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At least 505 records · Page 28Linked to original sources
PubMed1998

Strategy and cost in investigating solitary pulmonary nodules.

OBJECTIVE: To compare the probability of cancer in a solitary pulmonary nodule using standard criteria with Bayesian analysis and result of 2-[F-18] fluoro-2-deoxy-D-glucose-positron emission tomographic (FDG-PET) scan. SETTING: A university hospital and a teaching Veteran Affairs Medical Center. METHODS: Retrospective analysis of 52 patients who had undergone both CT scan of the chest and a FDG-PET scan for evaluation of a solitary pulmonary nodule. FDG-PET scan was classified as abnormal or normal. Utilizing Bayesian analysis, the probability of cancer using "standard criteria" available in the literature, based on patient's age, history of previous malignancy, smoking history, size and edge of nodule, and presence or absence of calcification were calculated and compared to the probability of cancer based on an abnormal or normal FDG-PET scan. Histologic study of the nodules was the gold standard. RESULTS: The likelihood ratios for malignancy in a solitary pulmonary nodule with an abnormal FDG-PET scan was 7.11 (95% confidence interval [CI], 6.36 to 7.96), suggesting a high probability for malignancy, and 0.06 (95% CI, 0.05 to 0.07) when the PET scan was normal, suggesting a high probability for benign nodule. FDG-PET scan as a single test alone was more accurate than the standard criteria and standard criteria plus PET scan in correctly classifying nodules as malignant or benign. CONCLUSION: FDG-PET scan as a single test was a better predictor of malignancy in solitary pulmonary nodules than the standard criteria using Bayesian analysis. FDG-PET scan can be a useful adjunct test in the evaluation of solitary pulmonary nodules.

Cost-Benefit Analysis↗
PubMed1997

Likelihood of malignancy in a solitary pulmonary nodule: comparison of Bayesian analysis and results of FDG-PET scan.

OBJECTIVE: To compare the probability of cancer in a solitary pulmonary nodule using standard criteria with Bayesian analysis and result of 2-[F-18] fluoro-2-deoxy-D-glucose-positron emission tomographic (FDG-PET) scan. SETTING: A university hospital and a teaching Veteran Affairs Medical Center. METHODS: Retrospective analysis of 52 patients who had undergone both CT scan of the chest and a FDG-PET scan for evaluation of a solitary pulmonary nodule. FDG-PET scan was classified as abnormal or normal. Utilizing Bayesian analysis, the probability of cancer using "standard criteria" available in the literature, based on patient's age, history of previous malignancy, smoking history, size and edge of nodule, and presence or absence of calcification were calculated and compared to the probability of cancer based on an abnormal or normal FDG-PET scan. Histologic study of the nodules was the gold standard. RESULTS: The likelihood ratios for malignancy in a solitary pulmonary nodule with an abnormal FDG-PET scan was 7.11 (95% confidence interval [CI], 6.36 to 7.96), suggesting a high probability for malignancy, and 0.06 (95% CI, 0.05 to 0.07) when the PET scan was normal, suggesting a high probability for benign nodule. FDG-PET scan as a single test alone was more accurate than the standard criteria and standard criteria plus PET scan in correctly classifying nodules as malignant or benign. CONCLUSION: FDG-PET scan as a single test was a better predictor of malignancy in solitary pulmonary nodules than the standard criteria using Bayesian analysis. FDG-PET scan can be a useful adjunct test in the evaluation of solitary pulmonary nodules.

Bayes Theorem↗
PubMed2002

Relationships between DVHs and late rectal bleeding after radiotherapy for prostate cancer: analysis of a large group of patients pooled from three institutions.

