Deployment of an Interventional Radiology Telemedicine Program During the COVID-19 Pandemic: Initial Experience With 10,056 Visits

Objective

To evaluate the clinical, operational, and financial effects of using telemedicine services in an academic interventional radiology setting during the coronavirus disease 2019 pandemic and to identify potential barriers to equitable telemedicine access for patients.

Methods

Evaluation and management (E&M) data over a 104-week period from September 2019 to August 2021 were reviewed. Data related to the visits were recorded including visit type, billing provider, patient demographic information, Current Procedural Terminology code charged, and reimbursement received. The ZIP code pertaining to the patient’s primary residence was matched with median household income from the US Census Bureau.

Results

In all, 14,754 E&M encounters were performed over the study period, of which 10,056 were conducted using telemedicine. Twenty-two percent of visits were performed with interactive video; the remainder were performed using audio only. Female patients were more likely than male patients to use interactive video visits for telemedicine encounters (23.7% versus 20.4%, P < .001). Patients availing of video visits (mean age, 58.1 years, SD = 14.0) were also significantly younger than those patients who used audio-only (telephone) encounters (mean age, 62.5 years, SD = 13.3). Patients with private insurance and those living in neighborhoods with higher median household income were more likely to avail of interactive video visits (P < .001). Professional E&M monthly revenue was between 23.3% and 53.2% of peak prepandemic levels (mean 37.7%).

Conclusion

Telemedicine services allowed for rapid restoration of E&M encounter volumes over the study period. Further work is required to determine the potential implementation barriers to increasing the use of video visits.

Safety and efficacy of percutaneous transabdominal and transesophageal decompression gastric catheters for palliation of malignant bowel obstruction

PURPOSE

To evaluate the safety and primary technical success rate of gastric decompression via percutaneous transabdominal gastrostomy (PTAG) or percutaneous transesophageal gastric (PTEG) catheter placement for management of malignant bowel obstruction (MBO). A secondary purpose was to evaluate the safety and success rate for PTAG catheter placement in patients with both MBO and ascites.

METHODS

A single-institution retrospective review of 385 patients who underwent attempted decompression gastric catheter placement from March 2013 to August 2018 was performed. Medical records and imaging studies were reviewed. A subgroup of patients with concomitant MBO and ascites were identified. The primary outcome measures were procedural technical success and procedural complications.

RESULTS

394 decompression gastrostomy catheters were attempted from 2013 to 2018, n = 353 PTAG and n = 41 PTEG. The success rate was 95.5% (n = 337 of 353) for PTAG and 97.6% (n = 40 of 41) for PTEG. There were 63 total complications involving 47 (13.9%) patients following PTAG and 13 total complications involving 9 (22.5%) patients following PTEG, P = 0.16. For the subgroup of patients with MBO and ascites, the success rate was 94.8% (n = 182 of 192 patients), and there were 20 complications involving 17 (12.9%) of 132 patients.

CONCLUSION

Gastric decompression for patients with MBO via PTAG or PTEG catheter placement is associated with high success rates and low complications.

Evaluation of Ultrafast Wave-Controlled Aliasing in Parallel Imaging 3D-FLAIR in the Visualization and Volumetric Estimation of Cerebral White Matter Lesions

BACKGROUND AND PURPOSE

Our aim was to evaluate an ultrafast 3D-FLAIR sequence using Wave-controlled aliasing in parallel imaging encoding (Wave-FLAIR) compared with standard 3D-FLAIR in the visualization and volumetric estimation of cerebral white matter lesions in a clinical setting.

MATERIALS AND METHODS

Forty-two consecutive patients underwent 3T brain MR imaging, including standard 3D-FLAIR (acceleration factor = 2, scan time = 7 minutes 50 seconds) and resolution-matched ultrafast Wave-FLAIR sequences (acceleration factor  = 6, scan time = 2 minutes 45 seconds for the 20-channel coil; acceleration factor = 9, scan time  = 1 minute 50 seconds for the 32-channel coil) as part of clinical evaluation for demyelinating disease. Automated segmentation of cerebral white matter lesions was performed using the Lesion Segmentation Tool in SPM. Student t tests, intraclass correlation coefficients, relative lesion volume difference, and Dice similarity coefficients were used to compare volumetric measurements among sequences. Two blinded neuroradiologists evaluated the visualization of white matter lesions, artifacts, and overall diagnostic quality using a predefined 5-point scale.

RESULTS

Standard and Wave-FLAIR sequences showed excellent agreement of lesion volumes with an intraclass correlation coefficient of 0.99 and mean Dice similarity coefficient of 0.97 (SD, 0.05) (range, 0.84-0.99). Wave-FLAIR was noninferior to standard FLAIR for visualization of lesions and motion. The diagnostic quality for Wave-FLAIR was slightly greater than for standard FLAIR for infratentorial lesions (P < .001), and there were fewer pulsation artifacts on Wave-FLAIR compared with standard FLAIR (P < .001).

CONCLUSIONS

Ultrafast Wave-FLAIR provides superior visualization of infratentorial lesions while preserving overall diagnostic quality and yields white matter lesion volumes comparable with those estimated using standard FLAIR. The availability of ultrafast Wave-FLAIR may facilitate the greater use of 3D-FLAIR sequences in the evaluation of patients with suspected demyelinating disease.

Severity of Chest Imaging is Correlated with Risk of Acute Neuroimaging Findings among Patients with COVID-19

BACKGROUND AND PURPOSE

Severe respiratory distress in patients with COVID-19 has been associated with higher rate of neurologic manifestations. Our aim was to investigate whether the severity of chest imaging findings among patients with coronavirus disease 2019 (COVID-19) correlates with the risk of acute neuroimaging findings.

