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.

SourceResearch connectionFrom yearThrough year

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

At least 559 records · Page 31Linked to original sources

PubMed1989

[Endosonography in gastroenterology. Update in 1989].

Endosonography consists of exploring the gastrointestinal wall and surrounding tissue with the aid of an ultrasound transducer introduced into the gastrointestinal lumen. High frequency ultrasound (more than 7 MHz) is used and provides high definition imaging. Its principal role is in oncology, and more particularly in the assessment of tumor extension. Regardless of whether it is the rectum, esophagus or stomach being considered, it is possible to predict the depth of tumor invasion in the wall in more than 80% of cases. The determination of invasion of adjacent organs is still somewhat imprecise. Endosonography provides better analysis of lymph nodes than CT scan (70 to 75% precision) and improvements will occur with better description of the criteria of malignancy. It appears interesting for the evaluation of pancreatic and biliary tumors and for follow-up of patients already treated for gastrointestinal cancer. Among its other indications, some have been well established (gastrointestinal submucosal tumors, giant gastropathy) and others require confirmation (villous tumors of the rectum, gastric ulcer).

Bile Duct Neoplasms↗

PubMed1984

Psychometric and cranial CT study in myotonic dystrophy.

Twenty-two adults with myotonic dystrophy were assessed for evidence of intellectual impairment and cranial CT abnormalities. Psychometric evaluation demonstrated significantly lower verbal and performance IQs in the MD subjects than in matched normal controls. The reduced performance IQ was not simply related to loss of fine motor skills. No significant differences were found in memory and personality assessments between the MD and control groups. Lateral ventricular surface area was measured on CT scans using a semiautomated image analysis technique and was found to have a positive correlation with age in a control group of 45 normal scans (r = 0.833, P less than 0.001). This correlation was lacking in the MD group of subjects (r = 0.345, P greater than 0.05), in eight of whom the ventricular surface area was above the upper limit for age found in the control group. Asymptomatic areas of focal atrophy were found in two subjects. There was no correlation between ventricular size and severity or duration of the disease or verbal or performance IQ.

Adolescent↗

PubMed1993

[The MASA syndrome (Mental retardation, Aphasia, Spastic paraplegia and Adducted thumbs), is it heterogeneous?].

BACKGROUND: MASA syndrome is the acronym for Mental retardation, Aphasia, Shuffling gait and Adducted thumbs. Linkage studies have shown linkage to markers in the Xq28 band. CASE REPORTS: Case no. 1: Mickaël was examined at the age of 3 yr 4 mo. He was mentally retarded (IQ = 40), aphasic, and had spastic gait, moderate facial dysmorphy and adducted thumbs. His parents were normal, except that his mother had similar facial dysmorphy. His brain CT scan was normal. Case no. 2: Philippe was the elder brother of Mickaël. When examined at the age of 5 years, he had the same features as his brother. His IQ was 40. His brain-CT scan was also normal. DNA analysis with markers for the Xq28 area showed that the brothers had received different X chromosomes from their mother. CONCLUSION: DNA studies suggest that the MASA syndrome is heterogeneous.

Aphasia↗

PubMed1998

[A successful case report on intralesional OK-432 therapy for cystic mediastinal lymphangiomas].

A 42-years-old female was referred to the university hospital because of cystic lesions of the right superior mediastinum. Drainage tube was found at right supraclavicular fossa with prolonged lymphatic discharge. We diagnosed this case as a benign cystic lymphangiomas with CT scan and CT scan with cystography and chemical analysis of the contents of the cyst. Intralesional OK-432 therapy for cystic mediastinal lymphangioma was performed. OK-432 was administered through intralesionally placed drainage tube. Excellent result was obtained. A few weeks later, residual lymphatic discharge through drainage tube became stopped. No expansion of the mediastinal cyst was found after drainage tube removal. Intralesional OK-432 therapy for cystic mediastinal lymphangioma was very effective and useful, it should be recommended for the management of the first choice of therapeutic method for cystic mediastinal lymphangioma because of no neurological deficit after this treatment.

Adult↗

PubMed2001

Peripheral pulmonary arteries: how far in the lung does multi-detector row spiral CT allow analysis?

