Negative Computed Tomography Results Research Articles

Comparison of the Effectiveness of Computed Tomography and Magnetic Resonance Imaging Techniques in Patient Groups Aged under and over 65 Years and Diagnosed with Ischemic Stroke in the Emergency Department

Objectives: Stroke is a condition with high morbidity and mortality. This study aims to investigate whether the effectiveness of Computed Tomography (CT) and diffusion-weighted Magnetic Resonance Imaging (MRI), the techniques that have a significant place in the diagnosis of ischemic stroke, the most common form of stroke, are affected by the physiological changes of advanced age. Methods: A total of 436 patients were included in the study. The study population was divided into two groups depending on age: those above 65 and those under 65. Medical files, both the emergency department and clinical ward files, of the patients who were admitted to the emergency department in nine months and admitted to the neurology clinic with the diagnosis of ischemic stroke were retrospectively analyzed. The time from admission to imaging was determined depending on patient files and the Hospital Management Information System (HBYS). The CT and MRI reports interpreted by radiologists were also reviewed. While recording the data, the presence of a lesion, its direction, and localization were also noted. Results: CT positivity was 21.3%, and the positivity of diffusion-weighted imaging was 82.1% in the study population. The time was shorter in the group of patients with positive CT results than in the group with negative CT results. In subjects under 65, the time between onset and imaging was shorter in the group with positive CT results than in the group with negative CT results. In subjects over 65, the time with positive CT results was not different from the group with negative CT results. It was determined that the mean time was shorter in the group with positive MRI results than in the group with negative results. In both the groups under the age of 65 and over the age of 65, the time interval was shorter in the patients with positive MRI results compared to those with negative MRI results. Conclusions: Regardless of the positivity or negativity of CT and MRI results, the mean time from symptom onset to imaging was shorter in the group under 65 years of age compared to the group over 65 years. Aging prolongs the time to admission and the neuroradiological response of geriatric patients.

PP296 Patient Involvement In An Assessment Of The Management Of Sudden Onset Severe Headache Presenting To The Emergency Department

IntroductionSudden onset severe headache is usually caused by a primary headache disorder but may be secondary to a more serious problem, such as subarachnoid hemorrhage (SAH). Very few patients who present to hospital with headache have suffered a SAH, but early identification is important to improve patient outcomes. A systematic review was undertaken to assess the clinical effectiveness of different care pathways for the management of headache, suspicious for SAH, in the Emergency Department. Capturing the perspective of patients was an important part of the research.MethodsThe project team included a patient collaborator with experience of presenting to the Emergency Department with sudden onset severe headache. Three additional patients were recruited to our advisory group. The patient's perspective was collected at various points through the project including at team meetings, during protocol development and when interpreting the results of the systematic review and drawing conclusions.ResultsPatients were reassured by the very high diagnostic accuracy of computed tomography (CT) for detecting SAH. Patients and clinicians emphasized the importance of shared decision making about whether to undergo additional tests to rule out SAH, after a negative CT result. When lumbar puncture was necessary, patients expressed a preference to have it on an ambulatory basis; further research on the safety and acceptability of ambulatory lumbar puncture was recommended.ConclusionsPatient input at the protocol development stage helped researchers understand the patient experience and highlighted important outcomes for assessment. Patient involvement added context to the review findings and highlighted the preferences of patients regarding the management of headache.

Short Observation Period and Aggressive Discharge of Patients With Head Injury and Serial CT Scans.

Background: Many patients undergo two head computed tomography (CT) scans after mild traumatic brain injury (TBI). Radiographic progression without clinical deterioration does not usually alter management. Evidence-based guidelines offer potential for limited repeat imaging and safe discharge. This study characterizes patients who had two head CTs in the Emergency Department (ED), determines the change between initial and repeat CTs, and describes timing of repeat scans.Methods: This retrospective series includes all patients with head CTs during the same ED visit at an urban trauma center between May 1st, 2016 and April 30th, 2018. Radiographic interpretation was coded as positive, negative, or equivocal.Results: Of 241 subjects, the number of positive, negative, and equivocal initial CT results were 154, 50, and 37, respectively. On repeat CT, 190 (78.8%) interpretations were congruent with the original scan. Out of the 21.2% of repeat scans that diverged from the original read, 14 (5.8%) showed positive to negative conversion, 1 (.4%) showed positive to equivocal conversion, 2 (.88%) showed negative to positive conversion, 20 (8.3%) showed equivocal to negative conversion, and 14 (5.8%) showed equivocal to positive conversion. Average time between scans was 4.4 hours, and median length of stay was 10.2 hours.Conclusions: In this retrospective review, most repeat CT scans had no new findings. A small percentage converted to positive, rarely altering clinical management. This study demonstrates the need for continued prospective research to update clinical guidelines that could reduce admission and serial CT scanning for mild TBI.