MATERIALS AND METHODS

This retrospective study included all patients with COVID-19 who received care at our hospital between March 3, 2020, and May 6, 2020, and underwent chest imaging within 10 days of neuroimaging. Chest radiographs were assessed using a previously validated automated neural network algorithm for COVID-19 (Pulmonary X-ray Severity score). Chest CTs were graded using a Chest CT Severity scoring system based on involvement of each lobe. Associations between chest imaging severity scores and acute neuroimaging findings were assessed using multivariable logistic regression.

RESULTS

Twenty-four of 93 patients (26%) included in the study had positive acute neuroimaging findings, including intracranial hemorrhage (n = 7), infarction (n = 7), leukoencephalopathy (n = 6), or a combination of findings (n = 4). The average length of hospitalization, prevalence of intensive care unit admission, and proportion of patients requiring intubation were significantly greater in patients with acute neuroimaging findings than in patients without them (P < .05 for all). Compared with patients without acute neuroimaging findings, patients with acute neuroimaging findings had significantly higher mean Pulmonary X-ray Severity scores (5.0 [SD, 2.9] versus 9.2 [SD, 3.4], P < .001) and mean Chest CT Severity scores (9.0 [SD, 5.1] versus 12.1 [SD, 5.0], P = .041). The pulmonary x-ray severity score was a significant predictor of acute neuroimaging findings in patients with COVID-19.

CONCLUSIONS

Patients with COVID-19 and acute neuroimaging findings had more severe findings on chest imaging on both radiographs and CT compared with patients with COVID-19 without acute neuroimaging findings. The severity of findings on chest radiography was a strong predictor of acute neuroimaging findings in patients with COVID-19.

Overall Body Composition and Sarcopenia Are Associated with Poor Liver Hypertrophy Following Portal Vein Embolization

PURPOSE

To explore whether body composition and/or sarcopenia are associated with liver hypertrophy following portal vein embolization (PVE) in patients with colorectal liver metastases (CLM).

METHODS

Patients with CLM who underwent right PVE prior to a planned right hepatectomy were identified from the institutional liver database from 2004 to 2014. Patients were excluded due to previous liver-directed therapy/hepatectomy, right PVE + segment IV embolization, or planned 2-stage hepatectomy. Advanced imaging software was used to measure body compartment volumes (cm²), which were standardized to height (m²) to create an index: skeletal muscle index (SMI), subcutaneous adipose index (SAI), and visceral adipose index (VAI). SMI, gender, and body mass index (BMI) were used to define sarcopenia. The main outcome of interest was hypertrophy of the future liver remnant (FLR) following PVE, which was reported as degree of hypertrophy (DH) and kinetic growth rate (KGR).

RESULTS

Patients were evenly divided into three KGR groups: lower third (KGR:0.7-2.0%), middle third (KGR:2.0-4.1%), and upper third (KGR:4.2-12.3%). Patients in the lower third KGR group had a lower VAI (31.0 vs 53.0 vs 54.5 cm²/m², p = 0.042) and were more commonly sarcopenic (60%) compared to the upper third (20%, p = 0.025). Eighteen patients (40%) met criteria for sarcopenia. Sarcopenic patients had a lower VAI (29.1 vs 57.4 cm²/m², p = 0.004), lesser degree of hypertrophy (8.3% vs 15.2%, p = 0.009), and lower KGR (2.0% vs 4.0%, p = 0.012).

CONCLUSION

Sarcopenia and associated body composition indices are strongly associated with clinically relevant impaired liver regeneration, which may result in increased liver-specific complications following hepatectomy for CLM.

Remediation of arsenic-contaminated paddy soil by intercropping aquatic vegetables and rice

Soil contamination by arsenic (As) is an important environmental issue globally. Intercropping of hyperaccumulators with main crop is typically applied for remediation of As-contaminated soil. Most hyperaccumulators are wild plants with small biomass and slow growth rates. Thus, remediation is slow. Here, we propose an effective intercropping system for remediation of As-contaminated paddy soil. Four treatments-intercropping with water spinach (Ipomoea aquatica Forsk) (T1), water celery (Oenanthe javanica (Blume) DC.) (T2), or Guangdong white arrowhead (Sagittaria sagittifolia L. var) (T3), with rice (Oryza sativa L.) monoculture (control, CK)-were used. Compared with the CK, grain yield per plant of rice under T1 and T2 increased by 58.13% and 10.48%, respectively, but decreased by 46.90% in T3. As concentration, bioaccumulation factor, and translocation factor in brown rice were significantly lower in the intercropping treatments than in CK. As removal by water spinach was 7.04 and 1.47 times that by water celery and arrowhead, respectively. The pH of paddy soil was significantly higher in all treatments than in CK, and iron plaque on rice roots under T1 and T2 decreased significantly but increased significantly under T3 compared with that of CK. Rice intercropped with water spinach had the best remediation effect. Novelty Statement: We believe that the following highlights of this manuscript will make it interesting to general readers of this journal.First, in recent years, many articles about intercropping system for the remediation of soil heavy metal pollution focus on dry land, and few studies have focused on paddy soil. The present study was on arsenic-contaminated paddy soil remediation.Second, water spinach, water celery, and arrowhead have great potential for phytoremediation. Studies have shown that these three aquatic vegetables play a role in the removal of certain pollutants, such as heavy metals. Moreover, when intercropped with rice, they can effectively increase rice yield and reduce rice diseases and insect pests. However, studies on remediation of arsenic-contaminated soil by intercropping aquatic vegetables and rice have not been reported. We propose here a rice-aquatic vegetables (water spinach, water celery and arrowhead) intercropping pattern for remediation of arsenic in soil.Third, according to the arsenic concentration and removal rate, we used a bioaccumulation factor, translocation factor, and arsenic removal per unit area of plants for the quantitative evaluation of the remediation effects of the intercropping systems. We found that the intercropping of rice and water spinach could be used to remediate arsenic-contaminated soil. Moreover, the extraction contents of arsenic using intercropping with water spinach was higher than that achieved in a previous study that applied intercropping with the arsenic hyperaccumulator Pteris vittata over the same growth time. This study provides a reference for realizing both remediation and increased production in arsenic-contaminated soil and for promoting sustainable development of agriculture.

