods.

CONCLUSION

The wireless IMU improves the angle accuracy and speed of CT-guided needle punctures as compared with laser protractor guidance and freehand techniques.

KEY POINTS

• The IMU-assisted method showed a significant decrease in the number of needle passes (IMU 1.2 ± 0.42, laser protractor 2.9 ± 1.6, freehand 3.6 ± 2.0 time, p < 0.001). • The IMU-assisted method showed a significant decrease in the procedure time (IMU 3.0 ± 1.2, laser protractor 6.4 ± 2.9, freehand 6.2 ± 3.1 min, p < 0.001). • The IMU-assisted method showed a significant decrease in the mediolateral angle error of the first pass and the caudocranial angle error of the first pass.

Procedural Software Toolkit in the Armamentarium of Interventional Therapies: A Review of Additive Usefulness and Current Evidence

Interventional radiology is a fast-paced specialty that uses many advanced and emerging technological solutions. Several procedural hardware and software products are available commercially. Image-guided procedural software helps save time and effort in interventionist practice and adds precision to the intraoperative decisions made by the end user. Interventional radiologists, including interventional oncologists, have access to a wide range of commercially available procedural software that can be integrated into their workflow. However, the resources and real-world evidence related to such software are limited. Thus, we performed a detailed review of the current resources available, such as software-related publications, vendors' multimedia materials (e.g., user guides), and each software's functions and features, to compile a resource for interventional therapies. We also reviewed previous studies that have verified the use of such software in angiographic suites. Procedural software products will continue to increase in number and usage; these will likely be advanced further with deep learning, artificial intelligence, and new add-ins. Therefore, classifying procedural product software can improve our understanding of these entities. This review significantly contributes to the existing literature because it highlights the lack of studies on procedural product software.

Case report: Experience with the Cube Navigation System in complex access routes during CT-guided lumbosacral infiltration therapy

Purpose

Computed tomography (CT)-guided infiltrations are a mainstay in the treatment of lower back pain. Needle placement is usually performed using the free-hand method, where the translation from the planned needle angle to the actual needle insertion angle is estimated. However, the free-hand method is especially challenging in cases where a double-oblique access route (out-of-plane) rather than an in-plane route is necessary. In this case series, we report our experience with the patient-mounted Cube Navigation System to guide needle placement for complex access routes in lumbar pain therapy.

Research design and methods

We retrospectively analyzed the cases of five patients in whom a double-oblique access route was necessary for CT-guided lumbar infiltration pain treatment. Each of those procedures was done using the Cube Navigation System to provide navigational guidance. The mean patient age was 69 ± 13 years (range 58-82 years; all females). Technical success, procedure time, and number of control scans were determined retrospectively.

Results

Technical success (i.e., positioning and accuracy) was obtained in all cases. Mean procedure time was 15 ± 7 min (10-22 min); on average, 2 ± 1 CT control scans were performed. There were no complications or material failures reported in the present study.

Conclusion

Double-oblique punctures with the Cube Navigation System in this initial case series of complex access routes at the lumbar spine were accurate and the procedure was time efficient. In the authors' view, the Cube Navigation System has the potential to improve needle guidance for complex access routes, especially considering the ease of use of the device.

Looking Into the Future: The Current and Future State of IR in Canada

This review explores the priorities and future opportunities of interventional radiology in Canada.

Robotics in Interventional Radiology: Review of Current and Future Applications

This review is a brief overview of the current status and the potential role of robotics in interventional radiology. Literature published in the last decades, with an emphasis on the last 5 years, was reviewed and the technical developments in robotics and navigational systems using CT-, MR- and US-image guidance were analyzed. Potential benefits and disadvantages of their current and future use were evaluated. The role of fusion imaging modalities and artificial intelligence was analyzed in both percutaneous and endovascular procedures. A few hundred articles describing results of single or several systems were included in our analysis.

Image Fusion Involving Real-Time Transabdominal or Endoscopic Ultrasound for Gastrointestinal Malignancies: Review of Current and Future Applications

Image fusion of CT, MRI, and PET with endoscopic ultrasound and transabdominal ultrasound can be promising for GI malignancies as it has the potential to allow for a more precise lesion characterization with higher accuracy in tumor detection, staging, and interventional/image guidance. We conducted a literature review to identify the current possibilities of real-time image fusion involving US with a focus on clinical applications in the management of GI malignancies. Liver applications have been the most extensively investigated, either in experimental or commercially available systems. Real-time US fusion imaging of the liver is gaining more acceptance as it enables further diagnosis and interventional therapy of focal liver lesions that are difficult to visualize using conventional B-mode ultrasound. Clinical studies on EUS guided image fusion, to date, are limited. EUS-CT image fusion allowed for easier navigation and profiling of the target tumor and/or surrounding anatomical structure. Image fusion techniques encompassing multiple imaging modalities appear to be feasible and have been observed to increase visualization accuracy during interventional and diagnostic applications.

