Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TOMOGRAPHY”

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 289 records · Page 16Linked to original sources
PubMedDate not supplied

Thallium-201 single photon emission tomography after injecting an antimuscarinic agent compared with computed tomography for the diagnosis of recurrent colorectal cancer. Report of three cases.

Thallium-201 chloride ((201)TlCl) is frequently used for imaging of a variety of malignant tumors viz., thyroid, lung, brain, bone and breast, however in patients with colorectal cancer, its role is not well established. In this case report we present three patients with colorectal cancer recurrence, with inconclusive computed tomography (CT) findings while (201)TlCl single photon emission tomography (SPET) after injecting an anti-muscarinic agent, showed findings corroborating with the final diagnosis. Correlating CT with (201)TlCl-SPET findings, recurrence of the colorectal cancer was diagnosed in two cases; surgical treatment accordingly planned, confirmed the diagnosis. In the third case, CT was falsely positive while (201)TlCl-SPET was negative, compatible with the final diagnosis.

Adult↗
PubMed2007

The imaging of pancreatic exocrine solid tumors: the role of computed tomography and positron emission tomography.

The only potentially radical treatment for pancreatic cancer is the removal of the tumor which can be performed by total or subtotal surgical resection of the pancreas; this is possible in the early stages of the disease when the tumor is confined to the pancreatic gland without metastasis to the liver, lymph nodes and/or the peritoneum, or involvement of the vascular system such as the celiac trunk and its branches and the superior mesenteric artery. In this paper, we describe the accuracy of computed tomography and positron emission tomography in the diagnosis of exocrine pancreatic cancer.

Humans↗
PubMedDate not supplied

Cerebellar infarction: computed tomography, magnetic resonance and IMP-single photon emission tomography findings.

In this report, a rare case of a child with cerebellar infarction (CI) confirmed by vertebral angiography, magnetic resonance imaging (MRI), computed tomography (CT) and N-isopropyl-p123-I-iodoamphetamine single photon emission tomography (IMP-SPECT) is presented. It was concluded that although all imaging modalities could demonstrate CI, MRI is superior to the other methods because of its fine display of anatomical detail, its lack of bony artifacts and its ability to show infarction in early stages.

Cerebellum↗
PubMed1990

[Single photon emission computed tomography of the brain in Sturge-Weber syndrome using N-isopropyl-p-[123I] iodoamphetamine--a comparative study with X-ray computed tomography].

Single photon emission computed tomography (SPECT) of the brain using N-isopropyl-p-[123I] iodoamphetamine (123I-IMP) was performed in 11 children with port wine stain on the face or head, aged 1.0-14.2 years at investigation. Four cases without neurologic symptoms had no specific abnormality on SPECT and X-ray computed tomography (CT). In 4 cases of so-called Sturge-Weber syndrome with developmental quotients (DQ) or intelligence quotients (IQ) more than 80 and the neurologic symptoms consisting of seizures and hemiplegia, SPECT showed localized reduction of IMP accumulation, and CT exhibited calcification, atrophy and enhancement in 2 cases of 3 with contrast medium infusion in the same areas. In 3 cases with DQ of 50-60 and severer neurologic symptoms, SPECT showed diffuse reduction or defect of IMP accumulation in the ipsilateral hemisphere, and CT exhibited remarkable atrophy, calcifications and enhancement in 2 cases with contrast medium infusion in the same hemisphere. In one case with severe neurologic symptoms, SPECT performed at an early stage showed high IMP accumulation in the ipsilateral hemisphere.

Adolescent↗
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↗
PubMedDate not supplied

Effect of cervical spinal cord stimulation (cSCS) on cerebral glucose metabolism and blood flow in a vegetative patient assessed by positron emission tomography (PET) and single photon emission computed tomography (SPECT).

This paper presents, for the first time, assessments of cerebral glucose metabolism and cerebral blood flow before and after cervical spinal cord stimulation (cSCS) in a vegetative patient. Regional cerebral metabolic rates for glucose (rCMRglc) were measured with positron emission tomography and 18F-fluoro-2-deoxy-D-glucose. Regional cerebral blood flow (rCBF) was determined with single photon emission computed tomography and N-isopropyl p-123I-iodoamphetamine. Global CMRglc in the patient was less than one-third of that in normal control subjects. An increase in rCMRglc after one week of cSCS was observed in the cerebral cortex, predominantly on the right side, where the baseline level of rCMRglc before cSCS was more severely depressed. The pattern of increase in rCBF was almost the same as that in rCMRglc. The results suggest that cSCS activates glucose metabolism and that this is followed by an increase in cerebral blood flow.

