Huge Fibroid in Pregnancy: A Case Presentation.

Uterine fibroid, widely known as leiomyoma, is one of the most common benign tumours of the female reproductive system. It is not uncommon for pregnancies to be complicated by uterine fibroids. Most commonly, the first line of large uterine fibroids management in pregnancy is conservative, with myomectomy counselling after delivery if necessary. In this paper, we present a case of a very high-risk pregnancy, that was managed by delivery via caesarean section at 34 weeks of gestation, which was performed for a patient, with an 18 centimetres (cm) fibroid, first diagnosed during pregnancy. Interventional radiology involvement was critical in this case for minimizing the final blood loss and surgical complications. Bilateral internal iliac artery balloons were used. Maternal and foetal risks, the timing of delivery, and the options for the management of fibroids in pregnancy will be discussed.

Artificial intelligence in interventional radiology: state of the art.

Artificial intelligence (AI) has demonstrated great potential in a wide variety of applications in interventional radiology (IR). Support for decision-making and outcome prediction, new functions and improvements in fluoroscopy, ultrasound, computed tomography, and magnetic resonance imaging, specifically in the field of IR, have all been investigated. Furthermore, AI represents a significant boost for fusion imaging and simulated reality, robotics, touchless software interactions, and virtual biopsy. The procedural nature, heterogeneity, and lack of standardisation slow down the process of adoption of AI in IR. Research in AI is in its early stages as current literature is based on pilot or proof of concept studies. The full range of possibilities is yet to be explored.Relevance statement Exploring AI's transformative potential, this article assesses its current applications and challenges in IR, offering insights into decision support and outcome prediction, imaging enhancements, robotics, and touchless interactions, shaping the future of patient care.Key points• AI adoption in IR is more complex compared to diagnostic radiology.• Current literature about AI in IR is in its early stages.• AI has the potential to revolutionise every aspect of IR.

Angioembolization for splenic injuries: does it help? Retrospective evaluation of grade III-V splenic injuries at two level I trauma centers.

Background: Splenic angioembolization (SAE) has increased in utilization for blunt splenic injuries. We hypothesized lower SAE usage would not correlate with higher rates of additional intervention or mortality when choosing initial non-operative management (NOM) or surgery. Study design: Trauma registries from two level I trauma centers from 2010 to 2020 were used to identify patients aged >18 years with grade III-V blunt splenic injuries. Results were compared with the National Trauma Data Bank (NTDB) for 2018 for level I and II centers. Additional intervention or failure was defined as any subsequent SAE or surgery. Mortality was defined as death during admission. Results: There were 266 vs 5943 patients who met inclusion/exclusion criteria at Stanford/Santa Clara Valley Medical Center (SCVMC) versus the NTDB. Initial intervention differed significantly between cohorts with the use of SAE (6% vs 17%, p=0.000). Failure differed significantly between cohorts (1.5% vs 6.5%, p=0.005). On multivariate analysis, failure in NOM was significantly associated with NTDB cohort status, age 65+ years, more than one comorbidity, mechanism of injury, grade V spleen injury, and Injury Severity Score (ISS) 25+. On multivariate analysis, failure in SAE was significantly associated with Shock Index >0.9 and 10+ units blood in 24 hours. On multivariate analysis, a higher risk of mortality was significantly associated with NTDB cohort status, age 65+ years, no private insurance, more than one comorbidity, mechanism of injury, ISS 25+, 10+ units blood in 24 hours, NOM, more than one hospital complications, anticoagulant use, other Abbreviated Injury Scale ≥3 abdominal injuries. Conclusions: Compared with national data, our cohort had less SAE, lower rates of additional intervention, and had lower risk-adjusted mortality. Shock Index >0.9, grade V splenic injuries, and increased transfusion requirements in the first 24 hours may signal a need for surgical intervention rather than SAE or NOM and may reduce mortality in appropriately selected patients. Level of evidence: Level II/III.

The Successful Resolution of a Large Splenic Abscess With Six Years of Follow-Up and Without Recurrence.

