Analyzing Radiation Use during Transjugular Intrahepatic Portosystemic Shunt Creation.

Portal vein access during transjugular intrahepatic portosystemic shunt creation was examined in 11 patients. Radiation metrics (kerma area product, reference point air kerma, and fluoroscopy times) during portal vein access were significantly greater for conventional versus intravascular US-guided transjugular intrahepatic portosystemic shunt (54.8 mGy ∙ cm2 ± 27.6 vs 8.4 mGy ∙ cm2 ± 5.0, P = .009; 210.4 mGy ± 109.1 vs 29.5 mGy ± 18.4, P = .009; 19.1 min ± 8.6 vs 8.9 min ± 4.6, P = .04). Wedged hepatic venography is a major contributor to radiation exposure. Intravascular US guidance is associated with significantly reduced radiation use.

Intranodal Lymphangiography with Thoracic Duct Embolization for Treatment of Chyle Leak after Thoracic Outlet Decompression Surgery.

From 2015 to 2019, 9 patients underwent ultrasound-guided intranodal lymphangiography for the treatment of a chyle leak following thoracic outlet decompression surgery. Chyle leaks were identified by Lipiodol (Guerbet, Roissy, France) extravasation near the left supraclavicular surgical bed in all patients. The technical success rate of thoracic duct embolization was 67% (6 of 9), including fluoroscopic transabdominal antegrade access (n = 4) and ultrasound-guided retrograde access in the left neck (n = 2). Clinical success was achieved in 89% of patients (8 of 9). The mean interval from lymphangiography to drain removal was 6.6 days (range, 4-18 d). No patients had a chyle leak recurrence during clinical follow-up (mean, 304 d).

Outcomes of Yttrium-90 Radioembolization for Unresectable Combined Biphenotypic Hepatocellular-Cholangiocarcinoma.

PURPOSE: To evaluate outcomes of yttrium-90 radioembolization in patients with combined biphenotypic hepatocellular-cholangiocarcinoma (cHCC-CC). MATERIALS AND METHODS: A retrospective review of patients with biopsy-confirmed cHCC-CC treated with yttrium-90 radioembolization between 2012 and 2018 was performed. Twenty-two patients with cHCC-CC (mean age 65.6 y, 17 men, 5 women) underwent 29 radioembolization treatments (5 resin, 24 glass microspheres). Survival data were available in 21 patients, and hepatic imaging response data were available in 20 patients. Hepatic imaging response to radioembolization was assessed on follow-up CT or MR imaging using modified Response Evaluation Criteria In Solid Tumours criteria. Univariate stepwise Cox regression analysis was used to evaluate the association between demographic and clinical factors and survival. Logistic regression evaluated associations between clinical factors and response to treatment, overall response, and disease control. RESULTS: Hepatic imaging response was as follows: 15% complete response, 40% partial response, 10% stable disease, and 35% progressive disease (55% response rate, 65% disease control rate). Two patients were downstaged or bridged to transplant, and 1 patient was downstaged to resection. Median overall survival was 9.3 mo (range, 2.5-31.0 mo) from time of radioembolization. Nonreponse to treatment, bilobar disease, presence of multiple tumors, and elevated carbohydrate antigen 19-9 before treatment were associated with reduced survival after radioembolization. CONCLUSIONS: Radioembolization is a viable option for locoregional control of cHCC-CC with good response and disease control rates.

Contrast-enhanced US for the Interventional Radiologist: Current and Emerging Applications.