Computed tomography for diagnosis of acute appendicitis in adults.

Diagnosing acute appendicitis (appendicitis) based on clinical evaluation, blood testing, and urinalysis can be difficult. Therefore, in persons with suspected appendicitis, abdominopelvic computed tomography (CT) is often used as an add-on test following the initial evaluation to reduce remaining diagnostic uncertainty. The aim of using CT is to assist the clinician in discriminating between persons who need surgery with appendicectomy and persons who do not. Primary objective Our primary objective was to evaluate the accuracy of CT for diagnosing appendicitis in adults with suspected appendicitis. Secondary objectives Our secondary objectives were to compare the accuracy of contrast-enhanced versus non-contrast-enhanced CT, to compare the accuracy of low-dose versus standard-dose CT, and to explore the influence of CT-scanner generation, radiologist experience, degree of clinical suspicion of appendicitis, and aspects of methodological quality on diagnostic accuracy. We searched MEDLINE, Embase, and Science Citation Index until 16 June 2017. We also searched references lists. We did not exclude studies on the basis of language or publication status. We included prospective studies that compared results of CT versus outcomes of a reference standard in adults (> 14 years of age) with suspected appendicitis. We excluded studies recruiting only pregnant women; studies in persons with abdominal pain at any location and with no particular suspicion of appendicitis; studies in which all participants had undergone ultrasonography (US) before CT and the decision to perform CT depended on the US outcome; studies using a case-control design; studies with fewer than 10 participants; and studies that did not report the numbers of true-positives, false-positives, false-negatives, and true-negatives. Two review authors independently screened and selected studies for inclusion. Two review authors independently collected the data from each study and evaluated methodological quality according to the Quality Assessment of Studies of Diagnostic Accuracy - Revised (QUADAS-2) tool. We used the bivariate random-effects model to obtain summary estimates of sensitivity and specificity. We identified 64 studies including 71 separate study populations with a total of 10,280 participants (4583 with and 5697 without acute appendicitis). Estimates of sensitivity ranged from 0.72 to 1.0 and estimates of specificity ranged from 0.5 to 1.0 across the 71 study populations. Summary sensitivity was 0.95 (95% confidence interval (CI) 0.93 to 0.96), and summary specificity was 0.94 (95% CI 0.92 to 0.95). At the median prevalence of appendicitis (0.43), the probability of having appendicitis following a positive CT result was 0.92 (95% CI 0.90 to 0.94), and the probability of having appendicitis following a negative CT result was 0.04 (95% CI 0.03 to 0.05). In subgroup analyses according to contrast enhancement, summary sensitivity was higher for CT with intravenous contrast (0.96, 95% CI 0.92 to 0.98), CT with rectal contrast (0.97, 95% CI 0.93 to 0.99), and CT with intravenous and oral contrast enhancement (0.96, 95% CI 0.93 to 0.98) than for unenhanced CT (0.91, 95% CI 0.87 to 0.93). Summary sensitivity of CT with oral contrast enhancement (0.89, 95% CI 0.81 to 0.94) and unenhanced CT was similar. Results show practically no differences in summary specificity, which varied from 0.93 (95% CI 0.90 to 0.95) to 0.95 (95% CI 0.90 to 0.98) between subgroups. Summary sensitivity for low-dose CT (0.94, 95% 0.90 to 0.97) was similar to summary sensitivity for standard-dose or unspecified-dose CT (0.95, 95% 0.93 to 0.96); summary specificity did not differ between low-dose and standard-dose or unspecified-dose CT. No studies had high methodological quality as evaluated by the QUADAS-2 tool. Major methodological problems were poor reference standards and partial verification primarily due to inadequate and incomplete follow-up in persons who did not have surgery. The sensitivity and specificity of CT for diagnosing appendicitis in adults are high. Unenhanced standard-dose CT appears to have lower sensitivity than standard-dose CT with intravenous, rectal, or oral and intravenous contrast enhancement. Use of different types of contrast enhancement or no enhancement does not appear to affect specificity. Differences in sensitivity and specificity between low-dose and standard-dose CT appear to be negligible. The results of this review should be interpreted with caution for two reasons. First, these results are based on studies of low methodological quality. Second, the comparisons between types of contrast enhancement and radiation dose may be unreliable because they are based on indirect comparisons that may be confounded by other factors.

