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At least 55 records · Page 3Linked to original sources
PubMed1999

Tomography versus computed tomography for assessing step off in intraarticular distal radial fractures.

Computed tomography scans have supplanted conventional tomography for many applications and often are considered the imaging study of choice for assessing intraarticular distal radial fractures. Concern about cost containment in healthcare delivery prompts the question of whether the two studies provide comparable information and at what cost. Common intraarticular distal radial fractures were created in 12 lightly embalmed cadaveric specimens. The fractures were fixed with radiolucent Kirschner wires. Articular step off was measured with a caliper. Plain radiographs, computed tomography scans, and trispiral tomograms were obtained of each specimen. Maximal step off was measured blindly by two musculoskeletal radiologists and four hand surgeons. The radiographic measurements were compared with the actual step off and expressed as a positive or negative deviation from the actual value. There was no statistically significant difference between computed tomography scans and tomograms in predicting step off. In addition, the difference between actual and radiographic measurements was insignificant in tomogram readings and different in one of the computed tomography measurements. In the authors' institution, a tomogram costs $200, and a computed tomography scan costs $562. Trispiral tomography is more accurate and cost effective than computed tomography, and thus when available should be considered the imaging modality of choice for assessing articular step off in distal radius fractures.

Analysis of Variance↗
PubMed1984

Magnetic resonance imaging of the chest: a diagnostic comparison with computed tomography and hilar tomography.

Computed tomography (with and without contrast enhancement) provides excellent diagnostic accuracy for the evaluation of the chest. Oblique (55 degrees) and anteroposterior hilar tomography is accurate for the evaluation of hilar nodes and masses. Magnetic resonance techniques provide excellent differentiation of vascular and nonvascular structures and therefore should be useful in the hilum and mediastinum. Magnetic resonance imaging was used in 55 patients with known pathologic conditions in the mediastinum, hilum, and lungs to determine the accuracy and efficacy of this technique compared with computed and hilar tomography. The pathologic conditions included primary and metastatic neoplasms, benign masses, vascular abnormalities, and pulmonary nodules and infiltrates. Spatial resolution with magnetic resonance imaging is less than with computed tomography with our instrument (0.15 T resistive magnet). However, in the hilum and mediastinum, magnetic resonance imaging provided diagnostic information equal to that of computed tomography with contrast in 90% of patients. Vascular and nonvascular structures were more easily differentiated than with hilar tomography. Computed tomography was far superior in the evaluation of multiple pulmonary nodules. Lesions of the chest wall were better seen with magnetic resonance imaging because of the improved soft tissue contrast.

Adolescent↗
PubMed1996

Positron emission tomography and single photon emission computed tomography.

Neuroimaging techniques have had a dramatic impact on the evaluation and treatment of patients with epilepsy. In order to take full advantage of their potential, it is important to place them in clinical and electrophysiological context and to understand their technical limitations. Positron emission tomography with 18F-2-deoxyglucose and single photon emission computed tomography can provide valuable data for presurgical localization of epileptogenic zones. Interictal cerebral blood flow studies, however, using either positron emission tomography or simple photon emission computed tomography are unreliable. Positron emission tomography cerebral blood flow activation studies, on the other hand, are becoming very useful for presurgical cognitive mapping and may be able to replace the intracarotid amytal test for language and memory lateralization. There are a number of receptor ligands available for both positron emission tomography and simple photon emission computed tomography studies, including benzodiazepine, opiate, and cholinergic tracers. Increased mu opiate, decreased benzodiazepine, and increased monoamine oxidase B receptor binding have been reported.

Epilepsy↗
PubMed2001

Prospective comparison of panoramic tomography (zonography) and helical computed tomography in the diagnosis and operative management of mandibular fractures.

