ABSTRACT BACKGROUND: Teleradiology consists of electronic transmission of radiological images from one location to another, including between countries, for interpretation and/or consultation. It is one of the most successful applications of telemedicine. Combining this methodology with ultrasound (called telesonography) can accelerate the process of making diagnoses. Despite this rationale, the quality of the evidence about the effectiveness and accuracy of teleradiology remains unknown. OBJECTIVE: To review the literature on the evidence that exists regarding use of telemedicine for ultrasound in situations of synchronous transmission. DESIGN AND SETTING: Narrative review conducted within the evidence-based health program at a federal university in São Paulo (SP), Brazil. METHODS: A search of the literature was carried out in April 2020, in the online databases MEDLINE, EMBASE, Cochrane Library, Tripdatabase, CINAHL and LILACS, for original publications in all languages. The reference lists of the studies included and the main reviews on the subject were also evaluated. RESULTS: We included ten studies that assessed procedures performed by different healthcare professionals, always with a doctor experienced in ultrasound as a distant mentor. Among these, only one study assessed disease diagnoses in relation to real patients. CONCLUSIONS: Despite the promising position of telesonography within telemedicine, no studies with reasonable methodological quality have yet been conducted to demonstrate its effectiveness.

BACKGROUND: Computed tomography (CT) accounts for 13% of all radiological examinations in the United States and 40-70% of the radiation that patients receive. Even with the advent of magnetic resonance imaging (MRI), CT continues to be the gold standard for diagnosing bone fractures. There is uncertainty as to whether CT with a low radiation dose has a fracture detection rate similar to that of standard-dose CT. OBJECTIVE: To determine the detection rate of low-dose radiation CT and standard-dose radiation CT for fractures, in patients with suspected fractures. DESIGN AND SETTING: Systematic review of comparative studies on diagnostic accuracy within the evidence-based health program at a federal university in São Paulo (SP), Brazil. METHODS: We searched the electronic databases Cochrane Library, MEDLINE, EMBASE and LILACS up to June 29, 2020, for studies evaluating the detection rates of low-dose CT and standard-dose CT for diagnosing bone fractures. The Research Triangle Institute (RTI) item bank tool was used for methodological quality evaluation. RESULTS: The fracture detection rate according to the number of bones evaluated, using CT with low-dose radiation was 20.3%, while with standard-dose radiation it was 19.2%, and the difference between the methods was not significant. The fracture detection rate according to the number of patients, using CT with low-dose radiation was 56.0%, while with standard-dose radiation it was 58.7%, and this difference between the methods was not significant, either. CONCLUSION: CT with low-dose radiation presented detection rates similar to those of CT with standard-dose radiation, regardless of the bones evaluated. REGISTRATION NUMBER: CRD42019148491 at the PROSPERO database.