Comparison Of Computed Tomography Research Articles

Differentiation between pancreatic metastases from renal cell carcinoma and hypervascular neuroendocrine tumour: Use of relative percentage washout value and its clinical implication

PurposeTo compare computed tomography (CT) findings in patients with pancreatic metastasis from renal cell carcinoma (pRCC) and patients with hypervascular pancreatic neuroendocrine tumour (pNET) with a focus on the relative percentage washout (RPW). MethodsWe evaluated 16 patients with 37 pRCCs and 28 patients with 31 hypervascular pNETs using a protocol consisting of arterial and portal phase CT. Imaging findings were analyzed for comparison between the two groups. The RPW of each tumour using biphasic CT was obtained by two observers for evaluation of diagnostic performance. Interobserver agreement of each value and optimal cut-off level of RPW for discrimination between groups were evaluated. ResultsTumour multiplicity showed significant difference in both groups. The mean RPW of the pRCC group (observer 1, 27.0%; observer 2, 29.4%) was significantly higher than that of the pNET group (observer 1, 0.5%; observer 2, 3.2%) (p<0.001 for each observer). Interobserver agreement for both attenuation values and RPWs was excellent. A RPW value of 19% was selected as the optimal cut-off for pRCC determination, and showed good performance (accuracy 83.8%, sensitivity 83.8%, and specificity 83.9%). ConclusionWith multiplicity, RPW of the tumour on CT could be helpful for differentiating pRCCs from hypervascular pNETs.

Clinical Utility of Computed Tomography and Magnetic Resonance Imaging for Diagnosis of Posterior Reversible Encephalopathy Syndrome after Stem Cell Transplantation in Children and Adolescents

Posterior reversible encephalopathy syndrome (PRES) is a clinical syndrome characterized by vision changes, altered mental status, and seizures, typically caused by an acute rise in blood pressure. PRES has been reported after hematopoietic stem cell transplantation (HSCT) in association with hypertension from calcineurin inhibitors and corticosteroids. The imaging evaluation of PRES after HSCT in children and young adults has not been well described. We performed a retrospective review of all HSCT recipients presenting to the intensive care unit with new neurologic symptoms. A neuroradiologist reviewed all radiologic images and compared computed tomography (CT) versus magnetic resonance imaging (MRI) findings indicative of diagnosis of PRES. Alternative imaging diagnoses explaining the patients' symptoms were also recorded. Fifty-four transplant recipients were admitted to the intensive care unit with new neurologic symptoms. Thirty-nine percent (21 of 54) of subjects had imaging findings consistent with PRES, 24% (13 of 54) had imaging findings consistent with an alternative diagnosis, 9% (5 of 54) had a nonspecific finding, and 28% (15 of 54) had no acute imaging findings. PRES was diagnosed at a median of 49 days (interquartile range, 29 to 94) after HSCT. The presenting symptom for the majority of patients with PRES was seizures (86%), whereas 14% presented with acute encephalopathy. Ninety-five percent of subjects diagnosed with PRES (20 of 21) underwent a head CT as their initial imaging evaluation. CT scan was diagnostic of PRES in 40% (8 of 20). Subsequently, 16 patients underwent brain MRI with 12 additional patients being diagnosed with PRES on MRI. The median time elapsed between negative CT and a positive MRI examination was 20 hours (range, 3.6 hours to 9 days). CT serves as an excellent screening test for acute pathology, such as intracranial hemorrhage; however, it lacks sensitivity for the diagnosis of PRES. Patients with clinical symptoms suggestive of PRES who have a negative CT should be treated appropriately for PRES and should undergo MRI of the brain as soon as clinically stable to confirm the diagnosis.