Predictors of abnormal brain computed tomography findings in patients with acute altered mental status in the emergency department.

ObjectiveBrain computed tomography (CT) is commonly performed to diagnose acute altered mental status (AMS), a critically important symptom in many serious diseases. However, negative CT results are common, which result in unnecessary CT use. Therefore, this study aimed to determine the clinical factors associated with positive CT findings.MethodsPatients with acute AMS selected from an emergency department-based registry were retrospectively evaluated. Patients with non-traumatic and noncommunicable diseases on initial presentation and with Glasgow Comal Scale scores of <15 were included in the study.ResultsAmong the 367 brain CT results of patients with AMS during the study period, 146 (39.8%) were positive. In a multivariate analysis, the presence of focal neurologic deficit (odds ratio [OR], 132.6; 95% confidence interval [CI], 37.8 to 464.6), C-reactive protein level <2 mg/dL (OR, 3.9; 95% CI, 1.4 to 10.6), and Glasgow Comal Scale score <9 (OR, 2.4; 95% CI, 1.2 to 4.8) were significantly associated with positive brain CT results.ConclusionThe presence of focal neurologic deficit, initial Glasgow Comal Scale score of <9, and initial C-reactive protein levels of <2 mg/dL can facilitate the selection of brain CT to diagnose patients with acute AMS in the emergency department.

Positron emission tomography in the management of documented or suspected recurrent ovarian cancer.

To prospectively evaluate the value of positron emission tomography (PET) or integrated computed tomography (CT) and PET (PET/CT) in the management of documented or suspected recurrent ovarian cancer. Patients with ovarian cancer who had completed primary cytoreductive surgery and standard adjuvant chemotherapy were studied to evaluate the following indications: (1) CA125 elevation after complete remission with negative CT or magnetic resonance imaging (MRI) result; (2) post-therapy surveillance CT/MRI-detected suspicious lesions that guided biopsy was not feasible; (3) documented relapse for restaging prior to or after curative salvage therapy. The clinical impact of PET, as compared with those of CT/MRI, was determined on a per scan basis. From 2002 to 2009, 73 patients were recruited, and 92 PET scans were performed. Up to June 2015, 53 patients had died of disease, four were alive with disease, and the remaining 16 were alive without disease. Among the 92 scans, PET had positive impacts in 72.8%, no clinical impacts in 21.7%, and negative impacts in 5.4%. For indication 1, the sensitivity and positive predictive value of PET in detecting recurrence were 80.0% and 92.3%, respectively. For indication 2, the sensitivity, specificity, positive predictive value, and negative predictive value of PET were 91.2%, 62.5%, 91.2%, and 62.5%, respectively. For indication 3, PET provided positive impact in 85.3% and negative impact in 2.9% of the 34 scans. PET has value in the management of suspected or documented recurrent ovarian cancer, with positive impacts on confirming recurrent status and offering a better treatment plan.

Cervical spine clearance in obtunded patients after blunt traumatic injury: a systematic review.

Cervical spine clearance protocols are controversial for unconscious patients after blunt traumatic injury and negative findings on computed tomography (CT). To review evidence about the utility of different cervical spine clearance protocols in excluding significant cervical spine injury after negative CT results in obtunded adults with blunt traumatic injury. MEDLINE, EMBASE, CINAHL, Google Scholar, and the Cochrane Library were searched from January 2000 through November 2014. English-language studies that examined patients with negative CT results having confirmatory routine testing with magnetic resonance imaging (MRI), dynamic radiography, or clinical examination and that reported outcome measures of missed cervical spine injury, need for operative stabilization, or prolonged use of cervical collars. Independent reviewers evaluated the quality of studies and abstracted the data according to a predefined protocol. Of 28 observational studies (3627 patients) that met eligibility criteria, 7 were prospective studies (1686 patients) with low risk of bias and well-interpreted, high-quality CT scans. These 7 studies showed that 0% of significant injuries were missed after negative CT results. The overall studies using confirmatory routine testing with MRI showed incidence rates of 0% to 1.5% for cervical spine instability (16 studies; 1799 patients), 0% to 7.3% for need for operative fixation (17 studies; 1555 patients), and 0% to 29.5% for prolonged collar use (16 studies; 1453 patients). Most studies were retrospective. Approaches to management of soft tissue changes with collars varied markedly. Cervical spine clearance in obtunded adults after blunt traumatic injury with negative results from a well-interpreted, high-quality CT scan is probably a safe and efficient practice. None.

