Redefining normal facial nerve enhancement: healthy subject comparison of typical enhancement patterns--unenhanced and contrast-enhanced spin-echo versus 3D inversion recovery-prepared fast spoiled gradient-echo imaging.

OBJECTIVE: Normal facial nerve enhancement patterns derived from spin-echo (SE) sequences have not been systematically compared on contrast-enhanced 3D inversion recovery-prepared fast spoiled gradient-echo (IR-FSPGR) sequences, now in widespread use. We hypothesize that features unique to IR-FSPGR may engender differences in the appearance of the normal facial nerve, which may confound analysis of pathologic enhancement. We compared unenhanced and contrast-enhanced SE and IR-FSPGR sequences in a cohort of patients without facial nerve pathology. MATERIALS AND METHODS: Twenty-three patients without facial nerve pathology were examined. Unenhanced and contrast-enhanced signal intensity (SI) of seven facial nerve segments was assessed on SE and IR-FSPGR by two neuroradiologists. SI was assigned a value of 0-3 (0, absent; 1, faint; 2, equivalent to brain; 3, equivalent to enhancing dural sinus). Statistically significant differences were assessed for each segment. RESULTS: Significantly higher unenhanced and contrast-enhanced SI was present in most facial nerve segments on IR-FSPGR compared with SE, including cisternal, canalicular, labyrinthine, and geniculate segments (p ≤ 0.01). Enhancement patterns were generally similar; however, significant enhancement of the labyrinthine segment was detected only on SE (p = 0.011). For unenhanced images, mean kappa statistic was 0.32, and for the contrast-enhanced images, mean kappa statistic was 0.04, implying fair and slight agreement between readers, respectively. CONCLUSION: Significantly greater SI is observed in most facial nerve segments on both unenhanced and contrast-enhanced IR-FSPGR among healthy subjects and may be misinterpreted as pathologic when evaluated in the context of existing enhancement paradigms. Examiners should remain cognizant of normal deviations from expected enhancement patterns in IR-FSPGR imaging to avoid misdiagnosis and other interpretive pitfalls.

MR imaging for acute nontraumatic abdominopelvic pain: rationale and practical considerations.

Medical imaging is becoming an increasingly vital component of patient care in the emergency department. Computed tomography has been the diagnostic imaging method of choice for emergency department patients with acute abdominopelvic pain; however, the use of ionizing radiation and the potential need for exogenous contrast material adversely affect patient safety and work flow efficiency, respectively. Magnetic resonance (MR) imaging holds promise as an alternative for the evaluation of acute abdominopelvic pain. Critical causes of abdominopelvic pain may be detected with MR imaging without exogenous contrast material. MR imaging is sensitive for depicting tissue or fluid changes related to inflammation, a common process in causes of acute abdominopelvic pain. Fat suppression allows the detection of abnormal signal caused by inflamed tissue. MR imaging has proved sensitive in the detection of acute inflammatory diseases of the gallbladder and bile ducts, liver, pancreas, kidneys, collecting system, bowel, and pelvic soft tissues. Moreover, MR imaging without exogenous contrast material may be safely used in pregnant patients. Evolving roles for emergency department MR imaging include the assessment of vascular disease (including thromboembolic disease) and right upper quadrant pain. Emergency department MR imaging currently has limited availability, and its continued use will require further education regarding operation and image interpretation as well as further validation of cost-effectiveness. Nevertheless, current understanding of the diagnostic utility of this imaging method warrants continued study and the increased use of MR imaging in the evaluation of emergency department patients with acute abdominopelvic pain.

Internal carotid artery dissection following wooden arrow injury to the posterior pharynx. Case report.

In this report the authors describe a case of internal carotid artery (ICA) dissection following a blunt posterior pharynx injury and review current literature on the identification and treatment of such disorders. An ICA dissection developed in a 6-year-old boy who had suffered blunt injury to the posterior pharynx and who was followed up via computed tomography (CT) angiography and clinic visits for 6 months. The ICA dissection healed with pseudoaneurysm development and was treated with anticoagulation therapy. The authors searched the January 1996 through March 2007 MEDLINE database by using the Ovid search engine. They requested all English-language articles with the term "carotid dissection." Reference lists from these articles were retrieved and searched for additional relevant sources. The authors found that given its availability and speed of acquisition, CT angiography typically is the preferred initial diagnostic method. Magnetic resonance angiography is usually recommended for follow-up examination especially in pediatric cases. According to the available literature, the current preferred treatment for ICA dissection is anticoagulation.

Progressive supranuclear palsy: a current review.

BACKGROUND: Progressive supranuclear palsy (PSP) is the second most common cause of parkinsonism after Parkinson's disease (PD). The classic syndrome of PSP is widely recognized by neurologists as a combination of down gaze palsy with progressive rigidity and imbalance leading to falls. At the same time, few clinicians are proficient at treating PSP and recognizing the nonclassic presentations of this debilitating disorder often resulting in delays in diagnosis and misguided treatment. REVIEW SUMMARY: Over the last decade many lines of investigation have helped refine PSP at the clinical, neuroimaging, pharmacologic and molecular levels. It is the purpose of this literature review to help clinicians identify PSP earlier in its course, to better understand its pathophysiology, and to provide a more focused, symptom-based treatment approach. Eighty-two peer-reviewed articles on the topic of PSP and other neurodegenerative disorders have been reviewed. CONCLUSION: It is clear that PSP continues to be an under-recognized disorder with multilevel involvement of the neuraxis that helps differentiate it from other akinetic rigid syndromes such as PD. A greater appreciation of its atypical presentations, more attention to its neurobehavioral signs and better imaging techniques are some of the advances that will help facilitate earlier detection, which may reduce morbidity by helping anticipate early falls and minimizing unnecessary diagnostic procedures. Surgical approaches to PSP have been ineffective so far. Carefully targeted symptomatic treatment with drugs and other therapies is available and effective at reducing morbidity and improving quality of life.

Microbial diversity of Indian Ocean hydrothermal vent plumes: microbes tolerant of desiccation, peroxide exposure, and ultraviolet and gamma-irradiation.

The microbial diversity of Kali chimney plumes, part of a hydrothermal vent field in the Rodriguez Triple Junction, Indian Ocean (depth approximately 2,240 m), was examined in an attempt to discover "extremotolerant" microorganisms that have evolved unique resistance capabilities to this harsh environment. Water and sediment samples were collected from the vent and from sediments located at various distances (2-20 m) away from and surrounding the chimney. Samples were screened for hypertolerant microbes that are able to withstand multiple stresses. A total of 46 isolates were selected for exposure to a number of perturbations, such as heat shock, desiccation, H(2)O(2), and ultraviolet (UV) and gamma-irradiation. The survival of Psychrobacter sp. L0S3S-03b following exposure to >1,000 J/m(2) UV(254) radiation was particularly intriguing amid a background of varying levels of resistance. Vegetative cells of this non-spore-forming microbe not only survived all of the treatments, but also exhibited a 90% lethal dose of 30 s when exposed to simulated martian UV radiation and a 100% lethal dose of 2 min when exposed to full spectrum UV, which is comparable to findings for bacterial endospores.