CT Volumetric Analysis of Pleural Effusions: A Comparison with Thoracentesis Volumes

The primary objective of this study was to compare computed tomography (CT) volumetric analysis of pleural effusions with thoracentesis volumes. The secondary objective of this study was to compare subjective grading of pleural effusion size with thoracentesis volumes. This was a retrospective study of 67 patients with free-flowing pleural effusions who underwent therapeutic thoracentesis. CT volumetric analysis was performed on all patients; the CT volumes were compared with the thoracentesis volumes. In addition, the subjective grading of pleural effusion size was compared with the thoracentesis volumes. The average difference between CT volume and thoracentesis volume was 9.4 mL (1.3%) ± 290 mL (30%); these volumes were not statistically different (P = .79, paired two-tailed Student's t-test). The thoracentesis volume of a "small," "moderate," and "large" pleural effusion, as graded on chest CT, was found to be approximately 410 ± 260 cc, 770 ± 270 mL and 1370 ± 650 mL, respectively; the thoracentesis volume of a "small," "moderate," and "large" pleural effusion, as graded on chest radiograph, was found to be approximately 610 ± 320 mL, 1040 ± 460 mL, and 1530 ± 830 mL, respectively. CT volumetric analysis is an accessible tool that can be used to accurately quantify the size of pleural effusions.

Tu1089 Optimal Imaging for the Diagnosis of Acute Appendicitis in Adults, Children and Pregnant Women: A Decision Analysis

Background: Accurate and timely diagnosis of acute appendicitis can reduce mortality, improve clinical outcomes, and optimize resource utilization. Our aim was to compare computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound (US) for the diagnosis of acute appendicitis in adults, children and pregnant women. Methods: For a hypothetical cohort of 10,000 patients, we constructed a decision analysis model to examine 3 imaging modalities for the diagnosis of acute appendicitis in adults, children and pregnant women presenting with abdominal pain. Imaging sensitivity and specificity were based on an AHRQ systematic review and meta-analysis of over 800 studies, e.g., sensitivity of CT (96%), MRI (91%) and US (83%) and specificity of CT (96%), MRI (86%) and US (89%) in adults. Prevalence and complication rates (perforation at presentation and after delayed diagnosis and mortality) were based on published estimates. Outcomes included overall surgery rate (initial+delayed), delayed surgery (false negatives), unnecessary surgery (false positives), perforated appendicitis (initial+delayed) and mortality. Results: In adults with a 25% risk of appendicitis, CT was the best strategy with 750 and 525 fewer total surgeries and unnecessary surgeries, 124 and 325 fewer delayed surgeries, 45 and 117 fewer perforations, and 9 and 22 more lives saved per 10,000 patients compared to MRI and US, respectively (Table 1). For children with a 10% risk of appendicitis, MRI performed best with 720 and 630 fewer total surgeries and unnecessary surgeries, 40 and 110 fewer delayed surgeries, 20 and 55 fewer perforations, and 1 and 1 more life saved per 10,000 patients compared to CT and US, respectively. For pregnant women with 30% risk of appendicitis, MRI was best with no fewer surgeries or unnecessary surgeries but with 40 and 110 fewer perforations, and 6 and 48 more lives saved per 10,000 patients compared to CT and US, respectively. In one-way sensitivity analysis of the 95% CI for sensitivity and specificity, the optimal strategies above remained preferred except when 1) the sensitivity of MRI increased, making it more favorable in adults, 2) the sensitivity and specificity of MRI fell in children and CT became favored and 3) the sensitivity of MRI fell and the sensitivity of CT increased in pregnant women and CT became favored. Conclusion: The results suggest that imaging should be tailored to the type of patient presenting with suspected acute appendicitis and that optimal imaging testing would reduce morbidity and mortality while reducing resource utilization. The results were sensitive to variation in test sensitivity and specificity, so patient care should consider local test performance. Future analyses should incorporate quality of life adjustments, costs and long-term effects of radiation, non-diagnostic imaging results, and serial imaging. Outcomes for 10,000 Patients with Suspected Acute Appendicitis

Reversibility of trapped air on chest computed tomography in cystic fibrosis patients