Navigation Guidance for Percutaneous Splanchnic Nerve Radiofrequency Neurolysis: Preliminary Results

Background and Objectives: To describe preliminary results upon the application of the “Cube Navigation System” (CNS) for computed tomography (CT)-guided splanchnic nerve radiofrequency neurolysis. Materials and Methods: CT-guided splanchnic nerve neurolysis was performed in five patients; in all cases, neurolysis was performed under CT guidance using the CNS. The mean patient age was 71.6 years (range 54–81 years; male/female: 5/0). Technical success, parameters of the neurolysis session and complications were evaluated. Technical success was defined as a needle position on the defined target. Session parameters included procedure time and number of scans. The CIRSE reporting system was used for complications’ classification and grading. Results: Technical success was obtained in all cases; in 1/5 patients, a slight correction in needle orientation was necessary. Mean procedure time was 12.4 min (range 8–19 min); an average of four CT scans was recorded in the five neurolysis sessions. There were no complications or material failures reported in the present study. Conclusions: Preliminary results of the present study show that computed tomography (CT)-guided splanchnic nerve radiofrequency neurolysis using the CNS is an accurate and time-efficient percutaneous procedure. More prospective and comparative studies with larger patient samples are necessary for verification of this system as well as for drawing broader conclusions.

Ultrasound-guided biopsy of challenging abdominopelvic targets

Percutaneous ultrasound-guided biopsies have become the standard of practice for tissue diagnosis in the abdomen and pelvis for many sites including liver, kidney, abdominal wall, and peripheral nodal stations. Additional targets may appear difficult or impossible to safely biopsy by ultrasound due to interposed bowel loops/vasculature, deep positioning, association with the bowel, or concern for poor visibility; however, by optimizing technique, it is often possible to safely and efficiently use real-time ultrasound guidance for sampling targets that normally would be considered only appropriate for CT guided or surgical/endoscopic biopsy.

Efficacy of Shadow-Based Needle Positioning System in Performing CT Image-Guided Percutaneous Biopsy of Lung Lesions: Our Initial Experience

Context  Computerized tomography (CT) is widely used for various interventions and there is a need for an effective navigation tool, for best outcomes.

Aim  The study was performed to evaluate the efficacy of light- and shadow-based needle positioning assistance device, an innovative navigation tool over the conventional freehand technique, in performing CT image-guided percutaneous interventions.

Settings and Design  This randomized control trial was performed among patients undergoing CT-guided percutaneous intervention for lung pathologies.

Methodology  A total of 60 participants were randomized into an intervention group and a control group. The accuracy of needle insertion and other efficacy parameters were assessed for both groups. Post needle placement, CT images were used to evaluate the study endpoints.

Statistical Analysis  Statistical analysis was performed using SPSS ver. 20 software.

Results  The mean needle positioning accuracy was 2.1 mm in the experimental group compared with 7.2 mm in the control group freehand procedures. The average time to position the needle at the desired target location was 2.5 minutes in the assisted procedure as compared with 5.3 minutes in the freehand procedure ( p  < 0.05). The total number of check scans required to position the needle was 1.3 for assisted procedures and 1.9 for freehand procedures.

Conclusion  The use of shadow-based assistance device for CT-guided interventions is proven to be efficient and safer with high needle positioning accuracy.

Robotic assistance for percutaneous needle insertion in the kidney: preclinical proof on a swine animal model

Background

We evaluated the accuracy, safety, and feasibility of a computed tomography (CT)-guided robotic assistance system for percutaneous needle placement in the kidney.

Methods

Fiducials surgically implanted into the kidneys of two pigs were used as targets for subsequent robotically-assisted needle insertion. Robotically-assisted needle insertions and CT acquisitions were coordinated using respiratory monitoring. An initial scan volume data set was used for needle insertion planning defining skin entry and target point. Then, needle insertion was performed according to robot positioning. The accuracy of needle placement was evaluated upon the distance between the needle tip and the predefined target on a post needle insertion scan. A delayed contrast-enhanced CT scan was acquired to assess safety.

Results

Eight needle trajectories were performed with a median procedural time measured from turning on the robotic system to post needle insertion CT scan of 21 min (interquartile range 15.5−26.5 min). Blind review of needle placement accuracy was 2.3 ± 1.2 mm (mean ± standard deviation) in lateral deviation, 0.7 ± 1.7 mm in depth deviation, and 2.8 ± 1.3 mm in three-dimensional Euclidian deviation. All needles were inserted on the first attempt, which determined 100% feasibility, without needle readjustment. The angulation and length of the trajectory did not impact on the needle placement accuracy. Two minor procedure-related complications were encountered: 2 subcapsular haematomas (13 × 6 mm and 35 × 6 mm) in the same animal.

