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PubMedDate not supplied

Comparison of technetium-99m methoxyisobutylisonitrile single photon emission computed tomography and computed tomography to detect recurrent or residual nasopharyngeal carcinomas after radiotherapy.

The diagnostic accuracy of technetium-99m methoxyisobutylisonitrile (Tc-MIBI) single photon emission computed tomography (SPECT) of head and neck to differentiate between recurrent or residual nasopharyngeal carcinomas (NPC) and benign lesions after radiotherapy was evaluated, and compared with computed tomography (CT). Thirty-six NPC patients 4 months after radiotherapy underwent Tc-MIBI SPECT and CT of head and neck, as well as histopathological examination of nasopharyngeal biopsies. Based on the biopsy results, the sensitivity, specificity, and accuracy of CT were 73%, 88%, and 83%, respectively. The sensitivity, specificity, and accuracy of Tc-MIBI SPECT were 64%, 96%, and 86%, respectively. The sensitivity, specificity, and accuracy of combined Tc-MIBI SPECT and CT were 100%, 88%, and 92%, respectively. Tc-MIBI SPECT had a better specificity and a lower sensitivity to differentiate benign lesions from recurrent/residual NPC when compared with CT The combined use of CT and Tc-MIBI SPECT significantly increased accuracy compared with the single use of either Tc-MIBI SPECT or CT to differentiate benign lesions recurrent/residual NPC.

Adolescent↗

PubMed2000

Intraoperative ultrasonography versus helical computed tomography and computed tomography with arterioportography in diagnosing colorectal liver metastases: lesion-by-lesion analysis.

Helical computed tomography with arterioportography (CTAP) and intraoperative sonography (IOUS) are both recognized to be extremely sensitive in the detection of liver metastases measuring <2 cm in diameter. As sensitivity and specificity values for both techniques differ significantly in the literature and in default of sufficient published data regarding this subject, a lesion-by-lesion analysis was considered necessary. Accuracy of IOUS was compared with helical computed tomography (CT) and portal-phase contrast enhancement (CTAP) in the preoperative detection of liver metastases from colorectal carcinoma projected as a prospective blinded study. Cost efficiency should be determined. Liver CTAP and IOUS were evaluated in 33 patients with colorectal carcinoma. Metastases were resected in 10 cases, and the remaining 23 patients were observed for follow-up with CT investigations every 3 months for a period of 1 year. CTAP and IOUS detected all 13 lesions measuring 5-10 mm (13/13). One metastasis measuring >10 mm was missed by IOUS. CTAP presented an ideal sensitivity of 100%, but specificity was as low as 68%. IOUS sensitivity was 98% and specificity was 95%. IOUS and CTAP are of comparable value regarding the detection of liver metastases <10 mm. Both techniques may be used if resections of synchronous or metachronous metastases are planned in order not to miss limiting small lesions and to prevent superfluous liver surgery. Helical CT scan with dynamic intravenous contrast enhancement is considered the most cost-effective preoperative staging method, although local staging may not be achieved because of insufficient intraabdominal survey.

Adult↗

PubMed1987

Estimation of pubertal mammary development in heifers by computed tomography.

Computed tomography scanning is introduced as a new technique to quantify parenchymal tissue of heifer mammary glands. Tissue types with different densities attenuate x-rays differently, and computed tomography is based on computer processing of such x-ray attenuation data. Different tissue types can be quantified by summation of defined x-ray attenuation data. Parenchymal tissue was quantified in mammary glands from 25 heifers by computed tomography as well as by dissection and chemical analysis. Parenchymal tissue amounted to 455 g when measured by dissection and 106 cm3 when measured by computed tomography. This difference is related to the ability of computed tomography to exclude extraparenchymal tissue from the estimate. Computed tomography estimates of parenchymal tissue were more closely correlated with amount of fat-free parenchyma than with total parenchyma weight. This suggests that estimates obtained by computed tomography have less variation than estimates obtained by dissection due to the ability of computed tomography to exclude extraparenchymal tissue. Use of computed tomography furthermore eliminates the element of subjectivity present in methods that include dissection. It is concluded that computed tomography can provide reliable estimates of parenchymal tissue of heifer mammary glands.

