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561.
562.
The impact of prescribed opioids on CD4 cell count recovery among HIV‐infected patients newly initiating antiretroviral therapy
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Unilateral hypoxic-ischemic injury in young children from abusive head trauma, lacking craniocervical vascular dissection or cord injury 总被引:1,自引:0,他引:1
McKinney AM Thompson LR Truwit CL Velders S Karagulle A Kiragu A 《Pediatric radiology》2008,38(2):164-174
Background Abusive head trauma (AHT) in young children usually has a severe outcome when associated with hypoxic-ischemic encephalopathy
(HIE), which is best characterized by MRI in the acute or subacute phase utilizing diffusion-weighted imaging (DWI). HIE in
this setting has been hypothesized to result from stretching of the spinal cord, brainstem, or vasculature.
Objective To provide clinical correlation in patients with unilateral HIE and to postulate a mechanism in the setting of suspected AHT.
Materials and methods IRB approval was obtained. Over a 5-year period, the medical records and images were reviewed of the 53 children ≤3 years
of age who presented with acute head trauma according to the hospital registry. The children were subselected in order to
determine how many suffered either HIE or AHT, and to detect those with unilateral HIE.
Results In 11 of the 53 children, the etiology of the head trauma was highly suspicious for abuse. In 38 the head trauma was accidental
and in 4 the trauma was of unknown etiology and at the time of this report was unresolved legally. Of the 53, 4 suffered HIE
confirmed by CT or MRI. In three of these four with HIE the trauma was considered highly suspicious for AHT. Two of these
three were the only patients with unilateral HIE, and both (7 months and 14 months of age) presented with early subacute phase
HIE seen on DW MRI (range 4–7 days) and are described in detail with clinical correlation. The third child with AHT and HIE
had bilateral findings. In the fourth patient the HIE was bilateral and was considered accidental. The work-up for both patients
with unilateral HIE included head CT, craniocervical MRI, and craniocervical MR angiography (MRA). In both, there was mostly
unilateral, deep white matter restricted diffusion, with subdural hematomas that were small compared to the extent of hypoxic-ischemic
insult, and no skull fracture. Craniocervical MRA and axial thin-section fat-saturation images were negative for dissection,
brainstem, or cord injury. Legal authorities obtained a confession of inflicted injury in one and a partial confession in
the second (which did not fit the extent of injury). Five other children with HIE (based on DWI) were found during this period
who had not suffered head trauma; all were bilateral insults.
Conclusion HIE associated with AHT might present with largely unilateral white matter injury on DWI following extensive cortical infarction.
We propose that unilateral HIE in a young child might be a sign of AHT and might result from cervical vascular compression,
whether from kinking during hyperflexion/hyperextension or from direct strangulation. 相似文献
566.
Martin AJ Hall WA Roark C Starr PA Larson PS Truwit CL 《Journal of magnetic resonance imaging : JMRI》2008,27(4):737-743
PURPOSE: To evaluate the capabilities of MR-guided "prospective stereotaxy" methods for accessing brain structures for biopsy or electrode implantation. MATERIALS AND METHODS: MR-guided biopsy and deep brain stimulator (DBS) electrode implantations were performed with a trajectory guide and real-time MR guidance. Imaging methods were used to plan the selected path through the brain, appropriately orient the trajectory guide, and monitor the device insertion to assure technical success and screen for hemorrhage. Assessments of technical success rate, targeting accuracy, and complications associated with this technique were performed. RESULTS: A total of 187 biopsy procedures were performed with guidance via prospective stereotaxy methods. All brain biopsies were diagnostic and two patients sustained superficial wound infections that were treated successfully with antibiotics. One patient died postoperatively of a myocardial infarction despite preoperative medical clearance. A total of 42 DBS electrode insertions were performed in patients with Parkinson's disease or dystonia. The difference between planned and actual electrode position averaged 1.2 mm +/- 0.7 mm on the first pass and only a single brain penetration was required in 90% of electrode insertions. Complications included a single asymptomatic hemorrhage and two early infections, with the latter addressed by an adjustment to sterile practice. CONCLUSION: Prospective stereotaxy, in combination with a trajectory guide, has been proven capable of efficiently and accurately targeting structures throughout the brain. 相似文献
567.