PurposeTo investigate changes in trapped air volume and distribution over time and compare computed tomography (CT) with pulmonary function tests for determining trapped air. MethodsThirty children contributed two CTs and pulmonary function tests over 2 years. Localized changes in trapped air on CT were assessed using image analysis software, by deforming the CT at timepoint 2 to match timepoint 1, and measuring the volume of stable (TAstable), disappeared (TAdisappeared) and new (TAnew) trapped air as a proportion of total lung volume. We used the difference between total lung capacity measured by plethysmography and helium dilution, residual volume to total lung capacity ratio, forced expiratory flow at 75% of vital capacity, and maximum mid-expiratory flow as pulmonary function test markers of trapped air. Statistical analysis included Wilcoxon's signed rank test and Spearman correlation coefficients. ResultsMedian (range) age at baseline was 11.9 (5–17) years. Median (range) of trapped air was 9.5 (2–33)% at timepoint 1 and 9.0 (0–25)% at timepoint 2 (p=0.49). Median (range) TAstable, TAdisappeared and TAnew were respectively 3.0 (0–12)%, 5.0 (1–22)% and 7.0 (0–20)%. Trapped air on CT correlated statistically significantly with all pulmonary function measures (p<0.01), other than residual volume to total lung capacity ratio (p=0.37). ConclusionTrapped air on CT did not significantly progress over 2 years, may have a substantial stable component, and is significantly correlated with pulmonary function markers.

Ivacaftor improves appearance of sinus disease on computerised tomography in cystic fibrosis patients with G551D mutation.

Most patients with Cystic fibrosis (CF) have chronic sinus disease which may require multiple sinus surgeries and antibiotic courses. Ivacaftor can improve lung function, lower sweat chloride levels and improve weight by targeting the primary defect, a faulty gene and its protein product, cystic fibrosis transmembrane conductance regulator (CFTR) in patients with the G551D mutation. Its role in improving sinus disease has not been evaluated. The objective of this study was to evaluate efficacy of ivacaftor in improving CF related sinus disease. Observational study. Twelve patients with cystic fibrosis and a G551D-CFTR mutation. Twelve patients with a G551D-CFTR mutation were monitored for at least one year before and after starting ivacaftor. Sinus disease progression was monitored by comparing computed tomography (CT) of sinuses before and at one year on therapy. Hospital admissions, pulmonary exacerbations, weight, BMI and lung function were also compared. Median age was 17years (range 10-44). Weight, BMI, FEV1 significantly increased and sweat chloride significantly decreased by six months on ivacaftor therapy. CT of the sinuses in all patients improved. Seven patients had severe sinus disease, improved to moderate in three and mild in remaining four. Four patients had moderate disease which improved to mild in all. One patient had normal sinus CT before and after the therapy. Patients with CF and G551D mutation, within 6 months of starting ivacaftor had significant improvements in weight, BMI and mean % FEV1. Significant lessening of underlying sinus disease measured by CT scan was noted, suggesting a disease modifying effect.

Computed tomography and magnetic resonance imaging findings of nasal cavity hemangiomas according to histological type.