Animals↗

PubMed2006

Breath-hold single-photon emission tomography and computed tomography for predicting residual pulmonary function in patients with lung cancer.

OBJECTIVE: We sought to evaluate the utility of integrated breath-hold single-photon emission tomography and computed tomography imaging compared with that of simple calculation with the lung segment-counting technique for predicting residual pulmonary function in patients undergoing surgical intervention for lung cancer. METHODS: A prospective series of 22 patients undergoing anatomic lung resection for cancer were enrolled in this study. Postoperative residual forced expiratory volume in 1 second was predicted by measuring the radioactivity counts of the affected lobes or segments to be resected within the entire lungs by placement of regions of interest on single-photon emission tomography and computed tomography images. Residual forced expiratory volume in 1 second was also estimated by using the segment-counting technique. RESULTS: Both predicted values agreed well with postoperative forced expiratory volume in 1 second. Although the residual forced expiratory volume in 1 second predicted by means of single-photon emission tomography and computed tomography correlated well with that predicted by using segment counting, the values were significantly underestimated by the segment-counting technique in 4 outliers with severe emphysema. There were 2 patients with borderline pulmonary functional reserve whose residual forced expiratory volume in 1 second values were predicted more accurately by means of single-photon emission tomography and computed tomography than by using segment counting. CONCLUSION: Integrated breath-hold single-photon emission tomography and computed tomography images allow the accurate prediction of postoperative pulmonary function but without statistical superiority over the simple segment-counting technique. Further study of the usefulness of single-photon emission tomography and computed tomography in patients with severe emphysema and borderline lung function should prove valuable because the segment-counting technique underestimates pulmonary functional reserve in these patients.

Aged↗

PubMed2004

Comparison of perfusion computed tomography and computed tomography angiography source images with perfusion-weighted imaging and diffusion-weighted imaging in patients with acute stroke of less than 6 hours' duration.

BACKGROUND AND PURPOSE: We aimed to determine the diagnostic value of perfusion computed tomography (PCT) and CT angiography (CTA) including CTA source images (CTA-SI) in comparison with perfusion-weighted magnetic resonance imaging (MRI) (PWI) and diffusion-weighted MRI (DWI) in acute stroke <6 hours. METHODS: Noncontrast-enhanced CT, PCT, CTA, stroke MRI, including PWI and DWI, and MR angiography (MRA), were performed in patients with symptoms of acute stroke lasting <6 hours. We analyzed ischemic lesion volumes on patients' arrival as shown on NECT, PCT, CTA-SI, DWI, and PWI (Wilcoxon, Spearman, Bland-Altman) and compared them to the infarct extent as shown on day 5 NECT. RESULTS: Twenty-two stroke patients underwent CT and MRI scanning within 6 hours. PCT time to peak (PCT-TTP) volumes did not differ from PWI-TTP (P=0.686 for patients who did not undergo thrombolysis/P=0.328 for patients who underwent thrombolysis), nor did PCT cerebral blood volume (PCT-CBV) differ from PWI-CBV (P=0.893/P=0.169). CTA-SI volumes did not differ from DWI volumes (P=0.465/P=0.086). Lesion volumes measured in PCT maps significantly correlated with lesion volumes on PWI (P=0.0047, r=1.0/P=0.0019, r=0.897 for TTP; P=0.0054, r=0.983/P=0.0026, r=0.871 for CBV). Also, PCT-CBV lesion volumes significantly correlated with follow-up CT lesion volumes (P=0.0047, r=1.0/P=0.0046, r=0.819). CONCLUSIONS: In hyperacute stroke, the combination of PCT and CTA can render important diagnostic information regarding the infarct extent and the perfusion deficit. Lesions on PCT-TTP and PCT-CBV do not differ from lesions on PWI-TTP and PWI-CBV; lesions on CTA source images do not differ from lesions on DWI. The combination of noncontrast-enhanced CT (NECT), perfusion CT (PCT), and CT angiography (CTA) can render additional information within <15 minutes and may help in therapeutic decision-making if PWI and DWI are not available or cannot be performed on specific patients.