Carotid bifurcation calcium and correlation with percent stenosis of the internal carotid artery on CT angiography 总被引:11,自引:1,他引:10
The aim of this paper was to determine the correlation between calcium burden (expressed as a volume) and extent of stenosis of the origin of the internal carotid artery (ICA) by CT angiography (CTA). Previous studies have shown that calcification in the coronary arteries correlates with significant vessel stenosis, and severe calcification (measured by CT) in the carotid siphon correlates with significant (greater than 50% stenosis) as determined angiographically. Sixty-one patients (age range 50–85 years) underwent CT of the neck with intravenous administration of iodinated contrast for a variety of conditions. Images were obtained with a helical multidetector array CT scanner and reviewed on a three-dimensional workstation. A single observer manipulated window and level to segment calcified plaque from vascular enhancement in order to quantify vascular calcium volume (cc) in the region of the bifurcation of the common carotid artery/ICA origin, and to measure the extent of ICA stenosis near the origin. A total of 117 common carotid artery bifurcations were reviewed. A significant stenosis was defined arbitrarily as >40% (to detect lesions before they become hemodynamically significant) of luminal diameter on CTA using NASCET-like criteria. All significant stenoses (21 out of 117 carotid bifurcations) had measurable calcium. We found a relatively strong correlation between percent stenosis and the calcium volume (Pearsons r = 0.65, P<0.0001). We also found that there was an even stronger correlation between the square root of the calcium volume and the percent stenosis as measured by CTA (r= 0.77, P<0.0001). Calcium volumes of 0.01, 0.03, 0.06, 0.09 and 0.12 cc were used as thresholds to evaluate for a significant stenosis. A receiver operating characteristic (ROC) curve demonstrated that thresholds of 0.06 cc (sensitivity 88%, specificity 87%) and 0.03 cc (sensitivity 94%, specificity 76%) generated the best combinations of sensitivity and specificity. Hence, this preliminary study demonstrates a relatively strong relationship between volume of calcium at the carotid bifurcation in the neck (measured by CT) and percent stenosis of the ICA below the skull base (as measured by CTA). Use of calcium volume measurements as a threshold may be both sensitive and specific for the detection of significant ICA stenosis. The significance of the correlation between calcium volume and ICA stenosis is that potentially a score can be obtained that will identify those at risk for high grade carotid stenosis.Presented at the 41st Annual Meeting of the American Society of Neuroradiology, Washington D.C., 2003. Sean Casey, MD and Charles Truwit, MD are members of the Medical Advisory Board of Vital Images (Plymouth, Minnesota), the company that developed the Vitrea 2 software. 相似文献
568.
The technique for performing brain biopsy has evolved significantly over the last three decades. Intraoperative MRI guidance has enhanced the diagnostic rate for brain biopsy by now allowing neurosurgeons to compensate for brain shift while performing the procedure in near-real time. The development of a trajectory guide enables the neurosurgeon to determine a safe and accurate path for intraoperative MRI-guided brain biopsy and to secure the position of the needle within the target tissue. Magnetic resonance spectroscopy (MRS) has been used to help distinguish recurrent brain tumor from the effect of previous treatments by measuring specific metabolites within the area of concern. Combining the use of a trajectory guide with MRS should enhance the diagnostic yield for MRI-guided brain biopsy. 相似文献
569.
Silva IA Nyland JF Gorman A Perisse A Ventura AM Santos EC Souza JM Burek CL Rose NR Silbergeld EK 《Environmental health : a global access science source》2004,3(1):11
Background
Mercury is an immunotoxic metal that induces autoimmune disease in rodents. Highly susceptible mouse strains such as SJL/N, A.SW, B10.S (H-2s) develop multiple autoimmune manifestations after exposure to inorganic mercury, including lymphoproliferation, elevated levels of autoantibodies, overproduction of IgG and IgE, and circulating immune complexes in kidney and vasculature. A few studies have examined relationships between mercury exposures and adverse immunological reactions in humans, but there is little evidence of mercury-associated autoimmunity in humans. 相似文献570.
McKinney AM Filice RW Teksam M Casey S Truwit C Clark HB Woon C Liu HY 《Neuroradiology》2004,46(4):291-295
Manganese is an essential trace metal required for normal central nervous system function, which is toxic when in excess amounts in serum. Manganese neurotoxicity has been demonstrated in patients with chronic liver/biliary failure where an inability to excrete manganese via the biliary system causes increased serum levels, and in patients on total parenteral nutrition (TPN), occupational/inhalational exposure, or other source of excess exogenous manganese. Manganese has been well described in the literature to deposit selectively in the globi pallidi and to induce focal neurotoxicity. We present a case of a 53-year-old woman who presented for a brain MR 3 weeks after liver transplant due to progressively decreasing level of consciousness. The patient had severe liver failure by liver function tests and bilirubin levels, and had also been receiving TPN since the transplant. The MR demonstrated symmetric hyperintensity on T1-weighted images in the globi pallidi. Apparent diffusion coefficient (ADC) map indicated restricted diffusion in the globi pallidi bilaterally. The patient eventually succumbed to systemic aspergillosis 3 days after the MR. The serum manganese level was 195 mcg/l (micrograms per liter) on postmortem exam (over 20 times the upper limits of normal). The patient was presumed to have suffered from manganese neurotoxicity since elevated serum manganese levels have been shown in the literature to correlate with hyperintensity on T1-weighted images, neurotoxicity symptoms, and focal concentration of manganese in the globi pallidi. Neuropathologic sectioning of the globi pallidi at autopsy was also consistent with manganese neurotoxicity.This work was presented in part at the 40th Annual Meeting of the American Society of Neuroradiology, Vancouver, BC, 2002. 相似文献