Conclusions

Robotically-assisted needle insertion was shown feasible, safe and accurate in a swine kidney model. Further larger studies are needed.

Thermal Ablation of Liver Tumors Guided by Augmented Reality: An Initial Clinical Experience

Background: Over the last two decades, augmented reality (AR) has been used as a visualization tool in many medical fields in order to increase precision, limit the radiation dose, and decrease the variability among operators. Here, we report the first in vivo study of a novel AR system for the guidance of percutaneous interventional oncology procedures. Methods: Eight patients with 15 liver tumors (0.7−3.0 cm, mean 1.56 + 0.55) underwent percutaneous thermal ablations using AR guidance (i.e., the Endosight system). Prior to the intervention, the patients were evaluated with US and CT. The targeted nodules were segmented and three-dimensionally (3D) reconstructed from CT images, and the probe trajectory to the target was defined. The procedures were guided solely by AR, with the position of the probe tip was subsequently confirmed by conventional imaging. The primary endpoints were the targeting accuracy, the system setup time, and targeting time (i.e., from the target visualization to the correct needle insertion). The technical success was also evaluated and validated by co-registration software. Upon completion, the operators were assessed for cybersickness or other symptoms related to the use of AR. Results: Rapid system setup and procedural targeting times were noted (mean 14.3 min; 12.0−17.2 min; 4.3 min, 3.2−5.7 min, mean, respectively). The high targeting accuracy (3.4 mm; 2.6−4.2 mm, mean) was accompanied by technical success in all 15 lesions (i.e., the complete ablation of the tumor and 13/15 lesions with a >90% 5-mm periablational margin). No intra/periprocedural complications or operator cybersickness were observed. Conclusions: AR guidance is highly accurate, and allows for the confident performance of percutaneous thermal ablations.

Augmented reality, virtual reality and new age technologies demand escalates amid COVID-19

The coronavirus disease (COVID-19) pandemic is having a significant impact on healthcare, education, economics and general human well-being. Augmented reality (AR) and virtual reality (VR) have experienced a tremendous increase in demand as they play an important role in avoiding travel, social contacts and providing adequate audiovisual communication and virtual presence. AR/VR is helping in the fight of this pandemic through their deployment in various crucial areas such as telemedicine, online education and training, marketing and healthcare monitoring. AR/VR provides resolutions for the distribution of antibiotics to control the spread of the COVID-19 virus. This paper discusses the demand for AR and VR as well as other notable new technologies explored recently to support the fight against COVID-19. The same technologies are in high demand, in the form of 2D-3D visualization and tracking software, flow and dynamic wearable headsets, potentially responsible for displaying the geographic location mostly affected with COVID-19.

Computed Tomography-Navigation™ Electromagnetic System Compared to Conventional Computed Tomography Guidance for Percutaneous Lung Biopsy: A Single-Center Experience

The aim of our study was to assess the efficacy of a computed tomography (CT)-Navigation™ electromagnetic system compared to conventional CT methods for percutaneous lung biopsies (PLB). In this single-center retrospective study, data of a CT-Navigation™ system guided PLB (NAV-group) and conventional CT PLB (CT-group) performed between January 2017 and February 2020 were reviewed. The primary endpoint was the diagnostic success. Secondary endpoints were technical success, total procedure duration, number of CT acquisitions and the dose length product (DLP) during step ∆1 (from planning to initial needle placement), step ∆2 (progression to target), and the entire intervention (from planning to final control) and complications. Additional parameters were recorded, such as the lesion’s size and trajectory angles. Sixty patients were included in each group. The lesions median size and median values of the two trajectory angles were significantly lower (20 vs. 29.5 mm, p = 0.006) and higher in the NAV-group (15.5° and 10° vs. 6° and 1°; p < 0.01), respectively. Technical and diagnostic success rates were similar in both groups, respectively 95% and 93.3% in the NAV-group, and 93.3% and 91.6% in the CT-group. There was no significant difference in total procedure duration (p = 0.487) and total number of CT acquisitions (p = 0.066), but the DLP was significantly lower in the NAV-group (p < 0.01). There was no significant difference in complication rate. For PLB, CT-Navigation™ system is efficient and safe as compared to the conventional CT method.

