Chest radiograph classification and severity of suspected COVID-19 by different radiologist groups and attending clinicians: multi-reader, multi-case study

OBJECTIVES

To quantify reader agreement for the British Society of Thoracic Imaging (BSTI) diagnostic and severity classification for COVID-19 on chest radiographs (CXR), in particular agreement for an indeterminate CXR that could instigate CT imaging, from single and paired images.

METHODS

Twenty readers (four groups of five individuals)-consultant chest (CCR), general consultant (GCR), and specialist registrar (RSR) radiologists, and infectious diseases clinicians (IDR)-assigned BSTI categories and severity in addition to modified Covid-Radiographic Assessment of Lung Edema Score (Covid-RALES), to 305 CXRs (129 paired; 2 time points) from 176 guideline-defined COVID-19 patients. Percentage agreement with a consensus of two chest radiologists was calculated for (1) categorisation to those needing CT (indeterminate) versus those that did not (classic/probable, non-COVID-19); (2) severity; and (3) severity change on paired CXRs using the two scoring systems.

RESULTS

Agreement with consensus for the indeterminate category was low across all groups (28-37%). Agreement for other BSTI categories was highest for classic/probable for the other three reader groups (66-76%) compared to GCR (49%). Agreement for normal was similar across all radiologists (54-61%) but lower for IDR (31%). Agreement for a severe CXR was lower for GCR (65%), compared to the other three reader groups (84-95%). For all groups, agreement for changes across paired CXRs was modest.

CONCLUSION

Agreement for the indeterminate BSTI COVID-19 CXR category is low, and generally moderate for the other BSTI categories and for severity change, suggesting that the test, rather than readers, is limited in utility for both deciding disposition and serial monitoring.

KEY POINTS

• Across different reader groups, agreement for COVID-19 diagnostic categorisation on CXR varies widely. • Agreement varies to a degree that may render CXR alone ineffective for triage, especially for indeterminate cases. • Agreement for serial CXR change is moderate, limiting utility in guiding management.

Synthesis and evaluation of novel aldose reductase inhibitors: Effects on lens protein kinase Cgamma

PURPOSE

To synthesize novel aldose reductase inhibitors (ARI) that will normalize losses in protein kinase Cgamma (PKCgamma) observed during diabetes and galactosemia.

METHODS

ARI were synthesized as tricyclic pyrones 1-6 (HAR-1 through HAR-6) from 3-methyl-1H,7H-5a,6,8,9-tetrahydro-1-oxopyrano[4,3-b][1]benzopyran and (5aS,7S)-7-isopropenyl-3-methyl-1H,7H-5a,6,8,9-tetrahydro-1-oxopyrano[4,3-b][1]benzopyran and were tested by inhibition of aldose reductase enzyme activity in vitro and by inhibition of polyol formation in lens epithelial cells in culture. Identified compounds were further tested in galactosemic rat lens in vivo for (a) normalized PKCgamma levels by Western blot, (b) reduction of phosphorylation of the gap junction protein Cx46 by analyses of co-immunoprecipitated proteins, and (c) by normalization of gap junction activity as measured by dye transfer.

RESULTS

HAR-1 (1H,7H-5a,6,8,9-tetrahydro-1-oxopyrano[4,3-b][1]benzopyran-3-acetic acid) was identified as an ARI with IC50 for aldose reductase inhibition at 2 nM. Polyol accumulation in lens epithelial cells was reduced by 80% at 10 microM. Rats fed 40% galactose for 9 days had an 80% reduction in PKCgamma levels which were normalized by HAR-1 at 100 mg/kg/day, fed orally. Phosphorylation of Cx46 was increased by 50% and this was normalized in HAR-1 treated rats (6 day treatment). Gap junction activity of galactosemic rats was reduced by 55% and this was normalized by HAR-1 in six day-treated rats.

CONCLUSIONS

HAR-1 is a novel ARI which normalized losses of PKCgamma, changes in Cx46 phosphorylation, and gap junction activity.