Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CT scan analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed2005

Quantification of emphysema severity by histogram analysis of CT scans.

Emphysema is characterized by the destruction and over distension of lung tissue, which manifest on high resolution computer tomography (CT) images as regions of low attenuation. Typically, it is diagnosed by clinical symptoms, physical examination, pulmonary function tests, and X-ray and CT imaging. In this paper we discuss a quantitative imaging approach to analyze emphysema which employs low-level segmentations of CT images that partition the data into perceptually relevant regions. We constructed multi-dimensional histograms of feature values computed over the image segmentation. For each region in the segmentation, we derive a rich set of feature measurements. While we can use any combination of physical and geometric features, we found that limiting the scope to two features - the mean attenuation across a region and the region area - is effective. The subject histogram is compared to a set of canonical histograms representative of various stages of emphysema using the Earth Mover's Distance metric. Disease severity is assigned based on which canonical histogram is most similar to the subject histogram. Experimental results with 81 cases of emphysema at different stages of disease progression show good agreement against the reading of an expert radiologist.

Algorithms↗
PubMed1979

Automated scene analysis of CT scans.

Since the advent of computed tomography, there has been an increasing realization that CT scans contain quantitative as well as qualitative information useful in the diagnostic process. Often however, the use of this information is impeded by the tedious manual outlining of the areas of interest in the scan. To alleviate this problem, we have developed a scene segmentation algorithm which will automatically delineate areas of interest in a CT scan. This procedure uses known information about the expected objects in the scan in conjuction with an algorithm to label those objects. The resultant scene segmentation divides the scan into four anatomical areas: skull, normal brain, high density lesions and CSF. After an area of interest is interactively selected by the clinician, volume, density or other quantitative measures may be computed. Limitations of the algorithm and its clinical applications are discussed.

Absorptiometry, Photon↗
PubMedDate not supplied

Effects of bromocriptine for prolactin-secreting adenomas: analysis by CT scan.

Effects of bromocriptine on the size of adenomas in CT scans were examined in eight patients with prolactin-secreting adenomas. The changes on CT scans were classified into three types: Type I showed a reduction of enhanced area, Type II showed a decrease of enhanced density and Type III showed no change on CT scans.

Adenoma↗
PubMed2005

Cerebrovascular accidents after cardiac surgery: an analysis of CT scans in relation to clinical symptoms.

There is a link between aortic manipulation, particle embolization, and cerebrovascular accidents (CVA) in cardiac surgery. The present aim was to study hemispheric side differences of CVA. Cardiac-surgery patients with CVA and with computer tomography (CT) performed (n = 77) were analyzed within a total group of 2641 consecutive cases. CT data were reviewed for hemispheric and vascular distribution, and compared with CVA-symptom data of immediate and delayed type. Of the included patients, 66% had positive CT. In the group of 'cardiac-type' operations (e.g., routine clamping and cannulation) and having immediate CVA, right-hemispheric lesions were more frequent than of the contra-lateral side (p = 0.005). Patients with aortic dissections had strong dominance of bilateral findings, which was different from the unilateral pattern of 'cardiac-type' operations (p = 0.001). The middle-cerebral artery territory dominated, and when involved showed a significant (p = 0.022) right-sided distribution. Both CT and clinical symptoms confirmed that CVA after cardiac surgery has a right-hemispheric predominance. These observations may imply that aortic manipulation directs embolic material towards the brachiocephalic trunk.

Aged↗
PubMed2006

Liver metastases: 3D shape-based analysis of CT scans for detection of local recurrence after radiofrequency ablation.

This HIPAA-compliant pilot study had internal review board approval; informed consent was waived. The purpose was to determine retrospectively the diagnostic performance of a computer-aided three-dimensional (3D) analytic tool for assessing local recurrences of liver metastases by quantifying shape changes in ablated tumors on computed tomographic (CT) scans for follow-up of radiofrequency (RF) ablation. Positron emission tomographic and long-term CT follow-up images were reference standards. Fifty-six follow-up CT scans of 12 liver metastases (mean size, 4.0 cm) in nine patients treated with RF ablation were retrospectively analyzed. After the 1st month following RF ablation, the 3D analytic tool helped quantify ablated tumor shape variations and revealed recurrences even in the absence of abnormal enhancement (sensitivity, seven of seven; specificity, three of five). The 3D tool would have revealed a recurrence before it was reported clinically in two patients. Although results are preliminary, a 3D analytic tool based on shape may be useful in assessing RF ablation results.

Aged↗
PubMed1986

Multivolumetric analysis of CT scans on patients with glioma.

Brain tumor volumes in patients having multimodal therapy for cerebral gliomas were calculated using graphic methods and Simpsonian integration. Volume assessment calculations differed from the clinical assessment of the patient significantly in some cases. These calculations may be useful in on-going tumor therapy and should be used as a true scientific end point in brain tumor treatment protocols.