This prospective study compared the sensitivity of panoramic tomography (zonography) and helical computed tomography (CT) in diagnosing 73 mandibular fractures in 42 consecutive patients and correlated the results with known surgical findings. The purpose of the study was to determine the optimal radiologic examination for the diagnosis and operative management of mandibular fractures. The attending surgeons' interpretations of panoramic tomograms and helical CT images in the axial plane were compared with the patients' known surgical findings. A series of questions assessed the relative contribution of these two radiologic examinations in formulating an optimal operative plan for each patient. In the 42 patients studied, the sensitivity of helical CT was 100 percent in diagnosing mandibular fractures; this compared with 86 percent (36 of 42) for panoramic tomography, in which significantly more fractures were missed (p = 0.0412). In the six patients with fractures not visualized, the operative management was altered because of the new fracture visualized on helical CT. Of the seven missed fractures, six were in the posterior portion of the mandible. Comparing fracture detection by region, seven fractures found on helical CT were not visualized on panoramic tomography. Helical CT improved the understanding of the nature of mandibular fractures by providing additional information regarding fracture displacement and comminution and by locating injuries missed using panoramic tomography. This study suggests that helical CT alone may be more diagnostic than panoramic tomography alone in evaluating mandibular fractures. Helical CT sufficiently demonstrated details of fractures in 41 of 42 patients; in one patient, the nature of a dental root fracture was better delineated by panoramic tomography.

Humans↗
PubMed1984

Computed tomography of the sacroiliac joints: comparison with complex-motion tomography.

Forty-seven patients with sacroiliac joint abnormalities were examined with computed tomography and conventional complex-motion tomography. Twenty-nine patients had spondyloarthritis. Of the 29, complex-motion tomography detected bone erosions in 16 patients, whereas computed tomography revealed erosions in nine. Computed tomography was more sensitive in detection of joint narrowing, joint widening, osteosclerosis, and intraarticular bony ankylosis. In the remaining 13 patients, computed tomography was the modality of choice in detection of paraarticular soft tissue pathology, such as abscess or tumor, and in detection of the lesions involving the sacral canal and neural foramina.

Adult↗
PubMed1995

Functional caudate imaging in symptomatic Huntington's disease: positron emission tomography versus single-photon emission computed tomography.

Functional neuroimaging with positron emission tomography previously demonstrated reduced caudate glucose metabolism in virtually all symptomatic patients with Huntington's disease (HD). Single-photon emission computed tomography studies of brain blood flow also have shown caudate abnormalities in patients with HD. The present study compared these two functional imaging modalities in 6 patients with HD who had been symptomatic for fewer than 5 years. All patients had significantly impaired caudate-thalamus and caudate-whole-slice glucose metabolism ratios as measured by positron emission tomography. However, only 3 had clearly abnormal caudate-thalamus activity ratios and 2 had clearly abnormal caudate-whole-slice ratios on single-photon emission computed tomography. These findings indicate that single-photon emission computed tomography imaging of caudate blood flow is a less sensitive indicator of caudate dysfunction in early HD than is positron emission tomography imaging of caudate glucose metabolism.

Anticonvulsants↗
PubMedDate not supplied

Relative properties of tomography, K-edge imaging, and K-edge tomography.

The properties of tomography, K-edge imaging, and K-edge tomography are discussed in relation to the imaging of small concentrations of elements such as iodine and xenon and are compared by means of phantom images. It is demonstrated that the complementary selectivities provided by depth and energy subtraction are combined in K-edge tomography. Using a three-spectrum subtraction technique, the iodine difference signal predicted by computer calculations is on the order of 8000 times that of an equal concentration fo bone. The corresponding ratio in tomography without energy subtraction is 20:1. It is argued that K-edge tomography can successfully eliminate artifacts due to tissue inhomogeneities which presently enable 0.6% variations in tissue attenuation to mimic minimum detectable iodine signals in conventional computed tomography. Various instrumentation possibilities and energy subtraction techniques are discussed.

Models, Structural↗
PubMed2003

Test performance of positron emission tomography and computed tomography for mediastinal staging in patients with non-small-cell lung cancer: a meta-analysis.

