Loss of visualization of digitations of hippocampal head in MRI in the evaluation of hippocampal sclerosis

Wenhua LI; Tianzhen SHEN; Jinyong ZHU; Weixing ZHONG

ABSTRACT

BACKGROUND:

At present, MRI is the key method to examine the hippocampal sclerosis of the patients with epilepsy. The main results are the abnormal signals of hippocampus, in addition, other symbols of MRI can also suggest the hippocampal sclerosis.

OBJECTIVE:

To study the significance and value of the loss of visualization of digitations of hippocampal head in diagnosis of hippocampal sclerosis through the analysis of MRI on patients with temporal lobe epilepsy.

DESIGN:

Non-randomized, blind procedure(data selection, result evaluation), blank controlled and clinical experiment.

SETTING:

Departments of radiology in two universities.

PARTICIPANTS:

Between September 1996 and December 2002, 18 patients with temporal lobe epilepsy were selected from the Department of Radiology,Xinhua Hospital Affiliated to Shanghai Second Medical University. Meanwhile,patients with headache were diagnosed with MRI. Eighteen healthy people,whose ages were matched, were as control group.

METHODS:

Among 18 patients, MRI of 16 patients and 18 people in the control group were performed with a GE 1.5T Horizon MR unit and another 2with a GE 1.5T Signa whole body MR unit. With the double blind procedure, whether the digitations of hippocampal head of 72 hippocampal heads of 36 people in both patient and control groups exist or not was recorded by two radiologists with knowledge of hippocampal dissection but without knowing the condition of clinical operation. The results were divided into 3 levelsloss, poorly visible and existing, and hippocampal atrophy and abnormal signals were also recorded.MAIN OUTCOME

MEASURES:

Image condition of digitations of head,size of hippocampal head and changes of signal.

RESULTS:

Of 18 patients with hippocampal sclerosis, the abnormal findings included smooth and the loss of visualization of digitations of hippocampal heads seen in 16 patients, poorly visible of digitations of hippocampal head in one patient, and existence of digitations of hippocampal head in one patient. Hippocampal atrophy and high signals on T2-weighted images and fluid-attenuated inversion recovery imaging were seen in all patients. The sensitivity of loss of digitations of hippocampal heads for diagnosis of hippocampal sclerosis was 88.9% (16/18), and the specificity was 100%.CONCLUSSION The loss of visualization of digitations of hippocampal head is a sensitive indicator for the diagnosis of hippocampal sclerosis. Atrophic changes of hippocampus combining with the increase of T2-weighted signal can definitely diagnose the hippocampal sclerosis.