Lung Thermal Ablation: Comparison between an Augmented Reality Computed Tomography (CT) 3D Navigation System (SIRIO) and Standard CT-Guided Technique

Simple Summary

Lung cancer is the leading cause of cancer mortality worldwide. In recent years, numerous technologies have been used to perform image-guided percutaneous thermal ablation, mainly including radiofrequency ablation, microwave ablation, and cryoablation. These image-guided ablation techniques have emerged as a safe, cost-effective, minimally invasive treatment alternative for patients who do not require surgery. Procedural planning, monitoring, and lesion targeting are generally performed with the help of computed tomography; navigation systems are emerging as valid tool to reduce procedural time and radiation dose administration. In the present paper, we investigate the efficacy of an optical-based navigation system (SIRIO) to perform lung thermal ablation. SIRIO proved to be a reliable and effective tool when performing CT-guided LTA, displaying a significant decrease in the number of required CT scans, procedure time, and radiation doses administered to patients.

Abstract

(1) Background: The aim of this retrospective study is to assess safety and efficacy of lung radiofrequency (RFA) and microwave ablation (MWA) using an augmented reality computed tomography (CT) navigation system (SIRIO) and to compare it with the standard CT-guided technique. (2) Methods: Lung RFA and MWA were performed with an augmented reality CT 3D navigation system (SIRIO) in 52 patients. A comparison was then performed with a group of 49 patients undergoing the standard CT-guided technique. All the procedures were divided into four groups based on the lesion diameter (>2 cm or ≤2 cm), and procedural time, the number of CT scans, radiation dose administered, and complications rate were evaluated. Technical success was defined as the presence of a “ground glass” area completely covering the target lesion at the immediate post-procedural CT. (3) Results: Full technical success was achieved in all treated malignant lesions for all the considered groups. SIRIO-guided lung thermo-ablations (LTA) displayed a significant decrease in the number of CT scans, procedure time, and patients’ radiation exposure (p < 0.001). This also resulted in a dosage reduction in hypnotics and opioids administrated for sedation during LTA. No significant differences were observed between the SIRIO and non-SIRIO group in terms of complications incidence. (4) Conclusions: SIRIO is an efficient tool to perform CT-guided LTA, displaying a significant reduction (p < 0.001) in the number of required CT scans, procedure time, and patients’ radiation exposure.

Impact of an Augmented Reality Navigation System (SIRIO) on Bone Percutaneous Procedures: A Comparative Analysis with Standard CT-Guided Technique

(1) Background: The purpose of this study is to evaluate the impact of an augmented reality navigation system (SIRIO) for percutaneous biopsies and ablative treatments on bone lesions, compared to a standard CT-guided technique. (2) Methods: Bioptic and ablative procedures on bone lesions were retrospectively analyzed. All procedures were divided into SIRIO and Non-SIRIO groups and in <2 cm and >2 cm groups. Number of CT-scans, procedural time and patient’s radiation dose were reported for each group. Diagnostic accuracy was obtained for bioptic procedures. (3) Results: One-hundred-ninety-three procedures were evaluated: 142 biopsies and 51 ablations. Seventy-four biopsy procedures were performed using SIRIO and 68 under standard CT-guidance; 27 ablative procedures were performed using SIRIO and 24 under standard CT-guidance. A statistically significant reduction in the number of CT-scans, procedural time and radiation dose was observed for percutaneous procedures performed using SIRIO, in both <2 cm and >2 cm groups. The greatest difference in all variables examined was found for procedures performed on lesions <2 cm. Higher diagnostic accuracy was found for all SIRIO-assisted biopsies. No major or minor complications occurred in any procedures. (4) Conclusions: The use of SIRIO significantly reduces the number of CT-scans, procedural time and patient’s radiation dose in CT-guided percutaneous bone procedures, particularly for lesions <2 cm. An improvement in diagnostic accuracy was also achieved in SIRIO-assisted biopsies.

Efficiently compressing 3D medical images for teleinterventions via CNNs and anisotropic diffusion

PURPOSE

Efficient compression of images while preserving image quality has the potential to be a major enabler of effective remote clinical diagnosis and treatment, since poor Internet connection conditions are often the primary constraint in such services. This paper presents a framework for organ-specific image compression for teleinterventions based on a deep learning approach and anisotropic diffusion filter.

METHODS

The proposed method, deep learning and anisotropic diffusion (DLAD), uses a convolutional neural network architecture to extract a probability map for the organ of interest; this probability map guides an anisotropic diffusion filter that smooths the image except at the location of the organ of interest. Subsequently, a compression method, such as BZ2 and HEVC-visually lossless, is applied to compress the image. We demonstrate the proposed method on three-dimensional (3D) CT images acquired for radio frequency ablation (RFA) of liver lesions. We quantitatively evaluate the proposed method on 151 CT images using peak-signal-to-noise ratio ( PSNR ), structural similarity ( SSIM ), and compression ratio ( CR ) metrics. Finally, we compare the assessments of two radiologists on the liver lesion detection and the liver lesion center annotation using 33 sets of the original images and the compressed images.