ObjectiveTo compare computed tomography (CT) and magnetic resonance imaging (MRI) findings between two histological types of nasal hemangiomas (cavernous hemangioma and capillary or lobular capillary hemangioma).Materials and MethodsCT (n = 20; six pre-contrast; 20 post-enhancement) and MRI (n = 7) images from 23 patients (16 men and seven women; mean age, 43 years; range, 13-73 years) with a pathologically diagnosed nasal cavity hemangioma (17 capillary and lobular capillary hemangiomas and six cavernous hemangiomas) were reviewed, focusing on lesion location, size, origin, contour, enhancement pattern, attenuation or signal intensity (SI), and bony changes.ResultsThe 17 capillary and lobular hemangiomas averaged 13 mm (range, 4-37 mm) in size, and most (n = 13) were round. Fourteen capillary hemangiomas had marked or moderate early phase enhancement on CT, which dissipated during the delayed phase. Four capillary hemangiomas on MRI showed marked enhancement. Bony changes were usually not seen on CT or MRI (seen on five cases, 29.4%). Half of the lesions (2/4) had low SI on T1-weighted MRI images and heterogeneously high SI with signal voids on T2-weighted images. The six cavernous hemangiomas were larger than the capillary type (mean, 20.5 mm; range, 10-39 mm) and most had lobulating contours (n = 4), with characteristic enhancement patterns (three centripetal and three multifocal nodular), bony remodeling (n = 4, 66.7%), and mild to moderate heterogeneous enhancement during the early and delayed phases.ConclusionCT and MRI findings are different between the two histological types of nasal hemangiomas, particularly in the enhancement pattern and size, which can assist in preoperative diagnosis and planning of surgical tumor excision.

Extra-Corporeal Membrane Oxygenation for Arrested Lung Ablative Radiation Therapy

Objectives: Due to breathing movements, radiotherapy of primary lung cancer requires sophisticated methods to ensure accuracy of the high-precision treatment applied. The aim of this study was to show the use of extracorporeal membrane oxygenation for ablative radiotherapy while the lung is totally arrested. Methods: A portable extracorporeal membrane oxygenation device was employed on three separate days without mechanical ventilation to apply stereotactic hypofractionated radiotherapy in three fractions (18 Gy x 3 54 Gy total) to a 68 year old male with a primary tumor (T1N0M0) in the right upper lobe (of the remaining lung). Linear accelerator quality controls (matched isocenter-lasers), patient immobilization monitoring (stereotactic infrared system) and image controls (in cinema mode to observe movements) were made during treatment, and a computed tomography comparison was carried out between pre and post treatment for image verification. Results: Total extra-corporeal membrane oxygenation time was 270, 283 and 380 minutes for each session respectively. Total administered nominal dose was 54 Gy and it was not necessary to discontinue the treatment since neither lung nor tumor movement was observed during this time. During the second and third treatment days, atelectasis appeared, involving the rear of the lower lobe and it was necessary to increase FiO2 to 0,5. The only post-procedure complication has been a seroma in the groin which was resolved with local wound care. Conclusion: The described technique of veno-arterial extra-corporeal membrane oxygenation allows the safe arrest of the lung, the immobilization of the tumor and provides enough time for highly accurate ablative radiation therapy.

Comparison of Attenuation of Striated Muscle between Postmortem and Antemortem Computed Tomography: Results of a Longitudinal Study

ObjectiveWe evaluated the postmortem changes of striated muscle by comparing computed tomography (CT) images obtained postmortem and antemortem in the same patients.Materials and MethodsWe studied 33 consecutive patients who underwent antemortem CT, postmortem CT, and pathological autopsy in our tertiary care hospital between April 2009 and December 2010. Postmortem CT was performed within 20 h after death and was followed by pathological autopsy. Pathological autopsy confirmed the absence of muscular diseases such as amyotrophic lateral sclerosis, muscular dystrophy, myositis, and myasthenia, in all of the patients. The CT attenuation values of four cardiac muscle sites (anterior wall of the left ventricle, left ventricular free wall, posterior wall of the left ventricle, and the ventricular septum) and two skeletal muscle sites (the pectoralis major muscle and the erector spinae muscle) were compared between antemortem and postmortem CT using paired t test.ResultsStriated muscle had significantly greater attenuation on postmortem CT than on antemortem CT (P<0.001) in all six tissue sites. No significant association was found between postmortem change in the CT attenuation of striated muscle and gender, age, or elapsed time since death.ConclusionThis is the first longitudinal study to show hyperattenuation of striated muscle on postmortem CT images compared with antemortem CT images in the same patients.

Are there imaging characteristics associated with lung adenocarcinomas harboring ALK rearrangements?