Optimization of the differentiation and quantification of high-Z nanoparticles incorporated in medical devices for CT-guided interventions

PURPOSE

Material differentiation has been made possible using dual-energy computed tomography (DECT), in which the unique, energy-dependent attenuating characteristics of materials can provide new diagnostic information. One promising application is the clinical integration of biodegradable polymers as temporary implantable medical devices impregnated with high-atomic number (high-Z) materials. The purpose of this study was to explore the incorporation of high atomic number (high-Z) contrast materials in a bioresorbable inferior vena cava filter for advanced CT-based monitoring of its location and differentiating from surrounding materials.

MATERIALS AND METHODS

Imaging optimization and calibration studies were performed using a body phantom. The dual-energy CT (DECT) ratios for iron, zirconium, barium, gadolinium, ytterbium, tantalum, tungsten, gold, and bismuth were generated for peak kilovoltage combinations of 80/150Sn, 90/150Sn, and 100/150Sn kVp in dual-source CT via linear regression of the CT numbers at low and high energies. A secondary calibration of the material map to the nominal material concentration was generated to correct for use of materials other than iodine. CT number was calibrated to the material concentration based on single-energy CT (SECT) with additional filtration (150Sn kVp). These quantification methods were applied to monitoring of biodegradable inferior vena cava filters (IVCFs) made of braided poly(p-dioxanone) sutures infused with ultrasmall bismuth nanoparticles (BiNPs) implanted in an adult domestic pig.

RESULTS

Qualitative material differentiation was optimal for high-Z (>73) contrast agents in DECT. However, quantification became nonlinear and inaccurate as the K-edge of the material increased. Using the high-energy (150Sn kVp) data component as a SECT scan, the linearity of quantification curves was maintained with lower limits of detection than with DECT. Among the materials tested, bismuth had optimal differentiation from iodine in DECT while maintaining increased contrast in high-energy SECT for quantification (11.5% error). Coating the IVCF with BiNPs resulted in markedly greater radiopacity (maximum CT number, 2028 HU) than that of an uncoated IVCF (maximum CT number, 127 HU). Using DECT imaging and processing, the BiNP-IVCF could be clearly differentiated from iodine contrast injected into the inferior vena cava of the pig.

CONCLUSIONS

These findings may improve widespread integration of medical devices incorporated with high-Z materials into the clinic, where technical success, possible complications, and device integrity can be assessed intraoperatively and postoperatively via DECT imaging.

Intratumoral Injection of Clostridium novyi-NT Spores in Patients with Treatment-refractory Advanced Solid Tumors

PURPOSE

Intratumorally injected Clostridium novyi-NT (nontoxic; lacking the alpha toxin), an attenuated strain of C. novyi, replicates within hypoxic tumor regions resulting in tumor-confined cell lysis and inflammatory response in animals, which warrants clinical investigation.

PATIENTS AND METHODS

This first-in-human study (NCT01924689) enrolled patients with injectable, treatment-refractory solid tumors to receive a single intratumoral injection of C. novyi-NT across 6 dose cohorts (1 × 10⁴ to 3 × 10⁶ spores, 3+3 dose-escalation design) to determine dose-limiting toxicities (DLT), and the maximum tolerated dose.

RESULTS

Among 24 patients, a single intratumoral injection of C. novyi-NT led to bacterial spores germination and the resultant lysis of injected tumor masses in 10 patients (42%) across all doses. The cohort 5 dose (1 × 10⁶ spores) was defined as the maximum tolerated dose; DLTs were grade 4 sepsis (n = 2) and grade 4 gas gangrene (n = 1), all occurring in three patients with injected tumors >8 cm. Other treatment-related grade ≥3 toxicities included pathologic fracture (n = 1), limb abscess (n = 1), soft-tissue infection (n = 1), respiratory insufficiency (n = 1), and rash (n = 1), which occurred across four patients. Of 22 evaluable patients, nine (41%) had a decrease in size of the injected tumor and 19 (86%) had stable disease as the best overall response in injected and noninjected lesions combined. C. novyi-NT injection elicited a transient systemic cytokine response and enhanced systemic tumor-specific T-cell responses.

CONCLUSIONS

Single intratumoral injection of C. novyi-NT is feasible. Toxicities can be significant but manageable. Signals of antitumor activity and the host immune response support additional studies of C. novyi-NT in humans.

Durability of partial splenic artery embolization on platelet counts for cancer patients with hypersplenism-related thrombocytopenia

PURPOSE

Partial splenic artery embolization (PSAE) has shown promise in increasing platelet counts in cancer patients with hypersplenism-related thrombocytopenia. The purpose of this study was to identify response predictors and to longitudinally evaluate PSAE efficacy and durability in a large cohort of cancer patients with hypersplenism-related thrombocytopenia.