Amphetamines↗
PubMedDate not supplied

Positron emission tomography compared with magnetic resonance imaging and computed tomography in supratentorial gliomas using multiple stereotactic biopsies as reference.

Ten patients with findings at computed tomography (CT) suggesting intracranial supratentorial glioma were investigated to compare the diagnostic efficacy of this technique with that of positron emission tomography (PET) using 11C-methionine and examinations with magnetic resonance (MR). The findings were related to histopathologic examination of serial stereotactic biopsies, which were guided by the appearance of the lesions on PET examination. To obtain corresponding slice orientation with the different examination techniques, an individually shaped helmet fixation was used. However, in 3 cases this fixation device could not be used for MR. Histopathologic diagnosis, obtained in all cases from multiple target stereotactic biopsies, included glioma in 9 patients and reactive gliosis in one case. A detailed comparison of the three imaging techniques and the findings at stereotactic biopsies was possible in 7 patients, while in 3 patients comparison with MR was less exact due to the patient's refusal to wear the helmet during this examination. MR was the most accurate method for outlining the total extent of a lesion, i.e. the tumor and the edema surrounding it. Four lesions had homogeneous signal characteristics and in 6 lesions two (or more) compartments could be distinguished with MR. In 5 cases the MR findings were in complete agreement with the histopathologic findings. However, a thorough correlation between signal characteristics and histology was not possible. Using PET the occurrence and the extent of tumor tissue was correctly predicted in 7 patients. The PET was normal in one case. Findings at CT were in agreement with the histopathologic diagnosis in 5 patients. MR was the most sensitive method for the detection of lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Positron emission tomography with 11C-methionine and computed tomography of intracranial tumours compared with histopathologic examination of multiple biopsies.

A selected group of 36 patients with suspected supratentorial gliomas were investigated with positron emission tomography (PET) using 11C-methionine and transmission computed tomography (CT) before and after intravenous injection of contrast medium. Every examination was performed with the head fixed in a plastic helmet and a baseplate to guarantee that the slice orientation was the same at examinations with the two modalities and over time. Guided by the examinations, multiple stereotactic biopsies were performed with the biopsy instrument mounted on the baseplate. Regional accumulation of methionine was compared with histology of the corresponding samples and with attenuation before and after injection of contrast medium as well as mass effect on CT. Typically, there was a low attenuating lesion with a slight mass effect on CT. There was an increased accumulation compared with normal brain tissue in 31 cases of tumours and ordinary or decreased accumulation in 3 cases of tumours. In 22 cases with increased accumulation of methionine the extension of the tumour judged by PET corresponded with that of histology. In 4 cases tumour cells were found outside the area with pathologic methionine uptake. In 5 patients there were areas with increased methionine accumulation where no tumour cells were found. In 22 cases PET using methionine was more accurate than CT in defining the tumour boundaries as determined from the histologic findings. Four groups of biopsy specimens with different amounts of methionine accumulation are described. The uptake in a single biopsy gives good but not exact information about the histology of the specimen.

Brain Neoplasms↗
PubMed1986

Tumour delineation with magnetic resonance imaging in gliomas. A comparison with positron emission tomography and computed tomography.

In ten patients with histopathologically confirmed low-grade (n = 4) and high-grade (n = 6) cerebral gliomas, the ability of magnetic resonance imaging (MRI) to delineate these tumours was examined. Spin echo (SE) technique with dual and multiple echoes and subtraction of images recorded with multiple echo sequences was applied. Computed tomography (CT) and positron emission tomography (PET) with 11C-L-methionine were used as reference methods. In high-grade gliomas multiple echo sequences and subtractions delineated the tumours better than ordinary SE sequences and equally well as CT, but slightly less well than PET. In low-grade tumours, the tumour delineation was better than with CT and comparable to that obtained with the present PET method. Multiple echo sequences and subtraction increase the reliability of MRI in delineating cerebral gliomas as compared with standard SE sequences.

