What's new in imaging? New magnetic resonance imaging of esophageal cancer using an endoluminal surface coil and antibody-coated magnetite particles.

An endoluminal surface coil: Esophageal cancer was studied by high resolution magnetic resonance imaging (MRI) to determine the histopathologic basis for signal intensity in these lesions and to determine the potential of this modality for evaluating the depth of cancer invasion. In a basic study, 14 tumors were examined with a 1.5-T superconductive MR system using a surface coil. The esophageal wall could be differentiated into four layers on the T1-weighted images and seven layers on the T2-weighted images. The signal intensity of the tumor varied from low to intermediate on the T1- and T2-weighted images. The submucosal layer is important in evaluating cancer invasion on the T2-weighted images. In a clinical study, 30 patients with esophageal cancer were examined with a 1.5-T superconductive MR system using an endoluminal surface coil. In terms of depth of cancer invasion, the accuracy rate of MRI using the endoluminal surface coil was 83%. In conclusion, MRI with an endoluminal surface coil will be a useful examination for esophageal cancer in the future. Antibody-coated magnetite particles: A highly specific and effective MRI contrast agent was prepared by coating superparamagnetite particles with monoclonal antibodies (MAbs) directed against epidermal growth factor receptors (EGFRs), which are overexpressed in esophageal squamous cell carcinoma. The agent was shown to have EGFR-specific MRI contrast capacity in vivo in athymic rats bearing TE8 or H69 tumors. Immunospecific MRI using magnetite particles coated with MAbs against EGFR seems to be useful in the diagnosis of squamous cell carcinoma of the esophagus.