Faculty Bibliography

A 66-year-old male was found unresponsive and diagnosed with acute carbon monoxide poisoning, with pathognomonic findings on radiological imaging. During his first day's the patient underwent acute neurological deterioration; however, this was followed 2 weeks later with a subsequent improvement to near baseline. The improvement back to baseline was short-lived, and the patient quickly worsened and underwent neurological decompensation. These findings were consistent with delayed post hypoxic leukoencephalopathy, serious sequelae of carbon monoxide poisoning. This case report shows the importance of recognition of carbon monoxide toxicity and aims to improve accurate diagnosis of the sequelae that may follow using computed tomography and magnetic resonance imaging sequences, magnetic resonance spectroscopy in order to prevent or ameliorate further neurological decline.

With the popularity of synthetic cannabinoid street drugs such as "K2 and Spice," a number of serious neurologic adverse events are coming to light. This case is a 36-year-old African American man, with no significant medical history, who presented with extensive left cervical and intracranial internal carotid artery occlusion and subsequent ischemic stroke. The patient endorsed smoking K2-a synthetic cannabinoid (SC) with structural similarity to cannabis. The mechanism by which SC abuse induces a prothrombotic state leading to ischemic neurovascular sequelae is currently unclear, although a temporal association in the absence of other stroke risk factors suggests a causal relationship. Our case highlights the need for emergent neuroimaging upon suspected SC overdose. Practitioners should be vigilant in recognizing that ischemic stroke and unexplained neurologic deficit can arise after SC abuse, especially in younger populations with few stroke risk factors and who are prone to chronic cannabis use.

Dabigatran etexilate is a relatively new anticoagulant from the class of direct thrombin inhibitors which is administered orally and does not require routine blood work monitoring. Dabigatran may be attractive to both clinicians and patients because of both its convenience and efficacy; however, clinical complications are still being elucidated. Here, we present a previously unreported case of spinal subarachnoid and subdural hematoma presenting as a Brown-Séquard-like myelopathy in a patient after minor trauma in the setting of Dabigatran anticoagulation.

Subcutaneous emphysema of the scalp is a process often attributed to secondary factors such as trauma, infection, or a myriad of iatrogenic etiologies. Here, we are presenting a case report of an adult patient with spontaneous subcutaneous emphysema of the scalp following a hair coloring/treatment. We performed an extensive review of literature on this topic, however, could not find a single case with similar presentation of subcutaneous emphysema. This case demonstrates an unreported etiology for this diagnosis and is thus being reported for its uniqueness and to raise clinical awareness.

PURPOSE: To examine the relative capabilities for the detection of vertebral metastases of three available fast spin-echo sequences: T1-weighted fast spin-echo, short tau inversion recovery (STIR) fast spin-echo, and T2-weighted fast spin-echo sequences with chemical shift selective saturation pulse fat suppression. METHODS: Fourteen patients were evaluated prospectively over a 2-month period with T1-weighted fast spin-echo (four echo train, four acquisitions, 1 min 59 sec-2 min 37 sec). STIR fast spin-echo (16 echo train, four acquisitions, 2 min 30 sec-3 min 19 sec), and T2-weighted fast spin-echo (16 echo train, 4 acquisitions, 2 min 27 sec-3 min 16 sec). For all three pulse sequences, measurements were obtained of the signal intensities of normal marrow, abnormal marrow, fat, and noise posterior to the spine. Contrast-to-noise ratios were calculated for metastases in each case. Lesions were evaluated by three observers and rated for size, location, and conspicuity. RESULTS: Signal intensities of fat, normal marrow, and noise were highest for T1-weighted fast spin-echo sequences. STIR fast spin-echo and fat-suppressed T2-weighted fast spin-echo had approximately similar fat-suppression capabilities. Though contrast-to-noise ratios were highest overall for STIR fast spin-echo, the finding was not statistically significant and lesion conspicuity was deemed better with fat-suppressed T2-weighted fast spin-echo and T1-weighted fast spin-echo images. Discrete lesions were well identified on all three pulse sequences. CONCLUSION: Fast spin-echo sequences appear promising for the detection of vertebral metastases. Further work should be directed toward comparison with conventional spin-echo to determine whether fast spin-echo may replace conventional spin-echo sequences for evaluation of vertebral metastases.