PURPOSE: To analyze the influence of multi-detector row spiral computed tomography (CT) on identification of peripheral pulmonary arteries. MATERIALS AND METHODS: Peripheral pulmonary arteries were analyzed on optimally opacified contrast material-enhanced spiral CT angiograms in 30 patients devoid of pleuroparenchymal disease who underwent scanning with multi-detector row CT (collimation, 4 x 1 mm; pitch, 1.7-2.0; scanning time, 0.5 second). Two series of scans were systematically generated from each data set, 1.25-mm-thick (group 1) and 3-mm-thick (group 2) sections, leading to the analysis of 600 segmental (20 arteries per patient), 1,200 subsegmental (40 arteries per patient), 2,400 fifth-order (80 arteries per patient), and 4,800 sixth-order (160 arteries per patient) pulmonary arteries in each group. RESULTS: Multi-detector row CT with reconstructed scans of 1.25-mm-thick sections (group 1) allowed (a) analysis of a significantly higher percentage of subsegmental arteries (94% in group 1 vs 82% in group 2; P <.001) and (b) a significantly higher percentage of fifth- and sixth-order arteries, respectively, identified in 74% and 35% of cases in group 1 and 47% and 16% in group 2 (P <.001). The causes for inadequate depiction of subsegmental branches in group 1 were partial volume effect (43%), anatomic variants (39%), and cardiac (17%) and respiratory (1%) motion artifacts. CONCLUSION: Multi-detector row CT with reconstructed scans of 1.25-mm-thick sections enables accurate analysis of peripheral pulmonary arteries down to the fifth order on spiral CT angiograms.

Angiography↗

PubMed1980

High Z elements in human sarcomata: assessment by multienergy CT and neutron activation analysis.

"Tumor equivalent" phantoms containing inorganic salts (KH2PO4, CH3COOK, NaCl and Kl) were scanned on an EMI 5005 body scanner at 140 kVp, 28 mA; 120 kVp, 33 mA; and 81 kVp, 42 mA. Significant signal gain for the detection of higher atomic number elements by multiple energy scanning was noted. Certain sarcomas are known to accumulate high Z elements. Accordingly, excised specimens of various histologies of human sarcomata (chondrosarcoma, liposarcoma, and malignant fibrous histiocytoma) were scanned at 140 kVp and 81 kVp. Using selected areas of interest in the computed tomographic (CT) image to direct the in vitro biopsy of various regions of excised tumors, interesting correlations between the CT number variation and the respective, high Z elemental composition variation, as determined by thermal neutron activation analysis were observed. Further investigation with phantoms and excised sarcomata at 62 kVp and 42 mA suggested that dual energy CT scanning (at 140 kVp and 62 kVp) may be a method of monitoring "effective Z" and heavy element compositional changes. The authors are also attempting to develop these same low kilovoltage techniques as a method for the noninvasive clinical monitoring of an antisarcoma chemotherapeutic agent, cis-diammineaichloroplatinum (11).

Activation Analysis↗

PubMed2006

External fixation for displaced intra-articular fractures of the calcaneum.

A minimally-invasive procedure using percutaneous reduction and external fixation can be carried out for Sanders' type II, III and IV fractures of the os calcis. We have treated 54 consecutive closed displaced fractures of the calcaneum involving the articular surface in 52 patients with the Orthofix Calcaneal Mini-Fixator. Patients were followed up for a mean of 49 months (27 to 94) and assessed clinically with the Maryland Foot Score and radiologically with radiographs and CT scans, evaluated according to the Score Analysis of Verona. The clinical results at follow-up were excellent or good in 49 cases (90.7%), fair in two (3.7%) and poor in three (5.6%). The mean pre-operative Böhler's angle was 6.98 degrees (5.95 degrees to 19.86 degrees), whereas after surgery the mean value was 21.94 degrees (12.58 degrees to 31.30 degrees) (p < 0.01). Excellent results on CT scanning were demonstrated in 24 cases (44.4%), good in 25 (46.3%), fair in three (5.6%) and poor in two (3.7%). Transient local osteoporosis was observed in ten patients (18.5%), superficial pin track infection in three (5.6%), and three patients (5.6%) showed thalamic displacement following unadvised early weight-bearing. The clinical results appear to be comparable with those obtainable with open reduction and internal fixation, with the advantages of reduced risk using a minimally-invasive technique.

Adult↗

PubMed1994

[Radiological survey imaging of the dentition: dental CT versus orthopantomography].

