Susceptibility Weighted Imaging and White Matter Abnormality Findings in Service Members With Persistent Cognitive Symptoms Following Mild Traumatic Brain Injury.

Mild traumatic brain injury (mTBI) is a major health concern among active duty service members and Veterans returning from combat operations, and it can result in variable clinical and cognitive outcomes. Identifying biomarkers that can improve diagnosis and prognostication has been at the forefront of recent research efforts. The purpose of this study was to compare the sensitivity and specificity of abnormalities identified using more traditional magnetic resonance imaging (MRI) sequences such as fluid attenuation inversion recovery (FLAIR) to more advanced MRI sequences such as susceptibility weighted imaging (SWI) among a cohort of active duty service members experiencing persistent cognitive symptoms after mTBI. One-hundred and fifty-two active duty service members (77 mTBI, 58 orthopedically injured [OI] only, 17 post-traumatic stress disorder [PTSD] only) underwent MRI and neuropsychological evaluation at a large military treatment facility. Results demonstrated that FLAIR white matter hyperintensities (WMHs) were present in all three groups at statistically similar rates (41% mTBI, 49% OI, and 29% PTSD). With the exception of a single OI participant showing a small discrete SWI lesion, SWI abnormalities were overwhelmingly present in mTBI patients (22% mTBI, 1% OI, and 0% PTSD). Functionally, mTBI participants with and without SWI abnormalities did not differ in demographics, symptom reporting, or cognitive performance. However, mTBI participants with and without WMH did differ for on measures of working memory with the mTBI participants with WMH having worse cognitive performance. No other significant differences were noted for those participants with and without imaging abnormalities for either the OI or PTSD only cohorts. These results appear to illustrate the sensitivity and specificity of SWI findings though these results did not have any significant functional impact in this cohort. In contrast, WMHs noted on FLAIR imaging were not sensitive or specific findings, but functionally relevant among mTBI participants. These findings emphasize the complexity of injury and functional outcome in mTBI patients that requires additional examination.

Comparing Two Processing Pipelines to Measure Subcortical and Cortical Volumes in Patients with and without Mild Traumatic Brain Injury.

PURPOSE: To compare volumetric results from NeuroQuant® and FreeSurfer in a service member setting. Since the advent of medical imaging, quantification of brain anatomy has been a major research and clinical effort. Rapid advancement of methods to automate quantification and to deploy this information into clinical practice has surfaced in recent years. NeuroQuant® is one such tool that has recently been used in clinical settings. Accurate volumetric data are useful in many clinical indications; therefore, it is important to assess the intermethod reliability and concurrent validity of similar volume quantifying tools. METHODS: Volumetric data from 148 U.S. service members across three different experimental groups participating in a study of mild traumatic brain injury (mTBI) were examined. Groups included mTBI (n = 71), posttraumatic stress disorder (n = 22), or a noncranial orthopedic injury (n = 55). Correlation coefficients and nonparametric group mean comparisons were used to assess reliability and concurrent validity, respectively. RESULTS: Comparison of these methods across our entire sample demonstrates generally fair to excellent reliability as evidenced by large intraclass correlation coefficients (ICC = .4 to .99), but little concurrent validity as evidenced by significantly different Mann-Whitney U comparisons for 26 of 30 brain structures measured. CONCLUSION: While reliability between the two segmenting tools is fair to excellent, volumetric outcomes are statistically different between the two methods. As suggested by both developers, structure segmentation should be visually verified prior to clinical use and rigor should be used when interpreting results generated by either method.

Postoperative imaging of the orbital contents.

Ophthalmologists perform a wide array of interventions on the orbital contents. The surgical treatment of glaucoma, cataracts, retinal detachment, and ocular trauma or malignancy results in alteration of the standard anatomy, which is often readily evident at radiologic examinations. The ability to accurately recognize the various imaging manifestations after orbital surgery is critical for radiologists to avoid misdiagnosis. Of particular importance is familiarity with the numerous types of implanted devices, such as glaucoma drainage devices, orbital implants, and eyelid weights. Although knowledge of patients' surgical history is helpful, this information is often not available at the time of interpretation. Fortunately, there are characteristic posttreatment findings that enable diagnosis. The imaging features of the most commonly performed ophthalmologic procedures are highlighted, with emphasis on computed tomography and magnetic resonance (MR) imaging, because they are currently the primary modalities involved in evaluating the orbits. Glaucoma drainage devices and orbital implants after enucleation are two of the more pertinent implanted devices because their composition has substantially evolved over the past 2 decades, which affects their imaging appearance. Some devices, such as the Baerveldt Glaucoma Implant and platinum-weighted eyelid implants, may distort radiologic images. The MR imaging safety profiles of numerous implanted devices are also reported.