Efficacy of computed tomography for abdominal stab wounds: a single institutional analysis.

There are several diagnostic tools to support the decision for abdominal stab wounds. The aim of this study is to evaluate the ability of computed tomography (CT) to facilitate decisions on the initial management in patients with anterior abdominal stab wounds. The medical records of all 118 patients who sustained abdominal stab wounds from March 2004 to January 2012 were reviewed retrospectively. The average age of patients was 41 years, and 84 (71%) patients were male. Ten patients underwent an immediate laparotomy due to hemodynamic instability, peritonitis, or definite evisceration. The other 108 patients underwent CT scans, and 91 patients had positive CT findings, leading to performance of laparotomy in 82 patients. One patient underwent a non-therapeutic laparotomy. Seventeen patients had negative CT results; however, seven patients underwent early laparotomy according to the attending surgeon's decision using serial physical examination or other diagnostic tools. The sensitivity of the CT scan was 94.2%, and the positive-predictive value was 98.8%. CT can be used efficiently along with physical examination as an initial diagnostic tool in patients with abdominal stab wounds. However, there can be missed injuries, then surgeon should consider other diagnostic methods.

Can the combination of a negative computed tomography result and a negative lumbar puncture safely exclude the diagnosis of subarachnoid hemorrhage in patients with thunderclap headache?

How many patients who had a negative computed tomography and lumbar puncture result on initial evaluation were diagnosed with subarachnoid hemorrhage in the subsequent 6 months to 3 years? Perry J, Spacek A, Forbes M, et al. Is the combination of negative computed tomography result and negative lumbar puncture result sufficient to rule out subarachnoid hemorrhage? Ann Emerg Med 2008;51:707-13. To determine the sensitivity of both a negative computed tomography and a negative lumbar puncture in ruling out subarachnoid hemorrhage.

What is the role of nasal endoscopy in the diagnosis of chronic rhinosinusitis?

BACKGROUND Chronic rhinosinusitis (CRS) is one of the most common chronic conditions in the United States, but clinical diagnostic criteria remain controversial. Nasal endoscopy is frequently employed by otolaryngologists in cases of suspected CRS. Although endoscopy allows visualization of pathology that may provide objective evidence for the diagnosis of CRS in the posterior nasal cavity, nasopharynx, and the middle and superior meati that would not be visible on anterior rhinoscopy, its appropriate role in the evaluation of CRS has been the subject of controversy. In 2007, the American Academy of Otolaryngology– Head and Neck Surgery (AAO-HNS) published guidelines for diagnosis of CRS that utilize a combination of symptom criteria and objective findings. A positive diagnosis was defined as 12 weeks or longer of two or more of the following signs and symptoms: mucopurulent drainage; nasal obstruction; facial pain, pressure, or fullness; or decreased sense of smell. In addition, an objective measure, such as evidence on nasal endoscopy of nasal polyps or purulent mucus in the middle meatus or ethmoid region, or radiographic evidence of paranasal sinus inflammation are also recommended. Given the high utilization rate and availability of computed tomography (CT) for CRS diagnosis, these guideline criteria designated nasal endoscopy as an optional diagnostic measure. Although endoscopic findings are frequently used to support a diagnosis of CRS, the true diagnostic value of nasal endoscopy in diagnosing CRS has not been clearly defined. LITERATURE REVIEW The diagnostic utility of nasal endoscopy, in relation to common clinical and radiologic criteria, has been assessed in relatively few clinical studies. A 1997 study by Benninger evaluated the role of nasal endoscopy in the diagnosis and treatment planning in 100 consecutive new clinic patients with sinonasal complaints. Of those, only 28 patients were diagnosed with CRS, and all diagnoses were made based on history and physical examination that included anterior rhinoscopy. The role of endoscopy in this study was to determine if the endoscopic findings contradict the established diagnosis. The study did not compare the results of endoscopy with CT scans. Although the addition of endoscopy did not change any of the diagnoses of CRS, the study concluded that it was useful in evaluating patients in whom anterior rhinoscopy is limited by anatomic abnormalities or in whom the diagnosis is otherwise unclear. A 1998 study by Rosbe et al. prospectively compared results of nasal endoscopy, CT scanning, and a symptom questionnaire, with a goal of determining whether a combination of patient symptoms and nasal endoscopy could accurately predict CRS on CT in 92 consecutive patients referred for sinonasal symptoms. The study obtained CT scans on all patients with endoscopic findings positive or equivocal for CRS. They found that 91% of patients with positive findings on endoscopy had CT scans consistent with CRS. Of the patients with a chief complaint of nasal obstruction who had a positive finding on nasal endoscopy, 100% had CT findings consistent with CRS. This study did calculate positive predictive values (PPVs) or negative predictive values (NPVs) for endoscopy as compared with CT results. The study concluded that combined with a symptom history, nasal endoscopy can be a highly specific technique for predicting positive CT findings of CRS. In a 2002 study of 78 patients meeting the current symptom-based definition of CRS, Stankiewicz and Chow evaluated the relationship between symptom history, nasal endoscopy, and CT findings. Nasal endoscopy was considered positive for CRS if it demonstrated purulence, nasal polyps, or watery congested From the Massachusetts Eye and Ear Infirmary (J.S.), Department of Otolaryngology–Head and Neck Surgery, Boston; the Division of Otolaryngology (N.B.), Brigham and Women’s Hospital, Boston, Department of Otology and Laryngology (J.S., N.B.), Harvard Medical School, Boston, Massachusetts, U.S.A. Editor’s Note: This Manuscript was accepted for publication April 5, 2012. Neil Bhattacharyya, MD, is a consultant for Intersect-ENT, Inc. and Entellus, Inc. The authors have no other funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Neil Bhattacharyya, MD, Division of Otolaryngology, 45 Francis St., Boston, MA 02115. E-mail: neiloy@massmed.org

