Length of Stay Predicts Risk of Early Infection for Hospitalized Patients Undergoing Central Venous Port Placement

PURPOSE

To compare early totally implantable central venous port catheter-related infection rates after inpatient vs outpatient placement and to determine whether the risk associated with inpatient placement is influenced by length of hospital stay.

MATERIALS AND METHODS

In this single-institution retrospective study, 5,301 patients (3,618 women; mean age 57 y) underwent port placement by interventional radiologists between October 2004 and January 2018. The 30-day infection rate was compared between inpatients and outpatients using survival analysis. Among inpatients, the effect of time from admission to port placement and from placement to discharge was analyzed using a survival regression tree.

RESULTS

The 30-day infection rate was 3.6% (95% confidence interval [CI] = 1.9%-6.1%) among 386 inpatients and 1.0% (95% CI = 0.7%-1.3%) among 4,915 outpatients (hazard ratio [HR] = 3.6, 95% CI = 2.0-6.6, P < .001). Inpatient placement was a significant risk factor after accounting for covariates in multivariate analysis (HR = 2.2, 95% CI = 1.0-4.7, P = .05) and controlling for demographic differences by propensity score matching (HR = 2.8, 95% CI = 1.0-7.8, P = .04). Infection rate was 11% (95% CI = 4.7%-22%) among 65 inpatients in whom time from admission to placement was ≥ 7 days, 5.1% (95% CI = 1.9%-11%) among 129 inpatients in whom admission to placement was < 7 days and time to discharge was > 3 days, and 0% (95% CI = 0%-2.1%) among 192 inpatients in whom admission to placement was < 7 days and time to discharge was ≤ 3 days (P < .001).

CONCLUSIONS

Inpatient port placement was associated with a higher risk of early infection. However, a clinical decision tree based on shorter length of stay before and after placement may identify a subset of hospitalized patients not at increased risk for infection.

The LI-RADS Version 2018 MRI Treatment Response Algorithm: Evaluation of Ablated Hepatocellular Carcinoma

Background The Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (TRA) is used to assess presumed hepatocellular carcinoma (HCC) after local-regional therapy, but its performance has not been extensively assessed. Purpose To assess the performance of LI-RADS version 2018 TRA in the evaluation of HCC after ablation. Materials and Methods In this retrospective study, patients who underwent ablation therapy for presumed HCC followed by liver transplantation between January 2011 and December 2015 at a single tertiary care center were identified. Lesions were categorized as completely (100%) or incompletely (≤99%) necrotic based on transplant histology. Three radiologists assessed pre- and posttreatment MRI findings using LI-RADS version 2018 and the TRA, respectively. Interreader agreement was assessed by using the Fleiss κ test. Performance characteristics for predicting necrosis category based on LI-RADS treatment response (LR-TR) category (viable or nonviable) were calculated by using generalized mixed-effects models to account for clustering by subject. Results A total of 36 patients (mean age, 58 years ± 5 [standard deviation]; 32 men) with 53 lesions was included. Interreader agreement for pretreatment LI-RADS category was 0.40 (95% confidence interval [CI]: 0.15, 0.67; P < .01) and was lower than the interreader agreement for TRA category (κ = 0.71; 95% CI: 0.59, 0.84; P < .01). After accounting for clustering by subject, sensitivity of tumor necrosis across readers ranged from 40% to 77%, and specificity ranged from 85% to 97% when LR-TR equivocal assessments were treated as nonviable. When LR-TR equivocal assessments were treated as viable, sensitivity of tumor necrosis across readers ranged from 81% to 87%, and specificity ranged from 81% to 85% across readers. Six (11%) of 53 treated lesions were LR-TR equivocal by consensus, with most (five of six) incompletely necrotic at histopathology. Conclusion The Liver Imaging Reporting and Data System treatment response algorithm can be used to predict viable or nonviable hepatocellular carcinoma after ablation. Most ablated lesions rated as treatment response equivocal were incompletely necrotic at histopathology. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Do and Mendiratta-Lala in this issue.

Ultrasound-guided non-targeted liver core biopsy: comparison of the efficacy of two different core needle biopsy systems using an ex-vivo animal model and retrospective review of clinical experience

PURPOSE

To compare the efficacy of two 18-gauge core needle biopsy systems, the Achieve® (Merit Medical) and the Marquee® (BD Bard), using an ex-vivo animal liver model and retrospective review of clinical experience.