Computed tomography imaging manifestations of commonly used materials in posttraumatic craniofacial repair.

An expansive array of materials exists within the armamentarium of craniofacial surgeons. For patients undergoing repair of posttraumatic injuries, computed tomography is the imaging modality of choice in the postoperative setting. Therefore, radiologists will invariably encounter implants constructed with various materials, depending on the surgeon's preference. The appearance of these materials on computed tomography is broad, ranging from hyperdense to radiolucent. To avoid misdiagnosis, radiologists should be familiar with all of the materials currently in use.

Brachial plexopathy: a review of traumatic and nontraumatic causes.

OBJECTIVE: This article reviews brachial plexus anatomy in the context of key landmarks, illustrates common findings of traumatic and nontraumatic causes of brachial plexopathies, describes symptoms associated with these maladies, and explains how proper diagnosis impacts clinical decisions. CONCLUSION: Knowledge of brachial plexus anatomy and of the imaging sequelae of traumatic and nontraumatic plexopathies enables the radiologist to more easily identify these afflictions, thereby facilitating a multidisciplinary treatment plan and improving patient outcome.

Prospective evaluation of the role of atherosclerosis on cerebral atrophy: pilot study.

PURPOSE: Our purpose was to study the association between atherosclerosis measured by arterial calcium on computed tomography (CT) and cerebral atrophy demonstrated by brain magnetic resonance imaging (MRI). MATERIALS AND METHODS: IRB approved this prospective study. Twenty-one consecutive patients with acute stroke-like symptoms who are scheduled to have brain MRI were recruited on a voluntary basis. electrocardiogram (ECG)-gated helical CT scans were used to determine the arterial calcium as a reliable index of underlying atherosclerosis. Extracranial arterial calcium content was measured quantitatively by special software available in our CT scanner. Intracranial calcium was graded qualitatively. Brain MRI was independently evaluated to identify cortical, central atrophy, and ischemic changes. Relationship between CT demonstrated atherosclerosis and cerebral ischemic changes, brain atrophy patterns were evaluated both without and with adjustment for age and hypertension. RESULTS: Out of 21 patients 20 were included in final study group. There was no correlation between atherosclerotic calcium measures and cortical atrophy, ischemic findings. Both intracranial and extracranial atherosclerosis had partial correlation with central atrophy (R= 0.43 and 0.52, respectively). After adjustment for age, only intracranial atherosclerosis maintained a partial correlation with central atrophy (R= 0.41). However, this correlation did not reach a statistically significant level (P= .10). CONCLUSIONS: Intracranial atherosclerosis demonstrated a possible correlation with central atrophy.

Magnetic resonance imaging of the cervix during pregnancy: effect of gestational age and prior vaginal birth.

OBJECTIVE: To investigate how gestational age and prior vaginal birth affect cervical anatomy on magnetic resonance imaging during pregnancy. STUDY DESIGN: Magnetic resonance images of the cervix were obtained in consecutive patients referred for a suspected fetal abnormality. We used an image processing protocol to measure cervical dimensions, orientation, and signal intensity. We determined how outcome variables were affected by gestational age and prior vaginal birth. RESULTS: Adequate images were obtained in 53 of 57 patients at 17 to 36 weeks. As gestational age increased by 12 weeks, the mean cross-sectional area of the cervical canal and cervical stroma increased 31% (95% confidence interval 0% to 73%) and 31% (95% confidence interval 11% to 55%), respectively. The normalized signal intensity of the stroma increased from 0.83 (95% confidence interval 0.81 to 0.85) at 20 weeks to 0.91 (95% confidence interval 0.88 to 0.94) at 32 weeks. None of the outcome variables were affected by prior vaginal birth. CONCLUSION: Magnetic resonance imaging revealed that cross-sectional area and signal intensity of the cervical stroma increase with increasing gestational age.

Granulomatous Pneumocystis carinii pneumonia in a non-AIDS patient: an atypical presentation.

We present the computed tomographic findings of pulmonary involvement by granulomatous Pneumocystis carinii pneumonia in a 73-year-old woman recently tapered from a high-dose long-term systemic corticosteroid therapy for Factor VII deficiency.