Dynamic contrast enhancement magnetic resonance imaging (DCE-MRI) for differential diagnosis in head and neck cancers.

PURPOSE: To examine the potential of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) for differential diagnosis of head and neck cancer. METHODS AND MATERIALS: DCE-MRI was performed in 26 patients with untreated squamous cell carcinoma (SCC), 28 undifferentiated carcinoma (UD) and 8 lymphoma. DCE-MRI was analyzed with the pharmacokinetic model proposed by Tofts and Kermode to produce the three DCE parameters: k(trans), v(e) and v(p). Areas under the curve (AUC) at the initial 60 and 90s (AUC60 and AUC90) were also recorded. Histogram analysis was conducted to obtain the mean, 25%, 50%, 75% and 95% percentile values and the Kruskal-Wallis test was used to compare the DCE parameters between the three groups of cancer. RESULTS: k(trans), AUC60 and AUC90 showed significant differences (p<0.01) between UD/SCC and UD/lymphoma, but not between SCC/lymphoma. The mean AUC90 demonstrated the highest accuracy of 78% (sensitivity of 68% and specificity of 88%) for distinguishing UD and SCC, and the 75% percentile AUC90 provided the highest accuracy of 97% (sensitivity of 100% and specificity of 88.5%) for distinguishing UD and lymphoma. CONCLUSIONS: There are significant differences in the DCE parameters which show the potential for distinguishing UD from SCC or lymphoma.

Radiation injury of the parotid glands during treatment for head and neck cancer: assessment using dynamic contrast-enhanced MR imaging.

The parotid gland is an important organ at risk of complications of radiotherapy for head and neck cancer. In this study, we examined the potential of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for assessment of radiation injury to the parotid glands. DCE-MRI was performed before and 3 months after radiotherapy in patients treated for head and neck cancer. DCE-MRI was analyzed using the pharmacokinetic model proposed by Tofts and Kermode to produce three DCE parameters: k(trans), v(e) and v(p). These parameters were correlated with the dose of radiation delivered to the parotid glands and the degree of radiation-induced parotid atrophy. The mean radiation dose received by the parotid glands was 47.1 ± 6.6 Gy. All patients received concurrent chemotherapy. There was a significant rise in all three parameters after therapy (P < 0.0001). Baseline v(e) and v(p) and the post-treatment rise in v(e) correlated with parotid gland atrophy (P  =  0.0008, 0.0003 and 0.0022, respectively). DCE-MRI has the potential to be used as a non-invasive technique for predicting and assessing radiation injury in the parotid glands.

Magnetic resonance imaging staging of nasopharyngeal carcinoma in the head and neck.

Magnetic resonance imaging (MRI) is the modality of choice for staging nasopharyngeal carcinoma in the head and neck. This article will review the patterns of primary and nodal spread on MRI with reference to the latest 7th edition of the International Union Against Cancer/American Joint Committee on Cancer staging system.

Effects of magnesium sulfate infusion on cerebral perfusion in patients after aneurysmal SAH.

BACKGROUND: A meta-analysis of current data suggests that magnesium sulfate infusion improves the outcome after aneurysmal subarachnoid hemorrhage through a reduction in delayed ischemic neurological deficit. Two multi-center randomized controlled trials are currently underway to investigate this hypothesis. The possible pharmacological basis of this hypothesis includes neuroprotection and vasodilatation. We aim to investigate the cerebral hemodynamic effects of magnesium sulfate infusion in aneurysmal subarachnoid hemorrhage patients. METHOD: A total of 12 patients who had experienced aneurysmal subarachnoid hemorrhage were randomized to magnesium sulfate infusion (n = 6) or placebo infusion (n = 6) for 14 days. Each patient had two perfusion MRIs performed, one in the first week after subarachnoid hemorrhage and one in the second week after subarachnoid hemorrhage. FINDINGS: Age, sex, and Fisher CT grade were not different between the two groups. All but one patient were of WFNS Grade I to II on presentation. There was no increase in rCBV, rCBF and MTT between the two perfusion scans within the same group or between the two groups. CONCLUSION: Magnesium sulfate infusion, in the dosage of current clinical trials, did not increase cerebral blood volume and cerebral blood flow, as postulated by dilation of small vessels and/or collateral pathways.