Introduction5% of lung adenocarcinomas harbor rearrangements of the anaplastic lymphoma kinase (ALK) gene. This study compared computed tomography (CT) imaging features in patients with ALK rearrangements and those with EGFR mutations. Material/methods30 patients with ALK rearrangements were studied. 97 patients with epidermal growth factor receptor (EGFR) mutations were used as controls. Features assessed included size and location of thoracic lymphadenopathy, and the size, contour, consistency and location of the primary tumor. Results127 lung adenocarcinomas were examined. 30 (24%) tumors harbored ALK rearrangements, 97 (76%) tumors harbored EGFR mutations. ALK tumors had larger thoracic lymphadenopathy than the control group (p=0.005). Both readers identified 17 (57%) patients in the ALK group with lymph nodes >1.5cm. Reader 1 identified 19 (20%) patients in the EGFR group with lymph nodes >1.5cm, and reader 2 identified 18 (19%) (kappa 0.969). Patients with ALK rearrangements were more likely to have multifocal lymphadenopathy. Reader 1 identified 22 (73%) ALK patients versus 35 (36%) EGFR patients with multifocal thoracic nodal enlargement, while reader 2 identified 20 (67%) ALK patients versus 30 (31%) EGFR patients (kappa 0.953). 92% of ALK positive lesions were solid. ConclusionALK positive lung adenocarcinomas are more likely than EGFR mutant lung adenocarcinomas to be associated with larger volume, multifocal thoracic lymphadenopathy. While routine testing for ALK should be standard, the presence of such characteristics in a solid tumor should further prompt testing for ALK rearrangement.

Detection of radiolucencies around endodontically treated teeth on routine CT scans.

This retrospective study compared computed tomography (CT) imaging to routine dental periapical radiographs in diagnosing radiolucencies around endodontically treated teeth. Of the 244 CT scans evaluated, 104 had no teeth on the scan. On the remaining 140 scans, 353 teeth fell into the following categories: 59 maxillary molars, 30 mandibular molars, 66 maxillary premolars, 56 mandibular premolars, and 141 anterior teeth. Positive and negative predictive values were calculated, as were sensitivity, specificity, and prevalence assuming the CT scan was the test standard. For the total tooth population periapical radiograph - CT slice sensitivity was 52, specificity was 90, the positive predictive value (PPV) was 97, the negative predictive value (NPV) was 25, and the prevalence 85. In the population studied, the CT scan had a greater ability to show radiolucencies that were not evident on periapical radiographs.

439P - Comparison of Ct and 18F-Flt Pet/Ct Imaging for Target Volume Delineating in Patients with Glioma

ABSTRACT Aim: The aim of this pilot study was to compare computed tomography (CT) and 3′-deoxy-3′-[18F] fluorothymidine (18F-FLT) positron emission tomography/ computed tomography (PET/CT) imaging for gross tumor volume (GTV) and clinical target volume (CTV) delineation, and to analyze the impact of proliferative tumor volume delineated by 18F-FLT PET/CT. Methods: 12 patients with glioma were enrolled into this study. The relation of 18F-FLT uptake and pathology, Ki-67 index were studied in 9 patients. All of the 12 patients underwent 18F-FLT PET/CT imaging before radiotherapy. The enhanced CT images and 18F-FLT PET/CT images were all transferred to planning system and the target volumes from each image were delineated and compared. Results: 18F-FLT PET/CT SUVmax increased significantly with glioma grade (p = 0.007). SUVmax of 18F-FLT PET/CT (p= 0.03), T/N ratio (p Conclusions: The uptakes of 18F-FLT were positively correlated with grade of glioma and tumor cell proliferation index. To delineate target volume by 18F-FLT PET/CT imaging, the GTV and CTV are smaller than CT. It maybe improves the accuracy of GTV and CTV in patients with glioma and, meanwhile, provides potential benefits to normal brain tissue. Disclosure: All authors have declared no conflicts of interest.