BACKGROUND: Accurate modeling of late rectal reactions needs the collection of individual 3D dose-volume data (i.e. DVH) as well as clinical information of large cohorts of patients. The possibility of collecting a large number of patients with many different dose-volume combinations is very suitable for this purpose. PURPOSE: The purpose of the study is to search for significant correlation between dose-volume histograms/dose statistics of the rectum and late rectum bleeding. MATERIALS AND METHODS: Data from three institutions for 402 patients previously treated for prostate cancer with three to four field techniques, were retrospectively pooled and were collected with a number of clinical and physical parameters, including DVHs of the rectum (including filling). Patients with large air/fecal content in the rectum during planning computerized tomography (CT) scan were excluded from the analysis (n = 74). Out of 328 patients, 229 patients received an ICRU dose between 70 and 76Gy and the current analysis is referred to this subgroup of patients (median follow up: 30 months, range: 12-85 months). Out of these 229 patients, 189 patients were treated with conformal techniques. Rectum was contoured from the anal verge up to the sigmoid flessure by one observer for each institution. Dosimetric and contouring consistencies between the three institutions were previously investigated and the impact on DVHs was found to be quite modest for the purposes of the study. Median/quartile values of all parameters were considered as cut-off values for statistical analysis. We considered as bleeders those patients who experienced grades II-III late bleeding (modified RTOG scoring scale). RESULTS: Twenty two of 229 patients experienced > or =grade II late bleeding (30 months actuarial incidence: 10.7%). Significant correlation between a number of parameters and late bleeding was found (log-rank test). With regard to DVH, all median and third quartile values for V50-V70 were found to be significantly associated with an increased risk of rectal bleeding, if excepting the median value of V70. Based on the results of univariate analysis, the patients were divided into two groups: 'high risk', with at least one value above quartiles in the range V50-V60 (V50: 70%, V55: 64%, V60: 55%); 'low risk', the remaining patients. The 30 months actuarial rates of bleeding were 19.2 and 5.9% for the 'high' and the 'low' risk group, respectively (P = 0.0003 log-rank test). A multivariate analysis (Cox regression model) including 'DVH grouping' and the main remaining variables (age, previous prostatectomy, diabetes, hypertension, adjuvant hormonal therapy, rectum volume and ICRU dose) showed that 'DVH grouping' is the most predictive parameter (P = 0.005) together with adjuvant hormonal therapy (P = 0.025) and ICRU dose (P = 0.06). CONCLUSIONS: Our data confirm the role of the rectal DVH in separating groups of patients having prostate radiotherapy in low and high risk of developing late bleeding. Based on these results, V50 below 60-65% and V60 below 50-55% seem to be the robust cut-off values to keep the risk of developing late rectal bleeding reasonably low. However, due to the 'heterogeneity' of the considered population, the results found should be applied with caution in 'more homogeneous' groups of patients. The association of adjuvant hormone deprivation seems to be associated with an increased risk of rectal toxicity; the mechanism for this effect should be a focus of further research.

Actuarial Analysis↗
PubMed1985

Densitometric analysis of scans: important sources of artefact.

Computed tomography (CT) research in psychiatry often relies on the assessment of minor structural changes. Recently, it has come to encompass changes in regional brain X-ray absorption density. The artefacts prone to be encountered in density measurements are reviewed, and illustrated by a series of studies carried out using a CT 1010 scanner. They are shown to be more important than hitherto assumed in the interpretation of CT scan research.

Adolescent↗
PubMed1978

Computed tomography in astrocytomas. A statistical analysis of the parameters of malignancy and the positive contrast-enhanced CT scan.

Four histopathological indices of malignancy--cellularity, pleomorphism, vascularity, and necrosis--were correlated with the positive-contrast CT scan in 84 patients with pathologically proved astrocytoma. Vascularity and necrosis correlated best with the scan in supratentorial tumors, while vascularity and cellularity correlated significantly with the scan in cerebellar astrocytomas. These findings indicate that the degree of malignancy of a supratentorial astrocytoma can be inferred from the contrast-enhanced scan, but that this is not generally possible with posterior fossa tumors.

Adolescent↗
PubMed1981

The detection of mediastinal parathyroid glands by computed tomography, selective arteriography, and venous sampling: an analysis of 17 cases.