In this study 15 patients with abnormalities in dentition and jaws were analysed by computer tomography for the purpose of determining the diagnostic value of dental CT scanning in relation to orthodontic problems. The dental CTs were then compared with conventional panoramic x-rays. After describing principles and methodology, the study discusses the possibilities for clinical applications. The study demonstrated that dental CT scanning is definitely superior for diagnosing dentition disturbances, for metrical analysis of maxillary antrum relations, and for examining bony jaw structures. However, the routine use of dental CT scanning as a diagnostic method is at this time constrained due to the relatively high amount of time and labour the procedure requires with resulting implications for cost factors.

Child↗

PubMed2006

Critical evaluation of chest computed tomography scans for blunt descending thoracic aortic injury.

BACKGROUND: Although aortography has been the long-held "gold standard" for diagnosis of traumatic blunt aortic injury, advances in imaging technology offer less-invasive, more-rapid, and potentially more cost-effective evaluation. The purpose of this study was to review this hospital's experience with the screening and diagnosis of blunt aortic injury with emphasis on the critical evaluation of computed tomography (CT) scans for defining descending thoracic aortic injury. METHODS: A retrospective single-center analysis of all patients undergoing aortography to evaluate for blunt aortic injury between January 1, 1997, and August 31, 2004, was performed. A policy of relying on CT scans to definitively diagnose blunt aortic injury was not in force, and all patients with positive, equivocal, and negative screening CT scans with significant injury mechanism underwent subsequent aortography; this contributed to an unbiased analysis. A subgroup of patients imaged with the latest generation multislice CT scanners (July 1, 2003, to August 31, 2004) was separately analyzed with rapid three-dimensional reconstruction. RESULTS: Of 856 aortograms, 206 (24.1%) were preceded by chest CT scan. Of 31 patients with confirmed aortic injury, 20 had undergone CT scan with 16 positive for definite injury, 3 positive for possible injury, and 1 false-negative study. Of the 206 patients scanned, 114 (55.3%) showed possible injury, 76 (36.9%) were negative, and 16 (7.8%) were positive. Only 3 of the 114 with possible injury (2.6%) were true positives whereas 1 of the 76 negative scans (1.3%) was a false negative and all 16 positive scans were true positives. These data for CT scan imaging result in a sensitivity of 95%, a specificity of 40%, a positive predictive value of 15%, and a negative predictive value of 99%. CONCLUSIONS: Chest CT is an acceptable screening tool based on prerequisite high sensitivity and ease of performance in the trauma patient suspected of having a descending thoracic aortic injury. Although the excellent negative predictive value resulted in an algorithm change at this institution, there were a significant number of equivocal scans that required subsequent aortography. Three-dimensional software reconstruction of the aorta can aid in diagnosing blunt aortic injury when findings are equivocal, but there will continue to be artifacts and limitations that require aortography for clarification.

Adolescent↗

PubMed1980

Cerebral blood flow determination by rapid-sequence computed tomography: theoretical analysis.

Dynamic computed tomography (CT) using rapid-sequence scanning can be used to determine cerebral blood flow noninvasively following an intravenous bolus injection of contrast material. Since the contrast material remains intravascular in the normal brain, principles of indicator dilution analysis for nondiffusible indicators are applied to the time course of the changes in contrast concentration. While a delay is introduced by the relatively prolonged intravenous injection, this can be corrected for if the arteries are seen on the scan; the corrected mean transit time of the first passage of the bolus through the vessels gives the blood flow per unit vascular volume. To find the blood flow per unit of total tissue volume requires measuring the concentration of contrast material in the blood, which cannot always be done directly from brain scans with current CT equipment; however, a relative volume for total tissue flow can be found by using the area under the curve of contrast concentration as a function of time, as this area is proportional to the fractional vascular volume of the tissue.

Cerebrovascular Circulation↗

PubMedDate not supplied

A comparison of symptom scores and radiographic staging systems in chronic rhinosinusitis.