US is a powerful and nearly ubiquitous tool in the practice of interventional radiology. Use of contrast-enhanced US (CEUS) has gained traction in diagnostic imaging given the recent approval by the U.S. Food and Drug Administration (FDA) of microbubble contrast agents for use in the liver, such as sulfur hexafluoride lipid-type A microspheres. Adoption of CEUS by interventional radiologists can enhance not only procedure guidance but also preprocedure patient evaluation and assessment of treatment response across a wide spectrum of oncologic, vascular, and nonvascular procedures. In addition, the unique physical properties of microbubble contrast agents make them amenable as therapeutic vehicles in themselves, which can lay a foundation for future therapeutic innovations in the field in drug delivery, thrombolysis, and vascular flow augmentation. The purpose of this article is to provide an introduction to and overview of CEUS aimed at the interventional radiologist, highlighting its role before, during, and after frequently practiced oncologic and vascular interventions such as biopsy, ablation, transarterial chemoembolization, detection and control of hemorrhage, evaluation of transjugular intrahepatic portosystemic shunts (TIPS), detection of aortic endograft endoleak, thrombus detection and evaluation, evaluation of vascular malformations, lymphangiography, and percutaneous drain placement. Basic physical principles of CEUS, injection and scanning protocols, and logistics for practice implementation are also discussed. Early adoption of CEUS by the interventional radiology community will ensure rapid innovation of the field and development of future novel procedures. Online supplemental material is available for this article. ©RSNA, 2020.

The muscle anabolic effect of protein ingestion during a hyperinsulinaemic euglycaemic clamp in middle-aged women is not caused by leucine alone.

KEY POINTS: It has been suggested that leucine is primarily responsible for the increase in muscle protein synthesis after protein ingestion because leucine uniquely activates the mTOR-p70S6K signalling cascade. We compared the effects of ingesting protein or an amount of leucine equal to that in the protein during a hyperinsulinaemic-euglycaemic clamp (to eliminate potential confounding as a result of differences in the insulinogenic effect of protein and leucine ingestion) on muscle anabolic signalling and protein turnover in 28 women. We found that protein, but not leucine, ingestion increased muscle p-mTORSer2448 and p-p70S6KThr389 , although only protein, and not leucine, ingestion decreased muscle p-eIF2αSer51 and increased muscle protein synthesis. ABSTRACT: It has been suggested that leucine is primarily responsible for the increase in muscle protein synthesis (MPS) after protein ingestion because leucine uniquely activates the mTOR-p70S6K signalling cascade. We tested this hypothesis by measuring muscle p-mTORSer2448 , p-p70S6KThr389 and p-eIF2αSer51 , as well as protein turnover (by stable isotope labelled amino acid tracer infusion in conjunction with leg arteriovenous blood and muscle tissue sampling), in 28 women who consumed either 0.45 g protein kg-1 fat-free mass (containing 0.0513 g leucine kg-1 fat-free mass) or a control drink (n = 14) or 0.0513 g leucine kg-1 fat-free mass or a control drink (n = 14) during a hyperinsulinaemic-euglycaemic clamp procedure (HECP). Compared to basal conditions, the HECP alone (without protein or leucine ingestion) suppressed muscle protein breakdown by ∼20% and increased p-mTORSer2448 and p-p70S6KThr389 by >50% (all P < 0.05) but had no effect on p-eIF2αSer51 and MPS. Both protein and leucine ingestion further increased p-mTORSer2448 and p-p70S6KThr389 , although only protein, and not leucine, ingestion decreased (by ∼35%) p-eIF2αSer51 and increased (by ∼100%) MPS (all P < 0.05). Accordingly, leg net protein balance changed from negative (loss) during basal conditions to equilibrium during the HECP alone and the HECP with concomitant leucine ingestion and to positive (gain) during the HECP with concomitant protein ingestion. These results provide new insights into the regulation of MPS by demonstrating that leucine and mTOR signalling alone are not responsible for the muscle anabolic effect of protein ingestion during physiological hyperinsulinaemia, most probably because they fail to signal to eIF2α to initiate translation and/or additional amino acids are needed to sustain translation.

Intravascular access devices from an interventional radiology perspective: indications, implantation techniques, and optimizing patency.