RESULTS

The results show that the method can significantly improve CR of most well-known compression methods. DLAD combined with HEVC-visually lossless achieves the highest average CR of 6.45, which is 36% higher than that of the original HEVC and outperforms other state-of-the-art lossless medical image compression methods. The means of PSNR and SSIM are 70 dB and 0.95, respectively. In addition, the compression effects do not statistically significantly affect the assessments of the radiologists on the liver lesion detection and the lesion center annotation.

CONCLUSIONS

We thus conclude that the method has a high potential to be applied in teleintervention applications.

Higher patient doses through X-ray imaging procedures

Medical imaging using X-rays has been one of the most popular imaging modalities ever since the discovery of X-rays 125 years ago. With unquestionable benefits, concerns about radiation risks have frequently been raised. Computed tomography (CT) and fluoroscopic guided interventional procedures have the potential to impart higher radiation exposure to patients than radiographic examinations. Despite technological advances, there have been instances of increased doses per procedure mainly because of better diagnostic information in images. However, cumulative dose from multiple procedures is creating new concerns as effective doses >100 mSv are not uncommon. There is a need for action at all levels. Manufacturers must produce equipment that can provide a quality diagnostic image at substantially lesser dose and better implementation of optimization strategies by users. There is an urgent need for the industry to develop CT scanners with sub-mSv radiation dose, a goal that has been lingering. It appears that a new monochromatic X-ray source will lead to replacement of X-ray tubes all over the world in coming years and will lead to a drastic reduction in radiation doses. This innovation will impact all X-ray imaging and will help dose reduction. For interventional procedures, the likely employment of robotic systems in practice may drastically reduce radiation exposures to operators- but patient exposure will still remain an issue. Training needs always need to be emphasized and practiced.

Eligibility and Radiologic Assessment for Adjuvant Clinical Trials in Kidney Cancer

Purpose

To harmonize the eligibility criteria and radiologic disease assessment definitions in clinical trials of adjuvant therapy for renal cell carcinoma (RCC).

Method

On November 28, 2017, US-based experts in RCC clinical trials, including medical oncologists, urologic oncologists, regulators, biostatisticians, radiologists, and patient advocates, convened at a public workshop to discuss eligibility for trial entry and radiologic criteria for assessing disease recurrence in adjuvant trials in RCC. Multiple virtual meetings were conducted to address the issues identified at the workshop.

Results

The key workshop conclusions for adjuvant RCC therapy clinical trials were as follows. First, patients with non-clear cell RCC could be routinely included, preferably in an independent cohort. Second, patients with T3-4, N+M0, and microscopic R1 RCC tumors may gain the greatest advantages from adjuvant therapy. Third, trials of agents not excreted by the kidney should not exclude patients with severe renal insufficiency. Fourth, therapy can begin 4 to 16 weeks after the surgical procedure. Fifth, patients undergoing radical or partial nephrectomy should be equally eligible. Sixth, patients with microscopically positive soft tissue or vascular margins without gross residual or radiologic disease may be included in trials. Seventh, all suspicious regional lymph nodes should be fully resected. Eighth, computed tomography should be performed within 4 weeks before trial enrollment; for patients with renal insufficiency who cannot undergo computed tomography with contrast, noncontrast chest computed tomography and magnetic resonance imaging of the abdomen and pelvis with gadolinium should be performed. Ninth, when feasible, biopsy should be undertaken to identify any malignant disease. Tenth, when biopsy is not feasible, a uniform approach should be used to evaluate indeterminate radiologic findings to identify what constitutes no evidence of disease at trial entry and what constitutes radiologic evidence of disease. Eleventh, a uniform approach for establishing the date of recurrence should be included in any trial design. Twelfth, patient perspectives on the use of placebo, conditions for unblinding, and research biopsies should be considered carefully during the conduct of an adjuvant trial.

Conclusions and Relevance

The discussions suggested that a uniform approach to eligibility criteria and radiologic disease assessment will lead to more consistently interpretable trial results in the adjuvant RCC therapy setting.

