PMC6243347_01
(a) Transaxial CT, (b) PET, (c) PET/CT fusion and (d) MRI T1 weighted post-gadolinium images. The intensely enhancing cerebral lesions seen on MRI appear hypometabolic on the PET/CT images when compared with normal grey matter. PET, positron emission tomography.
bjrcr.20150443.g001.jpg
PMC6243347_01_bjrcr.20150443.g001.jpg
fig1
T1 weighted post-gadolinium images, showed several lesions in the right temporal lobe, the largest measuring up to 2.4 x 1.9 cm with intense irregular ring-like enhancement (Figures 1d and 2d). The lesions were associated with T2 hyperintensity and the differential diagnoses of the MRI findings included high-grade astrocytoma, lymphoma, metastases and infection, and the patient was referred for an 18F-fludeoxyglucose (FDG) positron emission tomography (PET)/CT scan (Discovery The PET/CT scan failed to show extracerebral 18F-FDG-avid lesions, and the intensely enhancing cerebral lesions described on MRI were hypometabolic [maximum standardized uptake value (SUVmax) 5.4] when compared with normal grey matter (SUVmax 10.1 for the basal ganglia and 7.6 for the sensorimotor cortex) (Figures 1a-c and 2a-c), which increased the likelihood of an infectious aetiology.
(a) Coronal CT, (b) positron emission tomography, (c) positron emission tomography/CT fusion and (d) MRI T1 weighted post-gadolinium images. The largest single lesion in the right temporal lobe measured 2.4 x 1.9 cm in the coronal plane.
bjrcr.20150443.g002.jpg
PMC6243347_01_bjrcr.20150443.g002.jpg
fig2
T1 weighted post-gadolinium images, showed several lesions in the right temporal lobe, the largest measuring up to 2.4 x 1.9 cm with intense irregular ring-like enhancement (Figures 1d and 2d). The lesions were associated with T2 hyperintensity and the differential diagnoses of the MRI findings included high-grade astrocytoma, lymphoma, metastases and infection, and the patient was referred for an 18F-fludeoxyglucose (FDG) positron emission tomography (PET)/CT scan (Discovery The PET/CT scan failed to show extracerebral 18F-FDG-avid lesions, and the intensely enhancing cerebral lesions described on MRI were hypometabolic [maximum standardized uptake value (SUVmax) 5.4] when compared with normal grey matter (SUVmax 10.1 for the basal ganglia and 7.6 for the sensorimotor cortex) (Figures 1a-c and 2a-c), which increased the likelihood of an infectious aetiology.
A follow-up MRI performed 2 years later with (a) transaxial and (b) coronal T1 weighted post-gadolinium images showed complete resolution of the right temporal lobe Histoplasma capsulatum lesions.
bjrcr.20150443.g003.jpg
PMC6243347_01_bjrcr.20150443.g003.jpg
fig3
A 2-year follow-up MRI showed complete resolution of the CNS histoplasmosis lesions (Figure 3).