The occurrence of a neurologic event during pregnancy or the puerperium may have devastating consequences for mother and child. It is imperative that the radiologist be familiar with the entities likely to be encountered in pregnancy so that these patients can be examined rapidly and efficiently. The importance of early and accurate diagnostic imaging is underscored by the fact that most patients are otherwise young and healthy, and prompt institution of appropriate therapy can result in complete recovery. In this report, we illustrate some of the more common neurologic complications that occur during pregnancy and the immediate postpartum period.

STUDY OBJECTIVE: To describe the presentation, management, and outcome of children with traumatic epidural hematoma. DESIGN: Retrospective chart review. TYPE OF PARTICIPANTS: Fifty-three children diagnosed with traumatic epidural hematoma on computed tomography scan who were treated at Children's Hospital in Boston between 1980 and 1990. MAIN RESULTS: Twenty-four of 53 children developed an epidural hematoma after a fall of less than 5 ft. At the time of diagnosis, 51 of 53 children had one or more symptoms of vomiting, headache, or lethargy. Twenty-six patients were alert, 21 were responsive to verbal or painful stimuli, and five were unresponsive or posturing. Twenty-one (40%) had acute neurologic deterioration before surgery; however, 20 (38%) were alert with normal vital signs and neurologic examinations at diagnosis. All patients survived, and at the time of discharge 45 had normal examinations and eight had neurologic abnormalities; at follow-up only four of these eight had persistent (although mild) abnormalities. CONCLUSIONS: Although often dramatic in presentation, epidural hematoma may occur after relatively minor head trauma and in alert children with nonfocal neurologic examinations. In our study, incidence of neurologic sequelae increased if abnormal neurologic examination or depressed mental status was present at diagnosis. The outcome of children in this study is improved from that of previous studies, perhaps due to increased use of computed tomography and higher incidence of low- or moderate-impact trauma in this series.

Adult primary brain tumors comprise a diverse group of neoplasms that vary in their behavior depending on such factors as cell of origin, site of occurrence, morphology, and pattern of spread. Although the incidence of primary brain tumors is increasing in frequency, the prognosis of patients with these neoplasms has improved considerably due to recent advances in microsurgery, radiation treatment, and chemotherapy. Central to the efficacy of these techniques, however, is the ability of the radiologist to diagnose and interpret the growth pattern of these tumors. This article describes various types of primary intracranial neoplasms found in the adult, with emphasis on imaging characteristics and their importance in neuro-oncologic evaluation and management.

Hypertensive encephalopathy is a syndrome consisting of headache, seizures, visual changes, and other neurologic disturbances in patients with elevated systemic blood pressure. The purpose of this study was to analyze the imaging findings in 14 patients with hypertensive encephalopathy. CT (n = 13), MR (n = 12), and single-photon emission computed tomography (n = 2) examinations performed in these patients before and after resolution of symptoms were reviewed. Eight had the preeclampsia-eclampsia syndrome, and six had hypertensive encephalopathy due to other causes. CT and MR findings in all patients having these examinations were indicative of edema in the cortex and subcortical white matter in the occipital lobes. Two of the 14 patients also had similar findings in the cerebellum and frontal lobes. Single-photon emission computed tomography showed increased vascular perfusion adjacent to areas that appeared abnormal on CT and MR. The findings on the imaging studies resolved on follow-up examinations performed after the hypertension was corrected. Our results suggest that the radiologic findings associated with hypertensive encephalopathy may be useful in establishing the diagnosis in the appropriate clinical setting.

The authors hypothesized that magnetization transfer contrast (MTC) could be used to improve flow contrast in time-of-flight (TOF) magnetic resonance (MR) angiography. Two- and three-dimensional flow-compensated gradient-echo images were obtained with and without MTC. MTC images were obtained by applying low-power radio-frequency (RF) radiation with a frequency offset from the bulk "free" water resonance frequency before the excitation RF pulse. The signal intensity of stationary tissue decreased as the power applied for the MTC pulse was increased. A smaller decrease occurred in venous signal intensity as measured in the superior sagittal sinus, and less change was seen in the arterial signal intensity as measured in the middle cerebral artery. Cerebrospinal fluid showed no MTC effect. The use of MTC improved small-vessel depiction on maximum-intensity projection images. The authors conclude that use of MTC can substantially enhance the quality of TOF MR angiography of the brain.