Brain Neoplasms↗
PubMed1996

Analysis of CT scanning referrals for chronic rhinosinusitis.

The principal role of computed tomography (CT) scanning in rhinosinusitis is as a planning investigation for patients requiring functional endoscopic sinus surgery (FESS). The pre-operative scan is used to highlight any potential surgical hazards, and to delineate the extent of disease reducing unnecessary intervention in disease-free areas. It is inappropriate for CT to be used purely as a diagnostic investigation for chronic rhinosinusitis. As concern has been expressed over the steady rise in the referrals for CT of the sinuses, we conducted a retrospective review of all patients having these scans at two CT scanner sites in Scotland during 1993. Of the 162 scans performed for rhinosinusitis, 58 patients (36 per cent) had not had nasendoscopy performed or had a trial of medical treatment. Subsequently, only 61 patients (38 per cent) went on to FESS. The inappropriate use of CT for these patients can be reduced by insisting that nasendoscopy is performed prior to scanning. Furthermore, radiologists and surgeons should audit the number of patients not having FESS after scanning.

Chronic Disease↗
PubMed1998

CT scan texture analysis of the distal radius: influence of age and menopausal status.

OBJECTIVES: To gain information on bone architecture by performing bone texture analysis in a sample of women covering a broad age range. PATIENTS AND METHODS: We studied 29 healthy women aged 23 to 80 years (55 +/- 18 years), 19 of whom were postmenopausal. None was taking drugs known to influence bone mass or bone metabolism. Computed tomography of the nondominant distal radius was performed with 1 mm slice thickness and 1 mm gap. Four consecutive coronal and four consecutive axial sections were selected for each patient and entered into a PC-type computer. Bone texture was evaluated using grey level run length analysis (five parameters), differential local variation analysis (four parameters), fractal analysis (two parameters), trabecular network extraction and three-dimensional relief characterization. The mean of each study parameter for the four coronal sections and for the four axial sections was calculated. Absorptiometry was done in 16 patients. RESULTS: Linear correlations with age were strongest (P < 0.001) for parameters measured on coronal sections by trabecular network extraction, i.e., trabecular bone volume (r = -0.68), trabecular plate separation (r = -0.65), total skeletal length (r = -0.71), number of nodes (r = 0.73), number of node-node segments (r = -0.74) and trabecular bone pattern factor (r = 0.71). Also, these parameters were significantly different between premenopausal women (33 +/- 9 years) and postmenopausal women (67.3 +/- 9 years). Correlations between bone mineral density and texture parameters were few in number and modest in strength, suggesting that the parameters measured may reflect bone structure rather than bone mass. CONCLUSION: Bone texture in women undergoes changes with advancing age that may reflect alterations in bone microarchitecture.

Adult↗
PubMed1985

Pineal region tumors.

The management of pineal region tumors has changed considerably since the introduction of microsurgery and CT scanning. Analysis of our own series of 36 patients, comparing those treated in the pre-CT scan and microsurgery era with those treated afterwards, shows the important role these two techniques play. Current controversies in treatment and our own approach to management of pineal region tumors are discussed.

Adolescent↗
PubMed2006

[Volumetric measurement of human orbit by means of computed tomographic analysis based on CT scanning digital data].

OBJECTIVE: To establish and elucidate a feasible method by CT-scanning-based computed tomographic analysis for the volumetric measurement of orbit. METHODS: In this study, 19 dry intact dried skulls were used. CT digital data with continuous 0.625 mm transaxial sections was available for each and was inputted a professional tomographic analysis software in DICOM format. Subsequent to the orbital borderline lined on each of continuous axial images, software automatically generated three-dimensional orbital image and gave a value of orbital volume. In mean while, handicraft measurement of orbital volume was carried out for each and obtained another group of orbital volume value. Statistical analysis was made to test possible difference between two measurements. RESULTS: It was demonstrated that volumetric measurement by means of computed tomographic software had a accuracy of the 1.38%. Right and left orbital volumes were found to have a mean difference of 0.3 ml (0-1.4 ml). CONCLUSIONS: CT data-based computed tomographic analysis is a reliable method to measure orbital volume, which could be potentially used to determine the alternation of orbital volume after fracture.

Female↗
PubMed1993

The results of chemonucleolysis as a function of three dimensional volumetric analysis of disc herniation.

Spinal canal and dural sac morphometry as demonstrated by CT scan analysis in patients undergoing chemonucleolysis for the treatment of herniated lumbar discs was analyzed in an attempt to develop a method of predicting positive or negative follow-up clinical results. The morphometry of the canal and dural sac at the intervertebral disc level was defined by reviewing normal levels of CT scans. Levels with herniated discs were then analyzed for comparison of treatment results between successful and unsuccessful procedures. The concept of spinal reserve capacity was evaluated. Significant differences between canal morphometric parameters of patients with treatment success or failure were then identified. The concept of spinal reserve capacity may be applicable in spinal stenosis, but we were unable to delineate any predictive value in the evaluation of patients with herniated lumbar discs undergoing chemonucleolysis.

