Tomography Scanning (tomography + scanning)

Distribution by Scientific Domains

Kinds of Tomography Scanning

  • computed tomography scanning
  • emission tomography scanning
  • positron emission tomography scanning


  • Selected Abstracts


    National Study on Emergency Department Visits for Transient Ischemic Attack, 1992,2001

    ACADEMIC EMERGENCY MEDICINE, Issue 6 2006
    Jonathan A. Edlow MD
    Abstract Objectives: To describe the epidemiology of U.S. emergency department (ED) visits for transient ischemic attack (TIA) and to measure rates of antiplatelet medication use, neuroimaging, and hospitalization during a ten-year time period. Methods: The authors obtained data from the 1992,2001 National Hospital Ambulatory Medical Care Survey. TIA cases were identified by having ICD-9 code 435. Results: From 1992 to 2001, there were 769 cases, representing 2,969,000 ED visits for TIA. The population rate of 1.1 ED visits per 1,000 U.S. population (95% CI = 0.92 to 1.30) was stable over time. TIA was diagnosed in 0.3% of all ED visits. Physicians administered aspirin and other antiplatelet agents to a small percentage of patients, and 42% of TIA patients (95% CI = 29% to 55%) received no medications at all in the ED. Too few data points existed to measure a statistically valid trend over time. Physicians performed computed tomography scanning in 56% (95% CI = 45% to 66%) of cases and performed magnetic resonance imaging (MRI) in < 5% of cases, and there was a trend toward increased imaging over time. Admission rates did not increase during the ten-year period, with 54% (95% CI = 42% to 67%) admitted. Regional differences were noted, however, with the highest admission rate found in the Northeast (68%). Conclusions: Between 1992 and 2001, the population rate of ED visits for TIA was stable, as were admission rates (54%). Antiplatelet medications appear to be underutilized and to be discordant with published guidelines. Neuroimaging increased significantly. These findings may reflect the limited evidence base for the guidelines, educational deficits, or other barriers to guideline implementation. [source]


    Evaluation of a Pediatric-sedation Service for Common Diagnostic Procedures

    ACADEMIC EMERGENCY MEDICINE, Issue 6 2006
    Wendalyn K. King MD
    Abstract Background: Pediatric patients often require sedation for diagnostic procedures such as magnetic resonance imaging and computed tomography scanning. In October 2002, a dedicated sedation service was started at a tertiary care pediatric facility as a joint venture between pediatric emergency medicine and pediatric critical care medicine. Before this service, sedation was provided by the department of radiology by using a standard protocol, with high-risk patients and failed sedations referred for general anesthesia. Objectives: To describe the initial experience with a dedicated pediatric-sedation service. Methods: This was a retrospective analysis of quality-assurance data collected on all sedations in the radiology department for 23-month periods before and after sedation-service implementation. Study variables were number and reasons for canceled or incomplete procedures, rates of referral for general anesthesia, rates of hypoxia, prolonged sedation, need for assisted ventilation, apnea, emesis, and paradoxical reaction to medication. Results are reported in odds ratios (OR) with 95% confidence intervals (95% CI). Results: Data from 5,444 sedations were analyzed; 2,148 before and 3,296 after sedation-service activation. Incomplete studies secondary to inadequate sedation decreased, from 2.7% before the service was created to 0.8% in the post,sedation-service period (OR, 0.29; 95% CI = 0.18 to 0.47). There also were decreases in cancellations caused by patient illness (3.8% vs. 0.6%; OR, 0.16; 95% CI = 0.10 to 0.27) and rates of hypoxia (8.8% vs. 4.6%; OR, 0.50; 95% CI = 0.40 to 0.63). There were no significant differences between the groups in rates of apnea, need for assisted ventilation, emesis, or prolonged sedation. The implementation of the sedation service also was associated with a decrease in both the number of patients referred to general anesthesia without a trial of sedation (from 2.1% to 0.1%; OR, 0.33; 95% CI = 0.06 to 1.46) and the total number of general anesthesia cases in the radiology department (from 7.5% to 4.4% of all patients requiring either sedation or anesthesia; OR, 0.56; 95% CI = 0.45 to 0.71). Conclusions: The implementation of a dedicated pediatric-sedation service resulted in fewer incomplete studies related to inadequate sedation, in fewer canceled studies secondary to patient illness, in fewer referrals for general anesthesia, and in fewer recorded instances of sedation-associated hypoxia. These findings have important implications in terms of patient safety and resource utilization. [source]