Splenic abscess is an uncommon medical condition that presents many diagnostic difficulties. Although rare, this clinical disease can be potentially life-threatening, with a fatality rate exceeding 70% in immunocompromised patients. Clinical manifestations of splenic abscess include fever, tenderness in the upper left region of the abdomen, and leukocytosis with left shift. Performing abdominal ultrasonography (USG) and CT in patients presenting with clinical manifestations enables a prompt and accurate diagnosis. The treatment for splenic abscess includes medical therapy, imaging-guided drainage, and splenectomy. We discuss the case of a 60-year-old female patient who presented to our emergency department with a large splenic abscess; she was managed with an ultrasound-guided drainage catheter, which led to the successful resolution of the condition. She did not experience any recurrence during six years of follow-up. This case report aims to highlight the role of interventional radiology in managing splenic abscesses.

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

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

iSPAN: Explainable prediction of outcomes post thrombectomy with Machine Learning.

PURPOSE: This study aimed to develop and evaluate a machine learning model and a novel clinical score for predicting outcomes in stroke patients undergoing endovascular thrombectomy. MATERIALS AND METHODS: This retrospective study included all patients aged over 18 years with an anterior circulation stroke treated at a thrombectomy centre from 2010 to 2020 with external validation. The primary outcome was day 90 mRS ≥3. Existing clinical scores (SPAN and PRE) and Machine Learning (ML) models were compared. A novel clinical score (iSPAN) was derived by adding an optimised weighting of the most important ML features to the SPAN. RESULTS: 812 patients were initially included (397 female, average age 73), 63 for external validation. The best performing clinical score and ML model were SPAN and XGB (sensitivity, specificity and accuracy 0.290, 0.967, 0.628 and 0.693, 0.783, 0.738 respectively). A significant difference was found overall and our XGB model was more accurate than SPAN (p < 0.0018). The most important features were Age, mTICI and total number of passes. The addition of 11 points for mTICI of ≤2B and 3 points for ≥3 passes to the SPAN achieved the best accuracy and was used to create the iSPAN. iSPAN was not significantly less accurate than our XGB model (p > 0.5). In the external validation set, iSPAN and SPAN achieved sensitivity, specificity, and accuracy of (0.735, 0.862, 0.79) and (0.471, 0.897, 0.67) respectively. CONCLUSION: iSPAN incorporates machine-derived features to achieve better predictions compared to existing clinical scores. It is not inferior to our XGB model and is externally generalisable.

Review of craniofacial pain syndromes involving the greater occipital nerve: relevant anatomy, clinical findings, and interventional management.

Craniofacial pain syndromes exhibit a high prevalence in the general population, with a subset of patients developing chronic pain that significantly impacts their quality of life and results in substantial disabilities. Anatomical and functional assessments of the greater occipital nerve (GON) have unveiled its implication in numerous craniofacial pain syndromes, notably through the trigeminal-cervical convergence complex. The pathophysiological involvement of the greater occipital nerve in craniofacial pain syndromes, coupled with its accessibility, designates it as the primary target for various interventional procedures in managing craniofacial pain syndromes. This educational review aims to describe multiple craniofacial pain syndromes, elucidate the role of GON in their pathophysiology, detail the relevant anatomy of the greater occipital nerve (including specific intervention sites), highlight the role of imaging in diagnosing craniofacial pain syndromes, and discuss various interventional procedures such as nerve infiltration, ablation, neuromodulation techniques, and surgeries. Imaging is essential in managing these patients, whether for diagnostic or therapeutic purposes. The utilization of image guidance has demonstrated an enhancement in reproducibility, as well as technical and clinical outcomes of interventional procedures. Studies have shown that interventional management of craniofacial pain is effective in treating occipital neuralgia, cervicogenic headaches, cluster headaches, trigeminal neuralgia, and chronic migraines, with a reported efficacy of 60-90% over a duration of 1-9 months. Repeated infiltrations, neuromodulation, or ablation may prove effective in selected cases. Therefore, reassessment of treatment response and efficacy during follow-up is imperative to guide further management and explore alternative treatment options. Optimal utilization of imaging, interventional techniques, and a multidisciplinary team, including radiologists, will ensure maximum benefit for these patients.

Successful Interventional Treatment of Pyopneumothorax Caused by Streptococcus constellatus Associated with Hashimoto's Thyroiditis: A Case Report and Literature Review.