Central venous access has become invaluable in the treatment of patients with a wide array of acute and chronic disease entities. Central venous catheters provide durable, short-term and long-term access solutions while saving the patient from repeated peripheral needle sticks. Central venous catheters include: non-tunneled central venous catheters, tunneled central venous catheters, and port catheters. Typically, the placement of a central venous catheter is performed by Vascular and Interventional Radiologists. The purpose of this article is to familiarize the reader with the role of Interventional Radiology in the placement and management of intravascular or implantable access devices, with a focus on discussing indications for central venous catheter placement, implantation techniques, potential complications, and management of catheter dysfunction.

SEER study of ablation versus partial nephrectomy in cT1A renal cell carcinoma.

AIM: Compare ablation versus partial nephrectomy (PN) in T1A renal cell carcinoma (RCC) treatment, using the SEER database. METHODS: Patients with diagnosed T1A RCC from 2004 to 2013 were identified. Propensity matching paired subjects with similar background variables. Kaplan-Meier and Cox proportional hazards regression were performed before and after matching. RESULTS: Cohort included 4592 patients (809 ablation, 3783 PN). PN compared with ablation group had significantly increased overall survival (OS; 93.6% vs 81.9% 5-year survival; p < 0.0001) and cancer-specific survival (CSS; p < 0.0001). After matching (1222 pairs), PN group had significantly increased OS (91.0% vs 86.3% 5-year survival; p = 0.0457) but similar CSS (p = 0.4023). CONCLUSION: Ablation offers similar CSS but lower OS as PN for T1A RCC in this SEER database.

Thermal ablation versus surgical resection for localized hepatocellular carcinoma: a population study using the SEER database.

AIM: To compare overall survival (OS) and liver cancer-specific survival (LCSS) in patients with localized hepatocellular carcinoma treated with surgical resection (SR) or thermal ablation (TA) using the Surveillance, Epidemiology and End Results database. MATERIALS & METHODS: Kaplan-Meier, competing risk and Cox regression analyses were performed after identifying patients. Propensity score matching was then applied. RESULTS: There was significantly better OS in the SR group and significantly lower probability of LCSS in the TA group. After matching, there was significantly longer OS in the SR group and a lower probability of LCSS in the TA group. CONCLUSION: SR offered a significant survival benefit over TA for localized hepatocellular carcinoma.

Renal Embolization: Current Recommendations and Rationale for Clinical Practice.

PURPOSE OF REVIEW: Renal embolization (RE) is a minimally invasive endovascular procedure performed primarily by interventional radiology that can be used to treat a variety of urologic conditions including malignant renal tumors, angiomyolipomas, renal trauma, and complications following biopsy. The following review examines renal embolization indications, technique, and potential complications. RECENT FINDINGS: Renal embolization is a versatile therapeutic and adjunctive tool for many acute and chronic urologic conditions. RE has become a first-line therapy for renal trauma in lower grade injuries and increasing in prevalence for higher grade injuries. Additionally, the safety and efficacy of chemoembolization for primary treatment of renal cell carcinoma is under evaluation. A multidisciplinary approach between urology and interventional radiology should be pursued for all patients undergoing renal embolization regardless of indication. Preprocedural planning and careful monitoring of complications should be performed to optimize clinical outcomes.

Interventional approaches to deep venous thrombosis.

PURPOSE OF REVIEW: Catheter-directed therapy in deep vein thrombosis (DVT) is a beneficial adjunct treatment when anticoagulation alone does not provide an adequate therapeutic response. This review aims to deliver an up-to-date discussion behind the rationale, safety profile, and clinical outcomes in endovascular management of DVT. RECENT FINDINGS: Early studies have shown that the use of catheter-directed thrombolysis (CDT) to be successful in rapid thrombus removal, carry a lower incidence of postthrombotic syndrome (PTS), and improved quality of life. To date, the most robust study evaluating the use of CDT is the Catheter-Directed Venous Thrombolysis in Acute Iliofemoral Vein Thrombosis trial published in 2012, which demonstrated a relative risk reduction in PTS of 26% in the patients who received CDT at 2-year follow-up. The 5-year follow-up results from the trial has recently been published, which revealed persistent clinical benefit of CDT. Since, additional small randomized trials confer the efficacy and safety profile of CDT. Short-term results from pharmacomechanical catheter-directed thrombolysis are promising; however, the long-term efficacy has yet to be established. The recently completed Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis trial will be a pivotal study in defining the future role of pharmacomechanical catheter-directed thrombolysis in prevention of PTS. SUMMARY: CDT is a reasonable and well tolerated treatment option in selected patients with acute proximal DVT.