Computed tomography (CT) scans were reviewed in 19 cases of proved mediastinal parathyroid glands. Glands were detected in five of 17 cases (29%) with adequate scans; four of six (67%) anterior mediastinal glands larger than 2 cm were visible. The smallest lesion demonstrated by CT ws 1.6 cm. In the same series, selective arteriography was positive in 10 of 15 cases (67%), with the smallest lesion measuring 0.5 cm. Venous sampling was performed in 15 patients, and a thymic sample obtained in 10; a twofold step-up of parathyroid hormone in thymic veins was noted in eight of 15 cases (53%), but was not localizing, as samples in other veins were elevated in all but one case. Angiography appears more sensitive than second-generation CT for detecting mediastinal glands. However, CT is very useful in patients with previous failed explorations. Scanning must include contiguous sections extending several centimeters below the carina, in order to encompass low-lying mediastinal glands.

Adenoma↗
PubMed1989

Artifacts on lung CT scans: removal with Fourier filtration.

A preliminary study was done of Fourier analysis of high-resolution computed tomographic (CT) images of normal pulmonary parenchyma. A two-dimensional fast Fourier transform was applied to 20 regions of interest (64 x 64 pixels) obtained from CT images of six lungs. A qualitative analysis of the spectra and the application of filters in the frequency domain allowed the characterization and removal of reconstruction artifacts. Selective application of a low-pass filter removed these parasitic frequencies and clearly enhanced the quality of the image.

Filtration↗
PubMed1988

Tumors and tumor-like conditions of the middle ear and mastoid: role of CT and MRI. An analysis of 100 cases.

CT and MRI scanning provide valuable information in determining location and extension of middle ear and mastoid tumors and tumor-like conditions. The bone anatomy depicted by CT better delineates the involvement of the middle ear diseases. In glomus tumors, facial nerve tumors, and other cases including temporal bone metastases, the combination of CT and MR imaging is exceedingly useful in the diagnosis and management of patients.

Cranial Nerve Neoplasms↗
PubMed1980

Computerized tomography in the quantitative assessment of tumour response.

While Computerized Tomographic (CT) scans have been a valuable asset to radiotherapy treatment planning, their role in the critical assessment of tumour response has been less well defined. Recent refinements in radiotherapy treatment techniques have intensified the need for non-invasive methods to evaluate the local control of inaccessible neoplasms. In this study, 20 cases in which both pre- and post-treatment CT scans were available up to 27 months post-therapy were reviewed. The majority of the patients had pancreatic carcinoma. In both pre- and post-therapy scans, the tumour volume was calculated from contours outlined on sequential CT slices. These interpretations were compared with surgical findings, clinical course and patient survival. The rate of the primary tumour regression had little bearing on the clinical outcome. However, there was CT scan evidence of initial local tumour stabilization or regression in > 80% of the cases. In addition, CT scan evidence of tumour progression was correlated with clinical progression in > 90% of the patients. This suggests that a growth delay analysis might be possible with the use of CT scans, at least for the evaluation of pancreatic carcinoma.

Humans↗
PubMed1983

Intracranial metastases. Management and the place of the CT scan in patients who are treated with surgery only.

Five hundred and fifty-three patients with intracranial metastases were analysed, before and after the availability of CT scanning, from three neurosurgical centres. A further analysis of 318 patients, who had a total excision carried out, was made from the six groups (i.e. posterior fossa or craniotomy in each centre) before and after CT scanning was available. A statistically significant reduction in the excision rate occurred in one group after the CT scan was available, and the very small number of patients who survived for more than 12 months was not significantly increased in the groups who had a CT scan carried out. Median survival in the various groups, whether analysed on a unit basis or with all three units combined, was not only poor (two to five months) but was not significantly better in the groups investigated with CT scanning. It would therefore appear that the use of the CT scan has not enabled a more careful selection of patients suitable for excision to take place or improved the median survival. Thus, by implication, and from the evidence of the literature, a more intensive preoperative investigation should be considered in order to exclude possible extracranial metastases and appraise the place of cranial irradiation.

Brain Neoplasms↗
PubMed2002

Accuracy of high resolution CT in assessing idiopathic pulmonary fibrosis histology by objective morphometric index.