Background: Streptococcus constellatus rarely causes pyopneumothorax, which is a serious state and requires a surgery. However, not every patient can tolerate surgery and individualized solutions are needed. Furthermore, many known situations are risk factors of S. constellatus infection, but S. constellatus pyopneumothorax associated with Hashimoto's thyroiditis has not been reported. Case Presentation: We present the case of a 74-year-old male with multiple encapsulated pyopneumothorax caused by S. constellatus. Given his respiratory failure, we provided two-stage percutaneous right empyema radiography for catheter drainage in the radiology interventional department instead of surgery. Moreover, an occult Hashimoto's thyroiditis was discovered in the patient, which was possibly associated with S. constellatus pyopneumothorax. Levothyroxine was administered to improve his situation. Conclusion: To our knowledge, it is the first case described in this context. We provided an alternative treatment for S. constellatus encapsulated pyopneumothorax in patient who might not tolerate surgery. We also revealed the possible relationship between S. constellatus pyopneumothorax and Hashimoto's thyroiditis.

Thermal ablation with configurable shapes: a comprehensive, automated model for bespoke tumor treatment.

BACKGROUND: Malignant tumors routinely present with irregular shapes and complex configurations. The lack of customization to individual tumor shapes and standardization of procedures limits the success and application of thermal ablation. METHODS: We introduced an automated treatment model consisting of (i) trajectory and ablation profile planning, (ii) ablation probe insertion, (iii) dynamic energy delivery (including robotically driven control of the energy source power and location over time, according to a treatment plan bespoke to the tumor shape), and (iv) quantitative ablation margin verification. We used a microwave ablation system and a liver phantom (acrylamide polymer with a thermochromic ink) to mimic coagulation and measure the ablation volume. We estimated the ablation width as a function of power and velocity following a probabilistic model. Four representative shapes of liver tumors < 5 cm were selected from two publicly available databases. The ablated specimens were cut along the ablation probe axis and photographed. The shape of the ablated volume was extracted using a color-based segmentation method. RESULTS: The uncertainty (standard deviation) of the ablation width increased with increasing power by ± 0.03 mm (95% credible interval [0.02, 0.043]) per watt increase in power and by ± 0.85 mm (95% credible interval [0, 2.5]) per mm/s increase in velocity. Continuous ablation along a straight-line trajectory resulted in elongated rotationally symmetric ablation shapes. Simultaneous regulation of the power and/or translation velocity allowed to modulate the ablation width at specific locations. CONCLUSIONS: This study offers the proof-of-principle of the dynamic energy delivery system using ablation shapes from clinical cases of malignant liver tumors. RELEVANCE STATEMENT: The proposed automated treatment model could favor the customization and standardization of thermal ablation for complex tumor shapes. KEY POINTS: • Current thermal ablation systems are limited to ellipsoidal or spherical shapes. • Dynamic energy delivery produces elongated rotationally symmetric ablation shapes with varying widths. • For complex tumor shapes, multiple customized ablation shapes could be combined.

Feasibility of the chick chorioallantoic membrane model for preclinical studies on tumor radiofrequency ablation.

