Certain tumors of the head and neck use peripheral nerves as a direct conduit for tumor growth away from the primary site by a process known as perineural spread. Perineural spread is associated with decreased survival and a higher risk of local recurrence and metastasis. Radiologists play an important role in the assessment and management of head and neck cancer, and positron emission tomography/computed tomography (PET/CT) with 2-[fluorine 18]fluoro-2-deoxy-d-glucose (FDG) is part of the work-up and follow-up of many affected patients. Awareness of abnormal FDG uptake patterns within the head and neck is fundamental for diagnosing perineural spread. The cranial nerves most commonly affected by perineural spread are the trigeminal and facial nerves. Risk of perineural spread increases with a midface location of the tumor, male gender, increasing tumor size, recurrence after treatment, and poor histologic differentiation. Focal or linear increased FDG uptake along the V2 division of the trigeminal nerve or along the medial surface of the mandible, or asymmetric activity in the masticator space, foramen ovale, or Meckel cave should raise suspicion for perineural spread. If FDG PET/CT findings suggest perineural spread, the radiologist should look at available results of other imaging studies, especially magnetic resonance imaging, to confirm the diagnosis. Knowledge of common FDG PET/CT patterns of neoplastic involvement along the cranial nerves and potential diagnostic pitfalls is of the utmost importance for adequate staging and treatment planning.

Dural lymphoma (DL) is a rare type of primary CNS lymphoma arising from the dura mater. The optimal treatment is uncertain. A retrospective review was performed on 26 DL patients. Seventeen patients underwent resection and 9 had a biopsy. 23 patients could be assessed for a response to treatment after surgery. 13 received focal radiotherapy (RT), 6 whole brain RT (WBRT), 3 chemotherapy alone and 1 chemotherapy followed by WBRT. 22 achieved complete response (CR) and one a partial response (PR). Four patients relapsed (2 local and 2 systemic). Median follow up was 64 months, with median PFS and OS not reached. Three year PFS was 89% (95% CI 0.64–0.97). All patients are alive at last follow-up, demonstrating that DL is an indolent tumor with long survival. CR is achievable with focal therapy in the majority of cases, but there is a risk for relapses and long-term follow-up is recommended.

Object Cobalt-chromium alloy (CoCr) rods haves some preferred biomechanical properties over titanium rods for spinal fixation. The use of CoCr rods in spinal fusion is relatively new, and there is no study in the existing world literature assessing the artifact caused by these rods in patients undergoing postoperative MRI. The purpose of this study is to compare the amount of imaging artifact caused by these implants and to assess its impact on the visualization of neighboring neural structures. Methods This study investigated MR images in patients who underwent implantation of thoracolumbar instrumentation using 5.5-mm-diameter CoCr rods between November 2009 and March 2011 and images obtained in a comparison group of patients who had 5.5-mm titanium rods implanted during the same time period. Axial measurements of the artifact created by the rods between the screw heads were compared between the groups. Two blinded board-certified radiologists performed the measurements independently. They scored the visualization of the spinal canal using a subjective scoring system of 1–3, with 1 representing very good visualization and 2 and 3 representing reduced (good or suboptimal, respectively) visualization as a result of rod-related artifact. All measurements and scores were independently provided for T1-weighted and T2-weighted fast spin echo sequences (1.5-T magnet, 5-mm slice thickness). Results A total of 40 levels from the CoCr group (6 patients) and 30 levels from the titanium group (9 patients) were included in the analysis. Visualization of the canal at all levels was rated a score of 1 (very good) by both evaluators for both the CoCr and titanium groups. The average artifact on T1-weighted images measured 11.8 ± 1.8 mm for the CoCr group and 8.5 ± 1.2 mm for the titanium group (p < 0.01). The corresponding measurements on T2-weighted images were 11.0 ± 2.3 mm and 8.3 ± 1.7 mm (p < 0.01), respectively. In a mixed regression model, the mean artifact measurement for the CoCr group was, on average, 3.5 mm larger than for the control group. There was no significant difference between the measurements of the 2 evaluators (p = 0.99). Conclusions The artifact caused by CoCr rods is approximately 3.5 mm larger than that caused by titanium rods on axial T1- and T2-weighted MRI. However, artifact from either CoCr or titanium was not found to interfere with the evaluation of the spinal canal and surrounding neural elements.

A 21-year-old man with homozygous sickle cell disease maintained on hydroxyurea for 1 year developed thrombosis of the superior sagittal, right transverse, and right sigmoid dural sinuses with a large venous infarct. He was successfully treated with endovascular thrombolysis. Investigation did not reveal any inherited or acquired hypercoagulable state. This patient however had consistently elevated hemoglobin levels both at the time of the initial event and on follow up. One year later he developed symptomatic avascular necrosis of the right hip. High hemoglobin levels resulting from hydroxyurea therapy may have contributed to development of complications in this patient. Am. J. Hematol. 83:818-820, 2008. V

Osteoblastoma is a rare benign bone tumor that usually arises in the vertebral column and long bones of young adults. Craniofacial involvement is extremely rare. To date, osteoblastoma of the frontal sinus has not been reported in the English literature. We report an osteoblastoma of both frontal sinuses in a 23-year-old male who presented with headache and blurry vision in the left eye. Computed tomography (CT) demonstrated an expansile lesion involving both frontal sinuses with sclerotic and fibrous components, eroding into the roof of the left orbit. On magnetic resonance imaging (MRI) the dense portion of the lesion showed signal void on all sequences, while the fibrous matrix was isointense to grey matter on T1-weighted and T2-weighted images and showed avid enhancement following intravenous contrast administration. Surgical resection was performed and histology was consistent with osteoblastoma.