US-Guided, Direct Puncture Retrograde Thoracic Duct Access, Lymphangiography, and Embolization: Feasibility and Efficacy.

PURPOSE: To describe technical details, success rate, and advantages of direct puncture of the thoracic duct (TD) under direct ultrasound (US) guidance at venous insertion in the left neck. MATERIALS AND METHODS: All patients who underwent attempted thoracic duct embolization (TDE) via US-guided retrograde TD access in the left neck were retrospectively reviewed. Indications for lymphangiography were iatrogenic chyle leak, pulmonary lymphangiectasia, and plastic bronchitis. Ten patients with mean age 41.4 years (range, 21 d to 72 y) underwent US-guided TD access via the left neck. Technical details, procedural times, and clinical outcomes were evaluated. TD access time was defined as time from start of procedure to successful access of TD, and total procedural time was defined from start of procedure until TDE. RESULTS: All attempts at TD access via the neck were successful. Technical and clinical success of TDE was 60%. There were no complications. Mean TD access time was 17 minutes (range, 2-47 min), and mean total procedure time was 49 minutes (range, 25-69 min). Mean follow-up time was 5.4 months (range, 3-10 months). CONCLUSIONS: TDE via US-guided access in the left neck is technically feasible and safe with a potential decrease in procedure time and elimination of oil-based contrast material.

Very-low-density lipoprotein triglyceride and free fatty acid plasma kinetics in women with high or low brown adipose tissue volume and overweight/obesity.

Although a high amount of brown adipose tissue (BAT) is associated with low plasma triglyceride concentration, the mechanism responsible for this relationship in people is not clear. Here, we evaluate the interrelationships among BAT, very-low-density lipoprotein triglyceride (VLDL-TG), and free fatty acid (FFA) plasma kinetics during thermoneutrality in women with overweight/obesity who had a low (<20 mL) or high (≥20 mL) volume of cold-activated BAT (assessed by using positron emission tomography in conjunction with 2-deoxy-2-[18F]-fluoro-glucose). We find that plasma TG and FFA concentrations are lower and VLDL-TG and FFA plasma clearance rates are faster in women with high BAT than low BAT volume, whereas VLDL-TG and FFA appearance rates in plasma are not different between the two groups. These findings demonstrate that women with high BAT volume have lower plasma TG and FFA concentrations than women with low BAT volumes because of increased VLDL-TG and FFA clearance rates. This study was registered at ClinicalTrials.gov (NCT02786251).

Mechanical extraction of chronic venous thrombus using a novel device: a report of two cases.

In deep vein thrombosis (DVT), the structure and composition of the venous thrombus can change rapidly over time. Studies have shown mixed results with anticoagulant and thrombolytic therapies, and the issue will be exacerbated in the case of chronic DVT (defined as thrombus still present after ≥4 weeks of failed treatment after a DVT diagnosis), with no well-accepted interventions. In the present report, we have described two patients in whom mechanical thrombectomy with a novel device was used to remove extensive, chronic thrombus. At follow-up, both patients showed improved blood flow and patency with resolution of their edema and pain. Because thrombus can often be more chronic than expected from a patient's medical history alone, mechanical intervention as the first approach might be warranted.

Characterization of adrenal masses with diffusion-weighted imaging.

