Single Specialty-Operated Renal Stone Removal: Initial Experience from 3 Interventional Radiology Centers.

This retrospective analysis of the feasibility and safety of percutaneous renal stone removal using single-use flexible ureteroscopes was conducted at 3 academic centers. Twelve patients (58% men) underwent 14 percutaneous renal stone removal procedures between December 2021 and March 2023. All patients experienced symptom improvement and resolution of obstruction after stone removal. The procedural success rate was 92%. Only 1 patient required an additional stone removal procedure. No major adverse events occurred during or after the procedures. The percutaneous nephrostomy removal rate was 92%, with a median tube removal time of 5 weeks. The median procedural and pulsed fluoroscopy times were 106.5 and 16.3 minutes, respectively. Preliminary findings demonstrated that percutaneous renal stone removal using single-use endoscopes by interventional radiologists is feasible and safe.

Percutaneous Chemical and Mechanical Necrosectomy for Walled-Off Pancreatic Necrosis.

PURPOSE: To test the hypothesis that percutaneous combined chemical and mechanical necrosectomy using a Malecot anchor drain and an Arrow-Trerotola percutaneous thrombolytic device (PTD) in patients with walled-off pancreatic necrosis (WOPN) is feasible, safe, and effective compared with a control group undergoing mechanical necrosectomy alone. MATERIALS AND METHODS: In a retrospective analysis, patients with WOPN not amenable to endoscopic-guided cystogastrostomy placement were studied as case and control groups. The patients in the case group underwent percutaneous combined chemical (hydrogen peroxide 3%) and mechanical necrosectomy using a Malecot anchor drain and/or Arrow-Trerotola PTD from December 2020 to April 2022. The controls underwent mechanical necrosectomy alone without chemical necrosectomy. Clinical success was defined as complete resolution of the cavity on follow-up noncontrast computed tomography scans with subsequent drain removal. RESULTS: Thirteen patients in the case group and 11 patients in the control group underwent percutaneous drain placement followed by percutaneous combined chemical and mechanical necrosectomy (case group) or mechanical necrosectomy only (control group) for WOPN. Drain placement and necrosectomy were technically successful in all patients studied. One patient in the case group developed postprocedural sepsis because of communication between the cavity and the splenic vein. Another patient in the case group developed bleeding from a branch of the pancreaticoduodenal artery on postnecrosectomy day 9, which was successfully embolized by interventional radiology. No pancreaticocutaneous fistula was reported at the 3-month follow-up. The clinical success rates in the case and control groups were 100% and 38.4%, respectively (P = .003). CONCLUSIONS: Percutaneous combined chemical and mechanical necrosectomy is a feasible, safe, and effective treatment of WOPN.

Acetazolamide enhanced drug-eluting beads: manipulating the hepatocellular carcinoma microenvironment.

Hepatocellular carcinoma (HCC) is the most common type of primary liver malignancy. Intra-arterial therapies such as drug-eluting bead transarterial chemoembolization (DEB-TACE) can be effective forms of locoregional treatment for HCC. Solid liver tumors such as HCC promote a biochemical tumor microenvironment (TME) that allows tumor recurrence. The TME creates an environmental acidic pH, which induces chemotherapy resistance and immunosuppression. To address TME acidity, pharmacological agents like acetazolamide could be combined with primary transarterial therapies to optimize HCC treatment. We present a case of a 51-year-old male with a history of alcoholic cirrhosis and recently diagnosed HCC who underwent DEB-TACE with acetazolamide, resulting in complete tumor response on 1.5, 4.5, and 7.5 months follow-up.

Deep residual network for off-resonance artifact correction with application to pediatric body MRA with 3D cones.