Adolescent↗
PubMed1986

Regional cerebral blood flow determined with single photon emission computed tomography and positron emission tomography. A comparative study.

The regional uptake of 99Tcm-labelled HMPAO has been measured with single photon emission computed tomography (SPECT). The potential value of 99Tcm-HMPAO as a flow tracer was evaluated. The uptake of 99Tcm-HMPAO as a function of time indicated that the tracer was trapped in the brain. The uptake images were compared with results from quantitative regional cerebral blood flow (rCBF) measurements using positron emission tomography (PET) and with 11C-fluoromethane used as a tracer. There was a strong correlation between the uptake of 99Tcm-HMPAO and rCBF. The conclusion was that the uptake of 99Tcm-HMPAO was dependent on rCBF.

Cerebrovascular Circulation↗
PubMed1984

Evaluation of postoperative osteomyelitis of the sternum using tomography and computerized tomography.

Thirty-five patients were evaluated for possible postoperative sternal osteomyelitis by tomography. Frank bone destruction and severe demineralization were the only radiologic signs that helped to distinguish patients with sternal osteomyelitis from those with infections limited to soft tissues. We report a patient in whom sternal osteomyelitis was shown by computerized tomography (CT). This observation suggests that CT may provide added information, especially if the sternum is severely demineralized.

Female↗
PubMed1995

High-resolution computed tomography, magnetic resonance imaging, and positron emission tomography in interstitial lung disease.

In patients who have interstitial lung disease, chest radiography remains the primary imaging technique for both initial diagnosis and follow-up. For further investigation of selected patients the imaging modality of choice is currently high-resolution computed tomography. Magnetic resonance imaging and positron emission tomography have great potential in this field, particularly with respect to disease activity, but are still largely experimental and are not routinely employed.

Humans↗
PubMed1983

EEG, transmission computed tomography, and positron emission tomography with fluorodeoxyglucose 18F. Their use in adults with gliomas.

We evaluated the relationship between findings from EEG, transmission computed tomography (CT), and positron emission tomography in 23 adults with gliomas. The cortical metabolic rate was suppressed in patients with and without focal slowing. Focal delta activity was not related to involvement of gray or white matter. Rhythmic delta activity and focal attenuation of background amplitude on EEG, however, were correlated with involvement of the thalamus.

Adult↗
PubMed2002

Prospective comparison of [18F]fluorodeoxyglucose positron emission tomography with conventional assessment by computed tomography scans and serum tumor markers for the evaluation of residual masses in patients with nonseminomatous germ cell carcinoma.

BACKGROUND: To assess the ability of [(18)F]fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET) to predict the viability of residual masses after chemotherapy in patients with metastatic nonseminomatous germ cell tumors (GCT), PET results were compared in a blinded analysis with computed tomography (CT) scans and serum tumor marker changes (TUM) as established methods of assessment. METHODS: Independent reviewers who were blinded to each other's results evaluated the PET results and corresponding CT scan and TUM results in 85 residual lesions from 45 patients. All patients were treated within prospective clinical trials and received primary/salvage, high-dose chemotherapy with autologous blood stem cell support for primary poor prognosis disease or recurrent disease. PET results were assessed both visually and by quantifying glucose uptake (standardized uptake values). Results were validated either by histologic examination of a resected mass and/or biopsy (n = 28 lesions) or by a 6-month clinical follow-up after evaluation (n = 57 lesions). RESULTS: F-18 FDG PET showed increased tracer uptake in 32 of 85 residual lesions, with 29 true positive (TP) lesions and three false positive (FP) lesions. Fifty-three lesions were classified by PET as negative (no viable GCT), 33 lesions were classified by PET as true negative (TN), and 20 lesions were classified by PET as false negative (FN). In the blinded reading of the corresponding CT scan and TUM results, 38 residual lesions were assessed correctly as containing viable carcinoma and/or teratoma. Forty-six lesions were classified as non-suspicious by CT scan/TUM (33 TN lesions and 14 falsely classified lesions). PET correctly predicted the presence of viable carcinoma in 5 of these 14 and the absence of viable carcinoma in 3 of these 14 lesions. Resulting sensitivities and specificities for the prediction of residual mass viability were as follows: PET, 59% sensitivity and 92% specificity; radiologic monitoring, 55% sensitivity and 86% specificity; and TUM, 42% sensitivity and 100% specificity. The positive and negative predictive values for PET were 91% and 62%, respectively. The diagnostic efficacy of PET did not improve when patients with teratomatous elements in the primary tumor were excluded from the analysis. In patients with multiple residual masses, a uniformly increased residual F-18 FDG uptake in all lesions was a strong predictor for the presence of viable carcinoma. CONCLUSIONS: F-18 FDG PET imaging performed in conjunction with conventional staging methods offers additional information for the prediction of residual mass histology in patients with nonseminomatous GCT. A positive PET is highly predictive for the presence of viable carcinoma. Other useful indications for a PET examination include patients with multiple residual masses and patients with marker negative disease.

