Faculty Bibliography

The authors aimed to determine whether clinical findings of preeclampsia predict magnetic resonance imaging (MRI) diagnosis of posterior reversible encephalopathy syndrome (PRES). The course among preeclamptics/eclamptics with clinically suspected PRES with vs without MRI diagnosis of PRES was compared. Of 46 patients who underwent MRI (eight eclamptics, 38 preeclamptics), five eclamptics (62.5%) and four preeclamptics (10.5%) had confirmed PRES (P=.004). Patients with PRES were younger (26 years vs 31 years, P=.008) and had a higher prevalence of thrombocytopenia (33% vs 8%, P=.04), a greater prevalence of proteinuria (100% vs 61%, P=.04), and higher peak systolic and diastolic blood pressures (P<.05). As opposed to findings from previous reports, PRES was not seen uniformly among eclamptic women and was found in 10.5% of preeclamptics with clinical suspicion of PRES in this study. Given that no single or set of findings were reliable predictors of PRES, consideration for rigorous management of hypertension should be applied to all patients with preeclampsia and eclampsia.

BACKGROUND:Late postpartum eclampsia is defined as occurrence of eclampsia >48 h after delivery and is a rare clinical entity. The delayed onset and nonspecific symptoms at presentation make this entity a challenge to diagnose in patients presenting to the emergency department (ED); however, early recognition and timely interventions are the keys to reducing morbidity and mortality in patients with late postpartum eclampsia. CASE REPORT/METHODS:A 28-year-old woman presented to our ED with a chief complaint of headache of 4 days duration, 8 days after an uncomplicated, normal vaginal delivery. Her past medical history was unremarkable and her entire pregnancy was without medical incident. The patient's examination was within normal limits other than a blood pressure of 152/111 mm Hg and pulse of 54 beats/min. Given her undifferentiated headache and the possibility of preeclampsia, the patient was treated with magnesium sulfate, which was subsequently stopped due to worsening bradycardia. Hydralazine was administered for blood pressure control. Three hours after the magnesium was stopped, the patient reported blurry vision, which was immediately followed by a generalized tonic-clonic seizure. After the seizure, lorazepam was given for control of seizures, and the patient was admitted to the medical intensive care unit. The patient was transferred to the postpartum floor 6 days later in stable condition and without any further seizure activity. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Patients with late postpartum eclampsia are infrequently encountered in the ED due to the rarity of this condition. Increased awareness of this entity among emergency physicians will lead to early interventions, which are crucial in decreasing morbidity and mortality in these patients.

There are many causes of cerebrospinal (CSF) leaks. Most cases are secondary to blunt trauma and iatrogenic trauma caused by postoperative sequelae. Occasionally, CSF leakage may occur from nontraumatic or "spontaneous" causes, such as benign intracranial hypertension and "empty sella syndrome." Mass effect due to an encephalocele or meningocele may also be seen. Radionuclide cisternography is a sensitive method of determining CSF leak when combined with intranasal cotton pledget placement and analysis. We present a spontaneous CSF fluid leak that was detected when scintigraphic activity appeared first in the gastrointestinal tract.

OBJECTIVE:The objective of this study was to compare the efficacy of surveillance high-resolution computed tomography (HRCT) and physical examination/endoscopy (PE/E) with the efficacy of fluorodeoxyglucose (FDG)-positron emission tomography (PET)/HRCT for the detection of relapse in head and neck squamous cell carcinoma (HNSCC) after primary treatment. METHODS:This is a retrospective analysis of contemporaneously performed FDG-PET/HRCT, neck HRCT, and PE/E in 99 curatively treated patients with HNSCC during post-therapy surveillance to compare performance test characteristics in the detection of early recurrence or second primary cancer. RESULTS:Relapse occurred in 19 of 99 patients (20%) during a median follow-up of 21 months (range: 9-52 months). Median time to first PET/HRCT was 3.5 months. The median time to radiological recurrence was 6 months (range: 2.3-32 months). FDG-PET/HRCT detected more disease recurrences or second primary cancers and did so earlier than HRCT or PE/E. The sensitivity, specificity, and positive and negative predictive values for detecting locoregional and distant recurrence or second primary cancer were 100%, 87.3%, 56.5%, and 100%, respectively, for PET/HRCT versus 61.5%, 94.9%, 66.7%, and 93.8%, respectively, for HRCT versus 23.1%, 98.7%, 75%, and 88.6%, respectively, for PE/E. In 19 patients with true positive PET/HRCT findings, a significant change in the management of disease occurred, prompting either salvage or systemic therapy. Of the 14 curatively treated patients, 11 were alive with without disease at a median follow-up of 31.5 months. CONCLUSION/CONCLUSIONS:FDG-PET/HRCT has a high sensitivity in the early detection of relapse or second primary cancer in patients with HNSCC, with significant management implications. Given improvements in therapy and changes in HNSCC biology, appropriate modifications in current post-therapy surveillance may be required to determine effective salvage or definitive therapies.