PURPOSE: To enable rapid imaging with a scan time-efficient 3D cones trajectory with a deep-learning off-resonance artifact correction technique. METHODS: A residual convolutional neural network to correct off-resonance artifacts (Off-ResNet) was trained with a prospective study of pediatric MRA exams. Each exam acquired a short readout scan (1.18 ms ± 0.38) and a long readout scan (3.35 ms ± 0.74) at 3 T. Short readout scans, with longer scan times but negligible off-resonance blurring, were used as reference images and augmented with additional off-resonance for supervised training examples. Long readout scans, with greater off-resonance artifacts but shorter scan time, were corrected by autofocus and Off-ResNet and compared with short readout scans by normalized RMS error, structural similarity index, and peak SNR. Scans were also compared by scoring on 8 anatomical features by two radiologists, using analysis of variance with post hoc Tukey's test and two one-sided t-tests. Reader agreement was determined with intraclass correlation. RESULTS: The total scan time for long readout scans was on average 59.3% shorter than short readout scans. Images from Off-ResNet had superior normalized RMS error, structural similarity index, and peak SNR compared with uncorrected images across ±1 kHz off-resonance (P < .01). The proposed method had superior normalized RMS error over -677 Hz to +1 kHz and superior structural similarity index and peak SNR over ±1 kHz compared with autofocus (P < .01). Radiologic scoring demonstrated that long readout scans corrected with Off-ResNet were noninferior to short readout scans (P < .05). CONCLUSION: The proposed method can correct off-resonance artifacts from rapid long-readout 3D cones scans to a noninferior image quality compared with diagnostically standard short readout scans.

View-Sharing Artifact Reduction With Retrospective Compressed Sensing Reconstruction in the Context of Contrast-Enhanced Liver MRI for Hepatocellular Carcinoma (HCC) Screening.

BACKGROUND: View-sharing (VS) increases spatiotemporal resolution in dynamic contrast-enhanced (DCE) MRI by sharing high-frequency k-space data across temporal phases. This temporal sharing results in respiratory motion within any phase to propagate artifacts across all shared phases. Compressed sensing (CS) eliminates the need for VS by recovering missing k-space data from pseudorandom undersampling, reducing temporal blurring while maintaining spatial resolution. PURPOSE: To evaluate a CS reconstruction algorithm on undersampled DCE-MRI data for image quality and hepatocellular carcinoma (HCC) detection. STUDY TYPE: Retrospective. SUBJECTS: Fifty consecutive patients undergoing MRI for HCC screening (29 males, 21 females, 52-72 years). FIELD STRENGTH/SEQUENCE: 3.0T MRI. Multiphase 3D-SPGR T1 -weighted sequence undersampled in arterial phases with a complementary Poisson disc sampling pattern reconstructed with VS and CS algorithms. ASSESSMENT: VS and CS reconstructions evaluated by blinded assessments of image quality and anatomic delineation on Likert scales (1-4 and 1-5, respectively), and HCC detection by OPTN/UNOS criteria including a diagnostic confidence score (1-5). Blinded side-by-side reconstruction comparisons for lesion depiction and overall series preference (-3-3). STATISTICAL ANALYSIS: Two-tailed Wilcoxon signed rank tests for paired nonparametric analyses with Bonferroni-Holm multiple-comparison corrections. McNemar's test for differences in lesion detection frequency and transplantation eligibility. RESULTS: CS compared with VS demonstrated significantly improved contrast (mean 3.6 vs. 2.9, P < 0.0001) and less motion artifact (mean 3.6 vs. 3.2, P = 0.006). CS compared with VS demonstrated significantly improved delineations of liver margin (mean 4.5 vs. 3.8, P = 0.0002), portal veins (mean 4.5 vs. 3.7, P < 0.0001), and hepatic veins (mean 4.6 vs. 3.5, P < 0.0001), but significantly decreased delineation of hepatic arteries (mean 3.2 vs. 3.7, P = 0.004). No significant differences were seen in the other assessments. DATA CONCLUSION: Applying a CS reconstruction to data acquired for a VS reconstruction significantly reduces motion artifacts in a clinical DCE protocol for HCC screening. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:984-993.

Variable-Density Single-Shot Fast Spin-Echo MRI with Deep Learning Reconstruction by Using Variational Networks.

