Role of cervical spine MRI in the setting of negative cervical spine CT in blunt trauma: Critical additional information in the setting of clinical findings suggestive of occult injury.

BACKGROUND AND PURPOSE: Cervical spine injury is common in the setting of blunt trauma and there is consensus that cervical spine CT (CSCT) is the image modality of choice for initial evaluation for blunt trauma related injuries of the cervical spine. However, there is disagreement in the literature with regards to further evaluation of blunt trauma patients with cervical spine MRI (CSMRI) after negative CSCT when there is persistent clinical concern for occult trauma related injury. The purpose of this study is to examine the utility of CSMRI for detection of occult injury in blunt trauma patients after negative CSCT. MATERIALS AND METHODS: We reviewed records for 7,301 patients admitted for blunt trauma (November 2007-December 2013) and identified 259 who underwent CSMRI after a negative CSCT. These CSMRIs were reviewed to determine the number and type of significant CT occult injuries identified and clinical indications that led to CSMRI acquisition. RESULTS AND CONCLUSIONS: CSMRI detected significant injuries following negative CSCT in 31% (81/259) of patients. There were 15 cord contusions/infarcts, 9 bone contusions/fractures, 7 spinal canal hemorrhages and 66 soft tissue injuries. Upper extremity neurological deficit had greatest positive predictive value (PPV) for detection of CT-occult injury on CSMRI of 43% (23/53), followed by equivocal CSCT findings (38%, 18/47), presence of extra-cervical injuries (34%, 20/58), midline cervical tenderness (20%, 17/85), and isolated lower extremity neurological deficit (0%, 0/16). CSMRI is recommended following negative CSCT in the evaluation of blunt cervical spine trauma when appropriate clinical concerns are present.

Acute Radiologic Manifestations of America's Opioid Epidemic.

The United States is in the midst of an opioid use epidemic, which has severe medical, social, and economic consequences. Addictions to and abuse of prescription and illicit opioids are increasing, and emergency department radiologists are increasingly being faced with the task of examining patients who present with opioid-related complications. These complications may be the result of direct drug toxicity or nonsterile injection of the drugs. Neurologic, musculoskeletal, cardiopulmonary, genitourinary, and gastrointestinal complications may be evident at diagnostic imaging in emergent settings. Heroin-induced leukoencephalopathy, cerebral septic emboli, mycotic arterial aneurysms, soft-tissue infections, and infective endocarditis are some of the conditions that patients may be found to have after they present to the emergency department. In this article, the above topics, including clinical features, pathophysiology, imaging findings, and treatment options, are reviewed. Recognizing the limitations of diagnostic imaging modalities that are available to radiologists is equally important, as some conditions can be successfully diagnosed after the initial triage-for example, transesophageal echocardiography can be performed to diagnose infective endocarditis. The emergency department radiologist may be responsible for identifying acute conditions, which can be life threatening. Some of the more common emergent opioid-related conditions and complications are reviewed, with specific emphasis on cases in which emergency department radiologists encounter conditions for which additional expertise is required. Becoming familiar with the conditions directly related to the current opioid epidemic will enable the diagnosis of these entities in a timely and accurate manner. ©RSNA, 2018.

Imaging of Brain Trauma.

Conventional imaging in the acute setting of brain trauma, relevant pathophysiology of injury, and advanced imaging techniques that may provide value in understanding the immediate management and long-term sequela of traumatic brain injury are reviewed. Key imaging findings that can guide clinical management related to such injuries as concussions, hematomas, dissections, dural atrioventricular fistula, and diffuse axonal injury are discussed. The role and accuracy of computed tomography, dual-energy computed tomography, computed tomography angiography, and magnetic resonance angiography in the acute setting are evaluated. In addition, caveats related to imaging the elderly and pediatric population are addressed.

Long-term disuse osteoporosis seems less sensitive to bisphosphonate treatment than other osteoporosis.

UNLABELLED: We sought to determine whether risedronate can preserve cortical bone mass and mechanical properties during long-term disuse in dogs, assessed by histomorphometry and biomechanics on metacarpal diaphyses. Risedronate slowed cortical thinning and partially preserved mechanical properties, but it was unable to suppress bone loss to the degree seen in other osteoporoses. INTRODUCTION: Disuse induces dramatic bone loss resulting from greatly elevated osteoclastic resorption. Targeting osteoclasts with antiresorptive agents, such as bisphosphonates, should be an effective countermeasure for preventing disuse osteoporosis. MATERIALS AND METHODS: Single forelimbs from beagles (5-7 years old, n = 28) were immobilized (IM) for 12 months. Age-matched, non-IM dogs served as controls. One-half the animals received either risedronate (RIS, 1 mg/kg) or vehicle daily. Histomorphometry was performed on second metacarpal mid-diaphyses. Cortical mechanical properties were determined by testing third metacarpal diaphyses in four-point bending. RESULTS: IM caused marked reduction in cortical area (-42%) and cortical thinning (-40%) through endocortical resorption, extensive intracortical tunneling, and periosteal resorption; both bone resorption and formation were significantly elevated over control levels on all envelopes. IM also decreased maximum load and stiffness by approximately 80% compared with controls. RIS reduced both periosteal bone loss and marrow cavity expansion; however, cortical area remained significantly lower in RIS-treated IM animals than in untreated non-IM controls (-16%). RIS also increased resorption indices in all envelopes compared with nontreated IM, indicating that RIS suppressed osteoclast activity but not osteoclast recruitment. RIS did not affect bone formation. RIS treatment conserved some whole bone mechanical properties, but they were still significantly lower than in controls. There were no significant differences in tissue level material properties among the groups. CONCLUSION: RIS treatment reduces cortical bone loss at periosteal and endocortical surfaces caused by long-term immobilization, thus partially conserving tissue mechanical properties. This modest effect contrasts with more dramatic actions of the bisphosphonate in other osteoporoses. Our results suggest that risedronate impairs osteoclastic function but cannot completely overcome the intense stimulus for osteoclast recruitment during prolonged disuse.