MR evaluation of patients with congenital hyposmia or anosmia.
OBJECTIVE
The purpose of this study was to evaluate patients with reduced or no sense of smell since birth for sites of abnormality by MR imaging.


METHODS
Twenty-five patients who reported no olfactory function since birth were evaluated by olfactory testing, sinonasal endoscopy, and MR imaging. Surface coil and head coil images of the olfactory bulbs, olfactory tracts, subfrontal cortex, and temporal lobes in contiguous 3-mm sections were obtained. Two reviewers determined unilateral olfactory bulb and tract volumes and temporal lobe volumes in two separate sessions. Qualitative grading for olfactory bulb, olfactory tract, olfactory sulcus, subfrontal region, hippocampus, and temporal lobe damage also was performed.


RESULTS
The absence of olfactory bulbs and tracts (68-84%) or the presence of hypoplasia (16-32%) was noted in all cases. Eight individuals had Kallmann's syndrome (hypogonadotropic hypogonadism with anosmia). Temporal and/or frontal lobe volume loss was noted in five individuals and was mild in all but one individual.


CONCLUSIONS
Congenital anosmia or hyposmia appears to be an olfactory bulb-olfactory tract phenomenon rather than a cerebral process.
Yousem
D M
DM
Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104, USA.
Geckle
R J
RJ
Bilker
W
W
McKeown
D A
DA
Doty
R L
RL
D000328:Adult; D005260:Female; D005625:Frontal Lobe / Q000473:pathology; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D017436:Kallmann Syndrome / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D000857:Olfaction Disorders / Q000151:congenital* / Q000473:pathology*; D009830:Olfactory Bulb / Q000002:abnormalities / Q000473:pathology*; D009831:Olfactory Mucosa / Q000473:pathology; D009833:Olfactory Pathways / Q000002:abnormalities / Q000473:pathology*; D013702:Temporal Lobe / Q000473:pathology