To determine the accuracy of HRCT in assessing histology by objective morphometric index, twenty-five biopsy specimen-proved UIP were correlated with high-resolution CT (HRCT) by morphometric analysis. The scans were evaluated for the presence and extent of normal parenchyma, ground-glass attenuation, linear opacities, consolidation, honeycombing, vessels and bronchiectasis, and overall extent of histology involvement for normal parenchyma, honeycombing, alveolar septal inflammation, fibrosis, vessels, and bronchiectasis/bronchiolectasis. The comparison between morphometric measurements showed a strong correlation between HRCT and histologic parameters for extension (%) of normal tissue (p = 5 x 10(-5)), honeycombing (p = 6 x 10(-5)), and vessels (p = 0.0047). HRCT consolidation strongly correlated with alveolar septal inflammation (p = 0.015), whereas HRCT linear opacities had the highest correlation with histology for bronchiectasis or bronchiolectasis (p = 0.03). These associations also demonstrated that there was considerable residual scatter about the linear relationships found. By contrast, neither the ground glass patterns nor the bronchioectatic patterns determined by CT were associated with any histologic observation (p < 0.1). There was a borderline negative relationship between vessels determined by CT and histologic fibrosis (p = 0.069), i.e., the percentage of vessel patterns determined by CT was found to be lower when fibrosis was prominent histologically. Our results showed that HRCT patterns, usually employed to provide information about activity (ground glass) and fibrosis (consolidation) in IPF, failed to correlate with histology. On the other hand, chronic cystic lesions had a good correlation with histology. This finding suggests that in patients without a diffuse honeycomb pattern on HRCT, a lung biopsy may provide additional information. The more important limitation of our study was the lack of correlation related to the proximity of the biopsy site to the HRCT location evaluated by morphometry.

Lung↗
PubMed2005

Three-dimensional fetal cephalometry: an evaluation of the reliability of cephalometric measurements based on three-dimensional CT reconstructions and on dry skulls of sheep fetuses.

AIM: To develop a 3D CT cephalometric analysis for maxillary growth evaluation of sheep fetuses operated in utero, and to evaluate the reliability of this analysis by comparing it with a direct cephalometric analysis on dry skulls. MATERIAL AND METHODS: Five skulls of operated sheep fetuses were used, which after preparation were CT scanned and a 3D reconstruction was performed. A cephalometric analysis was performed directly on the dry skulls as well as on the reconstructed 3D CT images. In total, 56 linear distances were measured. In order to access the error of the method, the procedure was repeated after a 2 week interval. RESULTS: The comparison between the direct cephalometric and the 3D CT analysis revealed that only 5 variables were significantly different. The evaluation of the error of method revealed that 7 variables of the direct cephalometric analysis and none of the 3D CT analysis differed significantly. CONCLUSIONS: According to the results of this study, it can be concluded that a cephalometric analysis on 3D CT reconstructed images of the skulls includes fewer identification errors and seems to be an accurate and reliable method that could be regarded at least as equivalent to conventional cephalometry.

Animals↗
PubMed2000

Nodal volume reduction after concurrent chemo- and radiotherapy: correlation between initial CT and histopathologic findings.

BACKGROUND AND PURPOSE: The role of concurrent chemoradiation for treatment of head and neck squamous cell carcinoma is expanding. We sought to evaluate the CT appearance of diseased and normal cervical lymph nodes before and after concurrent chemoradiation and to correlate lymph node volume reduction as revealed by CT with histopathologic findings of resected nodes. METHODS: Using concurrent chemoradiation, we treated seven patients with locally advanced head and neck squamous cell carcinoma. Our chemotherapeutic regimen consisted of cisplatin (100 mg/m2 body surface area administered on days 1 through 4 and 29 through 32) and 5-fluorouracil (1000 mg/m2 body surface area, administered on days 1 through 4 and 29 through 32). Radiotherapy was administered twice per day on dosing days 1 through 42 to a total dose of 7200 cGy to the primary tumor and 6000 cGy to the involved lymph nodes. Pre- and post-treatment CT scans were used to calculate lymph node volumes for all CT-positive (size criteria or extracapsular spread or both) diseased nodes (n = 19) and one normal node per patient (n = 7). Volume reduction was determined by CT results and correlated with the histopathologic findings of resected nodes. RESULTS: Average volume reduction (+/- standard error of the mean) for the 19 diseased nodes was 91%+/-4% and for the seven normal nodes was 55%+/-21% (P < .02, two-sided t test). Fifteen of 19 of the diseased lymph nodes showed extracapsular spread before treatment and none of 19 after treatment. The histopathologic findings of resected nodes included persistent tumor in one of the 19 diseased lymph nodes. Six of seven patients remained alive and disease-free, with an average follow-up duration of 24 months. CONCLUSION: Nodal volume reduction of greater than 90% was associated with eradication of tumor as assessed by histopathologic analysis of resected nodes. Serial CT scans obtained both before and after concurrent chemoradiation may be useful for predicting which patients will benefit from adjuvant surgical therapy.