METHODS

A single-institution, IRB-approved, HIPAA-compliant retrospective review of all PSAEs for thrombocytopenia between 2012 and 2015 was performed. Patients were classified as complete responders (CR, no platelet value < 100 × 10⁹/L following PSAE), partial responders (PR, initial increase in platelets but subsequent decrease in platelets < 100 × 10⁹/L), and non-responders (NR, platelets never > 100 × 10⁹/L following PSAE).

RESULTS

Of the 98 patients included in the study, 58 had CR (59%), 28 had PR (29%), and 12 patients had NR (12%). The percent splenic tissue embolized was significantly greater in the CR group compared to the PR group (P = 0.001). The percent volume of splenic tissue embolized was linearly correlated with the magnitude of platelet increase without a minimum threshold. At least one line of chemotherapy was successfully restarted in 97% of patients, and 41% of patients did not experience recurrence of thrombocytopenia for the duration of their survival. The major complication rate was 8%, with readmission following initial hospitalization for persistent "post-embolization syndrome" symptoms the most common.

CONCLUSIONS

In cancer patients with hypersplenism-related thrombocytopenia, PSAE is a safe intervention that effects a durable elevation in platelet counts across a range of malignancies and following the re-initiation of chemotherapy.

Transjugular Intrahepatic Portosystemic Shunts Reduce Variceal Bleeding and Improve Survival in Patients with Cirrhosis: A Population-Based Analysis

PURPOSE

To investigate from a population health perspective the effects of transjugular intrahepatic portosystemic shunt (TIPS) creation on recurrent variceal bleeding and survival in patients with cirrhosis.

MATERIALS AND METHODS

Patients with cirrhosis who presented to outpatient and acute-care hospitals in California (2005-2011) and Florida (2005-2014) with variceal bleeding comprised the study cohort. Patients entered the study cohort at their first presentation for variceal bleeding; all subsequent hospital encounters were then evaluated to determine subsequent interventions, complications, and mortality data.

RESULTS

A total of 655,577 patients with cirrhosis were identified, of whom 42,708 (6.5%) had at least 1 episode of variceal bleeding and comprised the study cohort. The median follow-up time was 2.61 years. A TIPS was created in 4,201 (9.8%) of these patients. There were significantly greater incidences of coagulopathy (83.9% vs 72.8%; P < .001), diabetes (45.5% vs 38.8%; P < .001), and hepatorenal syndrome (15.3% vs 12.5%; P < .001) in TIPS recipients vs those without a TIPS. Following propensity-score matching, TIPS recipients were found to have improved overall survival (82% vs 77% at 12 mo; P < .001) and a lower rate of recurrent variceal bleeding (88% vs 83% recurrent bleeding-free survival at 12 months,; P < .001) than patients without a TIPS. Patients with a TIPS had a significant increase in encounters for hepatic encephalopathy vs those without (1.01 vs 0.49 per year; P < .001).

CONCLUSIONS

TIPS improves recurrent variceal bleeding rates and survival in patients with cirrhosis complicated by variceal bleeding. However, TIPS creation is also associated with a significant increase in hepatic encephalopathy.

Evaluation of Ultrafast Wave-CAIPI MPRAGE for Visual Grading and Automated Measurement of Brain Tissue Volume

BACKGROUND AND PURPOSE

Volumetric brain MR imaging typically has long acquisition times. We sought to evaluate an ultrafast MPRAGE sequence based on Wave-CAIPI (Wave-MPRAGE) compared with standard MPRAGE for evaluation of regional brain tissue volumes.

MATERIALS AND METHODS

We performed scan-rescan experiments in 10 healthy volunteers to evaluate the intraindividual variability of the brain volumes measured using the standard and Wave-MPRAGE sequences. We then evaluated 43 consecutive patients undergoing brain MR imaging. Patients underwent 3T brain MR imaging, including a standard MPRAGE sequence (acceleration factor [R] = 2, acquisition time [TA] = 5.2 minutes) and an ultrafast Wave-MPRAGE sequence (R = 9, TA = 1.15 minutes for the 32-channel coil; R = 6, TA = 1.75 minutes for the 20-channel coil). Automated segmentation of regional brain volume was performed. Two radiologists evaluated regional brain atrophy using semiquantitative visual rating scales.

RESULTS

The mean absolute symmetrized percent change in the healthy volunteers participating in the scan-rescan experiments was not statistically different in any brain region for both the standard and Wave-MPRAGE sequences. In the patients undergoing evaluation for neurodegenerative disease, the Dice coefficient of similarity between volumetric measurements obtained from standard and Wave-MPRAGE ranged from 0.86 to 0.95. Similarly, for all regions, the absolute symmetrized percent change for brain volume and cortical thickness showed <6% difference between the 2 sequences. In the semiquantitative visual comparison, the differences between the 2 radiologists' scores were not clinically or statistically significant.

CONCLUSIONS

Brain volumes estimated using ultrafast Wave-MPRAGE show low intraindividual variability and are comparable with those estimated using standard MPRAGE in patients undergoing clinical evaluation for suspected neurodegenerative disease.