When Should Magnetic Resonance Imaging Be Considered With Neck Pain?

Review of recent evidence with translation to practice for the advanced practice nurse role is presented using a case study module for "Cervical Spine Magnetic Resonance Imaging in Alert, Neurologically Intact Trauma Patients With Persistent Midline Tenderness and Negative Computed Tomography Results." The study was designed to identify factors predictive of clinically significant spinal injury in neurologically intact trauma patients with persistent midline cervical tenderness, despite negative computed tomography and plain film findings. The authors reported a lack of guidelines to help emergency care providers identify which of these patients should undergo magnetic resonance imaging studies. The authors highlight the need to develop a clinical prediction rule, or clinical decision rule, to help providers caring for patients such as those with persistent neck pain. The implications and clinical relevance of these findings for advanced practice nurses are discussed highlighting best evidence.

Cervical Spine Magnetic Resonance Imaging in Alert, Neurologically Intact Trauma Patients With Persistent Midline Tenderness and Negative Computed Tomography Results

We aim to determine the prevalence and factors associated with cervical discoligamentous injuries detected on magnetic resonance imaging (MRI) in acute, alert, neurologically intact trauma patients with computed tomography (CT) imaging negative for acute injury and persistent midline cervical spine tenderness. We present the cross-sectional analysis of baseline information collected as a component of a prospective observational study. Alert, neurologically intact trauma patients presenting to a Level I trauma center with CT negative for acute injury, who underwent MRI for investigation of persistent midline cervical tenderness, were prospectively recruited. Deidentified images were assessed, and injuries were identified and graded. Outcome measures included the presence and extent of MRI-detected injury of the cervical ligaments, intervertebral discs, spinal cord and associated soft tissues. There were 178 patients recruited during a 2-year period to January 2009. Of these, 78 patients (44%) had acute cervical injury detected on MRI. There were 48 single-column injuries, 15 two-column injuries, and 5 three-column injuries. Of the remaining 10 patients, 6 had isolated posterior muscle edema, 2 had alar ligamentous edema, 1 had epidural hematoma, and 1 had atlanto-occipital edema. The injuries to 38 patients (21%) were managed clinically; 33 patients were treated in cervical collars for 2 to 12 weeks, and 5 patients (2.8%) underwent operative management, 1 of whom had delayed instability. Ordinal logistic regression revealed that factors associated with a higher number of spinal columns injured included advanced CT-detected cervical spondylosis (odds ratio [OR] 11.6; 95% confidence interval [CI] 3.9 to 34.3), minor isolated thoracolumbar fractures (OR 5.4; 95% CI 1.5 to 19.7), and multidirectional cervical spine forces (OR 2.5; 95% CI 1.2 to 5.2). In patients with cervical midline tenderness and negative acute CT findings, we found that a subset of patients had MRI-detected cervical discoligamentous injuries and that advanced cervical spine degeneration evident on CT, minor thoracolumbar fracture, and multidirectional cervical spine forces were associated with increased injury extent. However, a larger study is required to validate which variables may reliably predict clinically important injury in such patients, thereby indicating the need for further radiographic assessment.