Adult↗

PubMed1999

Relationship between structural parameters, bone mineral density and fracture load in lumbar vertebrae, based on high-resolution computed tomography, quantitative computed tomography and compression tests.

Different noninvasive techniques for the assessment of the individual fracture risk in osteoporosis are introduced, and the relation between structural properties of high-resolution computed tomography (HR-CT) images of vertebral bodies, their bone mineral density (BMD) and the fracture load is analyzed. In 24 unfractured lumbar vertebrae with different degrees of demineralization from six specimens, the trabecular and cortical BMD was determined using quantitative CT. A lateral X-ray image revealed the number of fractures in the entire spine. A structural analysis of spongy and cortical bone was performed based on the HR-CT images. In the spongiosa, the fractal dimension was calculated as a function of the threshold value. In the cortical shell, the maximum number of clusters of low BMD was determined at varying threshold values. After the CT measurements the vertebrae were excised and compressed until fractured. On the basis of the spongiosa BMD and the number of fractures, 3 cases were found to be severely osteoporotic; the other 3 cases showed osteopenia. The average fracture loads were determined as 3533 N for the non-osteoporotic cases (range 2602-5802 N) and 1725 N for the osteoporotic cases (range 1311-2490 N). The parameters were determined as follows: average spongiosa BMD 115.2 mg/ml (101.8-135.3 mg/ml) for the non-osteoporotic cases, 46.2 mg/ml (34.8-57.6 mg/ml) for the osteoporotic cases; average cortical BMD 285.1 mg/ml (216.4-361.9 mg/ml) for the non-osteoporotic cases, 136. 1 mg/ml (142.5-215.2 mg/ml) for the osteoporotic cases; spongiosa structure: average 0.5 (range 0.32-0.75) for the non-osteoporotic cases, average 1.05 (range 0.87-1.24) for the osteoporotic cases; cortical structure: average 81 (range 55-104) for the non-osteoporotic cases), average 136 (range 102-159) for the osteoporotic cases. Single parameters (BMD and structure) and weighted sums of these parameters were correlated with the fracture load, resulting in correlation coefficients of r(sBMD) = 0.82 (spongiosa BMD), r(cBMD) = 0.82 (cortical BMD), r(sStr) = -0.75 (spongiosa structure) and r(cStr) = -0.86 (cortical structure). The weighted sum of cortical and spongiosa BMD resulted in r(BMD) = 0.86, of cortical and spongiosa structure in r(Str) = -0.86. A weighted combination of all four parameters correlates with the fracture load at r(4) = 0.89, all correlations being statistically significant (p<0.0001). The four individual parameters show only a slight overlap between non-osteoporotic and osteoporotic subjects. The high correlation of the cortical BMD and the structural parameter in cortical bone indicates the important contribution of the cortical shell to vertebral stability. A weighted sum of multiple parameters results in a higher correlation with the fracture load and does not show an overlap between the two groups. It is best suited to estimate the individual fracture risk. The presented methods are generally applicable in vivo; and allow an improvement of the diagnosis of osteoporosis compared with the measurement of the BMD alone.

Aged↗

PubMed1984

Malignant pleural mesothelioma: the role of computed tomography.

Computed tomography is believed to have a definite role in the evaluation of malignant pleural mesothelioma based on a review of computed tomography findings in 23 of our patients and previous reports. Twelve patients had a single computed tomography examination, and 11 had two or more studies. Computed tomography permits better appreciation of the extent of the tumor. This permits appropriate selection of therapy and may demonstrate that surgery or radiotherapy is not indicated. computed tomography often permits more accurate evaluation following chemotherapy and may be the only means by which to follow a patient after radical surgery. Computed tomography also has a role in differential diagnosis. It facilitates distinction of malignant pleural mesothelioma from rounded atelectasis, pleural changes of asbestosis, and pleural involvement with lymphoma and thymoma. It aids, but may not be diagnostic, in separating malignant pleural mesothelioma from metastases to the pleura.

Adult↗

PubMed1985

Assessment of bronchiectasis by computed tomography.

