Comparative study of CT and MRI in patients with seizures and a solitary cerebral cysticercus granuloma.
We hypothesized that when contrast-enhanced CT reveals a solitary cerebral cysticercus granuloma, MRI would not usually provide additional information that might assist in management. We retrospectively compared visualisation of solitary cysticercus granulomas on contrast-enhanced CT and MRI in 16 patients presenting with seizures; gadolinium (Gd) enhancement was used in 6 patients. The granuloma was delineated well on both CT and MRI in 15 patients; in one patient, in whom CT was performed with 10-mm slices, it was seen only on contrast-enhanced MRI, CT and unenhanced MRI revealing only the surrounding oedema. On CT the granuloma was seen best on thin (2-5 mm) contrast-enhanced sections (in 10 patients). On MRI, Gd-enhanced images showed the granuloma best, as a ring-enhancing lesion, in all 6 patients. In the other 10 patients, the granuloma was seen only on T2-weighted images in 8 and on both T1- and T2-weighted images in 2. On T2-weighted images a characteristic low-signal ring with a high-signal centre was seen in 12 patients. Sensitivity of the imaging techniques was: contrast-enhanced CT (5 and 10 mm slices) 93.8% (15/16); thin (2-5 mm) section contrast-enhanced CT 100% (6/6); unenhanced MRI 93.8% (15/16). MRI did not reveal additional granulomas or cysts in any patient. In patients strongly suspected to be harbouring this lesion, when 10-mm contrast-enhanced CT reveals only oedema, thin (2-5 mm) slice CT is a cost-effective alternative to MRI.
Rajshekhar
V
V
Department of Neurological Sciences, Christian Medical College Hospital, Vellore, India.
Chandy
M J
MJ
D000293:Adolescent; D000328:Adult; D001927:Brain Diseases / Q000175:diagnosis*; D001929:Brain Edema / Q000175:diagnosis; D003287:Contrast Media; D003551:Cysticercosis / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D005682:Gadolinium; D006099:Granuloma / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D012640:Seizures / Q000209:etiology*; D014057:Tomography, X-Ray Computed
D003287:Contrast Media; D005682:Gadolinium