Value of EUS in Determining Curative Resectability in Reference to CT and FDG-PET: The Optimal Sequence in Preoperative Staging of Esophageal Cancer?

BackgroundThe separate value of endoscopic ultrasonography (EUS), multidetector computed tomography (CT), and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the optimal sequence in staging esophageal cancer has not been investigated adequately.MethodsThe staging records of 216 consecutive operable patients with esophageal cancer were reviewed blindly. Different staging strategies were analyzed, and the likelihood ratio (LR) of each module was calculated conditionally on individual patient characteristics. A logistic regression approach was used to determine the most favorable staging strategy.ResultsInitial EUS results were not significantly related to the LRs of initial CT and FDG-PET results. The positive LR (LR+) of EUS-fine-needle aspiration (FNA) was 4, irrespective of CT and FDG-PET outcomes. The LR+ of FDG-PET varied from 13 (negative CT) to 6 (positive CT). The LR+ of CT ranged from 3–4 (negative FDG-PET) to 2–3 (positive FDG-PET). Age, histology, and tumor length had no significant impact on the LRs of the three diagnostic tests.ConclusionsThis study argues in favor of PET/CT rather than EUS as a predictor of curative resectability in esophageal cancer. EUS does not correspond with either CT or FDG-PET. LRs of FDG-PET were substantially different between subgroups of negative and positive CT results and vice versa.

Unrecognized Preanalytical Problem with the Spectrophotometric Analysis of Cerebrospinal Fluid for Xanthochromia

The primary diagnostic test for subarachnoid hemorrhage (SAH)1 is a computed tomography scan, but because SAH is found in a small percentage of patients with negative computed tomography results, lumbar puncture (LP) and spectrophotometric analysis of cerebrospinal fluid (CSF) for xanthochromia are still needed to make decisions about angiography (1). Oxyhemoglobin (O2Hb) is released from erythrocytes (RBCs) in the CSF in vivo and converted to bilirubin in the leptomeninges in a time-dependent process. Although the trauma of LP frequently produces RBCs in CSF and RBC lysis leads to the presence of O2Hb, no bilirubin is formed in such cases. The presence of bilirubin is considered the most specific sign of SAH, and a LP is recommended 12 h after the appearance of symptoms to test for the presence of bilirubin(2)(3). O2Hb and bilirubin have absorbance peaks at 413–415 nm and 450–460 nm, respectively, but because of the overlap in absorbance wavelengths with O2Hb, bilirubin is preferentially measured at 476 nm(2)(3)(4). Nevertheless, avoidance of hemolysis ex vivo will improve the analysis of bilirubin in CSF and may make O2Hb a more reliable marker of bleeding. We conducted experiments to elucidate why RBCs lyse in CSF. A CSF pool …

Thunderclap Headache With Normal CT and Lumbar Puncture

Thunderclap Headache With Normal CT and Lumbar Puncture

Is the Combination of Negative Computed Tomography Result and Negative Lumbar Puncture Result Sufficient to Rule Out Subarachnoid Hemorrhage?