Computed tomography and bronchography were used to assess the distribution of bronchiectasis in 15 lungs from eight patients with clinical features of the disease. Of the 36 lobes adequately displayed by bronchography, 22 were found to have bronchiectasis and 14 were found to be normal by both techniques. Cystic disease was readily identified by computed tomography but the cylindrical and varicose types of bronchiectasis could not be distinguished. Segmental localisation was less accurate, with agreement between computed tomography and bronchography in 116 out of 130 segments. It is concluded that with a modern high resolution scanner computed tomography provides a useful method of assessing lobar distribution in bronchiectasis.

Bronchiectasis↗

PubMed1996

Comparison of nickel-titanium and stainless steel hand-file instrumentation using computed tomography.

Computed tomography was used to evaluate root canals prepared by nickel-titanium (Ni-Ti) hand and stainless steel hand endodontic instruments. Thirty-six single-rooted teeth of similar shape and canal size were divided into three groups. The teeth were scanned by computed tomography before instrumentation. In group A, canals were instrumented using a quarter turn/pull technique with K-flex files. In group B, canals were prepared with Ni-Ti hand files (Mity files) using the same technique as group A. Group C was prepared with Ni-Ti hand files (Mity files) using a reaming technique. Instrumented teeth were again scanned using computed tomography, and reformated images of the uninstrumented canals were compared with images of the instrumented canals. Ni-Ti instruments (Mity file) used in a reaming technique caused significantly less canal transportation (p < 0.05), removed significantly less volume of dentin (p < 0.05), required less instrumentation time (p < 0.05), and produced more centered and rounder canal preparations than K-flex stainless steel files used in a quarter turn/pull technique. The computed tomography imaging system used in this study provided a repeatable, noninvasive method of evaluating certain aspects of endodontic instrumentation.

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↗

PubMed2001

State-of-the-art ultrasonography is as accurate as helical computed tomography and computed tomographic angiography for detecting unresectable periampullary cancer.

OBJECTIVE: To compare the ability of state-of-the-art ultrasonography with that of helical computed tomography and computed tomographic angiography in detecting unresectable periampullary cancer. In most patients periampullary cancer is unresectable because of either distant metastasis or local vascular involvement. The advent of gray scale and color Doppler ultrasonography has improved the ability of ultrasonography to detect vascular involvement. METHODS: Twenty-three consecutive patients with periampullary cancer were enrolled for prospective staging of their disease by comparing helical computed tomography and computed tomographic angiography with gray scale and color Doppler ultrasonography of the abdomen. Portal vein, superior mesenteric vein, splenic vein, and superior mesenteric artery involvement was graded 0 to 4, grade 0 being no vascular involvement and grade 4 being total occlusion of the vessel. Agreement between ultrasonography and computed tomographic angiography for determining vascular involvement was measured by chi2 analysis. RESULTS: Two patients (9%) were excluded because excessive overlying bowel gas hampered the ability of ultrasonography to visualize the pancreas. For the remaining 21 patients, there was significant agreement between ultrasonography and computed tomographic angiography for detecting vascular involvement in all vessels (P < .001; portal vein, kappa = 0.67; superior mesenteric vein, kappa = 0.67; splenic vein, kappa = 0.85; and superior mesenteric artery, kappa = 0.59). Ultrasonography was in agreement with computed tomographic angiography in all cases of unresectability. Both modalities were equally poor in preoperatively showing lymphadenopathy and metastases. CONCLUSIONS: Provided that there is adequate visualization on ultrasonography of the head of the pancreas in the periampullary region, then state-of-the-art gray scale and color Doppler ultrasonography are as accurate as helical computed tomography and computed tomographic angiography for detecting the unresectability of periampullary cancer. If performed as the initial investigation and the region of the pancreatic head is clearly shown, and if vascular encasement or occlusion or distant metastasis is identified, further investigations are unnecessary.

Adult↗

PubMed1980

Adenocystic carcinoma in computed tomography.