BACKGROUND: The aim of this study was to determine if one of the popular computed tomography (CT) scan staging systems exhibits better correlation with sinonasal symptom severity in chronic rhinosinusitis (CRS). METHODS: Adult patients meeting diagnostic criteria for CRS were prospectively studied with the Rhinosinusitis Symptom Inventory and their paranasal sinus CT scan was staged according to the Kennedy, Harvard, and Lund staging systems. From the Rhinosinusitis Symptom Inventory, Likert symptom severity scores were obtained and the nasal, facial, oropharyngeal, systemic, and total symptom scores were computed. Correlation analysis was conducted between symptom scores and CT scan stage for each of the three staging systems. RESULTS: Two hundred patients met inclusion criteria (mean age, 41.1 years; 42% men). The mean Lund score for the entire cohort was 10.0 (SD, 5.3). The Kennedy stage distributions were 40, 42, 84, and 34 patients for stages 1-4, respectively. The Harvard stage distributions were 17, 53, 85, and 45 patients for stages 1-4, respectively. All three staging systems exhibited statistically significant Pearson correlation (all p < 0.001) for the nasal symptom domain (nasal obstruction, rhinorrhea, and hyposmia), although the magnitude of the correlation coefficient generally was small (range of Pearson's r, 0.242-0.345). The Kennedy and Harvard systems exhibited significant but negative correlation with the oropharyngeal symptom domain. All three staging systems failed to significantly correlate CT stage with facial symptoms, systemic symptoms, and total symptom scores. CONCLUSION: The Lund staging system exhibited the best correlation between nasal symptom scores and CT stage in CRS, but the degree of correlation remained small. All three systems were lacking in staging value for nonnasal sinonasal symptoms.

Adult↗

PubMed1982

The reliability of noninvasive diagnostic procedures in children with brain tumors.

To determine the most reliable method of following the progress of disease in children with primary intracranial neoplasms, the noninvasive diagnostic procedures in 92 children were analyzed. Computerized tomographic (CT) scanning was found to be significantly superior to all other testing procedures in sensitivity, specificity, and overall accuracy. This superiority was seen regardless of tumor location or pathological subtype. When results in follow-up were compared to initial findings at diagnosis, the sensitivity of CT scanning was again significantly more reliable than the other procedures. Cerebrospinal fluid analysis was unreliable and added little information to that obtained from simultaneous CT and Radionuclide (RN) scanning. It is recommended that combined CT and RN scanning be used for management of intracranial neoplasms until a reliable method for detecting microscopic disease is available.

Adolescent↗

PubMed1989

Subacute sclerosing panencephalitis. Changes on CT scan during acute relapse.

A 19-year-old female patient presented in an acute state of akinetic mutism. Serological analysis of serum and cerebrospinal fluid demonstrated the presence of antibodies to measles virus. CT scan carried out during this acute phase of relapse demonstrated white matter enhancement affecting the cortical white matter of the frontal lobes and corpus callosum. These features indicate that active demyelination occurs during acute relapse in subacute sclerosing panencephalitis (SSPE) and suggest that immunotherapy should be considered during this acute phase.

Adolescent↗

PubMed2003

Cardiac arrest: long-term cognitive and imaging analysis.

BACKGROUND: Neurological and cognitive sequelae resulting from cardiac arrest (CA), despite their potential personal and social impact, are usually not considered as major outcome measures in long-term analysis of survivors. The aim of this study is to analyze the contribution of neuropsychological testing and cerebral imaging to the development of a long-term classification of neurological impairment. PATIENTS AND METHODS: A total of 19 patients admitted over a 3 years period in an eight-bed intensive care unit of a tertiary care hospital with a diagnosis of CA were alive and attended a 6-month follow-up consultation. Eleven of these patients agreed to participate in this study carried out between 1 and 3 years after CA. Patients were classified using the Cerebral Performance Categories (CPC), neurological examination, detailed cognitive testing and computerized tomography (CT) scan with qualitative and quantitative imaging analysis. RESULTS: Six of the 11 patients had good cerebral performance. Verbal and visuo-spatial short-term memory scores were associated with CPC. All patients with at least moderate cerebral disability had abnormal verbal memory test results compared with only one survivor with CPC 1; visuo-spatial short-term memory was abnormal in four moderately affected survivors and normal in those with CPC 1. The bicaudate ratio evaluated in the CT scan was correlated with the verbal memory score while the III ventricle diameter correlated with the executive functions score, suggesting involvement of different brain areas in these functions. CONCLUSIONS: Neuropsychological and CT scan measurements are proxy measures of long-term impairment of CA survivors, providing a dichotomized global evaluation of CA survivors in close agreement with CPC.

Adult↗

PubMed2006

Morphometric and qualitative analysis of congenital occipitocervical instability in children: implications for patients with Down syndrome.