Adult↗
PubMed2005

Increased risk of biochemical and local failure in patients with distended rectum on the planning CT for prostate cancer radiotherapy.

PURPOSE: To retrospectively test the hypothesis that rectal distension on the planning computed tomography (CT) scan is associated with an increased risk of biochemical and local failure among patients irradiated for prostate carcinoma when a daily repositioning technique based on direct prostate-organ localization is not used. METHODS AND MATERIALS: This study included 127 patients who received definitive three-dimensional conformal radiotherapy for prostate cancer to a total dose of 78 Gy at The University of Texas M. D. Anderson Cancer Center. Rectal distension was assessed by calculation of the average cross-sectional rectal area (CSA; defined as the rectal volume divided by length) and measuring three rectal diameters on the planning CT. The impact of rectal distension on biochemical control, 2-year prostate biopsy results, and incidence of Grade 2 or greater late rectal bleeding was assessed. RESULTS: The incidence of biochemical failure was significantly higher among patients with distended rectums (CSA >11.2 cm(2)) on the planning CT scan (p = 0.0009, log-rank test). Multivariate analysis indicates that rectal distension and high-risk disease are independent risk factors for biochemical failure, with hazard ratios of 3.89 (95% C.I. 1.58 to 9.56, p = 0.003) and 2.45 (95% C.I. 1.18 to 5.08, p = 0.016), respectively. The probability of residual tumor without evidence of radiation treatment (as scored by the pathologist) increased significantly with rectal distension (p = 0.010, logistic analysis), and a lower incidence of Grade 2 or greater late rectal bleeding within 2 years was simultaneously observed with higher CSA values (p = 0.031, logistic analysis). CONCLUSIONS: We found strong evidence that rectal distension on the treatment-planning CT scan decreased the probability of biochemical control, local control, and rectal toxicity in patients who were treated without daily image-guided prostate localization, presumably because of geographic misses. Therefore, an empty rectum is warranted at the time of simulation. These results also emphasize the need for image-guided radiotherapy to improve local control in irradiating prostate cancer.

Aged↗
PubMed1998

[Clinical observation and anatomical analysis of middle turbinate and ethmoidal internal wall moved to external side after microsurgery].

OBJECTIVE: To assess the effect of middle turbinate (MT) and ethmoidal internal wall(EIW) moved externally after microsurgery. METHODS: Twenty-four cases (45 sides) were followed-up endoscopically for (16.3 +/- 9.3) months. Thirteen cases (24 sides) were observed by CT scans. Three cadaver heads were measured for anatomical analysis. RESULTS: Forty-one (91%) of 45 sides obtained better olfactory function after operation. Twenty-two (91%) of 24 sides were found to have better CT changes in sinus ventilation as compared with preoperative CT scans. The gap between the MT and EIW to the orbital wall was (12.0 +/- 1.0) mm, while that between the ethmoidal bulla and processus uncinatus was only (2.3 +/- 0.6) mm as revealed in the autopsy. CONCLUSION: MT and EIW moderately moved suitably to externally had no bad effect on sinus ventilation, and it improved olfaction.

Adolescent↗
PubMedDate not supplied

Postreduction computed tomography in developmental dislocation of the hip: part I: analysis of measurement reliability.