Purpose To develop a deep learning reconstruction approach to improve the reconstruction speed and quality of highly undersampled variable-density single-shot fast spin-echo imaging by using a variational network (VN), and to clinically evaluate the feasibility of this approach. Materials and Methods Imaging was performed with a 3.0-T imager with a coronal variable-density single-shot fast spin-echo sequence at 3.25 times acceleration in 157 patients referred for abdominal imaging (mean age, 11 years; range, 1-34 years; 72 males [mean age, 10 years; range, 1-26 years] and 85 females [mean age, 12 years; range, 1-34 years]) between March 2016 and April 2017. A VN was trained based on the parallel imaging and compressed sensing (PICS) reconstruction of 130 patients. The remaining 27 patients were used for evaluation. Image quality was evaluated in an independent blinded fashion by three radiologists in terms of overall image quality, perceived signal-to-noise ratio, image contrast, sharpness, and residual artifacts with scores ranging from 1 (nondiagnostic) to 5 (excellent). Wilcoxon tests were performed to test the hypothesis that there was no significant difference between VN and PICS. Results VN achieved improved perceived signal-to-noise ratio (P = .01) and improved sharpness (P < .001), with no difference in image contrast (P = .24) and residual artifacts (P = .07). In terms of overall image quality, VN performed better than did PICS (P = .02). Average reconstruction time ± standard deviation was 5.60 seconds ± 1.30 per section for PICS and 0.19 second ± 0.04 per section for VN. Conclusion Compared with the conventional parallel imaging and compressed sensing reconstruction (PICS), the variational network (VN) approach accelerates the reconstruction of variable-density single-shot fast spin-echo sequences and achieves improved overall image quality with higher perceived signal-to-noise ratio and sharpness. © RSNA, 2018 Online supplemental material is available for this article.

Portal Vein Embolization: Rationale, Techniques, and Outcomes to Maximize Remnant Liver Hypertrophy with a Focus on Contemporary Strategies.

Hepatectomy remains the gold standard for curative therapy for patients with limited primary or metastatic hepatic tumors as it offers the best survival rates. In recent years, the indication for partial hepatectomy has evolved away from what will be removed from the patient to the volume and function of the future liver remnant (FLR), i.e., what will remain. With this regard, liver regeneration strategies have become paramount in transforming patients who previously had poor prognoses into ones who, after major hepatic resection with negative margins, have had their risk of post-hepatectomy liver failure minimized. Preoperative portal vein embolization (PVE) via the purposeful occlusion of select portal vein branches to promote contralateral hepatic lobar hypertrophy has become the accepted standard for liver regeneration. Advances in embolic materials, selection of treatment approaches, and PVE with hepatic venous deprivation or concurrent transcatheter arterial embolization/radioembolization are all active areas of research. To date, the optimal combination of embolic material to maximize FLR growth is not yet known. Knowledge of hepatic segmentation and portal venous anatomy is essential before performing PVE. In addition, the indications for PVE, the methods for assessing hepatic lobar hypertrophy, and the possible complications of PVE need to be fully understood before undertaking the procedure. The goal of this article is to discuss the rationale, indications, techniques, and outcomes of PVE before major hepatectomy.

Potential Immunotherapy Targets for Liver-Directed Therapies, and the Current Scope of Immunotherapeutics for Liver-Related Malignancies.

Liver cancer, including hepatocellular carcinoma and intrahepatic cholangiocarcinoma, is increasing in incidence and mortality across the globe. An improved understanding of the complex tumor microenvironment has opened many therapeutic doors and led to the development of novel pharmaceuticals targeting cellular signaling pathways or immune checkpoints. These interventions have significantly improved tumor control rates and patient outcomes, both in clinical trials and in real-world practice. Interventional radiologists play an important role in the multidisciplinary team given their expertise in minimally invasive locoregional therapy, as the bulk of these tumors are usually in the liver. The aim of this review is to highlight the immunological therapeutic targets for primary liver cancers, the available immune-based approaches, and the contributions that interventional radiology can provide in the care of these patients.

Interventional Radiological Treatment of Orthotopic Heart Transplant Complications.