Current clinical practice assumes a negative computed tomography (CT) head scan result and a negative lumbar puncture result together are adequate to rule out subarachnoid hemorrhage in patients with acute headache. Our objective is to determine the sensitivity of a negative CT result combined with a negative lumbar puncture result to exclude subarachnoid hemorrhage. This prospective cohort study was conducted at 2 tertiary care emergency departments (EDs) during 3 years. We enrolled all patients who were older than 15 years, had a nontraumatic acute headache and normal neurologic examination result, and who had a CT head scan and a lumbar puncture if the CT result was negative (ie, no blood in the subarachnoid space). Patients were followed up with a structured telephone questionnaire 6 to 36 months after their ED visit and electronic hospital records review to ensure no missed subarachnoid hemorrhage. We calculated sensitivity, specificity, and likelihood ratios of the strategy of CT and then lumbar puncture for subarachnoid hemorrhage. Five hundred ninety-two patients were enrolled, including 61 with subarachnoid hemorrhage. The mean patient age was 43.6 years, with 59.1% female patients. All cases of subarachnoid hemorrhage were identified on initial CT or lumbar puncture. One patient without subarachnoid hemorrhage was subsequently diagnosed with cerebral aneurysm, requiring surgery. The strategy classified patients with subarachnoid hemorrhage with sensitivity, specificity, and positive and negative likelihood ratios (with 95% confidence intervals [CIs]) of 100% (95% CI 94% to 100%), 67% (95% CI 63% to 71%), 3.03 (95% CI 2.69 to 3.53), and 0. For diagnosis of subarachnoid hemorrhage or aneurysm, these were 98% (95% CI 91% to 100%), 67% (95% CI 63% to 71%), 2.98 (95% CI 2.63 to 3.38), and 0.02 (95% CI 0.00 to 0.17), respectively. To our knowledge, this is the largest prospective study evaluating the accuracy of a strategy of CT and lumbar puncture to rule out subarachnoid hemorrhage in alert ED patients with an acute headache. This study validates clinical practice that a negative CT with a negative lumbar puncture is sufficient to rule out subarachnoid hemorrhage.

Fluorine-18-l-Dihydroxyphenylalanine (18F-DOPA) Positron Emission Tomography as a Tool to Localize an Insulinoma or β-Cell Hyperplasia in Adult Patients

Fluorine-18-L-dihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET) is a promising method in localizing neuroendocrine tumors. Recently, it has been shown to differentiate focal forms of congenital hyperinsulinism of infancy. The current study was set up to determine the potential of 18F-DOPA PET in identifying the insulin-secreting tumors or beta-cell hyperplasia of the pancreas in adults. We prospectively studied 10 patients with confirmed hyperinsulinemic hypoglycemia and presumed insulin-secreting tumor using 18F-DOPA PET. Anatomical imaging was performed with computed tomography (CT) and magnetic resonance imaging (MRI). All patients were operated on, and histological verification was available in each case. Semiquantitative PET findings in the pancreas using standardized uptake values were compared to standardized uptake values of seven consecutive patients with nonpancreatic neuroendocrine tumors. By visual inspection of 18F-DOPA PET images, it was possible in nine of 10 patients to localize the pancreatic lesion, subsequently confirmed by histological analysis. 18F-DOPA uptake was enhanced in six of seven solid insulinomas and in the malignant insulinoma and its hepatic metastasis. Two patients with beta-cell hyperplasia showed increased focal uptake of 18F-DOPA in the affected areas. As compared to CT or MRI, 18F-DOPA PET was more sensitive in localizing diseased pancreatic tissue. 18F-DOPA PET was useful in most patients with insulinoma and negative CT, MRI, and ultrasound results. In agreement with previous findings in infants, preoperative 18F-DOPA imaging seems to be a method of choice for the detection of beta-cell hyperplasia in adults. It should be considered for the detection of insulinoma or beta-cell hyperplasia in patients with confirmed hyperinsulinemic hypoglycemias when other diagnostic work-up is negative.

Use of Computed Tomography in Anterior Abdominal Stab Wounds

Computed tomography (CT) can be used to evaluate patients with anterior abdominal stab wounds (AASWs). Prospective observational study. Academic level I trauma center. All of the patients sustaining AASWs, excluding those with hemodynamic instability, peritonitis, or omental evisceration, were admitted for serial abdominal examinations with or without CT depending on attending preference. Patients with associated left thoracoabdominal stab wounds underwent diagnostic laparoscopy. Change in patient management as a direct result of the CT scan findings, as well as sensitivity, specificity, positive predictive value, and negative predictive value of CT scanning calculated against clinical outcome (the need for laparotomy, uneventful discharge without laparotomy, or return to the hospital for adverse events). One hundred fifty-six consecutive patients with AASWs were included over 24 months. Computed tomography was performed for 67 patients (CT group) whereas 89 patients were admitted for serial examination only (no-CT group). Nineteen of the 67 patients in the CT group had positive CT results, leading to laparotomy in 10 patients. Of the 48 patients with negative CT results, 3 underwent diagnostic laparoscopy for an associated thoracoabdominal stab wound and 2 eventually underwent laparotomy for clinical deterioration with negative results. Excluding patients with associated thoracoabdominal stab wounds, the negative predictive value of CT was 100%. In patients with AASWs, CT can be used to identify visceral injuries. It is a promising tool that may identify patients who can be discharged after a shorter period of observation. Further evaluation of its use in patients with AASWs is warranted.