Electromagnetic navigation to assist with computed tomography-guided thermal ablation of liver tumors

Purpose: To evaluate the advantages and primary technical efficacy of an electromagnetic (EM) navigation system for computed tomography (CT)-guided thermal ablation of liver tumors.Material and methods: From August 2016 to January 2018, 40 patients scheduled for CT- guided thermal ablation were prospectively enrolled and divided into two groups. Twenty patients underwent CT-guided thermal ablation with an EM navigation system (navigation group), while the other 20 patients underwent conventional CT-guided thermal ablation (control group). Data on skin punctures, instrument adjustments, puncture time to target, CT scans, CT fluoroscopy time and dose-length-product (DLP) were compared between the two groups. Any postoperative complications were recorded and the primary technical efficacy was evaluated four to six weeks after the procedure.Results: All 20 patients in the navigation group successfully underwent EM navigation. Compared to the control group, there were fewer instrument adjustments (mean 2.40 vs. 4.95; p = .003), fewer CT scans (mean 7.10 vs. 10.30; p = .006), less CT fluoroscopy time (mean 40.47 vs. 59.98 s, p = .046), and less DLP (mean 807.39 vs. 1578.67 mGy × cm; p = .001). Although not statistically significant, EM navigation resulted in fewer skin punctures (mean 1.20 vs. 1.25; p = .803) and slightly longer puncture time to target (mean 16.50 vs. 15.20 min; p = .725). No patients experienced major complications and the primary efficacy rate was 90% and 84.21% in the navigation and control groups, respectively (p = .661).Conclusions: EM navigation system optimizes the thermal ablation process and reduces radiation exposure in patients. However, further studies are warranted to determine whether an EM navigation system can improve procedure time, complication rates, and primary technical efficiacy of thermal ablation.

Efficacy of interventional therapy and effect on inflammatory factors in patients with gastric cancer after chemotherapy

The clinical effect of interventional therapy on gastric cancer after chemotherapy and effect on inflammatory factors in peripheral blood serum of patients were investigated. A retrospective analysis of 429 patients with gastric cancer treated in Xiangyang No. 1 People's Hospital, Hubei University of Medicine from July 2008 to December 2014 was performed. Among them, 220 patients received interventional therapy after chemotherapy as the experimental group, and 209 patients received conventional therapy as the control group. Serum carcinoembryonic antigen (CEA), tumor markers CA19-9, interleukin-6 (IL-6), interleukin-8 (IL-8) and interleukin-10 (IL-10) levels were measured before and after chemotherapy. The correlation between the concentration of CEA and CA19-9 before and after treatment and the levels of IL-6, IL-8 and IL-10 were analyzed in the experimental group, and all patients were followed up for 3 years. There were no significant differences in CEA, CA19-9, IL-6, IL-8 and IL-10 between the two groups before chemotherapy (P>0.05). After treatment, the concentrations of CEA, CA19-9, IL-6, IL-8 and IL-10 in the experimental group were significantly lower than those in the control group before and after treatment (P<0.05). The clinical efficacy and adverse reactions of the experimental group were significantly better than those in the control group (P<0.05). Pearson's correlation analysis showed that the concentrations of CEA and CA19-9 in the serum of the experimental group before and after treatment were positively correlated with the levels of IL-6, IL-8 and IL-10 (P<0.05). The 3-year overall survival rate of the study group was significantly higher than that of the control group (P<0.05). Cox regression analysis showed that age, Borrmann classification, degree of differentiation, and history of Helicobacter pylori infection were independent prognostic factors for patients with gastric cancer. Compared with traditional treatment, interventional therapy can greatly improve the recovery of gastric cancer patients after chemotherapy, reduce the occurrence of complications and inflammation, and improve the survival rate of patients.

Radiation Exposure During Transarterial Chemoembolization: Angio-CT Versus Cone-Beam CT

INTRODUCTION

Cone-beam computed tomography (CBCT) has been developed to improve reliability of many interventional radiology (IR) procedures performed with Angio system, such as transarterial chemoembolization (TACE). Angio-CT has emerged as a new imaging technology that combines a CT scanner with an Angio system in the same IR suite. The purpose of our study was to compare Angio system with CBCT capability and Angio-CT in terms of patient radiation exposure during TACE procedures.

MATERIALS AND METHODS

Consecutive TACE procedures performed between January 2016 and September 2017 with the two imaging modalities (Artis Zeego defining the CBCT group and Infinix-i 4D-CT defining the Angio-CT group) were reviewed. TACE and patient's characteristics and patient radiation exposure parameters were collected. Dose-area products (DAP) and dose-length products (DLP) were converted into effective doses (ED) using conversion factors. Accuracy of tumor targeting and response was retrospectively assessed.

RESULTS

A total of 114 TACE procedures in 96 patients were included with 57 procedures in each group. The total ED in the Angio-CT group was 2.5 times lower than that in the CBCT group (median 15.4 vs. 39.2 mSv, p < 0.001). Both 2D ED and 3D ED were lower in the Angio-CT group than in the CBCT group (5.1 vs. 20 mSv, p < 0.001, and 7.4 vs. 17.9 mSv, p < 0.001, respectively). There was no significant difference neither in terms of classes of tumor targeting (p = 0.509) nor in terms of classes of tumor response (p = 0.070) between both groups.

