Automatized "Semi-Whole-Body"-MRI Protocol for Cancer Staging

Whole-body imaging becomes increasingly important in oncologic patients not only for primary cancer staging, but also for assessment of response to therapy. So far, PET/CT is a key method to assess cancer-related changes of metabolism in tumors, which is crucial for response evaluation and to differentiate between benign and malignant lesions. Limitations of PET/CT include the assessment of sclerotic bone metastasis, which often do not show increased tracer uptake. Certain organ metastasis (especially in brain and liver) are also barely detectable due to physiologically increased uptake. Moreover, both CT and administration of radioactive tracer are associated with radiation exposure for patients. Whole-body MRI (wb-MRI) including functional techniques (e.g. Diffusion-weighted Imaging (DWI) to evaluate cell density) enables a functional staging and therapy assessment without use of ionizing radiation. Advantages to assess sclerotic bone lesions and organ metastases have been confirmed in recent literature. Limitations of MRI include detection of lesions in organs with high susceptibility and motion like the thorax.