Diagnostic evaluation of magnetic resonance imaging with turbo inversion recovery sequence in head and neck tumors

Non-contrast MRI for breast screening: preliminary study on detectability of benign and malignant lesions in women with dense breasts

PURPOSE

The importance of breast cancer screening has long been known. Unfortunately, there is no imaging modality for screening women with dense breasts that is both sensitive and without concerns regarding potential side effects. The purpose of this study is to explore the possibility of combined diffusion-weighted imaging and turbo inversion recovery magnitude MRI (DWI + TIRM) to overcome the difficulty of detection sensitivity and safety.

METHODS

One hundred and seventy-six breast lesions from 166 women with dense breasts were retrospectively evaluated. The lesion visibility, area under the curve (AUC), sensitivity and specificity of cancer detection by MG, DWI + TIRM, and clinical MRI were evaluated and compared. MG plus clinical MRI served as the gold standard for lesion detection and pathology served as the gold standard for cancer detection.

RESULTS

Lesion visibility of DWI + TIRM (96.6%) was significantly superior to MG (67.6%) in women with dense breasts (p < 0.001). There was no significant difference compared with clinical MRI. DWI + TIRM showed higher accuracy (AUC = 0.935) and sensitivity (93.68%) for breast cancer detection than MG (AUC = 0.783, sensitivity = 46.32%), but was comparable to clinical MRI (AUC = 0.944, sensitivity = 93.68%). The specificity of DWI + TIRM (83.95%) was lower than MG (98.77%), but higher than clinical MRI (77.78%).

CONCLUSIONS

DWI combined with TIRM could be a safe, sensitive, and practical alternative for screening women with dense breasts.

A subjective and objective comparison of tissue contrast and imaging artifacts present in routine spin echoes and in iterative decomposition of asymmetric spin echoes for soft tissue neck MRI

OBJECTIVE

FSE sequences play key roles in neck MRI despite the susceptibility issues in neck region. Iterative decomposition of asymmetric echoes (IDEAL, GE) is a promising method that separates fat and water images resulting in high SNR and improved fat suppression. We tested how neck tissue contrasts, image artifacts and fat separation as opposed to fat suppression in terms of image quality compare between routine and IDEAL FSE.

METHODS

IDEAL based and routine T₁ and T₂-weighted FSE sequences were applied for neck MRI at 1.5T and 3T. Overall image quality including fat suppression, tissue contrast, image artifacts and lesion conspicuity were subjectively assessed for 20 patients clinically indicated for neck MRI. Quantitative tissue contrast estimates from parotid area were compared between IDEAL and routine FSE for 7 patients. Four patients with oncocytoma were also reviewed to assess benefits of separately reconstructed fat specific image sets.

RESULTS

Subjective tissue contrast and overall image quality including image sharpness, fat suppression and image artifacts were superior for IDEAL sequences. For oncocytoma fat specific IDEAL images provided additional information. Objective CNR estimates from a central slice were equivalent for IDEAL and routine FSE at both field strengths.

CONCLUSIONS

We demonstrated that high SNR inherent in IDEAL FSE consistently translates into high tissue contrast with image quality advantages in neck anatomy where large susceptibility variation and physiological motions reduce image quality for conventional FSE T₁ and T₂. However, the objective contrast estimates for parotid gland at isocenter were statistically equivalent for IDEAL and conventional FSE perhaps because at or near isocenter routine FSE works well. Additionally, fat specific IDEAL image sets add to diagnostic specificity for fat deficient lesions.

Value of diffusion-weighted MR imaging performed with quantitative apparent diffusion coefficient values for cervical lymphadenopathy

PURPOSE

To assess diffusion-weighted magnetic resonance imaging (DWI-MRI) performed with apparent diffusion coefficient (ADC) values for the detection of cervical lymphadenopathy.

MATERIALS AND METHODS

Studies evaluating DWI-MRI for the detection of cervical lymphadenopathy were systematically searched for in the MEDLINE, EMBASE, Cancerlit, and Cochrane Library and other database from January 1995 to November 2010. By node-based data analyses, Cochrane methodology was used for the results of this meta-analysis.

RESULTS

Eight studies enrolling a total of 229 individuals were eligible for inclusion. Significant differences were found between malignant nodes and benign nodes of the mean ADC value (WMD [weighted-mean difference]: 1.19, 95% CI: [1.02, 1.35] × 10(-3) mm(2) /s, [P < 0.05]). In the secondary outcomes, significant differences were found between lymphomatous nodes and benign nodes (WMD: 1.33, 95% CI: [0.89, 1.77] × 10(-3) mm(2) /s), and nodes originating from highly or moderately differentiated cancer (WMD: 0.24, 95% CI: [0.21, 0.28] × 10(-3) mm(2) /s, [P < 0.05]), and nodes originating from poorly differentiated cancers (WMD: 0.10, 95% CI: [0.06, 0.14] × 10(-3) mm(2) /s, [P < 0.05]).

CONCLUSION

DWI-MRI performed with ADC values shows significant differences among malignant nodes, lymphomatous nodes, and benign nodes in cervical lymphadenopathy.

Imaging of oral cancer

This article reviews imaging modalities commonly used to evaluate oral cavity cancers and their metastases to lymph nodes. It discusses how the studies are performed and their relative merits. It also presents new techniques for evaluating these neoplasms.