PURPOSE: To compare the diagnostic accuracy of computed tomography (CT) and positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) for mediastinal staging in patients with non-small-cell lung cancer and to determine whether test results are conditionally dependent (the sensitivity and specificity of FDG-PET depend on the presence or absence of enlarged mediastinal lymph nodes on CT). DATA SOURCES: Computerized search of MEDLINE, EMBASE, BIOSIS, and CancerLit through March 2003 and reference lists of retrieved studies and review articles. STUDY SELECTION: Studies in any language that examined FDG-PET for mediastinal staging in patients with known or suspected non-small-cell lung cancer, enrolled at least 10 participants (including at least 5 participants with mediastinal metastasis), and provided enough data to permit calculation of sensitivity and specificity for identifying lymph node involvement. DATA EXTRACTION: One reviewer (of non-English-language studies) or 2 reviewers (of English-language studies) independently evaluated studies for inclusion, rated methodologic quality, and abstracted relevant data. DATA SYNTHESIS: Thirty-nine studies met inclusion criteria. Methodologic quality varied, but few aspects of study quality affected diagnostic accuracy. The authors constructed summary receiver-operating characteristic curves for CT and FDG-PET. Positron emission tomography with 18-fluorodeoxyglucose was more accurate than CT for identifying lymph node involvement (P < 0.001). For CT, median sensitivity and specificity were 61% (interquartile range, 50% to 71%) and 79% (interquartile range, 66% to 89%), respectively. For FDG-PET, median sensitivity and specificity were 85% (interquartile range, 67% to 91%) and 90% (interquartile range, 82% to 96%), respectively. Fourteen studies provided information about the conditional test performance of CT and FDG-PET. Positron emission tomography with 18-fluorodeoxyglucose was more sensitive but less specific when CT showed enlarged lymph nodes (median sensitivity, 100% [interquartile range, 90% to 100%]; median specificity, 78% [interquartile range, 68% to 100%]) than when CT showed no lymph node enlargement (median sensitivity, 82% [interquartile range, 65% to 100%]; median specificity, 93% [interquartile range, 92% to 100%]; P = 0.002). CONCLUSIONS: Positron emission tomography with 18-fluorodeoxyglucose is more accurate than CT for mediastinal staging. Positron emission tomography with 18-fluorodeoxyglucose is more sensitive but less specific when CT shows enlarged mediastinal lymph nodes.

Aged↗
PubMed1990

[A comparison of conventional tomography and computed tomography in cases of diseases of the sacroiliac joint].

16 patients with diseases of the sacroiliac joints were examined both with computer tomography and with conventional tomography. Both techniques were characterized by a high sensitivity. Computer tomography was superior in exactly delineating the extent of the pathologic changes. In conventional tomography the joint surface was more blurred, erosions were larger, and signs of ankylosis were more expanded, so that the joints seemed to be more altered in 8 cases than demonstrated by computer tomography. Very accurate changes like subchondral cysts were recognized only in the computer tomograms. In all cases in which anteroposterior radiographs revealed no clear result, the authors recommend to additionally employ computer tomography.

Adult↗
PubMed1986

Reconsideration of conventional tomography versus computerized tomography in the evaluation of lung metastases.

Several published reports compare linear chest tomography to computerized chest tomography regarding the detection of lung metastases in adults. As linear tomography does not result in a sectional image, a study comparing multidirectional tomography to computed tomography in the chest was carried out. Equal sensitivity and specificity of these two modalities is shown by reviewing 28 cases who had known extrathoracic malignancies prospectively. The currently prevailing impression that computerized tomography is superior in the detection of lung metastases is thus not justified.

Adolescent↗
PubMed1997

Experimental evaluation of scaphoid X-series, carpal box radiographs, planar tomography, computed tomography, and magnetic resonance imaging in the diagnosis of scaphoid fracture.

AIM: In this study, we evaluated scaphoid X-series, Carpal Box radiographs (longitudinal and transverse), planar tomography, computed tomography (CT), and magnetic resonance imaging (MRI) in the diagnosis of scaphoid fracture. The aim of this study was to evaluate the planar technique in the diagnosis of scaphoid fracture. The use of planar tomography, CT, and MRI was to see whether these methods are useful in the diagnosis of scaphoid fracture when other diagnostics modalities remains negative. METHODS: Twenty-eight embalmed human cadaver specimens were used, in 23 of which fractures of the scaphoid were produced mechanically. Scaphoid X-series, Carpal Box posterior-anterior radiographs in ulnar deviation (X-CB), Carpal Box posterior-anterior views with the hand in 15-degree supination and ulnar deviation (X-CB 15-degree) were acted in all specimens, CT in eight wrists, planar tomography in seven wrists, and MRI in five wrists. The anatomic analysis of the specimens was used as the gold standard for comparison. Scaphoid X-series, Carpal Box radiographs, and planar tomography were judged independently and in a blind fashion by six observers, and CT and MRI were also judged independently and in a blind fashion by three radiologists. The observers were asked if they could recognize a scaphoid fracture. The agreement among the six observers for the scaphoid X-series and X-CB was measured. RESULTS: In the 23 fractured wrists, scaphoid X-series, X-CB, X-CB 15-degree, was true positive in 12, 14, and 15 wrists, respectively, whereas these methods were true negative in cadaver wrists 1, 3, and 5. CT was true positive in five of five fractured wrists and true negative in three of three negative wrists. Planar tomography was true positive in one of four fractured wrists and true negative in two of three nonfractured wrists. MRI was obtained in five wrists (one without a fracture), of which the fracture was recognized in only two. The highest agreement between observers was found in the X-CB 15-degree. CONCLUSION: From the planar investigated methods, the 15-degree Carpal Box posterior-anterior, longitudinal and transverse views were most accurate in recognizing scaphoid fracture with also the highest agreement between the observers.