BACKGROUND: We evaluated the feasibility of a chick chorioallantoic membrane (CAM) tumor model for preclinical research on tumor radiofrequency ablation (RFA). METHODS: Fertilized chicken eggs were incubated and divided into five cohorts: RFA for 30 s (n = 5), RFA for 60 s (n = 5), RFA for 120 s (n = 4), sham (n = 8), and controls (n = 6). Xenografting using pancreatic neuroendocrine tumor cells of the BON-1 cell line was performed on embryonic day (ED) 8. The RFA was performed on ED 12. Survival, stereomicroscopic observations, and histological observations using hematoxylin-eosin (H&E) and Ki67 staining were evaluated. RESULTS: The survival rates in the 30-s, 60-s, and 120-s, sham and control cohort were 60%, 60%, 0%, 100%, and 50%, respectively. Signs of bleeding and heat damage were common findings in the evaluation of stereomicroscopic observations. Histological examination could be performed in all but one embryo. Heat damage, bleeding, thrombosis, and leukocyte infiltration and hyperemia were regular findings in H&E-stained cuts. A complete absence of Ki67 staining was recorded in 33.3% and 50% of embryos in the 30-s and 60-s cohorts that survived until ED 14, respectively. CONCLUSIONS: The CAM model is a feasible and suiting research model for tumor RFA with many advantages over other animal models. It offers the opportunity to conduct in vivo research under standardized conditions. Further studies are needed to optimize this model for tumor ablations in order to explore promising but unrefined strategies like the combination of RFA and immunotherapy. RELEVANCE STATEMENT: The chick chorioallantoic membrane model allows in vivo research on tumor radiofrequency ablation under standardized conditions that may enable enhanced understanding on combined therapies while ensuring animal welfare in concordance with the "Three Rs." KEY POINTS: • The chorioallantoic membrane model is feasible and suiting for tumor radiofrequency ablation. • Radiofrequency ablation regularly achieved reduction but not eradication of Ki67 staining. • Histological evaluation showed findings comparable to changes in humans after RFA. • The chorioallantoic membrane model can enable studies on combined therapies after optimization.

Modified telescopic sheath method for exchange of luminally encrusted ureteral stents.

A novel telescopic access sheath technique has been described to maintain access to the ureter in cases of stent encrustation, placing a suture on the externalised distal end of the stent followed by advancing a sheath over to peel off encrustations and maintain access in the ureter, as well as application of this technique in a child. Herein we present a modification of the telescopic sheath technique that allows exchange of luminally encrusted stents without requiring passage of the sheath into the ureter or ureteroscopy alongside the stent.

Endometrial adenocarcinoma recurring in the lung: impact of molecular profile and role of local therapies on prognosis.

OBJECTIVES: The objective of our study was to describe the characteristics of patients with endometrial cancer diagnosed with a first recurrence involving the lung, and to describe the prognostic role of the molecular profile. We also aimed to describe the prognostic outcomes after local treatment of recurrence (resection of lung metastases or stereotactic body radiation therapy) in a group of patients with isolated lung recurrence. METHODS: This was a retrospective, single-center study between June 1995 and July 2021. The study included patients diagnosed with a first recurrence of endometrial cancer involving the lung. We defined two groups of patients: patients with isolated lung recurrence (confined to the lung) and patients with multisystemic recurrence (in the lung and other locations). RESULTS: Among 1413 patients diagnosed with endometrial cancer in stage IA to IVA of the International Federation of Gynecology and Obstetrics (FIGO) 2009, 64 (4.5%) patients had a first recurrence involving the lung. Of these, 15 (39.1%) were of a non-specific molecular profile, 16 (25%) were p53-abnormal, 15 (23.4%) were mismatch-repair deficient, and 0% POLE-mutated. P53-abnormal patients had the shortest 3 year progression-free survival after recurrence and those with mismatch-repair deficient had the longest 3 year progression-free survival (14.3% (range; 1.6-40.3) and 47.6% (range; 9.1-79.5) respectively, p=0.001). We found no differences on overall survival after recurrence by molecular profile. Thirty-one of 64 (48.4%) patients had an isolated recurrence in the lung, and 16 (25%) patients received local treatment. When comparing patients with isolated lung recurrence, locally treated patients had a longer median progression-free survival than patients treated systemically (41.9 (range, 15.4-NA) vs 7.8 (range, 7.2-10.6) months respectively, p=0.029), a complete response rate of 80% for stereotactic body radiation therapy and a complete resection of 90.9% for surgery. CONCLUSION: Although few patients will benefit from local treatment (stereotactic body radiation therapy or resection) after a recurrence involving the lung, local therapies might be considered as an option in oligometastatic lung recurrences as they achieve high local control rates and better oncological outcomes than systemic treatment alone.

Contrast enhancement early after renal malignancy cryoablation: imaging findings associated with benignity.

