carcinoma of the prostate is a common condition , with over 21 000 cases and over 10 000 deaths every year in the united kingdom alone . we describe two patients with known carcinoma of the prostate who presented with visual disturbance and papilloedema on examination . the first patient was a 76-year - old gentleman who presented to the urology service complaining of a poor stream . he re - presented to the urology service 30 months later with a serum psa of 378 g / l with macroscopic haematuria . a trans - rectal biopsy of the prostate was performed and poorly differentiated adenocarcinoma of the prostate was diagnosed . an mri scan was performed , which showed bony metastases in the occipital bone and oedema in the cerebellum ( figs 1 and 2 ) . the slightly hyper - intense signal in the superior sagittal sinus indicates that the thrombosis is between 5 and 15 days old and is due to the presence of methaemoglobin . the patient responded well to 20 gy ( in five fractions ) of radiotherapy , delivered to the occipital region . figure 1 
 t2w sagittal image of patient 1 , showing metastases in the occipital bone and oedema of the cerebellum.figure 2 
 t2w axial image of patient 1 , showing mixed signal in the sagittal sinus compatible with thrombosis . after treatment of the metastases with radiotherapy , follow - up imaging showed a return of a normal signal void . 
 t2w sagittal image of patient 1 , showing metastases in the occipital bone and oedema of the cerebellum . 
 t2w axial image of patient 1 , showing mixed signal in the sagittal sinus compatible with thrombosis . after treatment of the metastases with radiotherapy , follow - up imaging showed a return of a normal signal void . the second patient was a 62-year - old gentleman who was admitted to hospital with a history of recent onset of headaches , nausea , nocturia and macroscopic haematuria . positive findings on examination included bilateral papilloedema and a markedly ataxic gait with cerebellar ataxia . isotope bone scanning showed bony metastases in the thoracolumbar spine , the pelvis and the base of the skull . computed tomography ( ct ) of the brain did not demonstrate cerebral metastases but mri scanning did reveal bony metastases in the occiput ( fig . venous infarcts in the occipital lobes adjacent to the superior sagittal sinus were also demonstrated ( fig . figure 3 
 t2w axial image of patient 2 , showing metastases in the occipital bone and iso - intense signal in the occluded sagittal sinus . note the fluid around both optic nerves.figure 4 
 mrv ( 2d tof ) of patient 2 showing thrombus in the superior sagittal sinus.figure 5 
 coronal t1w image of patient 2 demonstrating high signal adjacent to the superior sagittal sinus compatible with haemorrhage . t2w axial image of patient 2 , showing metastases in the occipital bone and iso - intense signal in the occluded sagittal sinus . mrv ( 2d tof ) of patient 2 showing thrombus in the superior sagittal sinus . coronal t1w image of patient 2 demonstrating high signal adjacent to the superior sagittal sinus compatible with haemorrhage . the patient was commenced on cyproterone acetate and received 30 gy to the skull in 10 fractions over 14 days . papilloedema has been described in prostate carcinoma due to transverse sinus thrombosis , but this was a result of dural metastases at the torcula and not in the bone of the skull vault . bony metastases in the optic canal have also been described , causing painless visual loss . mri is effective at showing both bony metastases in carcinoma of the prostate and is the imaging modality of choice for cerebral venous sinus thrombosis . intravenous contrast - enhanced ct scanning may show filling defects in the superior sagittal sinus , but mri is more sensitive in the detection of superior sagittal thrombosis and venous oedema and of bone metastases . we would suggest that in a patient with visual disturbance , who is known to be suffering from a malignancy that may spread to bone , mri is the imaging modality of choice and the venous sinuses should be examined with mrv at the time of imaging .