Computed tomography was introduced in 1972 by Ambrose and Hounsified in England. At first it was designed for diagnostic radiology and neurosurgery of the brain and skull. Soon, in 1974, whole-body computerized tomography scanners went into operation in the United States and then came into worldwide use. The use of computed tomography in maxillofacial regions is rare. In the report two adenocystic carcinomas in the maxilla are described by computed tomography, and the images thus produced are compared to those obtained by ordinary tomography and isotope scintigraphy.

Aged↗

PubMed1977

Evaluation of cholestatic jaundice by computed tomography.

Computed tomography of the abdomen can aid the clinician in distinguishing intrahepatic from extrahepatic causes of jaundice. Hepatobiliary and pancreatic disease may be clearly defined. The timing and selection of further diagnostic and surgical procedures can be guided by computed tomography and unnecessary operations and prolonged hospitalization can be reduced. Computed tomography of the abdomen should not be used as a screening procedure but should be used after simpler techniques fail to establish a definitive diagnosis.

Adolescent↗

PubMed1985

[Evaluation of the effectiveness of preoperative polychemotherapy of nephroblastomas in children by angiography, ultrasonic tomography and computed tomography].

The results of preoperative polychemotherapy of nephroblastoma in 14 children are presented. Ultrasonic tomography, computed tomography and angiography were performed in all the patients before and after medication. The findings on the efficacy of polychemotherapy were assessed on the basis of surgical evidence and, in particular, resected material examination. A high diagnostic value of all the methods was demonstrated and criteria of the effectiveness of preoperative polychemotherapy as evaluated by application of ultrasonic and computed tomography and angiography were worked out. Optimal terms of carrying out diagnostic procedures in patients with nephroblastoma during preoperative treatment are suggested.

Angiography↗

PubMed1985

Pediatric brain computed tomography.

Computed tomography today provides good anatomic depiction of the brain and its gross disease processes that have as a manifestation alteration of brain density, disturbance in blood-brain barrier, or mass effect. As such, computed tomography often provides valuable diagnostic information in the appropriate clinical setting. This article reviews many of the more common pediatric central nervous system disease states that have been demonstrated more easily as a result of computed tomography.

Adolescent↗

PubMed1990

Morphology of the condyles and mandibular fossa as seen by computed tomography.

Computed tomography allows detailed three-dimensional examination of the hard and soft tissue of the temporomandibular joint. The morphology of the mandibular fossa and the condyles together with the horizontal and vertical condylar inclinations was determined in 25 patients with temporomandibular joint dysfunction and 29 controls by use of axial and coronal computed tomography projections. The shape of the condyle was evaluated according to its general appearance. The temporomandibular joint measurements obtained by computed tomography were in good agreement with morphologic studies performed on dry skulls and autopsy material.

Adolescent↗

PubMed1985

New observations of soft tissue sarcomas with contrast medium-enhanced computed tomography.

Computed tomography examinations were performed on 74 patients who presented to the Children's Hospital of Philadelphia and the Hospital of the University of Pennsylvania with a known or suspected diagnosis of primary or secondary soft tissue sarcoma. Focal masses were detected on computed tomography study in 59 patients. These masses were classified into three broad categories: centrally necrotic masses with a large predominantly liquefactive center and higher density periphery (29); multilocular, septated masses with distinct linear bands or striations (21); and miscellaneous masses (9). The miscellaneous category included six inhomogeneous and three homogeneous masses. The apparent density differences within these sarcomas were best appreciated on dynamic postcontrast scans. The computed tomography appearance of these sarcomas may be explained by the pathologic findings of cystic degeneration, extensive necrosis, central cavitation, focal hemorrhage, and myxoid changes.

Adolescent↗

PubMed1975

The validity of criteria for the evaluation of cerebral atrophy by computed tomography.

Computed tomography of the brain was used in evaluating demented and nondemented elderly people. The incidence of convulutional atrophy and ventricular enlargement correlated well with pathologic and pneumoencephalographic examination of a similar population. Computed tomography also showed certain instances of dementia without atrophy and evidence of atrophy without dementia. The absence of brain atrophy in a demented patient should prompt a search for a potentially treatable cause of the dementia. The authors discuss criteria for diagnosing atrophy by computed tomography and conclude that, because of its noninvasive nature, it is a valuable aid in screening demented patients for treatable diseases.

Aged↗