Orthotopic heart transplantation is a life-saving procedure that has substantially improved the lives of countless patients since its inception. However, there are several procedure-related complications that require prompt management. Interventional radiology, with its ever expanding toolkit, is a cornerstone of the multidisciplinary team following post-cardiac transplant patients. Percutaneous, endovascular therapy provides minimally invasive, safe, and effective treatments for immediate and delayed cardiac transplant complications and this paper serves to highlight the various management options interventional radiology can provide for orthotopic heart transplantation complications.

Safety and feasibility of a novel bi-directional portal vein access kit during transjugular intrahepatic portosystemic shunt creation.

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) creation remains as one of the more technically challenging endovascular procedures. Portal vein access from the hepatic vein often requires multiple needle passes, which increases procedure times, risk of complications, and radiation exposure. With its bi-directional maneuverability, the Scorpion X access kit may be a promising tool for easier portal vein access. However, the clinical safety and feasibility of this access kit has yet to be determined. MATERIALS AND METHODS: In this retrospective study, 17 patients (12 male, average age 56.6 ± 9.01) underwent TIPS procedure using Scorpion X portal vein access kits. The primary endpoint was time taken to access the portal vein from the hepatic vein. The most common indications for TIPS were refractory ascites (47.1%) and esophageal varices (17.6%). Radiation exposure, total number of needle passes, and intraoperative complications were recorded. Average MELD Score was 12.6 ± 3.39 (range: 8-20). RESULTS: Portal vein cannulation was successfully achieved in 100% of patients during intracardiac echocardiography-assisted TIPS creation. Total fluoroscopy time was 39.31 ± 17.97 min; average radiation dose was 1036.76 ± 644.15 mGy, while average contrast dose was 120.59 ± 56.87 mL. The average number of passes from the hepatic vein to the portal vein was 2 (range: 1-6). Average time to access the portal vein once the TIPS cannula was positioned in the hepatic vein was 30.65 ± 18.64 min. There were no intraoperative complications. CONCLUSIONS: Clinical utilization of the Scorpion X bi-directional portal vein access kit is both safe and feasible. Utilizing this bi-directional access kit resulted in successful portal vein access with minimal intraoperative complications. LEVEL OF EVIDENCE: Retrospective cohort.

Predictors of endobronchial forceps utilization for inferior vena cava filter retrieval: when snare retrieval fails.

BACKGROUND: Endobronchial forceps are commonly used for complex IVC filter removal and after initial attempts at IVC filter retrieval with a snare have failed. Currently, there are no clear guidelines to help distinguish cases where primary removal should be attempted with standard snare technique or whether attempts at removal should directly be started with forceps. This study is aimed to identify clinical and imaging predictors of snare failure which necessitate conversion to endobronchial forceps. METHODS: Retrospective analysis of 543 patients who underwent IVC filter retrievals were performed at three large quaternary care centers from Jan 2015 to Jan 2022. Patient demographics and IVC filter characteristics on cross-sectional images (degree of tilt, hook embedment, and strut penetration, etc.) were reviewed. Binary multivariate logistic regression was used to identify predictors of IVC filter retrieval where snare retrieval would fail. RESULTS: Thirty seven percent of the patients (n = 203) necessitated utilization of endobronchial forceps. IVC filter hook embedment (OR:4.55; 95%CI: 1.74-11.87; p = 0.002) and strut penetration (OR: 56.46; 95% CI 20.2-157.7; p = 0.001) were predictors of snare failure. In contrast, total dwell time, BMI, and degree of filter tilt were not associated with snare failure. Intraprocedural conversion from snare to endobronchial forceps was significantly associated with increased contrast volume, radiation dose, and total procedure times (p < 0.05). CONCLUSION: IVC filter hook embedment and strut penetration were predictors of snare retrieval failure. Intraprocedural conversion from snare to endobronchial forceps increased contrast volume, radiation dose, and total procedure time. When either hook embedment or strut penetration is present on pre-procedural cross-sectional images, IVC filter retrieval should be initiated using endobronchial forceps. LEVEL OF EVIDENCE: Level 3, large multicenter retrospective cohort.