OBJECTIVE: The purpose of this article is to assess the role of diffusion-weighted MRI in characterizing adrenal masses. MATERIALS AND METHODS: A retrospective review of the MRI database from August 2007 to July 2009 was performed. The MRI examinations of 48 patients, with 49 lesions, were reviewed independently and blindly by two experienced abdominal radiologists who measured the signal intensities on in-phase and opposed-phase T1-weighted imaging and apparent diffusion coefficient (ADC). ADC measurements and quantitative parameters of chemical shift imaging (signal intensity index and adrenal-to-spleen ratio) were assessed separately and in combination. Lesions with indeterminate signal intensity index (< 16.5%) were considered benign if ADC was greater than or equal to 1.0 × 10(-3) mm(2)/s and malignant if ADC was less than 1.0 × 10(-3) mm(2)/s. Stepwise logistic regression analysis and receiver operating characteristic curves analysis were performed. RESULTS: There were 12 malignant and 37 benign lesions. On multivariate analysis, the only significant predictors of lesion status were signal intensity index from reviewer 2 (p = 0.05) and lesion size (p = 0.04); ADC values were not found to be useful. On receiver operating characteristic curve analysis, there was no significant difference in area under the curve for ADC, signal intensity index, adrenal-to-spleen ratio, or the combined signal intensity index and ADC assessment. For lesions that were indeterminate according to signal intensity index, ADC values greater than 1.50 × 10(-3) mm(2)/s were found only in benign lesions, and nine of 11 lesions with ADC less than 1.0 × 10(-3) mm(2)/s were malignant. CONCLUSION: In general, ADC values are not useful in differentiating adrenal lesions. However, when ADC values are applied to lesions that are indeterminate on signal intensity index, they may help in differentiating a subset of benign and malignant lesions.

Intestinal and multivisceral transplantation.

Intestinal transplantation is carried out in only a handful of centers in the world. However, patients with such transplantation may be seen at almost any institution and radiologists should be familiar with the expected normal anatomy and complications of intestinal transplantation and its variants. In this paper, we discuss the anatomy and complications following intestinal and multivisceral transplantations. We review the literature and present the findings in a cohort of 46 patients who underwent these procedures at our institution. It is important not to misinterpret the normal adaptation of the transplanted intestine for disease. Some of the complications, including infections, vascular complications, and recurrent tumor, are conclusively diagnosed on imaging studies. Imaging studies may raise the diagnosis of complications such as rejection, graft-versus-host disease, posttransplant lymphoproliferative disease, and sclerosing peritonitis.

Usefulness of diffusion-weighted imaging in the evaluation of renal masses.

OBJECTIVE: The objective of our study was to assess the value of diffusion-weighted imaging in differentiating among the various subgroups of renal masses. MATERIALS AND METHODS: This retrospective study measured the apparent diffusion coefficients (ADCs) of renal masses. Malignant lesions were confirmed with surgical pathology results. Benign cystic lesions were stable without treatment for a minimum follow-up of 24 months. RESULTS: There were 20 and 22 patients, respectively, with benign lesions (three abscess, 31 cysts) and malignant lesions (17 clear cell, five papillary, one chromophobe, and two transitional cell cancers). The malignant lesions were larger than the benign lesions (mean diameter, 4.2 vs 2.6 cm, respectively; p = 0.01, Student's t test). The ADC values of the benign lesions were significantly higher than those of the malignant lesions (mean, 2.72 vs 1.88 x 10(-3) mm(2)/s; p < 0.0001). The ADCs of the 31 benign cysts were significantly higher than those of the seven cystic renal cancers (2.77 vs 2.02 x 10(-3) mm(2)/s; p < 0.001). There was no significant difference between the ADCs of clear cell cancers and non-clear cell cancers (1.85 vs 1.97 x 10(-3) mm(2)/s; p = 0.18), but an ADC of less than 1.79 x 10(-3) mm(2)/s was seen only with clear cell cancer. The ADCs of high-grade clear cell cancers (Fuhrman grades III and IV) tended to be lower than those of low-grade clear cell cancers (1.77 vs 1.95 x 10(-3) mm(2)/s; p = 0.12). Among the clear cell cancers, an ADC value of greater than 2.12 x 10(-3) mm(2)/s was seen only with low-grade histology. For differentiating benign from malignant lesions, receiver operating characteristic (ROC) analysis showed an area under the ROC curve of 0.989 (95% CI, 0.919-0.996; p < 0.0001). CONCLUSION: ADC measurements may aid in differentiating among the various subgroups of renal masses, particularly benign cystic lesions from cystic renal cell cancers.