Adult↗
PubMed2006

An audit of imaging test utilization for the management of lymphoma in an oncology hospital: implications for resource planning?

The purpose of this study was to assist with resource planning by examining the pattern of physician utilization of imaging procedures for lymphoma patients in a dedicated oncology hospital. The proportion of imaging tests ordered for routine follow up with no specific clinical indication was quantified, with specific attention to CT scans. A 3-month audit was performed. The reasons for ordering all imaging procedures (X-rays, CT scans, ultrasound, nuclear scan and MRI) were determined through a retrospective chart review. 411 lymphoma patients had 686 assessments (sets of imaging tests) and 981 procedures (individual imaging tests). Most procedures were CT scans (52%) and chest radiographs (30%). The most common reasons for ordering imaging were assessing response (23%), and investigating new symptoms (19%). Routine follow up constituted 21% of the assessments (142/686), and of these, 82% were chest radiographs (116/142), while 24% (34/142) were CT scans. With analysis restricted to CT scans (296 assessments in 248 patients), the most common reason for ordering CT scans were response evaluation (40%), and suspicion of recurrence and/or new symptom (23%). Follow-up CT scans done with no clinical indication comprised 8% (25/296) of all CT assessments. Staging CT scans were under-represented at 6% of all assessments. Imaging with CT scans for follow up of asymptomatic patients is infrequent. However, scans done for staging new lymphoma patients were unexpectedly low in frequency, due to scans done elsewhere prior to referral. This analysis uncovered utilization patterns, helped resource planning and provided data to reduce unnecessary imaging procedures.

Adolescent↗
PubMed2004

Laparoscopic radiofrequency ablation of hepatic tumors: prospective clinical evaluation of ablation size comparing two treatment algorithms.

BACKGROUND: Radiofrequency ablation (RFA) is gaining increased acceptance for the local control of liver tumors. Essential for achieving local tumor control are reproducible volumes of ablation that encompass the tumor and a margin of normal liver parenchyma. The technical algorithm for performing ablations was arrived at in an animal model using normal liver. Limited amounts of data exist as to whether this translates to the human tumor model. METHODS: We analyzed 531 ablated lesions in 154 patients undergoing laparoscopic RFA using RITA Medical Systems Starburst XL catheter deployed to a final diameter of 2-5 cm. The first 54 patients (algorithm 1) were treated with a larger initial deployment to 3 cm and incremental advancement of the catheter to the final diameter with a 20-min ablation time for a 5-cm lesion. The subsequent 100 patients (algorithm 2) were treated with a smaller initial deployment of 2 cm, incremental advancement to the final diameter, and 14-min total ablation time for a 5-cm lesion. Lesion size was measured on 1 week postablation CT scans. Analysis was performed using the two-tailed t-test. RESULTS: Ablation zones tended to be larger with the second method. On 1 week postablation CT scans, mean +/- SEM lesion sizes created using the first and second algorithms were 3.7 +/- 0.1 cm vs 4.0 +/- 0.1 cm at 3 cm deployment ( p < 0.05); 4.3 +/- 0.1 cm vs 4.8 +/- 0.1 cm at 4 cm deployment ( p < 0.05), and 5.5 +/- 0.1 cm vs 5.6 +/- 0.2 cm at 5 cm deployment ( p > 0.05), respectively. The mean +/- SEM total ablation times for the first and second algorithms were 7.9 +/- 0.3 min vs 7.0 +/- 0.2 min at 3 cm deployment ( p < 0.05); 13.3 +/- 0.3 min vs 11.1 +/- 0.02 min at 4 cm deployment ( p < 0.05); and 27.8 +/- 1.2 min vs 21.4 +/- 1.2 min at 5 cm deployment ( p < 0.05), respectively. The small SEM values indicate little variation in lesion size. CONCLUSIONS: These results show that both algorithms create dependable and reproducible zones of ablation, essential for reliable tumor destruction. Algorithm 2 demonstrates that creating an initial small core of ablation with rapid coagulation of the center of the lesion allows for equivalent, if not larger, final volumes to be performed in less time.

Adenocarcinoma↗
PubMedDate not supplied

Schwannomas of the larynx: review and computed tomographic scan analysis.

Neurogenic tumors consist of schwannomas, neurofibromas, and neurosarcomas that arise from the Schwann cell of a peripheral nerve. Their occurrence in the larynx is rare, with only 115 cases having been reported. Three new cases are presented, the literature is reviewed, and the first computed tomographic (CT) scan of a benign schwannoma of the larynx is demonstrated. The diagnosis and treatment of these tumors and the CT scan analysis are discussed.

Adult↗