CONCLUSION

Angio-CT provides significant decrease in patient effective dose during TACE procedures compared to Angio system with CBCT.

Role of cone-beam CT augmented by navigational software in the single-session management of gastrointestinal hemorrhage and infected deep postoperative fluid collections

Utilization of cone-beam CT with navigational software augmentation allows performance of both vascular and nonvascular interventions in a traditional fluoroscopy suite without need for additional hardware. The improvements in target identification and procedure time associated with use of these technologies suggest that they may be particularly beneficial in emergent settings where decreased procedure time correlates with improved outcomes. We illustrate these potential advantages through the successful single-session management of a clinically unstable patient with both gastrointestinal (GI) hemorrhage and infected postoperative fluid collections.

Theranostics in Interventional Oncology: Versatile Carriers for Diagnosis and Targeted Image-Guided Minimally Invasive Procedures

We are continuously progressing in our understanding of cancer and other diseases and learned how they can be heterogeneous among patients. Therefore, there is an increasing need for accurate characterization of diseases at the molecular level. In parallel, medical imaging and image-guided therapies are rapidly developing fields with new interventions and procedures entering constantly in clinical practice. Theranostics, a relatively new branch of medicine, refers to procedures combining diagnosis and treatment, often based on patient and disease-specific features or molecular markers. Interventional oncology which is at the convergence point of diagnosis and treatment employs several methods related to theranostics to provide minimally invasive procedures tailored to the patient characteristics. The aim is to develop more personalized procedures able to identify cancer cells, selectively reach and treat them, and to assess drug delivery and uptake in real-time in order to perform adjustments in the treatment being delivered based on obtained procedure feedback and ultimately predict response. Here, we review several interventional oncology procedures referring to the field of theranostics, and describe innovative methods that are under development as well as future directions in the field.

Augmented reality for interventional oncology: proof-of-concept study of a novel high-end guidance system platform

Background

To assess the feasibility of a novel system that uses augmented reality to guide interventional oncology procedures.

Methods

This study was conducted in accordance to the guidelines of the local institutional review boards. Evaluation of an augmented reality system based upon a tablet, a needle handle and a set of markers was performed in three experimental models. Initially, a male anthropomorphic trunk phantom equipped with five polyvinyl chloride bars (two of 16 cm in length and 3 cm in diameter and four of 45, 30 or 20 cm in length and 2 cm in diameter) was used to study the accuracy of the system without respiratory motion or tissue compression. Next, small metallic targets were placed in a porcine model to evaluate how respiration affects the system accuracy. Finally, the performance of the system on a more complete model, a cadaver with liver metastasis, was tested.

Results

In all experimental settings, extremely high targeting accuracy of < 5 mm in all cases was achieved: 2.0 ± 1.5 mm (mean ± standard deviation) for the anthropomorphic model, 3.9 ± 0.4 mm for the porcine model, and 2.5 mm and 2.8 mm for the two metastases in the cadaver model.

Conclusions

Augmented reality can assist with needle guidance with great target accuracy for interventional procedures by simultaneously visualising three-dimensional reconstructed anatomical structures, tumour targets and interventional devices on a patient’s body, enabling performance of procedures in a simple and confident way.

Post-therapy lesions in patients with non-Hodgkin's lymphoma characterized by 18F-FDG PET/CT-guided biopsy using automated robotic biopsy arm

PURPOSE

The aim of this study was to analyse the positive predictive value (PPV) of post-therapy fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT performed for response or recurrence evaluation in patients with non-Hodgkin's lymphoma (NHL) and to appraise the diagnostic utility of F-FDG PET/CT-guided biopsy in this setting.

PATIENTS AND METHODS

A total of 17 patients with NHL showing F-FDG avid lesions in F-FDG PET/CT performed for response or recurrence assessment underwent F-FDG PET/CT-guided biopsy using automated robotic biopsy arm needle navigation technique. The objectives were analysed in reference to histopathology.

RESULTS

In all, 15 of the 17 (88.5%) procedures yielded adequate representative tissue samples. Nine out of 15 lesions were positive for residual disease and the remaining revealed benign findings on histopathology. One patient with inconclusive biopsy underwent surgical resection and histopathology confirmed the presence of residual disease. PPV of theF-FDG PET/CT was observed to be 62.5% (10/16).

CONCLUSION

F-FDG PET/CT for response evaluation in NHL possesses a low PPV and hence warrants histopathological correlation when F-FDG PET/CT findings influence management decision. Diagnostic yield of F-FDG PET/CT-guided biopsy is high and has the potential to reduce sampling errors.

