Publications

COVID-19, which is caused by SARS-CoV-2, can result in acute respiratory distress syndrome and multiple organ failure1-4, but little is known about its pathophysiology. Here we generated single-cell atlases of 24 lung, 16 kidney, 16 liver and 19 heart autopsy tissue samples and spatial atlases of 14 lung samples from donors who died of COVID-19. Integrated computational analysis uncovered substantial remodelling in the lung epithelial, immune and stromal compartments, with evidence of multiple paths of failed tissue regeneration, including defective alveolar type 2 differentiation and expansion of fibroblasts and putative TP63+ intrapulmonary basal-like progenitor cells. Viral RNAs were enriched in mononuclear phagocytic and endothelial lung cells, which induced specific host programs. Spatial analysis in lung distinguished inflammatory host responses in lung regions with and without viral RNA. Analysis of the other tissue atlases showed transcriptional alterations in multiple cell types in heart tissue from donors with COVID-19, and mapped cell types and genes implicated with disease severity based on COVID-19 genome-wide association studies. Our foundational dataset elucidates the biological effect of severe SARS-CoV-2 infection across the body, a key step towards new treatments.

Interventional radiology continues to evolve into a more robust and clinically dynamic specialty underpinned by significant advancements in training, education, and practice. This article, prepared by members of the 2020-2021 Association of University Radiologists' task force of the Radiology Research Alliance, will review these developments, highlighting the evolution of interventional radiology pathways with attention to growing educational differences, interrelation to diagnostic radiology training, post-training practice patterns, distribution of procedures and future trends, amongst other key features important to those pursuing a career in interventional radiology as well as those in practice.

OBJECTIVE: To determine safety of shortened observation time without follow-up chest x-ray (CXR) after CT-guided transthoracic procedures (lung biopsy or fiducial placement) in patients without immediate postprocedural pneumothorax (PTX).

METHODS: Consecutive patients that underwent CT-guided procedures between January 5, 2015, and June 19, 2017, were included in this retrospective institutional review board-approved HIPAA-compliant study. Data regarding postprocedural course, complications, and clinical follow-up of the patients were obtained through a review of electronic medical records. Descriptive statistics were used.

RESULTS: There were 441 procedures for 409 patients performed; 82 procedures were excluded because of predefined criteria. In 312 of 336 asymptomatic procedures (92.9%), asymptomatic patients did not undergo CXR after procedure, with 7 of 312 of these patients (2.2%) diagnosed with delayed PTX 2 to 10 days after the procedure. In 24 of 336 procedures (7.1%), asymptomatic patients underwent CXR within 4 hours with no PTX detected, and despite that 1 of 24 of these patients (4.2%) presented with delayed PTX 7 days after procedure. When no immediate postprocedural PTX was present, rate of observation PTX and delayed PTX was 1 of 359 (0.3%) and 8 of 359 (2.2%), respectively. Average duration of monitoring for outpatients (n = 295) was 2.0 hours with median of 1.8 hours. In 23 of 359 (6.4%) procedures, the patient became symptomatic during postprocedural observation with 1 of 23 (4%) developing PTX.

CONCLUSIONS: Obtaining routine postprocedural CXRs in asymptomatic patients without immediate postprocedural PTX after CT-guided transthoracic procedures is likely not necessary given the low likelihood of PTX.

Lack of diversity in Radiology is a public health problem and may be self perpetuating as diverse candidates view the field as hostile to their entry and advancement, and consequently do not apply into the field. Solutions require understanding the obstacles, which range from enrollment in medical school to achieving leadership positions in Radiology. An understanding of the effect of demographic data on diversity in Radiology, disparate effects of Step examinations, medical school grades and induction into academic honor societies, and existing faculty disparities will allow us to better recruit, train, and retain a diverse group of physicians in our field. The downstream effect of a diverse workforce is improvement in health outcomes and disparities in medical care for our communities.

PURPOSE: Hepatic thermal ablation therapy can result in c-Met-mediated off-target stimulation of distal tumor growth. The purpose of this study was to determine if a similar effect on tumor metabolism could be detected in vivo with hyperpolarized 13C MRI.

MATERIALS AND METHODS: In this prospective study, female Fisher rats (n = 28, 120-150 g) were implanted with R3230 rat breast adenocarcinoma cells and assigned to either: sham surgery, hepatic radiofrequency ablation (RFA), or hepatic RFA + adjuvant c-Met inhibition with PHA-665752 (RFA + PHA). PHA-665752 was administered at 0.83 mg/kg at 24 h post-RFA. Tumor growth was measured daily. MRI was performed 24 h before and 72 h after treatment on 14 rats, and the conversion of 13C-pyruvate into 13C-lactate within each tumor was quantified as lactate:pyruvate ratio (LPR). Comparisons of tumor growth and LPR were performed using paired and unpaired t-tests.

RESULTS: Hepatic RFA alone resulted in increased growth of the distant tumor compared to sham treatment (0.50 ± 0.13 mm/day versus 0.11 ± 0.07 mm/day; p < 0.001), whereas RFA + PHA (0.06 ± 0.13 mm/day) resulted in no significant change from sham treatment (p = 0.28). A significant increase in LPR was seen following hepatic RFA (+0.016 ± 0.010, p = 0.02), while LPR was unchanged for sham treatment (-0.048 ± 0.051, p = 0.10) or RFA + PHA (0.003 ± 0.041, p = 0.90).

CONCLUSION: In vivo hyperpolarized 13C MRI can detect hepatic RFA-induced increase in lactate flux within a distant R3230 tumor, which correlates with increased tumor growth. Adjuvant inhibition of c-Met suppresses these off-target effects, supporting a role for the HGF/c-Met signaling axis in these tumorigenic responses.

PURPOSE: Non-contrast CT ASPECTS (NCCTasp) has an established role in determining eligibility for mechanical thrombectomy in centers without ready access to perfusion or DWI. Moreover, it has been suggested that CTA source ASPECTS (CTAasp) may be superior to NCCTasp in predicting final infarct volume (FIV). In this study, we hypothesized that CTA maximum intensity projection ASPECTS (MIPSasp) would be superior compared to both NCCTasp and CTAasp in predicting FIV as measured by DWI.

MATERIALS AND METHODS: In 41 consecutive patients with MCA territory infarcts, NCCTasp, CTAasp and MIPSasp were visually assessed by 2 neuroradiologists. Disagreements were adjudicated by a third neuroradiologist, and the reconciled data used for all further analysis. MR-DWI was used as the standard for FIV determination. Receiver operating characteristic curve analysis was used to compare the area under the curve for all three CT-based methods in predicting FIV ≥70 ml.

RESULTS: MIPSasp (AUC: 0.98, CI: 0.88-1.00) were statistically better than NCCTasp (AUC: 0.87, 95% CI: 0.72-0.95; p=0.01) in predicting FIV ≥70 ml. MIPSasp were also superior to CTAasp (AUC: 0.9, CI: 0.79-.98; p˂0.05). Optimal test performance for predicting FIV ≥70 ml for MIPSasp was ≤6 (sensitivity=100%, specificity=91.4%; Youden's J=0.98).

CONCLUSION: Our preliminary study suggests that a novel CTA-MIPS derived ASPECTS better predicts large MCA territory infarcts compared to CTA source and non-contrast ASPECTS. Thus, MIPSasp may be a promising technique for future studies aimed at improving ischemic stroke treatment in centers using ASPECTS for stroke management.