Is MR-guided attenuation correction a viable option for dual-modality PET/MR imaging?

摘要: Habib Zaidi, PhD This is an exciting time for molecular imaging because medicine expected to lead a revolutionary paradigm shift in health care. While the nuclear community witnessing revolution practice of this specialty with introduction dual-modality positron emission tomography (PET) and computed (CT), many groups academic corporate settings are focusing their efforts on development promising multimodality technologies that will combine magnetic resonance (MR) PET components single gantry. One such preclinical system described by Judenhofer et al (1) issue Radiology, different design trends have been reported literature (2–8). Similar concepts also being investigated combined photon CT (SPECT) MR instrumentation (9). The recent interest simultaneous PET/MR not consequence controversies surrounding role clinical benefits PET/CT (10,11) but likely be subject similar critique debates. has motivated various factors several important incentives (12). First, used obtain anatomic structural images submillimeter spatial resolution offers better soft-tissue contrast sensitivity than offered CT. excellent between white gray matter allows functional brain studies, and, more importantly, it can assess flow, diffusion, perfusion, cardiac motion one examination (13). In addition, spectroscopy measure regional biochemical content metabolic status or presence neoplasia other diseases specific tissue areas. Finally, does involve use ionizing radiation; thus, without restrictions serial pediatric situations where radiation exposure concern. record distribution radiolabeled tracers; however, unlike spectroscopy, cannot distinguish species which radionuclide attached, imaging, provides little information. technical problems recently solved, there still challenges implementation operation must overcome. comparison x-ray CT, typically costly, involves longer times, produces from difficult at least as straightforward derive attenuation maps correction data (14). latter was (1), received only limited attention scientific few investigators addressed problem segmented construct map purposes (15). However, driving force behind worthwhile research undertaken groups. major difficulty lies fact signal intensity level directly related electronic attenuation, renders conversion less obvious when compared It worth emphasizing optimal transmission scanning technique (ie, versus sources) open remains (16). space available, placement external Published online 10.1148/radiol.2443070092