In vivo performance of gold nanoparticle-loaded absorbable inferior vena cava filters in a swine model

Absorbable inferior vena cava filters (IVCFs) offer a promising alternative to metallic retrievable filters in providing protection against pulmonary embolism (PE) for patients contraindicated for anticoagulant therapy. However, because absorbable filters are not radiopaque, monitoring of the filter using conventional X-ray imaging modalities (e.g. plain film radiographs, computed tomography [CT] and fluoroscopy) during deployment and follow-up is not possible and represents a potential obstacle to widespread clinical integration of the device. Here, we demonstrate that gold nanoparticles (AuNPs) infused into biodegradable filters made up of poly-p-dioxanone (PPDO) may improve device radiopacity without untoward effects on device efficacy and safety, as assessed in swine models for 12 weeks. The absorbable AuNP-infused filters demonstrated significantly improved visualization using CT without affecting tensile strength, in vitro degradation, in vivo resorption, or thrombus-capturing efficacy, as compared to similar non-AuNPs infused resorbable IVCFs. This study presents a significant advancement to the development of imaging enhancers for absorbable IVCFs.

[Effect and underling mechanism of 6% hydroxyethyl starch 130/0.4 on serum albumen in trauma orthopedic patients during operation]

Objective: To investigate the effect of 6% hydroxyethyl starch 130/0.4(HES) on protein in severe trauma orthopedic patients after acute hemodilution. Methods: Fourty-eight severe trauma patients who met the inclusion criteria were selected from June 2018 to December 2018 in Yantaishan Hospital, and were randomly divided into two groups (n=24): group A and group B. Group A was ringer's sodium lactate control group, and group B was HES treatment group. After the tracheal intubation, the patients of group A were infused with 10% blood volume of sodium lactate ringer at 0.5 ml·kg(-1)·min(-1), and the patients in group B were infused with 10% blood volume of HES at 0.5 ml·kg(-1)·min(-1). Total protein (TP), human serum albumin (HSA), numbers of circulating endothelium cells (CEC), C-reactive protein (CRP), and serum levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-10 and IL-6 were measured immediately after acute hemodilution (T(0)), 24 hours (T(1)) and 48 hours (T(2)) after acute hemodilution. After infusion into human body, HES bond to HSA, and fluorescence spectroscopy was used to analyze the binding relationship between HES and HSA in order to further study the effects of HES on HSA. Results: The HSA, TP, CEC, TNF-α, IL-6, IL-10, CRP at T(0) of group A were (38±5) g/L, (66±5) g/L, (5.5±0.4)/0.9 μl, (24±5) μg/L, (8.9±0.8) μg/L, (44±6) μg/L, (13.6±1.4) mg/L; While at T(1) were (33±5) g/L, (60±6) g/L, (10.2±0.7)/0.9 μl, (87±9) μg/L, (38.8±2.3) μg/L, (57±7) μg/L, (23.4±2.4) mg/L. The HSA, TP, CEC, TNF-α, IL-6, IL-10, CRP at T(0) of group B were(38±4)g/L, (66±5) g/L, (5.4±0.6)/0.9 μl, (24±6) μg/L, (9.1±0.9) μg/L, (45±6) μg/L, (13.4±1.8) mg/L; While at T(1) were (35±5)g/L, (62±5)g/L, (7.4±0.6)/0.9 μl, (70±8) μg/L, (29.5±3.1) μg/L, (72±6) μg/L, (19.7±2.2) mg/L. HSA and TP decreased at T(1) in group A as compared with T(0) (P<0.05), contrarily CEC increased significantly at T(1), TNF-ɑ, IL-6, IL-10 and CRP augmented at T(1) and T(2) in two groups (P<0.05). In comparison with the patients of group A, CEC decreased significantly at T(1) (P<0.05). TNF-ɑ, IL-6, CRP reduced significantly at T(1) and T(2) (P<0.05), but IL-10 increased at T(1) and T(2) in group B (P<0.05). The secondary structure of HSA changed after HES was added in the HES solution. The fluorescence intensity of HSA decreased with the increase of HES concentration,which suggested that HES induced HSA fluorescence quenching. HES could bind to Trp-214 residue in HSA at a molecular ration of 1∶1. Conclusions: 6% HES reduces the occurrence of low protein level in severe trauma patients after operation. HES could bind to Trp-214 amino acid residue in HSA and form the complex at a molecular ratio of 1∶1. The formation of HES-HSA complex increases the volume of HES, avoids the vascular leakage, protects the vascular endothelial cells, and induces anti-inflammatory immunity in the patients with capillary syndrome.

Association of Inferior Vena Cava Filter Placement With Rates of Pulmonary Embolism in Patients With Cancer and Acute Lower Extremity Deep Venous Thrombosis

IMPORTANCE

Venous thromboembolism is the second overall leading cause of death for patients with cancer, and there is an approximately 2-fold increase in fatal pulmonary embolism (PE) in patients with cancer. Inferior vena cava (IVC) filters are designed to prevent PE, but defining the appropriate use of IVC filters in patients with cancer remains a substantial unmet clinical need.

OBJECTIVE

To evaluate the association of IVC filters with the development of PE in patients with cancer and deep venous thrombosis (DVT).

DESIGN, SETTING, AND PARTICIPANTS

A population-based cohort study was conducted using administrative data on 88 585 patients from the state inpatient databases for California (2005-2011) and Florida (2005-2014). Based on diagnostic and procedure codes, patients with cancer and acute lower extremity DVT were identified. All subsequent hospital visits for these patients were evaluated for the placement of an IVC filter, the development of new PE, the development of new DVT, and in-hospital mortality. Data analysis was performed from September 1 to December 1, 2019.

EXPOSURES

Placement of an IVC filter.

MAIN OUTCOMES AND MEASURES

The association of IVC filter placement with rates of new PE and DVT was estimated using a propensity score matching algorithm and competing risk analysis.