METHODS

Sixty ex-vivo liver biopsy samples were obtained using the Achieve® (n = 30) and the Marquee® (n = 30) needles. In addition, 20 liver biopsy samples from 20 patients obtained using the Achieve® (n = 10) and Marquee® (n = 10) were compared retrospectively. One pathologist, blinded to needle type, recorded total core length and the number of complete portal triads. Ex vivo measurements were compared using mixed effects linear, logistic, and ordinal regression. In vivo measurements were compared using Student's t-test.

RESULTS

For the Achieve® and Marquee® needles, the mean(SD) total core length (mm) of ex vivo samples was 11.0(3.3) and 12.6(3.4), respectively (P = 0.069) and the adequacy rate was 23.3% and 50%, respectively (P = 0.04). Mean number of portal triads of ex vivo samples was 7.2(2.9) and 8.6(3.8), respectively (P = 0.13), and the adequacy rate was 73.3% and 83.3%, respectively (P = 0.32). For in vivo samples, the Achieve® and Marquee® needles demonstrates mean(SD) total core length (mm) of 24.6(7.1) and 32.0(4.6), respectively (P = 0.01), adequacy rate (P = 0.06). Mean number of portal triads was 14.9(4.8) and 19.6(4.1), respectively (P = 0.03), adequacy rate (P = 0.47).

CONCLUSIONS

Slightly longer core biopsies were obtained with the Marquee® needle compared with the Achieve® needle. Early clinical experience demonstrates no significant difference in sample adequacy rates. Both needle types can be expected to provide adequate samples for pathologic assessment of liver tissue.

Reproducibility of CT Radiomic Features within the Same Patient: Influence of Radiation Dose and CT Reconstruction Settings

Background Results of recent phantom studies show that variation in CT acquisition parameters and reconstruction techniques may make radiomic features largely nonreproduceable and of limited use for prognostic clinical studies. Purpose To investigate the effect of CT radiation dose and reconstruction settings on the reproducibility of radiomic features, as well as to identify correction factors for mitigating these sources of variability. Materials and Methods This was a secondary analysis of a prospective study of metastatic liver lesions in patients who underwent staging with single-energy dual-source contrast material-enhanced staging CT between September 2011 and April 2012. Technique parameters were altered, resulting in 28 CT data sets per patient that included different dose levels, section thicknesses, kernels, and reconstruction algorithm settings. By using a training data set (n = 76), reproducible intensity, shape, and texture radiomic features (reproducibility threshold, R2 ≥ 0.95) were selected and correction factors were calculated by using a linear model to convert each radiomic feature to its estimated value in a reference technique. By using a test data set (n = 75), the reproducibility of hierarchical clustering based on 106 radiomic features measured with different CT techniques was assessed. Results Data in 78 patients (mean age, 60 years ± 10; 33 women) with 151 liver lesions were included. The percentage of radiomic features deemed reproducible for any variation of the different technical parameters was 11% (12 of 106). Of all technical parameters, reconstructed section thickness had the largest impact on the reproducibility of radiomic features (12.3% [13 of 106]) if only one technical parameter was changed while all other technical parameters were kept constant. The results of the hierarchical cluster analysis showed improved clustering reproducibility when reproducible radiomic features with dedicated correction factors were used (ρ = 0.39-0.71 vs ρ = 0.14-0.47). Conclusion Most radiomic features are highly affected by CT acquisition and reconstruction settings, to the point of being nonreproducible. Selecting reproducible radiomic features along with study-specific correction factors offers improved clustering reproducibility. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Sosna in this issue.

Spinal Arterial Blood Supply Does Not Arise from the Bronchial Arteries: A Detailed Analysis of Angiographic Studies Performed for Hemoptysis

PURPOSE

To determine the angiographic prevalence of spinal arteries originating directly from the bronchial arteries in the setting of embolization for hemoptysis.

MATERIALS AND METHODS

Over a 14-year interval, 205 patients underwent angiography for hemoptysis. Twenty-five patients were excluded because their bronchial arteries were not visualized. The remaining 180 patients underwent a total of 254 angiographic procedures (range, 1-8 per patient). Images were reviewed jointly by 2 interventional radiologists with formal fellowship training in both peripheral and neurological interventional radiology. All catheterized arteries were evaluated for arterial contribution to the spinal cord. For patients with multiple studies, each unique artery was reported only once. Embolization was performed during at least 1 procedure in 158 patients (88%). Electronic record review was used to assess neurological sequelae after the procedure.