Cadaver↗
PubMed2002

Computed tomography urography, three-dimensional computed tomography and virtual endoscopy.

Spiral computed tomography technology allows an entire body region to be imaged as a continuous volume of computed tomography data. The acquisition of genitourinary images can be performed at different intervals after intravenous contrast injection in order to characterize the renal vasculature, the renal parenchyma or the collecting system. Computed tomography scanning as contrast is excreted into the collecting system is termed a 'computed tomography urogram'. Volumetric data from spiral computed tomography can be rendered into conventional two-dimensional images or even reformatted into three-dimensional views of organ systems or hollow structures, as in 'fly-through' virtual endoscopy. Although virtual endoscopy of the urinary tract remains in its infancy, three-dimensional imaging is currently a useful adjunct in the evaluation of renal transplant and donor patients and partial nephrectomy candidates. The role of computed tomography urography compared with intravenous urography in the evaluation of hematuria is discussed.

Humans↗
PubMed1993

[Nuclear spin tomography, magnetic resonance tomography (MRT), nuclear magnetic resonance imaging (NMR). Technical and methodical hypotheses for the use of nuclear spin tomography on the hip joint of the dog].

The theoretical principles of nuclear magnetic resonance imaging and its application in human medicine are described. The most important parameters to produce informative images are explained. The tomographic examination of the canine hip joints demands a precise choice of section planes and measuring parameters. The resulting images of the hip joints of eight beagle puppies are evaluated and discussed.

Animals↗
PubMed2001

Accuracy of mandibular cross-sectional imaging with tuned- aperture computed tomography (TACT), iteratively reconstructed TACT, and multidirectional, linear, and transverse panoramic tomography.

OBJECTIVE: This study was designed to compare 5 modalities with respect to accuracy in mandibular cross-sectional imaging. The modalities tested were tuned-aperture computed tomography (TACT), iteratively reconstructed TACT, multidirectional tomography, linear tomography, and transverse panoramic tomography. STUDY DESIGN: Twenty sites were selected from 3 dry human mandibles, and cross-sectional views were imaged through use of each of the 5 modalities. A quantitative analysis included measurements of 2 linear distances; a qualitative study included image evaluation by 6 observers. A nested mixed analysis of variance model was used to control for mandibles and locations within mandibles for the quantitative analysis; the Cochran-Mantel-Haenszel test was used for the qualitative analysis. RESULTS: There was a significant difference in measurement error for maximum height but not for width. There was also a significant difference in qualitative image evaluation results. CONCLUSIONS: Of the 5 modalities tested, the narrow-layer multidirectional tomographic technique produced the greatest diagnostic accuracy and quality in cross-sectional imaging. The transverse panoramic tomographic technique produced the least diagnostic accuracy and quality. Linear tomography, TACT, and iteratively reconstructed TACT were intermediate in accuracy and quality.

Analysis of Variance↗
PubMed1978

Comparison of whole lung tomography and computed tomography for detecting pulmonary nodules.