Using principal component analysis for the prediction of tumor response to transarterial chemoembolization.

PURPOSE: To quantitate the tumor blush of hepatocellular carcinoma (HCC) at the time of transarterial chemoembolization (TACE) using principal component analysis (PCA), and to correlate the quantitated tumor blush to response to therapy. MATERIALS AND METHODS: In this proof-of-concept study, 27 primary HCC tumors in 25 patients (18 men, 7 women; mean age 66 years ± 9) were analyzed. We conducted a retrospective analysis of TACE procedures that were performed during March through July of 2017. Digital subtraction angiography (DSA) was combined with PCA to condense spatial and temporal information into a single image. The tumor and liver contrast enhancements were calculated, and the ratio was used to determine the relative vascular enhancement of the tumor. Tumor response to therapy was determined at 1-month post procedure. RESULTS: Using PCA-generated fluoroscopic imaging (PCA-FI), we quantitated the tumor blush and assigned a vascular enhancement value (VEV) to each tumor. Tumors that responded to treatment (N = 12) had statistically higher VEVs compared with the nonresponders (N = 15), with a mean value of 0.96 ± 0.455 vs. 0.57 ± 0.309, (p = 0.013). CONCLUSIONS: We developed a method for quantitating tumor blush using routine angiographic images. The VEVs calculated using these images may allow for the prediction of tumor response to therapy. This pilot study suggests that there is a correlation between tumor blush intensity and tumor response.

Embolization of a congenital arteriovenous malformation arising off the internal mammary artery.

Congenital arteriovenous malformations (AVM) of the internal mammary artery (IMA) are exceptionally rare. Patients with AVMs arising off the left IMA may present with continuous precordial murmurs and/or a pulsatile chest mass. AVMs in this location pose a risk of enlargement, rupture, infection, or high-output cardiac failure. The potential risks associated with AVMs warrant early therapeutic intervention. We describe a case of a congenital AVM originating from the left IMA, which was successfully embolized with n­butyl cyanoacrylate (NBCA) using a transcatheter arterial approach.

Comparison of Response and Outcomes of Drug-eluting Bead Chemoembolization (DEB-TACE) Versus Radioembolization (TARE) for Patients With Colorectal Cancer Liver Metastases.

BACKGROUND: To compare outcomes for patients with colorectal cancer liver metastases (CRCLM) treated by drug-eluting bead chemoembolization (DEB-TACE) or radioembolization (TARE). PATIENTS AND METHODS: A single-center retrospective review was carried out on 202 patients with CRCLM, treated by DEB-TACE (n=47) or TARE (n=155) patients. Propensity-matching yielded 44 pairs. Paired statistical analysis was performed on matched pair demographics, treatment response, and survival. RESULTS: Patients treated with DEB-TACE had worse extra-hepatic metastasis (68.1 vs. 47.7%, p=0.014) and ≥10 liver lesions (42.2 vs. 68.8%, p=0.001). Matched patients treated with DEB-TACE had a trend towards worse toxicity (27% vs. 9.1% (p=0.057). Index DEB-TACE treatment was not a prognostic factor for overall survival (hazard ratio=0.94, 95% confidence intervaI=0.54-1.65; p=0.83). CONCLUSION: In the matched CRCLM cohort, there was a trend towards worse toxicity post-DEB-TACE treatment, but it was not an independent prognostic factor for survival.