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Results for “computed tomography”

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PubMed1976

Evaluation of pediatric hydrocephalus by computed tomography.

Computed tomography (CT) is a safe and reliable technique for the study of children with increased head circumference. Hydrocephalic children requiring drainage of cerebrospinal fluid may be shunted on the basis of the CT scan alone and their postsurgical course followed by serial CT scans thereafter. Any additional pneumographic studies required may be performed via the existing shunt tube, eliminating transcerebral catheterization and its attendant complications.

Brain Edema↗

PubMed1976

Demonstration of purulent bacterial intracranial infections by computed tomography.

Computed tomography is shown to be an important modality in both diagnosis and management of cerebral infections. Representative findings from CT scans of patients with purulent bacterial infection of the meninges, cerebrum, ventricles, and adjacent structures are presented. Material is taken from 2,645 CT scans done in a 1 year period at the Hospital of the University of Pennsylvania. It is hoped that the use of CT will lead to a decrease of morbidity and mortality in entities such as brain abscess and subdural empyema.

Adolescent↗

PubMed1976

Evaluation of sellar and parasellar masses by computed tomography.

Computed tomography is the method of choice for initial evaluation of patients with potential suprasellar masses. In our experience, CT has proved completely reliable for detecting or ruling out the presence of a suprasellar mass, the direction and degree of parasellar extension, and the presence of any calcific or cystic component of the lesion. When multiple cut CT has been negative, further diagnostic studies have proved unrewarding. When CT has been positive, additional studies have been required in some cases to rule out aneurysm prior to craniotomy.

Adenoma↗

PubMed1988

Minamata disease demonstrated by computed tomography.

Computed tomography was studied in the patients with Minamata disease, a methylmercury poisoning caused by the ingestion of contaminated sea foods. The characteristic changes in the acquired cases were atrophy of the visual calcarine cortex and of the cerebellar vermis and/or hemisphere. Marked atrophy of the calcarine cortex produced the sac-shaped low density areas between the occipital lobes and diffuse and marked cerebellar atrophy with enlargement of the fourth ventricle and cisterns of the posterior fossa produced a shrunken image on CT. Morphometric analysis confirmed these findings. In the fetal cases, the changes on CT were slight and no definite atrophy was demonstrated in either the calcarine cortex or the cerebellum. Morphometric analysis disclosed an increase of size of the middle portions of the lateral ventricle and the third and fourth ventricles.

Adult↗

PubMed1999

Delivery of diagnostic agents in computed tomography.

Computed tomography is a reliable, widely available imaging modality with high spatial resolution. Except for trauma detection, in practically all cases contrast agents are administered for improving image quality. The presently available agents are nonspecific compounds with distribution in the extracellular space. Specificity (i.e. high contrast in selected tissues) is only possible when the pharmacokinetic behavior (peak levels at the region of the interest) is followed on a time scale which counts in seconds. If the peak time is missed, a second injection of contrast material is necessary. The objective of extensive research efforts have therefore been the search for tissue-specific contrast agents which should result both in higher and in longer lasting local concentrations. For the tissue targets, liver, spleen, lymph nodes and the blood pool, efficient contrast enhancing compounds have been described utilizing different active transport systems or passive diffusion-limiting molecular sizes. The agents include water-soluble metal chelates, iodinated polymeric compounds and contrast agent-carrying liposomes. The remaining task for the future will be to improve the tolerability of the contrast agents to such an extent that the side-effect incidence and severity is low enough to allow for the use of these agents in patients.

Journal Article↗

PubMed1984

Prediction of delayed cerebral ischaemia after subarachnoid haemorrhage by computed tomography.

Computed tomography was performed in 100 patients within 4 days of aneurysmal subarachnoid haemorrhage. The CT appearances have been divided into five grades by the thickness and extent of the subarachnoid blood. Delayed cerebral ischaemia occurred in 62.5% of patients with most blood on CT, in 33.3% of those in the next grade and in none of the other grades with less amounts of blood. The outcome from delayed ischaemia was worse in those with most CT blood.

