IVIM imaging may be helpful for differentiation between benign and malignant salivary gland tumors.

BACKGROUND AND PURPOSE: ADCs may help distinguish benign from malignant head and neck diseases. We sought to evaluate the effectiveness of ADC for differentiating between carcinomas and lymphomas of the nasopharynx and oropharynx.

BACKGROUND AND PURPOSE:The sinonasal region is a platform for a broad spectrum of benign and malignant diseases, and image-based differentiation between benign and malignant diseases in this area is often difficult. Here, we evaluated multiparametric MR imaging with combined use of TICs and ADCs for the differentiation between benign and malignant sinonasal tumors and tumorlike diseases.

Purpose:To compare the diagnostic abilities of magnetic resonance imaging (MRI) and computed tomography (CT) based on the architectural changes in the nodal parenchyma. Materials and Methods:We retrospectively studied histologically proven 70 metastatic and 52 reactive nodes in the necks of 38 patients with head and neck squamous cell carcinomas who had undergone both CT and MRI. We assessed the detectability of the architectural changes in the nodal parenchyma that were suggestive of cancer focus (cancer nest, necrosis, and keratinization). The diagnostic abilities of CT and MRI were assessed by three observers separately for the small (Ͻ10 mm in minimum axis diameter) and large (Ն10 mm) nodes.Results: MRI was significantly more effective than CT in diagnosing small metastatic nodes, yielding 83% sensitivity, 88% specificity, and 86% accuracy. However, the diagnostic abilities of MRI and CT were similar for large metastatic nodes; MRI yielded 100% sensitivity, 98% specificity, and 99% accuracy. receiver operating characteristic analysis also indicated that the Az values were significantly higher for MRI than for CT (0.927 vs. 0.822, P ϭ 0.00054) for the detection of small nodes. Conclusion:MRI is superior to CT in the diagnosis of metastatic nodes from head and neck squamous cell carcinomas. THE PRESENCE of metastatic lymph node(s) in the neck significantly reduces the 5-year disease-specific survival in patients with head and neck squamous cell carcinomas (1). Therefore, staging of neck metastasis is a crucial step in managing patients with head and neck squamous cell carcinoma (2). Imaging has greatly contributed to the diagnosis of neck diseases in patients with head and neck cancers. For example, advances in cross-sectional imaging, including helical computed tomography (CT) and magnetic resonance imaging (MRI), have enabled detailed evaluation of both metastatic nodes in the necks and the primary lesions of patients with head and neck carcinomas (3). Compared to conventional CT, the helical CT improved the spatial resolution of the images and could offer information on the nodes, such as nodal size and architectures (4,5). Both nodal size and nodal necrosis have been widely used as criteria for metastatic nodes (6,7). A recent study using the receiver operating characteristic (ROC) curve analysis demonstrated that the performance of CT in detecting metastatic nodes was moderate, with the minimum axis diameter being a better size criterion compared with the maximum axial diameter (8). Nodal necrosis, the other diagnostic criterion, is identified on contrastenhanced CT as a low-attenuated focal defect with or without enhancement of the nodal periphery (9).MRI was expected to improve the ability to diagnose metastatic nodes in the neck. However, Curtin et al (10) demonstrated that the performance of MR was equivalent to or less effective than that of CT in the diagnosis of metastatic nodes in the neck. Given the fact that a necrotic focus is identified as a focal defect on contrastenhanced T1-weighted image...

Purpose:To evaluate the parallel imaging technique in the external carotid artery and its branches using 3D balanced turbo field echo (3D bTFE), 3D phase-contrast (3D PC), and 3D time-of-flight (3D TOF) MR angiography (MRA) sequences. Materials and Methods:A total of 26 healthy volunteer subjects underwent 3D bTFE, 3D PC, and 3D TOF MRA with the parallel imaging sensitivity encoding (SENSE) technique. The obtained images were read in a blinded fashion by three radiologists. Interreader and intersequence statistical analyses were performed to compare the visibility of the arteries. Results:Friedman's ranking test demonstrated that there was no significant difference in visibility between any two pairs of sequences for the external carotid artery and its first branches. However, of the three techniques, 3D PC MRA performed the best for the second-order branches (P Ͻ 0.01) and for overall visibility of the external carotid artery and its branches (P Ͻ 0.01). The 3D bTFE sequence is superior to 3D TOF; however, an effective means of separating arteries from veins and salivary ducts is needed. Conclusion:The combination of parallel imaging and the 3D PC technique is a promising approach for face and neck MRA.