Response of Pelvic Lymph Nodes to Neoadjuvant Hormonal Therapy in Prostate Cancer Patients: Computed Tomography for Radiation Therapy Treatment Planning as “Second Look” Imaging

It has become standard to perform neoadjuvant hormonal therapy (HT) for high-risk prostate cancer patients treated with radiation therapy. This analysis evaluated the value of comparing computed tomography (CT) images before and after HT by analyzing the rates and characteristics of pelvic lymph nodes that shrank following HT in high-risk prostate cancer patients.

Stent Graft Placement for Postsurgical Hemorrhage from the Hepatic Artery: Clinical Outcome and CT Findings

PurposeTo evaluate the clinical results and imaging follow-up findings of stent grafts placed for hemorrhage from hepatic arteries following surgery. Materials and MethodsThe investigation included 17 patients (14 men and 3 women) who underwent endovascular stent graft placement for hepatic arterial hemorrhage following surgery. Bleeding occurred from the common hepatic artery (n = 1; 6%), right hepatic artery (n = 1; 6%), proper hepatic artery (n = 6; 35%), and gastroduodenal artery stump (n = 9; 53%). Stent graft patency, thrombus at the graft, target hepatic artery diameter, and liver perfusion status were analyzed by comparing computed tomography (CT) scans performed before the procedure with follow-up CT scans. Laboratory data were also analyzed before the procedure and at follow-up intervals. ResultsThere were 17 stent grafts placed in 17 patients. The mean follow-up period was 356 days (range, 1–2,119 d). The stent graft primary patency rate was 79.5% at 1 month, 69.6% at 6 months, and 69.6% at 1 year. The clinical success rate was 82% (14 of 17 patients), and the technical success rate was 94% (16 of 17 patients). Mortality related to the stent graft was 12% (2 of 17 patients). Occlusion occurred in 4 of 16 stent grafts (25%). There was one technical failure. The mean stent graft diameter was 6.2 mm (range, 3.5–8.0 mm), and the degree of stent graft oversizing was 38% of the hepatic artery diameter on CT scans and 58% on angiography. Hepatic parenchymal perfusion was preserved in 80% of patients (12 of 15). ConclusionsHepatic artery hemorrhage following surgery can be treated effectively with stent graft placement.

CT sensitivities for large (≥3cm) adrenal adenoma and cortical carcinoma.

To retrospectively compare computed tomography (CT) sensitivities of large (≥3cm) adenoma and cortical carcinoma. Between January 2004 and November 2012, 43 non-oncologic patients with 43 adrenal masses [31 large adenomas, and 12 carcinomas] underwent unenhanced CT, early contrast-enhanced CT, and delayed contrast-enhanced CT scans prior to adrenalectomy. Three types of region-of-interest (ROI) were used on early contrast-enhanced CT images:aROI (large ROI) covering more than half of a mass and two small ROIs fitted to the highest (high ROI) or lowest (low ROI) attenuation area. These ROIs were also placed in the same area on the other CT images. Adenoma was diagnosed if a mass measured≤10 HU on unenhanced CT image, or if it had≥60% absolute percentage washout (APW)or≥40% relative percentage washout (RPW).Carcinoma was diagnosed if a mass had<60% APW and<40% RPW. CT sensitivities for large adenoma and carcinoma were compared. CT sensitivities for large adenoma vs. carcinoma were 64.5% (20/31) vs. 100% (12/12) using a large ROI, 100% (31/31) vs. 50.0% (6/12) using a high ROI, and 51.6% (16/31) vs. 100% (12/12) using a low ROIs, respectively. CT sensitivities for large adenoma and cortical carcinoma are influenced by the size or location of an ROI.A large ROI helps to minimize loss of CT sensitivity for large adenoma and to detect carcinoma.