OBJECT: Congenital occipitocervical (OC) instability is uncommon in healthy children but can occur in many children with Down syndrome. A simple morphometric method of evaluating the OC joint in children with OC instability is presented, supported by a qualitative image analysis based on computed tomography (CT). METHODS: Thin-cut CT scans of the OC joint were obtained in eight patients with Down syndrome and one patient with congenital OC instability. These patients' CT scans were compared with those of 15 healthy age-matched control individuals. Morphometric analysis was performed by measuring the depth and length of the superior articular surface (SAS) of C-1, and these values were normalized for a comparison between groups. Qualitative data were acquired using a surface-rendering technique for a visual comparison of the C-1 SAS. Morphometric analysis demonstrated an absence of the concave C-1 SAS anatomy in patients with congenital OC instability compared with age-matched control individuals (0.083 compared with 0.202, p < 0.001). Three-dimensional (3D) image analysis of the C-l SAS supported this finding. CONCLUSIONS: Congenital differences in the shape of the OC joint are highly associated with atraumatic OC instability in children with Down syndrome. High-resolution CT imaging combined with 3D rendering techniques and surface mapping provides support for this assessment. It appears that abnormal OC joint shape is a contributing factor to congenital OC instability, especially in patients with Down syndrome.

Adolescent↗

PubMed1990

Applicability of X-ray computerized tomography in endodontics.

This study was carried out to observe the teeth of the maxillary and mandibular bones in computerized tomographic (CT) scans. In addition to using CT images, a 3-dimensional analysis was conducted for further visualization. The anatomical configurations of the teeth were clearly observed in the CT scans, as was the relation of the teeth to the periodontal tissues. Further, using CT scans made it possible to determine buccolingual and mesiodistal widths of teeth, and the presence or absence of root canal filling materials and metal posts. In addition, carious lesions of a certain size and expansions of the maxillary sinus and proximity to the roots were observed. The 3-dimensional image analysis was interesting, but detailed observations could not be made with this technique.

Adult↗

PubMed2003

Optical-CT gel-dosimetry I: basic investigations.

Comprehensive verification of the intricate dose distributions associated with advanced radiation treatments is now an immediate and substantial problem. The task is challenging using traditional dosimeters because of restrictions to point measurements (ion chambers, diodes, TLD, etc.) or planar measurements (film). In essence, rapid advances in the technology to deliver radiation treatments have not been paralleled by corresponding advances in the ability to verify these treatments. A potential solution has emerged in the form of water equivalent three dimensional (3D) gel-dosimetry. In this paper we present basic characterization and performance studies of a prototype optical-CT scanning system developed in our laboratory. An analysis of the potential role or scope of gel dosimetry, in relation to other dosimeters, and to verification across the spectrum of therapeutic techniques is also given. The characterization studies enabled the determination of nominal operating conditions for optical-CT scanning. "Finger" phantoms are introduced as a powerful and flexible tool for the investigation of optical-CT performance. The modulation-transfer function (MTF) of the system is determined to be better than 10% out to 1 mm(-1), confirming sub-mm imaging ability. System performance is demonstrated by the acquisition of a 1 x 1 x 1 mm3 dataset through the dose distribution delivered by an x-ray lens that focuses x rays in the energy range 40-80 KeV. This 3D measurement would be extremely difficult to achieve with other dosimetry techniques and highlights some of the strengths of gel dosimetry. Finally, an optical Monte Carlo model is introduced and shown to have potential to model light transport through gel-dosimetry systems, and to provide a tool for the study and optimization of optical-CT gel dosimetry. The model utilizes Mie scattering theory and requires knowledge of the variation of the particle size distribution with dose. The latter was determined here using the technique of dynamic-light-scattering.

Algorithms↗

PubMed1984

Computed tomographic analysis of urinary calculi.

Excised urinary calculi were subjected to computed tomographic (CT) scanning in an attempt to determine whether CT attenuation values would allow accurate analysis of stone composition. The mean, maximum, and modal pixel densities of the calculi were recorded and compared; the resulting values reflected considerable heterogeneity in stone density. Although uric acid and cystine calculi could be identified by their discrete ranges on one or more of these criteria, calcium-containing stones of various compositions, including struvite, could not be distinguished reliably. CT analysis of stone density is not likely to be more accurate than standard radiography in characterizing stone composition in vivo.

Calcium Oxalate↗