Feasibility of non-contrast-enhanced four dimensional (4D) MRA in head and neck tumors, comparison with contrast-enhanced 4D MRA.

BACKGROUND: Information of tumor vascular architecture and hemodynamics is important in treating patients with head and neck tumors (HNTs). The purpose of this study is to investigate the feasibility of non-contrast-enhanced four-dimensional magnetic resonance angiography (non-CE 4DMRA) using arterial spin labeling for anatomical and hemodynamic evaluation of vascularity of head and neck tumors. RESULTS: Non-CE 4DMRA images of 15 patients with HNTs were compared with those of contrast-enhanced 4DMRA (CE 4DMRA) by two independent observers. For qualitative evaluation, overall image quality, visualization of arterial branches and main arterial tumor feeders were assessed. For hemodynamic evaluation, signal-intensity-over-time curves within the tumors were compared. The sensitivity of non-CE 4DMRA for the identification of arterial branches and the main arterial tumor feeders was 75 and 20 %, respectively (interobserver agreement, κ = 0.56 and 0.54, respectively), while that of CE 4DMRA was 99 and 95 %, respectively (interobserver agreement, κ = 0.62 and 0.70, respectively). All three arterial/hypervascularized tumors determined on CE 4DMRA showed distinct signal-intensity-over-time curve pattern on non-CE 4DMRA, with distinct peak and wash out phases. Other tumors showed no wash out on non-CE 4DMRA. CONCLUSIONS: Use of non-CE 4DMRA for the anatomical and hemodynamic evaluation of vascularity of head and neck tumors is feasible, although the technique needs to be improved.

Different spatial distributions of brain metastases from lung cancer by histological subtype and mutation status of epidermal growth factor receptor.

BACKGROUND: The purpose of this study was to test the hypothesis that the genetic backgrounds of lung cancers could affect the spatial distribution of brain metastases. METHODS: CT or MR images of 200 patients with a total of 1033 treatment-naive brain metastases from lung cancer were retrospectively reviewed (23 by CT and 177 by MRI). All images were standardized to the human brain MRI atlas provided by the Montreal Neurological Institute 152 database. Locations, depths from the brain surface, and sizes of the lesions after image standardization were analyzed. RESULTS: The posterior fossa, the anatomic "watershed areas," and the gray-white matter junction were confirmed to be more commonly affected by lung cancer brain metastases, and brain metastases with epidermal growth factor receptor (EGFR) L858R mutation occurred more often in the caudate, cerebellum, and temporal lobe than those with exon 19 deletion of EGFR. Median depths of the lesions from the brain surface were 13.7 mm (range, 8.6-21.9) for exon 19 deleted EGFR, 11.5 mm (6.6-16.8) for L858R mutated, and 15.0 mm (10.0-20.7) for wild-type EGFR. Lesions with L858R mutated EGFR were located significantly closer to the brain surface than lesions with exon 19 deleted or wild-type EGFR (P = .0032 and P < .0001, respectively). Furthermore, brain metastases of adenocarcinoma lung cancer patients with a history of chemotherapy but not molecular targeted therapy were located significantly deeper from the brain surface (P = .0002). CONCLUSION: This analysis is the first to reveal the relationship between EGFR mutation status and the spatial distribution of brain metastases of lung cancer.

Correlation between the area of high-signal intensity on SPIO-enhanced MR imaging and the pathologic size of sentinel node metastases in breast cancer patients with positive sentinel nodes.

BACKGROUND: We previously demonstrated that superparamagnetic iron oxide (SPIO)-enhanced MR imaging is promising for the detection of metastases in sentinel nodes localized by CT-lymphography in patients with breast cancer. The purpose of this study was to determine the predictive criteria of the size of nodal metastases with SPIO-enhanced MR imaging in breast cancer, with histopathologic findings as reference standard. METHODS: This study included 150 patients with breast cancer. The patterns of SPIO uptake for positive sentinel nodes were classified into three; uniform high-signal intensity, partial high-signal intensity involving ≥50% of the node, and partial high-signal intensity involving <50% of the node. Imaging results were correlated with histopathologic findings. RESULTS: Thirty-three pathologically positive sentinel nodes from 30 patients were evaluated. High-signal intensity patterns that were uniform or involved ≥50% of the node were observed in 23 nodes that contained macro-metastases and no node that contained micro-metastases, while high-signal intensity patterns involving <50% of the node were observed in 2 nodes that contained macro-metastases and 8 nodes that contained micro-metastases. When the area of high-signal intensity was compared with the pathological size of the metastases, a pathologic >2 mm sentinel node metastases correlated with the area of high-signal intensity, however, a pathologic ≤2 mm sentinel node metastases did not. CONCLUSIONS: High-signal intensity patterns that are uniform or involve ≥50% of the node are features of nodes with macro-metastases. The area of high-signal intensity correlated with the pathological size of metastases for nodes with metastases >2 mm in this series.