RESULTS

The study cohort comprised 88 585 patients (45 074 male; median age, 71.0 years [range, 1.0-104.0 years]) with malignant neoplasms who presented to a health care institution with a diagnosis of acute lower extremity DVT. Of these patients, 33 740 (38.1%) underwent IVC filter placement; patients with risk factors such as upper gastrointestinal bleeding (odds ratio, 1.32; 95% CI, 1.29-1.37), intracranial hemorrhage (odds ratio, 1.21; 95% CI, 1.19-1.24), and coagulopathy (odds ratio, 1.09; 95% CI, 1.08-1.10) were more likely to receive an IVC filter. A total of 4492 patients (5.1%) developed a new PE after their initial DVT diagnosis. There was a significant improvement in PE-free survival for these patients compared with those who did not receive IVC filters across the full, unbalanced study cohort as well as after propensity score matching and competing risk analysis (hazard ratio, 0.69; 95% CI, 0.64-0.75; P < .001). Furthermore, IVC filter placement reduced the development of PE in patients with very high-risk malignant neoplasms (eg, pancreaticobiliary cancer), high-risk malignant neoplasms (eg, lung cancer), and low-risk malignant neoplasms (eg, prostate cancer). After accounting for anticoagulation use and imbalanced risk factors, IVC filter placement did not increase the risk of new DVT development.

CONCLUSIONS AND RELEVANCE

This study suggests that, for patients with cancer and DVT and bleeding risk factors, IVC filter placement is associated with an increased rate of PE-free survival.

Hepatic vein embolization after portal vein embolization to induce additional liver hypertrophy in patients with metastatic colorectal carcinoma

OBJECTIVES

To assess the effect of salvage hepatic vein embolization (HVE) on the volume of the future liver remnant (FLR) for patients with metastatic colorectal cancer (mCRC) and inadequate hypertrophy following initial portal vein embolization (PVE).

METHODS

From April 2011 to October 2018, 9 patients with mCRC underwent HVE following PVE. The right or middle hepatic vein was embolized with coils and/or vascular plugs. Liver volumes were calculated at baseline, following PVE, and following HVE, in order to assess the hypertrophic effect of PVE and HVE on the FLR.

RESULTS

Nine patients underwent HVE (n = 3, right HVE; n = 6, middle HVE) because of inadequate FLR hypertrophy following PVE. The standardized FLR increased from 0.16 (median, range 0.08-0.24) at baseline to 0.22 (median, range 0.13-0.29) following PVE (p = 0.0005) to 0.26 (median, range 0.19-0.37) following HVE (p = 0.0050). HVE was performed 40 days (median, range 19-128 days) following PVE, and assessment of FLR hypertrophy was performed 41 days (median, range 19-92 days) following HVE. Four of nine patients underwent hepatectomy; 5 patients failed to undergo hepatectomy (n = 3, inadequate hypertrophy; n = 1, disease progression; n = 1, portal hypertension). One patient required repeat HVE due to a patent accessory vein.

CONCLUSIONS

Salvage HVE is an effective technique to induce additional FLR hypertrophy in patients with mCRC and inadequate FLR after initial PVE.

KEY POINTS

• Hepatic vein embolization is effective to induce additional liver hypertrophy in surgical patients with metastatic colorectal carcinoma and inadequate hypertrophy after portal vein embolization. • Increases in future liver remnant volume are feasible in patients who receive hepatotoxic neoadjuvant systemic therapy for metastatic colorectal carcinoma. • Sequential portal vein embolization and hepatic vein embolization can be a viable technique to induce liver hypertrophy in patients with small baseline future liver remnant volumes (< 20%).

Energy Cascade Rate Measured in a Collisionless Space Plasma with MMS Data and Compressible Hall Magnetohydrodynamic Turbulence Theory

The first complete estimation of the compressible energy cascade rate |ϵ_{C}| at magnetohydrodynamic (MHD) and subion scales is obtained in Earth's magnetosheath using Magnetospheric MultiScale spacecraft data and an exact law derived recently for compressible Hall MHD turbulence. A multispacecraft technique is used to compute the velocity and magnetic gradients, and then all the correlation functions involved in the exact relation. It is shown that when the density fluctuations are relatively small, |ϵ_{C}| identifies well with its incompressible analog |ϵ_{I}| at MHD scales but becomes much larger than |ϵ_{I}| at subion scales. For larger density fluctuations, |ϵ_{C}| is larger than |ϵ_{I}| at every scale with a value significantly higher than for smaller density fluctuations. Our study reveals also that for both small and large density fluctuations, the nonflux terms remain always negligible with respect to the flux terms and that the major contribution to |ϵ_{C}| at subion scales comes from the compressible Hall flux.

Absence of Evidence of Electrical Switching of the Antiferromagnetic Néel Vector

Much theoretical and experimental attention has been focused on the electrical switching of the antiferromagnetic (AFM) Néel vector via spin-orbit torque. Measurements employing multiterminal patterned structures of Pt/AFM show recurring signals of the supposedly planar Hall effect and magnetoresistance, implying AFM switching. We show in this Letter that similar signals have been observed in structures with and without the AFM layer, and of an even larger magnitude using different metals and substrates. These may not be the conclusive evidence of spin-orbit torque switching of AFM, but the thermal artifacts of patterned metal structure on substrate. Large current densities in the metallic devices, beyond the Ohmic regime, can generate unintended anisotropic thermal gradients and voltages. AFM switching requires unequivocal detection of the AFM Néel vector before and after SOT switching.