OBJECTIVES: Contrast enhancement by MRI done early after cryoablation for renal malignancies may suggest residual tumor (RT). However, we have observed MRI enhancement within 48 h of cryoablation in patients who had no contrast enhancement 6 weeks later. Our purpose was to identify features of 48-h contrast enhancement in patients without RT. METHODS: This single-center retrospective study included consecutive patients who underwent percutaneous cryoablation of renal malignancies in 2013-2020, exhibited cryoablation-zone MRI contrast enhancement 48 h later, and had available 6-week MRI scans. Persistent or growing CE at 6 weeks vs. 48 h was classified as RT. A washout index was calculated for each 48-h MRI, and its performance for predicting RT was assessed by receiver operating characteristic curve analysis. RESULTS: We included 60 patients with 72 cryoablation procedures and 83 cryoablation zones exhibiting 48-h contrast enhancement; mean age was 66 ± 17 years. Clear-cell renal cell carcinoma accounted for 95% of tumors. Of the 83 48-h enhancement zones, RT was observed in eight while 75 were benign. The 48-h enhancement was consistently visible at the arterial phase. Washout was significantly associated with RT (p < 0.001) and gradually increasing contrast enhancement with benignity (p < 0.009). A washout index below - 1.1 predicted RT with 88% sensitivity and 84% specificity. CONCLUSION: MRI contrast enhancement 48 h after cryoablation of renal malignancies was usually benign. Washout was associated with residual tumor, with a washout index value below - 1.1 exhibiting good performance in predicting residual tumor. These findings may help to guide decisions about repeat cryoablation. CLINICAL RELEVANCE STATEMENT: Magnetic resonance imaging contrast enhancement 48 h after cryoablation of renal malignancies rarely indicates residual tumor, which is characterized by washout with a washout index lower than - 1.1. KEY POINTS: • Contrast enhancement at the arterial phase of magnetic resonance imaging done 48 h after cryoablation of a renal malignancy is usually benign. • Residual tumor manifesting as contrast enhancement at the arterial phase is characterized by subsequent marked washout. • A washout index below - 1.1 has 88% sensitivity and 84% specificity for residual tumor.

[Presurgical hypogastric lymph node marking under CT guidance, aided by hidrodissection] / Marcación prequirúrgica de ganglio hipogástrico con tomografía computada asistido por hidrodisección.

Introduction: Pre-surgical lymph node marking is an established medical procedure of vital importance in the treatment of cancer patients. Materials: A 60-year-old man with a history of prostatic adenocarcinoma in a plan for resection of hypogastric adenopathy. Image guided pre-surgical marking was indicated. Results: Preoperative marking was performed with local anesthesia under computed tomography with transosseous access and hydrodissection. Conclusion: We present a technique that has been little studied and rarely reported in the international literature for the surgical identification of deep pelvic adenopathy.

Introducción: La marcación pre quirúrgica de ganglios es un procedimiento médico establecido y de vital importancia en el tratamiento de pacientes oncológicos. Materiales: Hombre de 60 años con antecedentes de adenocarcinoma prostático en plan de resección de adenopatía hipogástrica. Se indicó marcación prequirúrgica mediante guía imagenológica. Resultados: Se realizó marcación prequirúrgica con anestesia local bajo tomografía computada con acceso transóseo e hidrodisección. Conclusiones: presentamos una técnica poco estudiada y escasamente reportada en la bibliografía internacional para la identificación quirúrgica de una adenopatía pélvica profunda.

Retrograde ureteral sheathed forceps technique to retrieve a proximally migrated stent in a young infant.

Ureteral stents are commonly externalised retrogradely by cystoscopy and exchanged under imaging guidance. When a ureteral stent has migrated proximally into the ureter, it may be snared by ureteroscopy or antegrade percutaneous access; however, ureteroscopy can be challenging in young infants where there is difficulty visualizing the ureteral orifice or a small-calibre ureter. The presented case describes a radiologic technique for retrieval of a proximally migrated ureteral stent in a young infant using a 0.025-in. hydrophilic wire, 4-Fr angiographic catheter, 8-Fr vascular sheath and cystoscopic forceps, without requiring transrenal antegrade access or surgical ureteral meatotomy.

Catheter-directed hemorrhoidal embolization for rectal bleeding due to hemorrhoids (Goligher grade I-III): prospective outcomes from a Spanish emborrhoid registry.