    Clinical and imaging characterization of a patient with idiopathic progressive ataxia and palatal tremor

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 8 2007
    R. Cilia
    We describe clinical and imaging features of a patient with sporadic progressive ataxia and palatal tremor (PAPT) of unknown etiology. There was hypertrophy of bilateral inferior olivary nuclei with hyperintense T2-weighted signal and mild cerebellar atrophy at brain magnetic resonance imaging. 18F-fluoro-2-desoxy- d -glucose positron emission tomography scanning (FDG-PET) showed hypometabolism in the red nucleus, external globus pallidus and precuneus while FP-CIT-SPECT imaging revealed mild and progressive loss of striatal dopaminergic terminals. Our findings suggest that in idiopathic PAPT involvement of the dentato-rubro-olivary pathway occurs along with some dopaminergic dysfunction. [source]


    Diagnostic accuracy of digitized periapical radiographs validated against micro-computed tomography scanning in evaluating orthodontically induced apical root resorption

    EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2008
    Alexander Dudic
    The aim of this study was to validate the use of digitized periapical radiographs in evaluating orthodontically induced apical root resorption against micro-computed tomography (micro-CT) scanning as a criterion standard test. In a standardized experimental protocol, 29 premolars in 16 subjects were tipped buccally for 8 wk. Nineteen contralateral premolars not subjected to orthodontic movement served as controls. Standardized periapical radiographs were taken before and after the experimental period (Rx method). These teeth were extracted and scanned using a micro-CT technique with a 9 ,m resolution. Two calibrated examiners assessed blindly the presence or absence of apical root resorption on digitized radiographs and three-dimensional reconstructions of the scans. Significant differences were detected between the orthodontically moved teeth and controls: 86% of the orthodontically moved teeth and 21% of the control teeth showed apical root resorption when using micro-CT as a validation method. A total of 55% of the experimental teeth and 5% of the control teeth showed resorption when assessed using Rx method. The Rx method showed a specificity of 78% and a sensitivity of 44%, which means that less than half of the cases with root resorption identified using a CT scanner were identified by radiography. Nearly all the orthodontically moved teeth showed apical root resorption. Apical root resorption may be underestimated when evaluated using digitized periapical radiographs. [source]


    F-18-fluoro-deoxy-glucose positron-emission tomography scanning in detection of local recurrence after radiotherapy for laryngeal/ pharyngeal cancer

    HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 11 2001
    Chris H. Terhaard MD
    Abstract Background The objective of this investigation was to determine whether F18-fluoro-deoxy-glucose (FDG) positron-emission tomography (PET) could differentiate between local recurrence and late radiation effects after radiotherapy for laryngeal/pharyngeal cancer. Methods In a prospective study of 75 patients (67 larynx, eight oro/hypopharynx), 160 laryngoscopies and 109 FDG PET scans were performed on the head and neck region. The mean follow-up time after the first FDG PET scan was 23 months (minimum 1 year). Results Local recurrence was diagnosed in 37 patients: 19 after the first biopsy and 18 after follow-up biopsies. For all of the negative initial FDG scans (27), the biopsies that were taken at the same time were negative and no recurrence was seen for at least 1 year. The first FDG scan was a true positive in 34 of 48 patients. In 12 of the 14 patients with false-positive results, FDG scans were repeated; a decreased FDG uptake was found in 9 of the 12. The sensitivity and specificity of the first scan were respectively 92% and 63%; including subsequent FDG scans, the rates were 97% and 82%, respectively. Conclusions When a local recurrence is suspected after radiotherapy for cancer of the larynx/pharynx, an FDG PET scan should be the first diagnostic step. No biopsy is needed if the scan is negative. If the scan is positive and the biopsy negative, a decreased FDG uptake measured in a follow-up scan indicates that a local recurrence is unlikely. © 2001 John Wiley & Sons, Inc. Head Neck 23: 933,941, 2001. [source]