We sought to determine whether laboratory parameters could be found, predictive of a negative abdominal CT scan in young adults with nontraumatic abdominal pain. Following institutional review board approval, we evaluated CT reports of 522 patients, aged 21-35 years old, who presented to the Emergency Department with nontraumatic abdominal pain. Bivariate analyses relating ten laboratory parameters to whether the CT detected a cause for abdominal pain were conducted. A multivariate logistic regression model was then derived, with all variables in the final model significant at p < 0.05. Variables were dichotomized to yield odds ratios and 95% confidence intervals. Of the 522 patients meeting inclusion criteria, 45% had a cause for pain demonstrated by CT. Predictors of a negative CT in men were normal hematocrit and negative urine blood (p = 0.045, p = 0.016, respectively), and in women normal hematocrit, granulocyte percent, and alkaline phosphatase (p = 0.023, p = 0.039, p < 0.0001, respectively). When standard normal values were used to calculate descriptive statistics, only granulocyte percent in women had a significant confidence interval (odds ratio 2.5, confidence interval 1.6-4.0). Among the 208 women with normal granulocyte percent, the final clinical diagnosis was appendicitis, cholecystitis, and diverticulitis, in three, three, and two cases, respectively (4% combined). In summary, no laboratory test was sufficient to offer reassurance that a CT is not necessary in a young adult patient with nontraumatic abdominal pain. Alternative strategies should be considered to decrease the use of CT, and its associated radiation exposure, in young adults with nontraumatic abdominal pain.

PURPOSE/OBJECTIVE:Advances in medical imaging have been associated with increased utilization and increased radiation exposure, especially for patients with chronic and recurrent conditions. The authors estimated the cumulative radiation doses from medical imaging for specific cohorts with chronic and recurrent conditions. METHODS:All patients diagnosed with hydrocephalus (n = 1,711), pulmonary thromboembolic disease (n = 3,220), renal colic (n = 5,855), and cardiac disease (n = 11,072) from January 1, 2000, to December 31, 2005, were retrospectively identified. Each imaging examination that used ionizing radiation from 2000 to 2008 was incorporated into an estimate of total effective dose and organ-specific doses. Patients with high levels of radiation exposure after 3 years (total effective dose > 50 mSv; dose to the ocular lens > 150 mSv) were identified. RESULTS:The mean estimated effective doses for the surviving diagnostic cohorts after 3 years were 12.3 mSv for patients with hydrocephalus, 21.7 mSv for those with pulmonary thromboembolic disease, 18.7 mSv for those with renal colic, and 14.0 mSv for those with cardiac disease. Among patients with hydrocephalus, 26.3% (339 of 1,291) had radiation doses > 150 mSv to the ocular lens within 3 years. In all cohorts, the proportion of patients with total effective doses > 50 mSv within 3 years was significantly higher for those diagnosed in 2004 and 2005 than for those diagnosed in 2000 and 2001. CONCLUSION/CONCLUSIONS:Patients with hydrocephalus, pulmonary thromboembolic disease, renal colic, and cardiac disease received radiation exposures that may put them at increased risk for cancer. Moreover, the proportion who received estimated total effective doses > 50 mSv within 3 years was significantly higher for those diagnosed most recently. It is the responsibility of institutions and physicians to critically evaluate their infrastructures, diagnostic strategies, and imaging techniques for each individual patient, with an eye toward minimizing cumulative medical radiation exposure.