OBJECTIVES: To evaluate the safety and efficacy of catheter-directed hemorrhoidal embolization (CDHE) by microcoil embolization for rectal bleeding due to hemorrhoids classified as Goligher grade I-III. METHODS: Eighty patients (62.5% males) with a mean age of 48 ± 9 years were recruited prospectively. All patients had symptomatic bleeding hemorrhoids. All patients were classified according to Goligher classification: grade I (13.7%), grade II (71.1%), grade III (15%), and no grade IV were recruited in this study. In all cases, microcoils were used to embolize the superior rectal artery(SRA), and microspheres if recurrence of bleeding occurred. Follow-up evaluation (1, 3, 6, and 12 months) included clinical examination and anoscopy. A questionnaire was conducted to determine improvement regarding bleeding, quality of life before, and the degree of patient satisfaction of each participant. RESULTS: Technical success was achieved in 100% of the cases. Fifty-five (68.7%) participants had the absence of rectal bleeding after 12 months of embolization. VAS and QL improved 4 points and 1.5 respectively after embolization. A total of 25/80 (31.3%) had a recurrence in rectal bleeding. Seventeen (21.3%) patients underwent a second embolization, and four patients (5%) were treated with open hemorrhoidectomy. No major complications were observed. Sixteen participants had minor complications. Subjective post-treatment symptom and QL surveys showed significant differences from the baseline survey. Likewise, the degree of satisfaction in the telephone survey at 12 months revealed a high degree of patient satisfaction (8.3±1.1). CONCLUSIONS: The present study demonstrates that CDHE is a feasible, well-tolerated, ambulatory, anal sphincter-sparing procedure for the treatment of internal hemorrhoids. CLINICAL RELEVANCE STATEMENT: CDHE is a simple procedure, well tolerated and accepted by patients, that preserves the anal sphincter and presents few complications when metal devices or microspheres are used as embolic agents. KEY POINTS: • The technical success rate of CDHE, defined as the closure of all the SRA in their distal segment, was achieved 100% of all patients. However, a second embolization treatment was required since 21.25% of the patients experienced rectal bleeding. • Overall, CDHE's safety profile is acceptable. After the procedure and 1 year of follow-up, no significant complications were observed. • Encouraging clinical outcomes have demonstrated CDHE in individuals with hemorrhoids and mild prolapse Goligher grades I-III with persistent rectal bleeding.

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.

Bridging the simulation-to-real gap for AI-based needle and target detection in robot-assisted ultrasound-guided interventions.

BACKGROUND: Artificial intelligence (AI)-powered, robot-assisted, and ultrasound (US)-guided interventional radiology has the potential to increase the efficacy and cost-efficiency of interventional procedures while improving postsurgical outcomes and reducing the burden for medical personnel. METHODS: To overcome the lack of available clinical data needed to train state-of-the-art AI models, we propose a novel approach for generating synthetic ultrasound data from real, clinical preoperative three-dimensional (3D) data of different imaging modalities. With the synthetic data, we trained a deep learning-based detection algorithm for the localization of needle tip and target anatomy in US images. We validated our models on real, in vitro US data. RESULTS: The resulting models generalize well to unseen synthetic data and experimental in vitro data making the proposed approach a promising method to create AI-based models for applications of needle and target detection in minimally invasive US-guided procedures. Moreover, we show that by one-time calibration of the US and robot coordinate frames, our tracking algorithm can be used to accurately fine-position the robot in reach of the target based on 2D US images alone. CONCLUSIONS: The proposed data generation approach is sufficient to bridge the simulation-to-real gap and has the potential to overcome data paucity challenges in interventional radiology. The proposed AI-based detection algorithm shows very promising results in terms of accuracy and frame rate. RELEVANCE STATEMENT: This approach can facilitate the development of next-generation AI algorithms for patient anatomy detection and needle tracking in US and their application to robotics. KEY POINTS: • AI-based methods show promise for needle and target detection in US-guided interventions. • Publicly available, annotated datasets for training AI models are limited. • Synthetic, clinical-like US data can be generated from magnetic resonance or computed tomography data. • Models trained with synthetic US data generalize well to real in vitro US data. • Target detection with an AI model can be used for fine positioning of the robot.