Although being a radiation free modality, MRI is not the first choice imaging tool for detection as well as classification of pulmonary nodules. Two methodical drawbacks predominate: Unfavourable artifacts through pulsation and breathing, particularly when standard spin echo sequences are used and the signal loss due to the microscopically heterogeneous magnetic susceptibility in the millions of air/tissue interfaces resulting in extremely short T2-star relaxation time. Furthermore, the low proton density of inflated lung tissue and the signal dephasing due to pulmonary blood flow hamper imaging. Long examination times, high costs and limited availability have also to be considered. On the other hand, new developments of MRI technique with the possibility of whole body imaging for screening and for staging malignant tumors, as well as the fusion of morphological and functional imaging, (i.e. PET/MRI as a new modality in the future) motivate research in this field. In the past, most of the MRI studies have investigated either the detection rate of pulmonary nodules in comparison with CT or the characterisation of SPN using dynamic contrast enhanced imaging. The latter approach seems to be a promising technique which reveals a higher accuracy than dynamic contrast CT in differentiating malignant from benign lesions.
Lernziele:
The objectives of this course are:
(a) to highlight the difficulties of proton imaging in normal lung,
(b) to discuss the technical aspects of dedicated imaging protocols,
(c) to review of the recent literature and
(d) to discuss the clinical impact of the method.
Korrespondierender Autor: Schäfer JF
Universitätsklinikum Tübingen, Abteilung für Radiologische Diagnostik, Hoppe-Seyler-Str. 3, 72076 Tübingen
E-Mail: juergen.schaefer@med.uni-tuebingen.de