Safety of Withholding Anticoagulant Therapy in Patients Who Have Clinically Suspected Pulmonary Embolism and Negative Results on Helical Computed Tomography

Background: Several studies have focused on the safety of withholding anticoagulant therapy in patients with negative results on helical computed tomography (CT). However, these studies were either retrospective or had a selection bias, since spiral CT was performed only in selected patients. Moreover, no special attention has been directed towards an alternative diagnosis which might explain patients’ signs and symptoms. Objectives: To determine the safety of withholding anticoagulants in patients with clinically suspected pulmonary embolism (PE) and negative CT results when ultrasonography (US) was performed only in patients with clinical suspicion of deep vein thrombosis (DVT). Another goal was to evaluate the effect of CT findings on the final clinical diagnosis. Methods: Among 192 consecutive patients who underwent CT for possible acute PE, 98 patients had negative images and 88 of them – without clinical suspicion of DVT – were prospectively followed up for 3 months for evidence of subsequent thromboembolic disease. They did not receive anticoagulation. Clinical probability of PE was assessed applying the Geneva score. These patients were also classified into several diagnostic categories according to the CT findings and clinical presentation. In addition, all patients who were alive (or a member of his or her family) were interviewed by phone once the last patient’s follow-up was completed. Results: One patient was lost to follow-up. Among the remaining 87 patients (35 with low, 47 with intermediate and 5 with high clinical probability), subsequent thromboembolic disease was found in 1 (1.1%; 95%CI: 0.03–6.2%). Two patients died during the follow-up period, but no deaths were attributed to PE. Alternative diagnoses were: nonspecific thoracic pain (43.3%), nonspecific pleuritis (19.5%), pneumonia (18.4%), other (18.8%). The telephone survey was performed in 74 patients (median follow-up: 11 months; range: 4–23). None of them had newly diagnosed episodes of PE and none of them had received anticoagulation for any reason. Conclusions: With the limitations of a small single-center series, our data suggest that withholding anticoagulation in patients with suspected acute PE and negative CT results appears to be safe when the clinical probability of PE is assessed as low or intermediate. This technique also provides useful information to pose an alternative diagnosis. US could be avoided in patients without clinical suspicion of DVT.

Nasal endoscopy and the definition and diagnosis of chronic rhinosinusitis.

Although endoscopy has been shown by a few authors to be a valuable tool for the diagnosis of chronic rhinosinusitis, its true role in the evaluation of the patient with chronic rhinosinusitis has not been elucidated. The current definition of chronic rhinosinusitis is a symptom-based definition, and objective testing such as endoscopy or computed tomography (CT) is not included. However, the current treatment paradigm for chronic rhinosinusitis is dependent on the definition for diagnosis. Patients are treated with 4 weeks of antibiotics and decongestant/antihistamines/steroids based on the definition. This study aims to evaluate in a prospective fashion the place of endoscopy in the diagnosis of chronic rhinosinusitis. A group of 78 patients meeting the definition of chronic rhinosinusitis were subjected to same-day endoscopy and CT scanning. Seventeen (22%) of 78 patients had positive endoscopic and CT results. There were 20 (26%) of 78 patients with negative endoscopic and positive CT results. Six (8%) patients had positive endoscopic and negative CT results, and 35 (45%) had negative endoscopic and negative CT results. Overall, 37 (47%) patients had positive CT results, and 41 (53%) patients had negative CT results. Endoscopy showing the presence of purulence, nasal polyps, or watery congested mucosa correlated well with CT results. Negative endoscopy correlated with CT results in 65% of patients. The use of endoscopy to corroborate the diagnosis in nonpolypoid or nonpurulent rhinosinusitis in previously unoperated patients is questioned. Patients who meet the subjective definition of chronic rhinosinusitis should have a high degree of sensitivity and specificity with endoscopy or CT. The fact this is not the case questions the accuracy of the definition and the treatment paradigm. According to this study, positive endoscopic results correlated well with CT, and negative endoscopic results correlated in 71% of patients with negative CT results.