Chest X-rays Highly Predictive of Covid-19

A paper published in Radiology; Cardiothoracic Imaging reports on a study of 366 patients who had a clinical presentation suspicious for Covid-19.  Radiologists reviewed the patients' chest X-rays along with concurrent reverse polymerase chain reaction (RT-PCR)  virus tests.  The patients mean age was 52.7 (range 17-98 years). RT-PCR tests took an average of 2.5 days until a final diagnosis became available. Radiologists found characteristic X-ray pattern such as confluent, ground glass opacification in the mid and lower lung fields highly specific (96.6%) with a positive predictive value of (83.8%) for making the diagnosis of SARS-CoV-2 viral infection.   

Double Reading Improves Breast Cancer Screening

A study by Taylor-Phillips et al published in Radiology reports that double reading of mammography screening studies increases the number of cancers detected and reduces recalls. 

The authors conducted a retrospective analysis, 805 206 women who were evaluated through screening and diagnostic studies at 33 English breast centers.

The first reader recalled (4.76%; 38 295 of 805 206 women). Two readers recalled 6.19% of women in total (49 857 of 805 206 women) but arbitration of discordant readings reduced the recall rate to 4.08%. A total of 7055 cancers were detected, of which 627 or 8.89% were detected by the second reader only. These additional cancers were more likely to be ductal carcinoma in situ 30.5%; (183 of 600 vs. 22.0%; 1344 of 6114, and additional invasive cancers were smaller (mean size, 14.2 vs. 16.7 mm), had fewer involved nodes, and were likely to be lower grade.

The authors concluded that double reading with arbitration reduces recall rates and increases cancer detection compared with single reading. 

Ambulance-Based Thrombolysis in Acute Ischemic Stroke

Ebinger et al report in JAMA the result a specialized ambulance has in the initiation of treatment in patients with acute ischemic strokes.

Their study was conducted in Berlin, Germany over a 21 months period between 2011 and 2013 when a Stroke Emergency Mobile (STEMO) unit was dispatched every other week to care of patients with strokes. The STEMO was an ambulance equipped with a CT scanner, point-of-care laboratory, with telemedicine connection, a physician, a paramedic and an x-ray technician. Thrombolysis was started before transport to hospital if ischemic stroke was confirmed and contraindications excluded.  During the study period 6182 adult patients were included.

There was a reduction of 25-minutes in alarm-to-treatment times for STEMO compared to control weeks.  The 25-minute reduction was due to faster alarm-to-imaging and imaging-to-treatment intervals. Fifty eight percent of patients were treated within 90 minutes of onset versus 37% in the control.  The intervention also resulted in 33% patients treated with tPA versus 21% in the control.  STEMO deployment incurred no increased risk for intra-cerebral hemorrhage (7/200 vs 22/323); or 7-day mortality (9/199 versus 15/323).

A prior study by Walter et al¹ who also used a mobile stroke unit and treated patients with acute ischemic stroke with tPA safely within 70 to 80 minutes.

The authors conclude the use of ambulance-based thrombolysis resulted in decreased time to treatment without an increase in adverse events. 

1.  Walter S, Kostopoulos P,  Haass A et al. Diagnosis and treatment of patients with stroke in a mobile unit versus hospital: a randomized study controlled trial Lancet Neurol. 2012;11(5):397-404