    Murine TNF,ARE Crohn's disease model displays diminished expression of intestinal Ca2+ transporters

    INFLAMMATORY BOWEL DISEASES, Issue 6 2008
    Sylvie Huybers MSc
    Abstract Background: Patients suffering from Crohn's disease (CD) show increased incidence of low bone mineral density. Investigating this complication is difficult because the exact etiology of CD remains elusive. Mice carrying a deletion in the tumor necrosis factor (TNF) AU-rich elements (ARE) are reported as a model for human CD and are characterized by elevated TNF-, levels and inflammations in the terminal ileum. To evaluate whether these mice have a Ca2+ handling problem, this study analyzed the Ca2+ homeostasis in heterozygous TNF,ARE mice (TNF,ARE/+) in comparison to wildtype littermates. Methods: Beside serum Ca2+ and vitamin D levels, the expression of Ca2+ transporters was analyzed in intestine, kidney and bone using quantitative real-time PCR, Western blot and immunohistochemistry. Bone scans were performed to measure bone parameters. Results: Ca2+ transporters in duodenum (TRPV6, calbindin-D9K, PMCA1b) and kidney (TRPV5, calbindin-D28K, NCX1) showed significantly reduced mRNA expression levels in TNP,ARE/+ mice, except for renal TRPV5. In bone, only calbindin-D9K mRNA displayed a significant down-regulation. These findings were supported by declined duodenal calbindin-D9K and renal calbindin-D28K protein values. Likely, this down-regulation of Ca2+ transporters in TNP,ARE/+ mice is mediated by the 58 ± 9% reduction in serum 1,25(OH)2D3 levels. Diminished expression of Ca2+ transporters combined with unchanged serum Ca2+ levels assumes Ca2+ loss from bone to compensate for the body's overall Ca2+ shortage. Indeed, microcomputed tomography scanning demonstrated reduced trabecular and corticol bone thickness and volume in TNF,ARE/+ mice. This finding is further supported by increased total deoxypyridinoline in serum. Conclusions: Our results imply that TNF,ARE/+ mice have a disturbed Ca2+ homeostasis characterized by reduced duodenal and renal Ca2+ transporters, diminished 1,25(OH)2D3 levels, and increased bone resorption associated with profound bone abnormalities. (Inflamm Bowel Dis 2008) [source]


    Radiation exposure and the justification of computed tomography scanning in an Australian hospital emergency department

    INTERNAL MEDICINE JOURNAL, Issue 11 2009
    M. Street
    Abstract In an emergency department (ED), computed tomography (CT) is particularly beneficial in the investigation of high-speed trauma patients. With the advent of multidetector CT (MDCT) scanners, it is becoming faster and easier to conduct scans. In recent years, this has become evident with an increasing number of CT requests. Patients who have multiple CT scans during their hospital stay can receive radiation doses that have an increased theoretical risk of induction of cancer. It is essential that the clinical justification for each CT scan be considered on an individual basis and that due consideration is given to the radiation risk and possible diagnostic benefit. The current lack of a central State or Commonwealth data repository for medical images is a contributing factor to excessive radiation dosage to the population. The principles of justification and radiation risks are discussed in this study. [source]


    Primary Pulmonary Artery Sarcoma: Surgical Management and Differential Diagnosis with Pulmonary Embolism and Pulmonary Valve Stenosis