Adolescent↗

PubMed1984

Hepatocellular carcinoma treated by transcatheter arterial embolization: progress evaluated by computed tomography.

Computed tomography (CT) was performed after 65 transcatheter arterial embolizations (TAE) in 50 patients with hepatocellular carcinoma. Nonenhanced high-density areas were seen in the tumors within 3 days in 17/25 cases (though they soon disappeared) and low-density areas within 2 weeks in 62/65. Gas bubbles were seen in these areas within 2 weeks in 60% of embolizations. Within 3 to 6 months after the first TAE, enhanced lesions developed around or inside the low-density areas in 15/22 patients. Complications appearing within 2 weeks included non-enhanced low-density areas in the liver and spleen, gallbladder thickening, swelling of the head of the pancreas, contrast retention in the kidneys and gallbladder, ascites, and pleural effusion.

Adult↗

PubMed2001

Noninvasive coronary angiography by magnetic resonance imaging, electron-beam computed tomography, and multislice computed tomography.

In recent years, several techniques for noninvasive imaging of the coronary artery lumen (noninvasive coronary angiography) have been developed. These techniques include magnetic resonance imaging, electron-beam computed tomography, and, most recently, multislice computed tomography. Each of these techniques has specific advantages and disadvantages. Currently, EBCT seems to permit the most robust coronary artery imaging. In the future, imaging modalities will have to be further improved and validated in order to define specific areas for potential clinical applications.

Clinical Trials as Topic↗

PubMed2002

Detecting mediastinal lymph node metastases in non-small-cell lung cancer using a combination of technetium-99m tetrofosmin chest single photon emission computed tomography and chest computed tomography.

UNLABELLED: The staging of non-small-cell lung cancer (NSCLC) to detect mediastinal lymph node (MLN) metastases is very important for determining the therapeutic strategy. METHODS: Thirty-four patients with proven NSCLC were enrolled in this study. All patients underwent chest computed tomography (CT) and technetium-99m (Tc-99m) tetrofosmin chest single photon emission computed tomography (SPECT) preoperative staging. Mediastinal lymph node metastases were determined on the basis of postoperative pathologic findings to compare the diagnostic accuracy of chest CT with that of Tc-99m tetrofosmin chest SPECT. RESULTS: Tc-99m tetrofosmin chest SPECT showed a diagnostic accuracy rate of 85.3% in detecting MLN metastases. Chest CT had an accuracy rate of 73.5%. If either Tc-99m tetrofosmin chest SPECT or chest CT with positive findings was considered as positive findings, the sensitivity was 94.7%. If either Tc-99m tetrofosmin chest SPECT or chest CT with negative findings was considered as negative, the specificity was 93.3%. CONCLUSION: Tc-99m tetrofosmin chest SPECT was more accurate than chest CT in detecting MLN metastases in NSCLC patients. In addition, the combined use of Tc-99m tetrofosmin chest SPECT and chest CT could significantly increase the sensitivity and specificity compared with the single use of either Tc-99m tetrofosmin chest SPECT or chest CT.

Adult↗

PubMed1994

Comparison of spiral-acquisition computed tomography and conventional computed tomography in the assessment of pulmonary metastatic disease.

In a prospective study, spiral-acquisition computed tomography (SACT) of the thorax was evaluated in 104 patients with extrathoracic malignancy and suspected pulmonary metastases, and was directly compared with conventional computed tomography (CCT) in 23 patients. The following parameters were assessed: lesion detectability; the effect on lesion detectability of reconstruction of scans at 5 mm and 10 mm slice increments; breathing artefact and slice misregistration. The radiation dose of the two techniques was measured using thermoluminescent dosimeters placed within an anthropomorphic chest phantom, and the visibility of simulated metastases inserted into the phantom was also compared using CCT, standard SACT and SACT with pitch greater than 1.0. Where metastases were present, SACT scans showed significantly better lesion detectability than CCT scans (p < 0.001). Image reconstruction of SACT data at 5 mm increments conferred no significant advantage in lesion detectability over 10 mm increment reconstructions. Compared with CCT, SACT scans showed reduced breathing artefact, and a complete absence of slice misregistration (p < 0.01). Phantom measurements of radiation dose and resolution were similar for both techniques. Increasing the pitch of the spiral in SACT caused only a small decrease in phantom resolution, but with the advantage of a reduction in the radiation dose. Spiral-acquisition CT is superior to conventional CT for the assessment of pulmonary metastatic disease.