COMPARISON BETWEEN COMPUTED TOMOGRAPHY, FLUOROSCOPY, AND ULTRASONOGRAPHY FOR GUIDING PERCUTANEOUS INJECTION OF THE CANINE INTERVERTEBRAL DISC

A minimally invasive method for delivering injectable therapeutic agents would be desirable for the treatment of intervertebral disc disease in dogs. The purpose of this study was to compare computed tomography (CT), ultrasonography (US), and fluoroscopy modalities for guiding percutaneous injection into canine intervertebral discs. Intervertebral discs of 14 dog cadavers were injected with a gelified ethanol therapeutic agent. Successful injectate placement and injectate leakage were determined based on necropsy inspection of discs. Injection into the nucleus pulposus was successful in 55 of 78 (71%) of all injected discs. Injections guided using CT and fluoroscopy were significantly more successful than US-guided injections. Odds of successful injection without leakage were greater for CT vs. US (P = 0.0026) but there was no significant difference between CT and fluoroscopy (P = 0.0620). Injection success rates did not differ among vertebral sites or dog cadavers of varying weights. Forty-nine (63%) of injection sites had injectate leakage outside the disc and 10 of these involved structures within the vertebral canal. The highest rate of injection success with the least amount of leakage was achieved with CT guidance. Findings indicated that CT, fluoroscopy, and US are feasible modalities for guiding percutaneous injection of a gelified ethanol therapeutic agent into the canine intervertebral disc, with moderate to high success rates for different regions of the spine. However, a moderately high rate of injectate leakage occurred outside of the disc and this should be taken into consideration for future safety and efficacy studies.

A Synthesis of Research Examining Timely Removal of Cervical Collars in the Obtunded Trauma Patient With Negative Computed Tomography

Currently, the standard to clear the cervical spine in obtunded blunt trauma patients is computed tomography in combination with plain films, dynamic fluoroscopy, or magnetic resonance imaging. The objective of this study was to answer the question "Can computed tomography alone provide adequate clinical information to clear the cervical spine in the obtunded patient?" The author performed a search of the literature for studies that compared computed tomography (CT) with other radiologic modalities utilized to clear the cervical spine in obtunded patients. PubMed, TRIPdatabase, SUMsearch, Cochrane library, and Google Scholar were the databases applied. Additional sources included bibliographies of selected articles. Studies that integrated CT scan with at least 1 other diagnostic examination were included. A review of 11 studies and 1 meta-analysis encompassing 2458 and 14327 patients, respectively, met inclusion criteria. The meta-analysis generated a negative predictor value for CT scan of 100% without evidence of acute injury with an overall sensitivity and specificity of 99.9% each. The results suggest that CT alone is a reliable clinical indicator to clear the cervical spine in obtunded patients.

Comparison of the Spectrum of Radiologic and Clinical Manifestations of Pulmonary Disease Caused by Mycobacterium avium Complex and Mycobacterium xenopi

AimMycobacterium xenopi is described with upper lobe cavitation (“fibrocavitary” pattern), whereas the Mycobacterium avium complex (MAC) is described with bronchiectasis and centrilobular nodules (“nodular bronchiectasis”). We retrospectively described and compared computed tomography (CT) chest manifestations of disease caused by MAC and M xenopi. Materials and MethodsWe reviewed patients who had either MAC or M xenopi lung disease and who had CTs between January 2002 and December 2003. Clinical data were recorded, and the patterns on chest CTs were categorized as “fibrocavitary,” “nodular bronchiectatic,” and “unclassified.” ResultsThere were 74 patients; 50 with MAC and 24 with M xenopi. The patients with MAC were older (mean 69 vs 58 years; P = .007). Patients with M xenopi more often had emphysema (50% vs 20%; P = .02), cavities (46% vs 16%; P = .01), and nodules ≤5 mm (88% vs 58%; P = .02). M xenopi cases more commonly had a fibrocavitary radiologic pattern (33% vs 18%), with no statistically significant difference (P = .24). MAC was more often associated with a nodular bronchiectatic pattern (68% MAC vs 4% M xenopi; P < .0001). Sixty-three percent of patients with M xenopi had a pattern that was predominantly randomly distributed nodules (11/15 [73%]) or consolidation and/or ground-glass opacities (4/15 [27%]). ConclusionCompared with MAC, patients with M xenopi infection develop more cavities and more nodules, and they less often have a predominant nodular bronchiectatic pattern. Although a predominantly cavitary pattern appears to be more common with M xenopi, the majority of patients with M xenopi had CT patterns of random nodules or consolidation and/or ground-glass opacities rather than classically described findings.