    JOURNAL OF CARDIAC SURGERY, Issue 6 2009
    Xiao-Peng Hu M.D.
    We present six cases of primary pulmonary artery sarcomas and discuss clinical features, differential diagnosis, surgical treatment, and outcome of the tumors. Methods: Between January 1994 and July 2008, six patients were identified with the disease during operation. Three patients were initially diagnosed with pulmonary valve stenosis, and two patients had a presumptive diagnosis of chronic pulmonary embolism. Two patients had simple or partial tumor resection. Four patients had radical tumor resection and homograft reconstruction of the pulmonary arteries. Results: Histological examinations showed five malignant mesenchymomas and one fibrosarcoma. One patient died of refractory pulmonary hypertension during operation. Two patients died 4 months postoperatively because of brain metastases. Two patients were alive for 3 and 9 months, respectively after the operation with recurrent tumor. One patient is alive even 2 years after resection with no signs of recurrence or metastasis. Conclusions: Because of similar clinical features, pulmonary artery sarcomas are often confused with other pulmonary vascular obstructive diseases. Computed tomography scanning and gadolinium-enhanced magnetic resonance imaging could be useful methods for differential diagnosis. The prognosis is very poor. The survival time after resection varies from several months to several years depending on the presence of recurrence or metastasis. Early diagnosis and radical surgical resection presents the only opportunity for a potential cure. [source]


    Severe traumatic brain injury: maximizing outcomes

    MOUNT SINAI JOURNAL OF MEDICINE: A JOURNAL OF PERSONALIZED AND TRANSLATIONAL MEDICINE, Issue 2 2009
    Mary E. Tang MD
    Abstract Severe traumatic brain injury is one of the leading causes of death and disability in the United States. The initial management of traumatic brain injury involves early resuscitation, computed tomography scanning, and surgical evacuation of mass lesions, when indicated. Recent research suggests that the prevention and treatment of secondary brain injury decrease mortality and improve outcomes. Specifically, treatment should address not only cerebral protection but also prevention of injury to other organ systems. To achieve the best outcomes, attention must be focused on optimizing blood pressure and brain tissue oxygenation, maintaining adequate cerebral perfusion pressures, and preventing seizures. In addition, maximizing good outcomes depends on proactively addressing the risk of common sequelae of brain injury, including infection, deep venous thrombosis, and inadequate nutrition. Guidelines developed for the management of severe traumatic brain injury have dramatically improved functional neurological outcomes. Mt Sinai J Med 76:119,128, 2009. © 2009 Mount Sinai School of Medicine [source]


    Limy bile syndrome: review of seven cases

    ANZ JOURNAL OF SURGERY, Issue 9 2005
    Konstantinos D. Ballas
    Background: Milk of calcium bile or limy bile is a rare disorder in which the gall bladder is filled with a thick, paste-like, radiopaque material. Methods: Seven patients with limy bile syndrome were treated in our department from 1980 to 2003. There were five women and two men, and their age ranged from 30 to 64 years. A retrospective analysis of clinical symptoms, diagnostic work-up, treatment approach and operative findings was performed. Results: All patients presented with intermittent right upper abdominal quadrant pain. Three of the seven patients (42.85%) presented with complications like acute cholecystitis (two of seven patients) and obstructive jaundice (one of seven patients). Diagnosis was based on clinical findings, plain abdominal X-rays, ultrasonography and computed tomography scanning. Surgery was the treatment of choice and cholecystectomy alone or in combination with common bile duct exploration and drainage (if needed) was performed. Conclusion: The clinical aspect of the disease is similar to that of biliary lithiasis and the diagnosis is easily made by the characteristic spontaneous opacification of the gall bladder on plain abdominal X-rays. Complications such as acute cholecystitis, pancreatitis or obstructive jaundice can also be present. Although some cases of conservative pharmaceutical treatment as well as cases of spontaneous disappearance of limy bile have been reported, surgical treatment remains the treatment of choice. [source]


    18F-fluorodeoxyglucose,positron emission tomography scanning is more useful in followup than in the initial assessment of patients with Erdheim-Chester disease