RESULTS

One or 2 bronchial arteries originating from the aorta were identified in 57 patients (32%) on the right and in 75 patients (42%) on the left. Conjoined bronchial arteries were found in 76 patients (42%). Spinal arterial supply was absent in all. A total of 102 patients (57%) had at least 1 right and 11 patients (6%) at least 1 left intercostobronchial artery. Spinal arterial supply from the intercostal portion of an intercostobronchial artery was found in 6 patients (5 right, 1 left). Medical record review revealed no postprocedure symptoms referable to spinal cord injury in any patient.

CONCLUSIONS

Spinal arterial supply does not originate directly from the bronchial artery but can originate from the intercostal portion of an intercostobronchial artery.

Focusing on the nuclear and subnuclear dynamics of light and circadian signalling

Circadian clocks provide organisms the ability to synchronize their internal physiological responses with the external environment. This process, termed entrainment, occurs through the perception of internal and external stimuli. As with other organisms, in plants, the perception of light is a critical for the entrainment and sustainment of circadian rhythms. Red, blue, far-red, and UV-B light are perceived by the oscillator through the activity of photoreceptors. Four classes of photoreceptors signal to the oscillator: phytochromes, cryptochromes, UVR8, and LOV-KELCH domain proteins. In most cases, these photoreceptors localize to the nucleus in response to light and can associate to subnuclear structures to initiate downstream signalling. In this review, we will highlight the recent advances made in understanding the mechanisms facilitating the nuclear and subnuclear localization of photoreceptors and the role these subnuclear bodies have in photoreceptor signalling, including to the oscillator. We will also highlight recent progress that has been made in understanding the regulation of the nuclear and subnuclear localization of components of the plant circadian clock.

LI-RADS Treatment Response Algorithm: Performance and Diagnostic Accuracy

Background In 2017, the Liver Imaging Reporting and Data System (LI-RADS) included an algorithm for the assessment of hepatocellular carcinoma (HCC) treated with local-regional therapy. The aim of the algorithm was to enable standardized evaluation of treatment response to guide subsequent therapy. However, the performance of the algorithm has not yet been validated in the literature. Purpose To evaluate the performance of the LI-RADS 2017 Treatment Response algorithm for assessing the histopathologic viability of HCC treated with bland arterial embolization. Materials and Methods This retrospective study included patients who underwent bland arterial embolization for HCC between 2006 and 2016 and subsequent liver transplantation. Three radiologists independently assessed all treated lesions by using the CT/MRI LI-RADS 2017 Treatment Response algorithm. Radiology and posttransplant histopathology reports were then compared. Lesions were categorized on the basis of explant pathologic findings as either completely (100%) or incompletely (<100%) necrotic, and performance characteristics and predictive values for the LI-RADS Treatment Response (LR-TR) Viable and Nonviable categories were calculated for each reader. Interreader association was calculated by using the Fleiss κ. Results A total of 45 adults (mean age, 57.1 years ± 8.2; 13 women) with 63 total lesions were included. For predicting incomplete histopathologic tumor necrosis, the accuracy of the LR-TR Viable category for the three readers was 60%-65%, and the positive predictive value was 86%-96%. For predicting complete histopathologic tumor necrosis, the accuracy of the LR-TR Nonviable category was 67%-71%, and the negative predictive value was 81%-87%. By consensus, 17 (27%) of 63 lesions were categorized as LR-TR Equivocal, and 12 of these lesions were incompletely necrotic. Interreader association for the LR-TR category was moderate (κ = 0.55; 95% confidence interval: 0.47, 0.67). Conclusion The Liver Imaging Reporting and Data System 2017 Treatment Response algorithm had high predictive value and moderate interreader association for the histopathologic viability of hepatocellular carcinoma treated with bland arterial embolization when lesions were assessed as Viable or Nonviable. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Gervais in this issue.

Physiological and Genetic Dissection of Sucrose Inputs to the Arabidopsis thaliana Circadian System

Circadian rhythms allow an organism to synchronize internal physiological responses to the external environment. Perception of external signals such as light and temperature are critical in the entrainment of the oscillator. However, sugar can also act as an entraining signal. In this work, we have confirmed that sucrose accelerates the circadian period, but this observed effect is dependent on the reporter gene used. This observed response was dependent on sucrose being available during free-running conditions. If sucrose was applied during entrainment, the circadian period was only temporally accelerated, if any effect was observed at all. We also found that sucrose acts to stabilize the robustness of the circadian period under red light or blue light, in addition to its previously described role in stabilizing the robustness of rhythms in the dark. Finally, we also found that CCA1 is required for both a short- and long-term response of the circadian oscillator to sucrose, while LHY acts to attenuate the effects of sucrose on circadian period. Together, this work highlights new pathways for how sucrose could be signaling to the oscillator and reveals further functional separation of CCA1 and LHY.