A practical guide for planning pelvic bone percutaneous interventions (biopsy, tumour ablation and cementoplasty)

Percutaneous approaches for pelvic bone procedures (bone biopsies, tumour ablation and cementoplasty) are multiple and less well systematised than for the spine or extremities. Among the different imaging techniques that can be used for guidance, computed tomography (CT) scan is the modality of choice because of the complex pelvic anatomy. In specific cases, such as cementoplasty where real-time evaluation is a determinant, a combination of CT and fluoroscopy is highly recommended. The objective of this article is to propose a systematic approach for image-guided pelvic bone procedures, as well as to provide some technical tips. We illustrate the article with multiple examples, and diagrams of the approaches and important structures to avoid to perform these procedures safely.

TEACHING POINTS

• Pelvic bone procedures are safe to perform if anatomical landmarks are recognised. • The safest approach varies depending on the pelvic level. • CT is the modality of choice for guiding pelvic percutaneous procedures. • Fluoroscopy is recommended when real-time monitoring is mandatory. • MRI can also be used for guiding pelvic percutaneous procedures.

Clinical utility of real-time ultrasound-multimodality fusion guidance for percutaneous biopsy of focal liver lesions

OBJECTIVES

To prospectively evaluate the clinical value of real-time ultrasonography (US)-computed tomography (CT)/magnetic resonance imaging (MRI) fusion imaging for percutaneous needle biopsy of focal liver lesions (FLLs), and to compare its biopsy success rate with that of conventional US-guided biopsy in a propensity-score matched group.

METHODS

This study was approved by our Institutional Review Board and informed consent was obtained from all patients enrolled in the prospective study group. Ninety patients referred to the Department of Radiology for percutaneous biopsy of FLLs were enrolled in this study. Tumor visibility, attainment of a safe access route, and technical feasibility were assessed on conventional US first and later on real-time fusion imaging by one of four abdominal radiologists. Thereafter, differences in scores between real-time fusion imaging and conventional US were determined. In addition, overall diagnostic success rates of a real-time fusion imaging-guided biopsy group and a propensity-score matched, conventional US-guided biopsy group, consisting of 100 patients used as historical control, were compared.

RESULTS

With real-time fusion imaging, tumor visibility, attainment of a safe access route, and operator's technical feasibility were significantly improved compared with conventional US (P < .001). In addition, all invisible (n = 13) and not feasible (n = 10) FLLs on conventional US became visible and feasible for percutaneous US-guided biopsy after applying the fusion system. The diagnostic success rate of real-time fusion-guided biopsy was 94.4% (85/90), which was significantly better than that obtained with the conventional US-guided biopsy (94.4% vs. 83%, P < .03), with reduced biopsy procedure times (7.1 ± 3.5 vs. 9.7 ± 2.8, P < .02).

CONCLUSIONS

Real-time US-CT/MR fusion imaging guidance was able to provide clinical value for percutaneous needle biopsy of FLLs by improving the diagnostic success rate of biopsy and by reducing procedure time.

Real-time intraprocedural 18F-FDG PET/CT-guided biopsy using automated robopsy arm (ARA) in the diagnostic evaluation of thoracic lesions with prior inconclusive biopsy results: initial experience from a tertiary health care centre

OBJECTIVE

The aim of this study was to assess the feasibility and appraise the diagnostic utility of real time ¹⁸F-FDG PET/CT-guided biopsy under automated robopsy arm (ARA) guidance for the evaluation of thoracic lesions with prior inconclusive biopsy results.

METHODS

PET/CT-guided biopsy of thoracic lesions was performed in patients who had at least one previous inconclusive biopsy. A total of 25 patients (male:female-18 males, 7 females; age: range, 13-75; mean, 53.7) were included in this study. All these patients underwent percutaneous needle biopsies under real-time PET/CT guidance using ARA (ROBIO-EX, Perfint healthcare Pvt Ltd, Chennai, India) needle navigation technique. Histopathology and clinical follow-up results were reviewed for assessing the accuracy of procedures.

RESULTS

Adequate representative tissue sample could be retrieved in all the patients. No major procedure-related complications were encountered in any patient. Of the 25 procedures, 21 lesions were positive for malignancy and benign findings were observed in the other 4 lesions on histopathology. None of the patients required further biopsy in arriving at a final diagnosis. Overall diagnostic yield of the procedure was 100%.

CONCLUSION

Real time ¹⁸F-FDG PET/CT guidance for percutaneous biopsies of lung and mediastinal lesions is a feasible technique with potential utility in patients with previous inconclusive biopsy results. Advances in knowledge: ¹⁸F-FDG PET/CT guidance reduces the sampling errors by specifically targeting areas of viability and avoiding necrosis/atelectasis. A navigational tool like ARA is thought to help in accurately targeting these areas.