    ARTHRITIS & RHEUMATISM, Issue 10 2009
    Laurent Arnaud
    Objective Erdheim-Chester disease (ECD) is a rare form of non,Langerhans' cell histiocytosis. The aim of this study was to assess the value of whole-body scanning with 18F-fluorodeoxyglucose,positron emission tomography (FDG-PET) in a large cohort of ECD patients from a single center. Methods We retrospectively reviewed all PET scans performed on 31 patients with ECD who were referred to our department between 2005 and 2008. PET images were reviewed by 2 independent nuclear medicine specialist physicians and were compared with other imaging modalities performed within 15 days of each PET scan. Results Thirty-one patients (10 women and 21 men; median age 59.5 years) underwent a total of 65 PET scans. Twenty-three patients (74%) were untreated at the time of the initial PET scan, whereas 30 of the 34 followup PET scans (88%) were performed in patients who were undergoing immunomodulatory therapy. Comparison of the initial and followup PET scans with other imaging modalities revealed that the sensitivity of PET scanning varied greatly among the different organs studied (range 4.3,100%), while the specificity remained high (range 69.2,100%). Followup PET scans were particularly helpful in assessing central nervous system (CNS) involvement, since the PET scan was able to detect an early therapeutic response of CNS lesions, even before magnetic resonance imaging showed a decrease in their size. PET scanning was also very helpful in evaluating the cardiovascular system, which is a major prognostic factor in ECD, by assessing the heart and the entire vascular tree during a single session. Conclusion The results of our large, single-center, retrospective study suggest that the findings of a FDG-PET scan may be interesting in the initial assessment of patients with ECD, but its greater contribution is in followup of these patients. [source]


    Is 18F-fluorodeoxyglucose positron emission tomography scanning a reliable way to assess disease activity in takayasu arteritis?

    ARTHRITIS & RHEUMATISM, Issue 4 2009
    Laurent Arnaud
    Objective 18F-fluorodeoxyglucose,positron emission tomography (FDG-PET) scanning has been proposed as a new way of assessing disease activity in Takayasu arteritis (TA), but previous studies have used the nonvalidated National Institutes of Health (NIH) global activity criteria, and thus might be biased. This study was undertaken to determine the value of PET scanning for assessment of disease activity in TA, by comparing PET scan data with clinical, biologic, and magnetic resonance imaging (MRI) data assessed separately. Methods Twenty-eight patients with TA (according to the American College of Rheumatology criteria) underwent a total of 40 PET scans. Images were reviewed by 2 pairs of independent nuclear medicine physicians and assessed for pattern and intensity of vascular uptake. TA activity data were obtained within 15 days of the PET scans. Results PET scanning revealed abnormal vascular uptake in 47% of the 40 examinations. The uptake intensity grade was 0 in 7 scans, grade 1 in 7 scans, grade 2 in 13 scans, and grade 3 in 13 scans. Morphologic analysis was conducted by grading the pattern of the vascular uptake as diffuse (73%), segmental (20%), or focal (13%). There was a trend toward an association between clinically active disease and the semiquantitative assessment of FDG uptake (P = 0.08). We found no statistical association between levels of acute-phase reactants and intensity of uptake. There was no significant association between the semiquantitative assessment of FDG uptake and the presence of vascular wall thickening (P = 0.23), gadolinium uptake (P = 0.73), or the presence of vascular wall edema (P = 0.56). Conclusion Our findings indicate that there is no association between FDG vascular uptake intensity and clinical, biologic, or MRI assessment of disease activity. Previous studies using the nonvalidated NIH global activity criteria are likely biased. [source]


    Granulomatous mycosis fungoides with extensive chest wall involvement

    AUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 1 2004
    Jamie Von Nida
    SUMMARY A 40-year-old woman presented with a 5-year history of a mass overlying her right pectoralis major muscle. Histopathology of the lesion revealed a florid granulomatous infiltrate including an atypical lymphocytic component with marked epidermotropism consistent with granulomatous mycosis fungoides. Staging investigations demonstrated the tumour to be localized to the right chest. Consequently, the patient was treated with radiotherapy (50 Gy) to the lesion with good clinical effect. However, she soon developed a clinically palpable lesion on the left chest outside the radiotherapy field. Positron emission tomography scanning demonstrated an extensive left-sided chest wall tumour and also residual tumour on the right. This left-sided lesion failed to respond to systemic chemotherapy. Further radiotherapy (50 Gy) has recently been administered to the left chest lesion; the response is being monitored. While granulomatous inflammation has been previously described in cutaneous T-cell lymphomas, it is rare and is often associated with a delay in the diagnosis and difficulty with clinical staging. The clinical presentation can be extremely variable and consequently, diagnosis rests with histological features, immunohistochemical studies and gene rearrangement analysis. [source]