Comparison of CT-Guided Percutaneous Biopsy with and Without Registration of Prior PET/CT Images to Diagnose Mediastinal Tumors

To compare computed tomography (CT)-guided percutaneous biopsy with and without registration of prior positron emission tomography (PET)/CT images in the diagnosis of mediastinal tumors. We performed clinically indicated percutaneous biopsy in 106 patients with mediastinal tumors in the anterior (n = 61), posterior (n = 21), middle (n = 16), and superior mediastinum (n = 8). The final diagnosis was based on surgical outcomes, or imaging findings and the results of at least 6-month follow-up. The patients underwent CT-guided percutaneous biopsy with (group 1, n = 56) or without (group 2, n = 50) registration of prior PET/CT images obtained no more than 22 days earlier. The registered images were used to plan the procedure and help target the tumors. CT-guided percutaneous needle biopsy yielded adequate samples in 101 of 106 (95 %) patients (group 1, n = 53; group 2, n = 48); in 95 patients (94 %), the diagnosis was confirmed by specific histological typing (group 1, n = 51; group 2, n = 44). The diagnostic accuracy of CT-guided percutaneous biopsy with and without the registration of prior PET/CT images was not statistically different (group 1, 96 %; group 2, 93 %, p = 0.324). CT-guided percutaneous biopsy is an easy and safe procedure that can provide a precise diagnosis in the majority of mediastinal tumors. PET/CT-guided biopsy yielded no special diagnostic advantages.

Comparison of Epicardial Fat Volume by Computed Tomography in Black Versus White Patients With Acute Chest Pain

Disparities in the risk of coronary artery disease (CAD) between races may be influenced by differences in the thoracic adipose tissue. We compared computed tomography (CT)-derived volumes of epicardial adipose tissue (EAT), mediastinal adipose tissue (MAT), and pericoronary fat thickness (PFT) and correlations with CAD between black and white patients. This institutional review board-approved Health Insurance Portability and Accountability Act-compliant study included 372 age- and gender-matched black versus white patients (186 black, 54 ± 11 years, 50% men; 186 white, 54 ± 11 years, 50% men) who underwent CT for chest pain evaluation. EAT, MAT, and PFT were measured. The amount of coronary calcium was quantified as calcium score. CAD was defined as ≥50% coronary artery narrowing. EAT and MAT volumes were significantly lower in black than white patients (59 [twenty-fifth to seventy-fifth percentile 39 to 84] vs 97 [67 to 132] cm(3) and 44 [27 to 77] vs 87 [52 to 157] cm(3), for both p <0.001). Mean PFT in black patients was slightly lower than white patients (17.2 ± 3.2 vs 18.1 ± 3.4 mm, p <0.01). The relation between race and extent of adipose tissue remained significant after adjustment for cardiovascular risk factors. Significant correlations were observed between EAT and MAT volumes and calcium score in black and white patients (r = 0.19 to 0.26, p <0.01). For both races, the level of thoracic fat measurements was higher in present versus absent coronary calcification. A greater amount of thoracic fat was found with obstructive CAD only in white patients. In conclusion, CT-derived measurements of thoracic fat differ between symptomatic black and white patients, suggesting a differential relation between thoracic adipose tissue and CAD pathophysiology by race.