Whole-body magnetic resonance imaging with ultra-short echo time sequence versus fluorodeoxyglucose-positron emission...

This study aimed to assess the diagnostic performance of whole-body magnetic resonance imaging (wbMRI) in comparison with gold standard ¹⁸F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) for detecting metastases in patients with gynecological cancer (GCa).

We prospectively enrolled five histologically proven GCa patients who underwent FDG-PET/CT and were identified with metastatic disease in their lungs. We customized a wbMRI protocol including ultra-short echo time (UTE) MRI sequence with a stack-of-spiral acquisition and imaged the patients on a 3 Tesla MRI scanner. Nuclear medicine physicians and radiologists reviewed the PET/CT and MRI images respectively and compared the findings for each patient. PET/CT images were accepted gold standard. We calculated the sensitivities of wbMRI and assessed the differences in diagnostic performance between PET/CT and wbMRI using McNemar's test (P < 0.05).

Three patients had cervical cancer while two had ovarian cancer. FDG-PET/CT detected a total of 44 findings (including nodules, lesions, and lymph nodes) across the five patients. WbMRI showed 39 findings with a sensitivity of 89%. McNemar's test revealed no statistically significant difference between wbMRI and PET/CT. The pre-contrast UTE sequence displayed 33 findings (33/44) and in detecting lung nodules, it displayed an accuracy of 70% (7/10).

This pilot study suggests that wbMRI demonstrates no statistically significant difference compared to ¹⁸FDG-PET/CT for detecting gynecological metastases. Furthermore, the UTE sequence proved valuable as part of the wbMRI protocol for detecting metastases without the need for a contrast agent.