Validation of Highly Accelerated Wave-CAIPI SWI Compared with Conventional SWI and T2*-Weighted Gradient Recalled-Echo for Routine Clinical Brain MRI at 3T

BACKGROUND AND PURPOSE

SWI is valuable for characterization of intracranial hemorrhage and mineralization but has long acquisition times. We compared a highly accelerated wave-controlled aliasing in parallel imaging (CAIPI) SWI sequence with 2 commonly used alternatives, standard SWI and T2*-weighted gradient recalled-echo (T2*W GRE), for routine clinical brain imaging at 3T.

MATERIALS AND METHODS

A total of 246 consecutive adult patients were prospectively evaluated using a conventional SWI or T2*W GRE sequence and an optimized wave-CAIPI SWI sequence, which was 3-5 times faster than the standard sequence. Two blinded radiologists scored each sequence for the presence of hemorrhage, the number of microhemorrhages, and severity of motion artifacts. Wave-CAIPI SWI was then evaluated in head-to-head comparison with the conventional sequences for visualization of pathology, artifacts, and overall diagnostic quality. Forced-choice comparisons were used for all scores. Wave-CAIPI SWI was tested for superiority relative to T2*W GRE and for noninferiority relative to standard SWI using a 15% noninferiority margin.

RESULTS

Compared with T2*W GRE, wave-CAIPI SWI detected hemorrhages in more cases (P < .001) and detected more microhemorrhages (P < .001). Wave-CAIPI SWI was superior to T2*W GRE for visualization of pathology, artifacts, and overall diagnostic quality (all P < .001). Compared with standard SWI, wave-CAIPI SWI showed no difference in the presence or number of hemorrhages identified. Wave-CAIPI SWI was noninferior to standard SWI for the visualization of pathology (P < .001), artifacts (P < .01), and overall diagnostic quality (P < .01). Motion was less severe with wave-CAIPI SWI than with standard SWI (P < .01).

CONCLUSIONS

Wave-CAIPI SWI provided superior visualization of pathology and overall diagnostic quality compared with T2*W GRE and was noninferior to standard SWI with reduced scan times and reduced motion artifacts.

Imaging G-Ratio in Multiple Sclerosis Using High-Gradient Diffusion MRI and Macromolecular Tissue Volume

BACKGROUND AND PURPOSE

Remyelination represents an area of great therapeutic interest in multiple sclerosis but currently lacks a robust imaging marker. The purpose of this study was to use high-gradient diffusion MRI and macromolecular tissue volume imaging to obtain estimates of axonal volume fraction, myelin volume fraction, and the imaging g-ratio in patients with MS and healthy controls and to explore their relationship to neurologic disability in MS.

MATERIALS AND METHODS

Thirty individuals with MS (23 relapsing-remitting MS, 7 progressive MS) and 19 age-matched healthy controls were scanned on a 3T MRI scanner equipped with 300 mT/m maximum gradient strength using a comprehensive multishell diffusion MRI protocol. Macromolecular tissue volume imaging was performed to quantify the myelin volume fraction. Diffusion data were fitted to a 3-compartment model of white matter using a spheric mean approach to yield estimates of axonal volume fraction. The imaging g-ratio was calculated from the ratio of myelin volume fraction and axonal volume fraction. Imaging metrics were compared between groups using 2-sided t tests with a Bonferroni correction.

RESULTS

The mean g-ratio was significantly elevated in lesions compared with normal-appearing WM (0.74 vs 0.67, P < .001). Axonal volume fraction (0.17 vs 0.23, P < .001) and myelin volume fraction (0.17 vs 0.25, P < .001) were significantly lower in lesions than normal-appearing WM. Myelin volume fraction was lower in normal-appearing WM compared with that in healthy controls (0.25 vs 0.27, P = .009). Disability, as measured by the Expanded Disability Status Scale, was significantly associated with myelin volume fraction (β = -40.5, P = .001) and axonal volume fraction (β = -41.0, P = .016) in normal-appearing WM.

CONCLUSIONS

The imaging g-ratio may serve as a biomarker for the relative degree of axonal and myelin loss in MS.

Localised grey matter atrophy in multiple sclerosis is network-based: a coordinate-based meta-analysis

AIM

To test the network degeneration hypothesis in multiple sclerosis (MS) with a two-stage coordinate-based meta-analysis by: (1) characterising regional selectivity of grey matter (GM) atrophy and (2) testing for functional connectivity involving these regions.

MATERIALS AND METHODS

Meta-analytic sources included 33 journal articles (1,666 MS patients and 1,269 healthy controls) with coordinate-based results from voxel-based morphometry analysis demonstrating GM atrophy. Mass univariate and multivariate coordinate-based meta-analyses were performed to identify a convergent pattern of GM atrophy and determine inter-regional co-activation (as a surrogate of functional connectivity), with anatomical likelihood estimation and functional meta-analytic connectivity modelling, respectively.

RESULTS

Localised GM atrophy was demonstrated in the thalamus, putamen, caudate, sensorimotor cortex, insula, superior temporal gyrus, and cingulate gyrus. This convergent pattern of atrophy displayed significant inter-regional functional co-activations.

CONCLUSION

In MS, GM atrophy was regionally selective, and these regions were functionally connected. The meta-analytic model-based results of this study are intended to guide future development of quantitative neuroimaging markers for diagnosis, evaluating disease progression, and monitoring treatment response.

