Faculty Bibliography

In modern medicine brain imaging is an essential prerequisite not only to acute stroke triage but also to determining the specific therapy indicated. This article reviews the need for imaging the brain in acute stroke, penumbral pathophysiology, penumbral imaging techniques, as well as current status of various imaging modalities that are being employed to select patients for specific therapeutic approaches.

BACKGROUND: Cerebral radiation necrosis is a serious complication of radiation treatment for brain tumors. Therapeutic options include corticosteroids, anticoagulation and hyperbaric oxygen with limited efficacy. Bevacizumab, an antibody against VEGF had been reported to reduce edema in patients with suspected radiation necrosis. We retrospectively reviewed 6 patients with biopsy proven cerebral radiation necrosis treated with bevacizumab between 2006 and 2008. RESULTS: Interval MRI follow-up demonstrated radiographic response in all patients with an average reduction of 79% for the post gadolinium studies and 49% for the FLAIR images. The initial partial radiographic response was noted for up to a mean follow-up time of 5.9 months (6 weeks to 18 months). CONCLUSION: Bevacizumab appears to produce radiographic response and clinical benefits in the treatment of patients with cerebral radionecrosis.

Our objective is to assess treatment efficacy, safety and pattern of response and recurrence in patients with recurrent high-grade glioma treated with bevacizumab and irinotecan. We reviewed retrospectively 51 patients with recurrent high-grade glioma treated with this combination at the Henry Ford Hermelin Brain Tumor Center from 11/15/2005 to 04/01/2008. The 6-month progression-free survival (PFS) for anaplastic gliomas (AGs) was 78.6 and 63.7% for glioblastoma. The median PFS was 13.4 months for AG and 7.6 months for those with glioblastoma. The overall survival rate (OS) at 6 months was 85.7% for AG and 78.0% for glioblastoma. The 12-month OS was 77.9% for AG and 42.6% for glioblastoma. The median OS time for AGs was not reached and was 11.5 months for those with glioblastoma. Thirty-six out of 51 (70.59%) patients demonstrated partial (32/51) or complete (4/51) radiographic response to treatment and 8/51 (15.69%) remained stable. Of the 38 who demonstrated progression on post-gadolinium studies, 23 showed distant progression with or without local recurrence. Seven patients showed progression on FLAIR without concordant findings on post-Gd sequences. Six patients (11.76%) discontinued treatment due to a treatment-emergent adverse event, including one with end-stage renal failure and another with gastric perforation. No symptomatic intracranial hemorrhages were reported. Patients with recurrent high-grade glioma treated with bevacizumab plus irinotecan demonstrate an excellent radiographic response rate and improved clinical outcome when compared to historical data. The high rate of distant tumor progression suggests that tumors may adapt to inhibition of angiogenesis by increased infiltration and vascular co-option.

BACKGROUND AND PURPOSE: Glioma angiogenesis and its different hemodynamic features, which can be evaluated by using perfusion CT (PCT) imaging of the brain, have been correlated with the grade and the aggressiveness of gliomas. Our hypothesis was that quantitative estimation of permeability surface area product (PS), cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) in astroglial brain tumors by using PCT will correlate with glioma grade. High-grade gliomas will show higher PS and CBV as compared with low-grade gliomas. MATERIALS AND METHODS: PCT was performed in 32 patients with previously untreated astroglial tumors (24 high-grade gliomas and 8 low-grade gliomas) by using a total acquisition time of 170 seconds. World Health Organization (WHO) glioma grades were compared with PCT parameter absolute values by using Student or nonparametric Wilcoxon 2-sample tests. Receiver operating characteristic (ROC) analyses were also done for each of the parameters. RESULTS: The differences in PS, CBV, and CBF between the low- and high-grade tumor groups were statistically significant, with the low-grade group showing lower mean values than the high-grade group. ROC analyses showed that both CBV (C-statistic 0.930) and PS (C-statistic 0.927) were very similar to each other in differentiating low- and high-grade gliomas and had higher predictability compared with CBF and MTT. Within the high-grade group, differentiation of WHO grade III and IV gliomas was also possible by using PCT parameters, and PS showed the highest C-statistic value (0.926) for the ROC analyses in this regard. CONCLUSIONS: Both PS and CBV showed strong association with glioma grading, high-grade gliomas showing higher PS and CBV as compared with low-grade gliomas. Perfusion parameters, especially PS, can also be used to differentiate WHO grade III from grade IV in the high-grade tumor group.

Acute calcific retropharyngeal tendinitis or longus colli tendinitis is an uncommon benign condition presenting as acute neck pain. Clinically, it can be misdiagnosed as retropharyngeal abscess, traumatic injury, or infectious spondylitis. The diagnosis is made radiographically by calcification anterior to C1-C2 and prevertebral soft-tissue swelling. We present two cases of this uncommon condition to illustrate the classic findings on CT and MRI. In addition to the typical calcifications anterior to C1-C2, we detected a retropharyngeal effusion in both patients and effusions involving both lateral atlantoaxial joints in one patient, which to our knowledge has not been published in the literature. In both patients, the correct diagnosis was established by prospective review of the radiographic studies. Recognition of the pathognomonic imaging appearance allows for easy diagnosis preventing unnecessary tests and treatment.