Authors' reply

We welcome the interest in our study on the prevalence of MRI abnormalities in patients with FEP. MRI scanning could not be completed in 2.5% of patients (n = 6) in the clinical sample. According to the radiological reports, this was due to patient intolerance. As no further details were given, we are unable to provide any information regarding the reasons for this.

Although we agree with Van den Noort and colleagues that gender effects play an important role in MRI studies in patients with schizophrenia, we did not control for gender effects because our study did not reveal any gender differences in terms of the prevalence of radiological abnormalities, as we stated in the Results section.

As previous estimates of the prevalence of radiological abnormalities in patients with psychosis have mainly been based on studies with smaller sample sizes, using heterogeneous samples of patients recruited to research studies and heterogeneous imaging methods, the true prevalence of such abnormalities in patients with FEP is unclear. Because we adopted an exploratory approach to estimate the prevalence of radiological abnormalities, no specific rate was hypothesised. The implications of our findings for making decisions, particularly regarding the routine use of MRI in FEP, thus depend on the perspectives adopted.

As our study was not designed to examine cost–benefit analyses, we cannot draw any definite conclusions about health economic considerations. However, foiling to detect radiological abnormalities at an early stage can result in the patient not receiving the appropriate medical treatment for an underlying ‘organic’ condition, which may have serious consequences for that individual. We therefore think that it is prudent to scan patients with FEP in order to avoid this scenario, even if it is relatively uncommon.