Adolescent↗

PubMed2003

Staging of non-small-cell lung cancer with integrated positron-emission tomography and computed tomography.

BACKGROUND: We compared the diagnostic accuracy of integrated positron-emission tomography (PET) and computed tomography (CT) with that of CT alone, that of PET alone, and that of conventional visual correlation of PET and CT in determining the stage of disease in non-small-cell lung cancer. METHODS: In a prospective study, integrated PET-CT was performed in 50 patients with proven or suspected non-small-cell lung cancer. CT and PET alone, visually correlated PET and CT, and integrated PET-CT were evaluated separately, and a tumor-node-metastasis (TNM) stage was assigned on the basis of image analysis. Nodal stations were identified according to the mapping system of the American Thoracic Society. The standard of reference was histopathological assessment of tumor stage and node stage. Extrathoracic metastases were confirmed histopathologically or by at least one other imaging method. A paired sign test was used to compare integrated PET-CT with the other imaging methods. RESULTS: Integrated PET-CT provided additional information in 20 of 49 patients (41 percent), beyond that provided by conventional visual correlation of PET and CT. Integrated PET-CT had better diagnostic accuracy than the other imaging methods. Tumor staging was significantly more accurate with integrated PET-CT than with CT alone (P=0.001), PET alone (P<0.001), or visual correlation of PET and CT (P=0.013); node staging was also significantly more accurate with integrated PET-CT than with PET alone (P=0.013). In metastasis staging, integrated PET-CT increased the diagnostic certainty in two of eight patients. CONCLUSIONS: Integrated PET-CT improves the diagnostic accuracy of the staging of non-small-cell lung cancer.

Aged↗

PubMedDate not supplied

Positron emission tomography and computed tomography in differential diagnosis between recurrent or residual glioma and treatment-induced brain lesions.

In previous studies of supratentorial gliomas with positron emission tomography (PET) and computed tomography (CT), high uptakes of L-methyl-11C-methionine (11C-L-methionine) were found even in astrocytomas without blood-brain barrier defects as judged by CT or 68Ga-EDTA PET. In a number of patients examined after radiation therapy, there were no consistent changes in the high uptake values. In the present investigation PET and CT were compared with regard to their abilities to visualize and delineate recurrent tumors and treatment-induced brain defects and to differentiate between them. The study was undertaken on four patients who were long-term survivors after treatment for high-grade gliomas. For PET, 11C-L-methionine and 68Ga-EDTA were used. In two patients recurrent/residual tumors appeared considerably larger with 11C-L-methionine PET than with CT or 68Ga-EDTA PET. In one patient, no signs of recurrence were seen with any of these three methods, and in a fourth patient, whose condition was clinically stable, the findings at PET with 11C-L-methionine were non-specific. In areas corresponding to the surgical parenchymal defects, the 11C-L-methionine uptake and, except in one case, the local blood volume was markedly reduced. PET with 11C-L-methionine thus has a potential for distinguishing between postoperative brain lesions and tumor recurrence with a higher accuracy than CT.

Adult↗

PubMed2004

Radiation exposure during midfacial imaging using 4- and 16-slice computed tomography, cone beam computed tomography systems and conventional radiography.