Twenty computed tomographic (CT) scans of infants in spica casts after closed or open reduction for developmental hip dislocation (DDH) were analyzed for intra- and interrater reliability. Ten measurements of infant hip anatomy were assessed by three raters by using standard statistical analysis. All six measurements of acetabular anteversion and lateral or posterior displacement of the femoral metaphysis from the acetabulum or from a modified Shenton's line drawn from the pubic rami demonstrated both intra- and interrater reliability. All four measurements of acetabular structure could not be reliably measured either within or between observers. We also introduced a new measurement based on the principle of Shenton's line to aid in the assessment of femoral-head location after reduction in patients with DDH; this was reliably determined both within and among observers.

Female↗
PubMed2000

[Diagnostic and therapeutic consequences of kidney injuries in pediatric blunt abdominal trauma].

Renal lesions are frequently encountered in blunt pediatric abdominal trauma. In this retrospective study, we analyzed the incidence of renal trauma in these trauma patients to determine which diagnostic and therapeutic approaches were most predictive. From 1976 to 1996, 308 children sustaining blunt abdominal trauma were admitted to our department. Patients were evaluated using abdominal paracentesis, ultrasonography, and urinary analysis. In specific cases, i.v. urography, CT scan, and/or angiography were applied. We used the Organ Injury Scale (OIS) for classification of renal trauma into five grades. We encountered 69 serious abdominal traumas. Thirty-six patients sustained renal lesions grade 2 (G2) or higher; 20 children were polytraumatized. There were 67 renal lesions with 28 G1, 22 G2, 8 G3, 5 G4, 1 G5, and 3 lesions of the urinary tract. Ultrasonography and urinary analysis were found to be optimal diagnostic means for screening and observing the course of renal lesions. For lesions G2 or higher, CT scan was the most reliable in classifying and diagnosing renal lesions. This superseded i.v. urography. If no contrast medium was excreted in the CT scan, angiography was indicated. Only ten patients proceeded to operative therapy. During the period reviewed, a shift from operative to conservative treatment was notable with a tendency toward minimally invasive therapy. If lesions were G4 or G5, operative treatment was always indicated.

Abdominal Injuries↗
PubMed2005

The segments of the hepatic veins-is there a spatial correlation to the Couinaud liver segments?

PURPOSE: To investigate and describe the volume, position and shape of venous segments within the human liver and define their spatial correlation to the Couinaud segments (CS) and to the portal vein segments (PVS). MATERIAL AND METHODS: This study was based on 64 routinely acquired CT scans of patients undergoing hepatic surgery. The final analysis included 19 patients. All 19 CT data sets were transformed into 3D liver models. Three venous segments were postulated reflecting the left, middle, and right hepatic vein. Each venous segment was furthermore divided in two venous subsegments. Volume, position and shape of these venous segments/subsegments were calculated and, finally, compared with the volume, position and shape of the Couinaud segments and the portal vein segments. RESULTS: The right hepatic vein covers with 539.8 +/- 119.5 ml (47.1%) the largest part of total liver volume followed by the middle hepatic vein 372.7 +/- 151.1 ml (32.5%) and the left hepatic vein 248 +/- 75.9 ml (20.4%). The Couinaud liver segments and portal vein segments 2, 3, 5, 7, and 8 have consistent positional assignments within the three venous segments. Only the CS 4a, 4b, and 6 showed significantly different positions compared to the PVS 4a, 4b, and 6 (P < 0.03). The venous subsegments have a broad volumetric distribution reaching from 79 to 337 ml. There is no positional correlation of venous subsegments compared to Couinaud segments or portal vein segments at all (kappa < 0.75). In contrast, the venous segments/subsegments which can be assigned to either liver halve and either liver lobe have an identical volume, shape and position compared to the corresponding Couinaud liver segments (kappa > 0.75). CONCLUSION: The venous segments distinguish liver areas divided by the left and middle hepatic vein in exactly the same pattern as Couinaud segments and portal vein segments do. However, the comparison of shape and position of venous subsegments showed no correlation with both liver segmental approaches.

Adult↗