OBJECTIVE:The purpose of our study was to determine whether the radiation exposure to patients with suspected pulmonary embolism (PE) could be decreased by safely increasing the use of ventilation-perfusion (V/Q) scanning and decreasing the use of CT pulmonary angiography (CTPA) through an educational intervention. MATERIALS AND METHODS/METHODS:Collaborative educational seminars were held among the radiology, nuclear medicine, and emergency medicine departments in December 2006 and January 2007 regarding the radiation dose and accuracies of V/Q scanning and CTPA for diagnosing PE. To reduce radiation exposure, an imaging algorithm was introduced in which emergency department patients with a clinical suspicion of PE underwent chest radiography. If the chest radiograph was normal, V/Q scanning was recommended, otherwise CTPA was recommended. We retrospectively tallied the number and results of CTPA and V/Q scanning and calculated mean radiation effective dose before and after the intervention. False-negative findings were defined as subsequent thromboembolism within 90 days. RESULTS:The number of CTPA examinations performed decreased from 1,234 in 2006 to 920 in 2007, and the number of V/Q scans increased from 745 in 2006 to 1,216 in 2007. The mean effective dose was reduced by 20%, from 8.0 mSv in 2006 to 6.4 mSv in 2007 (p < 0.0001). The patients who underwent CTPA and V/Q scanning in 2006 were of similar age. In 2007, the patients who underwent V/Q scanning were significantly younger. There was no significant difference in the false-negative rate (range, 0.8-1.2%) between CTPA and V/Q scanning in 2006 and 2007. CONCLUSION/CONCLUSIONS:The practice patterns of physicians changed in response to an educational intervention, resulting in a reduction in radiation exposure to emergency department patients with suspected PE without compromising patient safety.

OBJECTIVE:To determine the prevalence and clinical significance of normal, variant, and anomalous branching patterns of the aortic arch and the central veins on computed tomographic (CT) angiography in adults. METHODS:We retrospectively reviewed 1000 consecutive CT angiograms of the chest in 658 women and 342 men with a median age of 53 years. RESULTS:A total of 65.9% of patients had both normal aortic arch branching patterns and normal venous anatomy. Variants in the aortic arch branching pattern were present in 32.4% and anomalies in 1.5%. Venous anomalies were present in 0.7%. Review of CT reports showed that cardiothoracic radiologists correctly reported the anomaly more frequently than other radiologists (94% vs 20%, P = 0.003). CONCLUSIONS:Whereas anomalies of the central thoracic vasculature are uncommon, variants in the aortic arch branching pattern are common. An appreciation of the appearance of these entities on CT angiography allows for precise reporting and is useful in preprocedure planning.

After the publication of the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study in 1990, there was considerable controversy concerning the ventilation-perfusion (V/Q) study in regard to its low sensitivity and high number of nondiagnostic examinations when used in patients with suspected pulmonary embolism (PE). Many lessons have been learned from the PIOPED database that have greatly improved our interpretive skills in the 2 decades since the study was performed. One of the key problems negatively impacting interpretation was the predominantly inpatient population that was studied. Inpatients generally are sicker patients with abnormal chest x-rays. This factor significantly degrades V/Q interpretation. A normal chest x-ray greatly facilitates accurate interpretation of the lung scan. The emergence of computed tomography angiography (CTA) in the early to mid-1990s provided a superb new means of imaging patients with suspected PE. As this technology became more sophisticated with multidetector units, it became the procedure of choice in the great majority of medical centers. CT scanners located in or proximal to many emergency departments as well as its 24/7 availability supported this preference. Within the past 2 to 3 years, the publication of the PIOPED II study as well as some other prospective and retrospective studies have confirmed similar diagnostic accuracy for CTA and V/Q studies. Additionally, there have been several recent publications cautioning physicians about the large radiation dose associated with CTA, particularly to the female breast. Considering the great benefits of both techniques as well as their limitations, it is prudent for both clinicians and imaging physicians to develop an appropriate approach to studying patients with suspected PE. Considerations such as objective clinical assessment, D-dimer assay and the chest x-ray appearance all play significant roles in this decision-making process.