Prevalence of radiographic semicircular canal dehiscence in very young children: an evaluation using high-resolution computed tomography of the temporal bones.

BACKGROUND: Previous studies suggest that semicircular canal dehiscences (SCDs) have a developmental origin. OBJECTIVE: We hypothesized that if SCDs originate during development, incidence of radiographic SCDs in young children will be higher than in adults. MATERIALS AND METHODS: Thirty-four temporal bone HRCTs of children younger than 2 years and 40 temporal bone HRCTs of patients older than 18 years were reformatted and re-evaluated for presence of SCD or canal thinning. Results were compared with indications for HRCT and clinical information. RESULTS: SCDs were detected in 27.3% of children younger than 2 years of age (superior, 13.8%; posterior, 20%) and in 3% of adults (P < 0.004). Of children with one radiographic dehiscence, 55.6% had multiple and 44% had bilateral SCDs on HRCT. No lateral canal SCDs were present. Thinning of bone overlying the semicircular canals was found in 44% of children younger than 2 years and 2.5% of adults (P < 0.0001). CONCLUSION: SCDs are more common on HRCTs of very young children. This supports the hypothesis that SCDs originate from discontinuation of bone deposition/maturation. However, SCDs on imaging do not necessarily correlate with canal dehiscence syndrome and should therefore be interpreted carefully.

Safety and efficacy of inferior vena cava filter retrieval: a 5-year single center retrospective review from a tertiary care center.

BACKGROUND: Inferior vena cava (IVC) filter retrieval is typically accomplished with standard snare technique. When this fails, more advanced techniques are necessary, especially when removal falls outside a 12-month window. Complications during filter retrieval depend heavily on technique, type of filter, and filter position. In this study we examined safety and efficacy of 536 filter retrievals at a tertiary care center and compared complication rates between standard snare and endobronchial forcep retrieval. METHOD: We reviewed 536 cases between August 2015 and August 2020, recording retrieval success rates, patient comorbidities, and complication rates at the time of removal. RESULTS: Total overall retrieval success was 97.9% (525/536), and complications occurred in approximately 6.0% (32/536) of all cases. Success and complications with standard snare technique alone were 99.4% (345/347) and 1.7% (5 Grade I/II, 1 Grade III) and advanced forcep technique 98.8% (171/173) and 14.5% (22 Grade I/II, 2 Grade III, and 1 Grade IV), respectively. There was no significant difference between the technical success rates of the standard snare technique and forceps techniques (p = 0.60) despite a significantly longer dwell time in patients undergoing forceps retrieval (p < 0.001). CONCLUSION: To our knowledge, this is the largest cohort of forceps directed IVC filter retrieval present in the literature. Rates of successful endobronchial forceps and standard snare retrievals in this study are similar to previous reports. Although use of endobronchial forceps may be associated with higher complication rates, this is likely due to prolonged dwell times, filter tilt, and attempted removal of non retrievable filters. Overall, forceps-directed retrieval offers a safe, effective means of removal in difficult cases. LEVEL OF EVIDENCE: Level 3, Large Retrospective Study.

Sudden sensorineural hearing loss: a review of diagnosis, treatment, and prognosis.

Sudden sensorineural hearing loss (SSNHL) is commonly encountered in audiologic and otolaryngologic practice. SSNHL is most commonly defined as sensorineural hearing loss of 30 dB or greater over at least three contiguous audiometric frequencies occurring within a 72-hr period. Although the differential for SSNHL is vast, for the majority of patients an etiologic factor is not identified. Treatment for SSNHL of known etiology is directed toward that agent, with poor hearing outcomes characteristic for discoverable etiologies that cause inner ear hair cell loss. Steroid therapy is the current mainstay of treatment of idiopathic SSNHL in the United States. The prognosis for hearing recovery for idiopathic SSNHL is dependent on a number of factors including the severity of hearing loss, age, presence of vertigo, and shape of the audiogram.