Phase Ib clinical investigation of intraperitoneal ipilimumab and nivolumab in patients with peritoneal carcinomatosis due to gynecologic malignancy

TPS5606

Background: The peritoneal cavity is a frequent site of metastasis and recurrence for gynecologic malignancy, including approximately 80% of epithelial ovarian cancer (EOC) that presents with peritoneal involvement. These observations have led to the use of intraperitoneal (IP) route of administration for traditional cytotoxic chemotherapy. IP immunotherapy is a recognized but under explored area of clinical investigation with many potential advantages. Indeed, IP administered antibodies in both animals and human subjects are associated with absent or much lower peripheral blood concentrations. In addition to higher local and lower systemic exposure, other theoretical advantages include preferential binding to intraperitoneal and intratumoral immune cells, and absorption through the draining lymphatics of the peritoneal cavity. These pelvic and peri-aortic lymph nodes represent the most relevant lymphoid organs and as such may be the ideal site for T cell activation and trafficking back to the peritoneal tumor. Methods: The trial (NCT03508570) is a single-institution phase Ib trial to determine the recommended phase II dosing (RP2D) of IP administration of nivolumab in combination with ipilimumab. For the purpose of dose finding, the assessment period for dose limiting toxicity (DLT) is 12 weeks. The trial starts with a safety lead-in to confirm the safety of IP nivolumab before combining it with ipilimumab. A maximum sample size of 12 will be used to find the RP2D for nivolumab, up to 24 patients for the combination, and a planned expansion will be carried out such that at least 12 EOC patients are treated at RP2D of the intraperitoneal combination strategy. The secondary objectives are to describe the pharmacokinetics and toxicities, and to estimate the clinical benefit rate for the expansion cohort. Translational objectives include description of immunologic and biologic changes in serial blood and IP fluid collections as well as pre and on-treatment biopsies. Eligibility criteria include recurrent or progressive biopsy-confirmed platinum resistant EOC or other gynecologic cancer with measurable peritoneal disease, and no exposure to prior treatment with checkpoint inhibition. Enrollment began in January of 2019 with 3 subjects enrolled to date. Accrual update will be provided at the annual meeting. Clinical trial information: NCT03508570.

Pulmonary Hemorrhage Following Percutaneous Computed Tomography-Guided Lung Biopsy: Retrospective Review of Risk Factors, Including Aspirin Usage

BACKGROUND

To evaluate the significance of aspirin, as well as, other potential confounding risk factors, on the incidence and volume of pulmonary hemorrhage in patients undergoing percutaneous computed tomography-guided lung biopsy.

METHODS

This retrospective study was approved by the institutional review board. Between September 2013 and December 2014, 252 patients taking aspirin underwent transthoracic computed tomography-guided lung biopsy. Patient, technical, and lesion-related risk factors were evaluated. Univariate analysis was performed with a Student's t test, chi-square test, or Fisher's exact test, as appropriate followed by multivariate logistic regression.

RESULTS

Of 252 patients, 49 (19.4%) continued or stopped aspirin ≤4 days prior to biopsy and 203 (80.6%) patients stopped aspirin ≥5 days prior to biopsy. Pulmonary hemorrhage occurred in 174 cases (69.0%). The median volume of hemorrhage was 3.74 cm³ (range, 0-163.5 cm³). Multivariate analysis revealed that lesion size (P < 0.0001) and lesion depth (P < 0.0001) were independent risk factors for the incidence of pulmonary hemorrhage, while lesion size (P = 0.0035), transgression of intraparenchymal vessels (P < 0.0001), and lesion depth (P = 0.0047) were independent risk factors for severity of hemorrhage. Aspirin stopped ≤4 days from a percutaneous lung biopsy was not associated with pulmonary hemorrhage.

CONCLUSION

Aspirin taken concurrently or stopped within 4 days of transthoracic lung biopsy is not an independent risk factor for pulmonary hemorrhage. The incidence of hemorrhage following lung biopsy is associated with lesion size and depth, while the severity of hemorrhage is associated with lesion size, depth, as well as traversal of intraparenchymal vessels.

Development of a predictive model for 6 month survival in patients with venous thromboembolism and solid malignancy requiring IVC filter placement

PURPOSE

Our purpose was to develop a predictive model for short-term survival (i.e. <6 months) following inferior vena cava filter placement in patients with venous thromboembolism (VTE) and solid malignancy.

METHODS

Clinical and laboratory parameters were retrospectively reviewed for patients with solid malignancy who received a filter between January 2009 and December 2011 at a tertiary care cancer center. Multivariate Cox proportional hazards modeling was used to assess variables associated with 6 month survival following filter placement in patients with VTE and solid malignancy. Significant variables were used to generate a predictive model.

RESULTS

397 patients with solid malignancy received a filter during the study period. Three variables were associated with 6 month survival: (1) serum albumin [hazard ratio (HR) 0.496, P < 0.0001], (2) recent or planned surgery (<30 days) (HR 0.409, P < 0.0001), (3) TNM staging (stage 1 or 2 vs. stage 4, HR 0.177, P = 0.0001; stage 3 vs. stage 4, HR 0.367, P = 0.0002). These variables were used to develop a predictive model to estimate 6 month survival with an area under the receiver operating characteristic curve of 0.815, sensitivity of 0.782, and specificity of 0.715.

CONCLUSIONS

Six month survival in patients with VTE and solid malignancy requiring filter placement can be predicted from three patient variables. Our predictive model could be used to help physicians decide whether a permanent or retrievable filter may be more appropriate as well as to assess the risks and benefits for filter retrieval within the context of survival longevity in patients with cancer.