Detecting pulmonary metastasis is important when planning surgical therapy, radiotherapy, or chemotherapy in patients with known malignancy. A series of 91 patients was studied by both whole lung tomography and computed tomography (CT) of the lungs. More pulmonary nodules were detected with CT than with whole lung tomography in 32 (35%) of the patients. Of the 91 patients in the study, 31 had resection of some or all of the pulmonary nodules. In 27 patients, the nodules were primary or metastatic malignant lesions. Bilateral pulmonary nodules were detected with CT in 13 patients when whole lung tomography had demonstrated nodules in only one lung. CT has replaced whole lung tomography as the method preferred by the authors for detecting pulmonary nodules in selected patients at risk to develop pulmonary metastasis.

Adolescent↗
PubMed1982

Diagnosis of vertebral fractures. A comparison of conventional radiography, conventional tomography, and computed axial tomography.

Thirty patients with acute thoracic, lumbar, or thoracolumbar fractures, dislocations, or fracture-dislocations were evaluated with standard radiographs, conventional polytomography, and computerized axial tomography. The resulting ninety studies were coded, randomized, and independently interpreted by three radiologists. The diagnostic accuracy of the interpretations based on the computerized tomography scans combined with standard radiographs equaled that of the interpretations based on just the tomograms in the evaluation of fractures of posterior elements. In addition, computerized tomography was superior to the other methods in demonstrating impingement on the neural canal as well as injuries to other organ systems. Also, when compared with conventional polytomography, computerized tomography could be completed with less risk to the patient (no changes in position and ten times less radiation). We concluded that computerized tomography should replace conventional polytomography as the initial study to augment standard radiographs in the assessment of thoracic and lumbar fractures. Conventional polytomography should be reserved for patients in whom precise evaluation of the pars interarticularis is deemed necessary.

Adolescent↗
PubMedDate not supplied

Improvement of sensitivity and interrater reliability to detect acute stroke by dynamic perfusion computed tomography and computed tomography angiography.

OBJECTIVE: To assess the benefits of additional computed tomography perfusion (CTP) and computed tomography angiography (CTA) on the detection of early stroke, vessel occlusion, estimated infarct size, and interrater reliability. METHODS: Sixty-seven consecutive patients underwent nonenhanced computed tomography (CT) imaging, CTA, and CTP. The final diagnosis of stroke was made from follow-up neuroimaging. A first diagnosis was made on-site by the physician on duty. Three experienced neuroradiologists blinded to follow-up findings analyzed the data set off-line, evaluated CT for signs of acute stroke, and subsequently evaluated CTP and CTA for infarction-related perfusion deficits and vessel abnormalities. RESULTS: Computed tomography perfusion and CTA increased the time from CT start to diagnosis from 2 minutes to 10 minutes. Sensitivity to detect acute stroke increased significantly in all investigators from 0.46-0.58 to 0.79-0.90 compared with CT (<0.005). The interrater weighted kappa value increased from 0.35 to 0.64. Estimation of infarct size was not improved. CONCLUSION: Computed tomography perfusion and CTA provide an effective add-on to standard CT in acute stroke imaging by significantly increasing the sensitivity and reliability of infarct detection.

Acute Disease↗
PubMed1991

[Current role of conventional tomography in the staging of pulmonary neoplasms. Reflections based on the comparison of tomography-magnetic resonance in 81 cases].

The preoperative conventional tomographic and Magnetic Resonance images were reviewed of 81 patients affected with bronchogenic carcinoma; all patients underwent surgery 1986 to 1988. Radiological findings were compared with surgical and pathological results to evaluate the actual role of conventional tomography in the staging of bronchogenic carcinoma. MR Imaging proved to be more useful in the evaluation of mediastinal and hilar lymph nodes. As for mediastinal node status, conventional tomography had 23.5% sensitivity, 90.6% specificity, and 76.5% overall accuracy; MR Imaging had 82.3% sensitivity, 84.4% specificity, and 84% overall accuracy. As for hilar adenopathies, tomographic sensitivity, specificity and overall accuracy were 53.3%, 72.5%, and 65.4% versus 50%, 82.3% and 70.4% with MR Imaging. Tomography was slightly superior in identifying the primary tumor (97.5% versus 92.6% for MR), as well as in the demonstration of central bronchial involvement (100% for conventional tomography versus 50% for MR Imaging). Conventional tomography is useful as a complementary technique to MR Imaging in the preoperative staging of bronchogenic carcinoma when information on central bronchial involvement is needed.

Carcinoma↗