OBJECTIVES: Radiation doses were determined to balance risks against usefulness of the different modalities available for the imaging of the facial skeleton. METHODS: An Alderson Rando Phantom, armed with lithium fluoride thermoluminescent dosemeters (TLDs) was exposed using a set of four conventional radiographs (orbital view, modified Waters view, orthopantomography, skull posterior--anterior 0 degrees ), two different cone beam computed tomography (CBCT) (NewTom 9000 and Siremobil Iso-C3D), and multislice computed tomography (CT) modalities (Somatom VolumeZoom and Somatom Sensation 16). TLDs from 14 well defined anatomical sites lying within the primary beam as well as the TLD corresponding to the thyroid gland were evaluated. RESULTS: Multislice CT showed the highest exposure values. Exposure levels of the CBCT systems lay between CT and conventional radiography. Dose measurement for the 16-slice CT revealed nearly the same radiation exposure as the 4-slice system when adapted examination protocols were used. CONCLUSIONS: Selection of the most appropriate imaging modality should be performed in view of the delivered doses, required image quality and information and the clinical circumstances.

Facial Bones↗

PubMed1984

[Value of intravesical ultrasound tomography and computer tomography in the evaluation of the depth of infiltration of bladder tumors].

In 83% of cases the tumour could be correctly staged by intravesical sonography. Computed tomography gave a correct staging in 80%. By a combination of both methods the depths of tumour infiltration could be established exactly in 90%. Both methods are supplementary since the lower stages are better assessable by intravesical ultrasonic tomography whereas in the advanced stages computer tomography combined with pneumocystography permits a more exact evaluation of the depth of tumour infiltration.

Humans↗

PubMed1988

Single photon emission computed tomography and transmission computed tomography in the evaluation of liver disease.

To assess the relative strengths of hepatic SPECT and transmission computed tomography (TCT), a comparison of these methods was made in 88 patients during a 20-month period. The scans were classified into four categories: normal, solitary focal, multifocal, or diffuse hepatocellular patterns. The final disease category was determined by histologic evaluation-biopsy/autopsy, surgery, or a combination of ultrasound, laboratory, and clinical follow-up for a minimum of 6 months. Both SPECT and TCT were normal in the 47 patients classified as normal. Of the 16 patients with diffuse hepatocellular disease, SPECT correctly identified 16 and TCT identified two patients. Eleven patients had solitary focal disease; 11 were detected by SPECT and 10 by TCT. Fourteen patients were in the multifocal disease group; 13 were detected by SPECT and 10 by TCT. Overall, SPECT and TCT findings were in agreement in 68 (77%) of the cases. This study demonstrates that SPECT is equal to TCT in the assessment of the liver parenchyma in normal and focal disease states and that SPECT is superior in the assessment of diffuse disease.

Adult↗

PubMed2006

Staging accuracy in mycosis fungoides and sezary syndrome using integrated positron emission tomography and computed tomography.

OBJECTIVES: To evaluate the usefulness of integrated positron emission tomography and computed tomography (PET/CT) in staging mycosis fungoides (MF) and Sézary syndrome and to correlate PET/CT data with histopathologic diagnosis of lymph nodes (LNs). DESIGN: A single-center, prospective cohort analysis. SETTING: Academic referral center for cutaneous lymphoma. PATIENTS: Thirteen patients with MF and SS at risk for secondary LN involvement. Interventions Patients were clinically evaluated based on general physical examination, total body skin examination, and laboratory screening. They underwent integrated PET/CT followed by excisional biopsy of LNs. MAIN OUTCOME MEASURES: We used PET/CT to assess LN size and metabolic activity. Enlarged LNs were defined as axillary or inguinal LNs with a short axis 1.5 cm or larger; or cervical LN, with a short axis 1.0 cm or larger. We classified LN pathologic results according to National Cancer Institute (LN1-4) and World Health Organization (WHO 1-3) criteria. We quantified PET activity using standardized uptake value (SUV) and correlated with LN grade. RESULTS: Based on CT size criteria alone, only 5 patients had enlarged LNs, whereas PET revealed hypermetabolic LNs in all 13 patients. Six patients had LN1-3, and 7 had effacement of LN architecture by lymphoma cells (LN4). Of the 7 patients with LN4 nodes, 4 had SS, and 3 had tumorous MF. Two patients with LN4 nodes had inguinal LNs smaller than 1.5 cm and would have been assigned an N0 classification without the use of integrated PET/CT. Correlation of SUV with LN grade revealed that LN1-3 nodes were associated with a mean SUV of 2.7 (median SUV, 2.2; range, 2.0-4.7) and LN4 nodes were associated with a mean SUV of 5.4 (median SUV, 3.9; range, 2.1-11.8). Patients with large cell transformation had the highest SUVs. CONCLUSIONS: For staging MF and SS, PET/CT was more sensitive in detecting LN involved by lymphoma compared with CT data alone and thus may provide more accurate staging and prognostic information. The intensity of PET activity correlated with histologic LN grade.

