Iodine mapping in brain tumor imaging using dual-energy computed tomography

There is now a plethora of different imaging techniques used for diagnosing and treating brain tumors. Brain tumors are among the top causes of tumor-related deaths, with 10–15 out of every 100,000 people diagnosed in Europe and USA every year. The evaluation of tumors with medical imaging is now one of the primary concerns of radiology departments. Computed tomography (CT), magnetic resonance imaging (MRI), advanced techniques like perfusion and dynamic-susceptibility-contrast MRI and positron emission tomography (PET) play a vital role in brain tumor assessment with the high cost associated. The information provided by imaging modalities in evaluating brain lesions is critical for accurate diagnosis, therapeutic intervention and prognosis. Another area, which has been investigated extensively in tumor imaging, is differentiating between recurrent tumor and treatment-related changes – for example, radiationnecrosis or postsurgical changes. We propose the newly available dual-energy computed tomography (DECT) technology which will be the most cost-effective imaging modality to answer all the neuro-tumor assessment questions with one scan. DECT is a new innovation in CT technology. DECT employ two X-ray sources and two detector arrays fixed orthogonal to each other equipped for simultaneous acquisition operated at different energy levels for atomic iodine characterization [1]. Brain tumor under assessment can be imaged with one iodine contrast-enhanced DECT scan. The virtual-non-contrast images can be generated with post-processing; used for skull base erosion assessment and metastatic changes. The contrast-enhanced dualenergy images can generate iodine map of the tumor and iodine load which will be related to tumor vascularity and hence its malignant potentials [2]. Iodine mapping of brain will also help in grading the tumor and assessment of high tumor load zones which will be beneficial in radiotherapy planning. The similar contrast-enhanced DECT-imaging scan can be used in the follow-up after chemoradiotherapy. The recurrent/remnant tumor will again show iodine uptake but radiation-necrosis will be iodine-free zone. This proposed tumor assessment protocol will reduce the diagnostic financial load to patient without compromising equally good diagnostic assessment quality.