Adult↗

PubMed2006

The role of positron emission tomography and computed tomography fusion in the management of early-stage and advanced-stage primary head and neck squamous cell carcinoma.

OBJECTIVE: To evaluate the role of positron emission tomography and computed tomography (PET-CT) fusion in the management of early-stage and advanced-stage primary head and neck squamous cell cancer. DESIGN: Retrospective analysis, with a blinded evaluation of clinical data and formation of a treatment plan. SETTING: Single tertiary academic medical institution. Patients Thirty-six patients with previously untreated head and neck squamous cell carcinoma who underwent staging CT or magnetic resonance imaging of the neck prior to undergoing PET-CT as part of their initial diagnostic evaluation between July 2000 and January 2005. MAIN OUTCOME MEASURES: Confirmation or alteration of the treatment plan with the addition of the PET-CT information compared with traditional clinical and radiological data alone for early-stage and advanced-stage disease. When available, histopathological results were correlated with the PET-CT findings. RESULTS: Among the 36 patients, PET-CT provided additional information that confirmed the treatment plan in 25 patients (69%) and altered the treatment plan in 11 patients (31%). Six of 11 patients in the altered-treatment group had their tumors upstaged. Four of 8 patients with early-stage tumors had their treatment plan altered, compared with 7 of 28 patients with advanced-stage disease. Among 18 patients who underwent a surgical intervention for their primary tumor, PET-CT identified the primary tumor in all 18 patients and, based on histopathological findings, correctly staged the regional nodal disease in 9 of 16 patients who had their nodal disease addressed. CONCLUSION: The use of PET-CT is important in the initial treatment planning of early-stage and advanced-stage head and neck squamous cell carcinoma.

Adolescent↗

PubMed2005

Combined positron emission tomography and computed tomography for the detection of recurrent ovarian mucinous adenocarcinoma.

BACKGROUND: The role of combined positron emission tomography and computed tomography (PET-CT) in the diagnosis of recurrent ovarian mucinous adenocarcinoma is uncertain because of previous reports that PET has limited sensitivity in the detection of mucinous neoplasms. CASE: A 71-year-old white woman presented with complaints of right lower quadrant pain and a palpable adnexal mass. Physical examination and transvaginal ultrasonography revealed a 12 x 13 cm cystic mass in the left side of the pelvis. Exploratory laparotomy, optimal tumor-reductive surgery, total abdominal hysterectomy, bilateral salpingo-oophorectomy, appendectomy, and omentectomy were performed. The diagnosis was FIGO stage IIIC well-differentiated ovarian mucinous adenocarcinoma. The patient was treated with 6 cycles of carboplatin and paclitaxel. Four months after completing chemotherapy, the patient was noted to have an elevated serum CA125 level (72 U/mL), being otherwise asymptomatic. Findings on abdominal and pelvic CT were compatible with postsurgical changes. PET-CT was performed and revealed increased metabolism along the posterior aspect of the right rectus abdominis muscle and abutting the anterior wall of an adjacent loop of bowel. CONCLUSION: PET-CT may identify clinically occult recurrent ovarian mucinous adenocarcinoma.

Adenocarcinoma, Mucinous↗