Adult↗
PubMed2006

Determination of characteristics of degenerative joint disease using optical coherence tomography and polarization sensitive optical coherence tomography.

BACKGROUND AND OBJECTIVES: Previous studies have demonstrated that optical coherence tomography (OCT) could be used to delineate alterations in the microstructure of cartilage, and have suggested that changes in the polarization state of light as detected by OCT could provide information on the birefringence properties of articular cartilage as influenced by disease. In this study we have used both OCT and polarization sensitive optical coherence tomography (PS-OCT) technologies to evaluate normal and abnormal bovine articular cartilage according to established structural, organizational, and birefringent characteristics of degenerative joint disease (DJD) in order to determine if this technology can be used to differentiate various stages of DJD as a minimally invasive imaging tool. MATERIALS AND METHODS: Fresh bovine femoral-tibial joints were obtained from an abattoir, and 45 cartilage specimens were harvested from 8 tibial plateaus. Whole ex vivo specimens of normal and degenerative articular cartilage were imaged by both OCT and PS-OCT, then fixed and processed for histological evaluation. OCT/PS-OCT images and corresponding histology sections of each specimen were scored according to a modified Mankin structural grading scale and compared. RESULTS: OCT and PS-OCT imaging allowed structural evaluation of intact articular cartilage along a 6 mm surface length to a depth of 2 mm with a transverse resolution of 12 microm and an axial resolution of 10 microm. The OCT and PS-OCT images demonstrated characteristic alterations in the structure of articular cartilage with a high correlation to histological evaluation (kappa = 0.776). The OCT images were able to demonstrate early to advanced structural changes of articular cartilage while the optical phase retardation images obtained by PS-OCT imaging were able to discriminate areas where disorganization of the cartilage matrix was present, however, these characteristics are much different than those reported where OCT images alone were used to characterize tissue birefringence. No evidence of differences in OCT or PS-OCT images were detected between specimens of similar structural characteristics where proteoglycan was judged present or absent by safranin-O Fast Green staining. CONCLUSIONS: The combined use of OCT and PS-OCT technologies to obtain images from a single system is able to demonstrate and discriminate between characteristics of very early stages of surface irregularities not previously reported for OCT imaging, to deep clefts and collagen matrix disorganization for tissue at depths of up to 2 mm with good correlation to histology. PS-OCT and accumulated optical phase retardation images of articular cartilage as constructed from alterations in Stokes vector parameters appear to give a valuable but different assessment of alterations in tissue birefringence and organization than have been reported for OCT images obtained with the use of polarized or non-polarized light sources. This is the first time that alterations in the polarization state of light reflected from within the tissue have been demonstrated to be consistent with changes observed in the orientation and organization of the collagen matrix in advanced stages of DJD. The degree of phase transformation of light reflected from within the tissue as determined by PS-OCT imaging does not appear to be altered by the presence or absence of proteoglycan.

Animals↗
PubMed1996

[Computerized tomography and magnetic resonance tomography studies before and after para-tibial fasciotomy].

Paratibial fasciotomy has been employed since 1981 to treat patients with chronic venous insufficiency (CVI) and therapy-resistant leg ulcers with severe lipodermatosclerosis. The characteristic morphological changes in CVI were evaluated shown before and after paratibial fasciotomy using computerized tomography (CT) and magnet resonance tomography (MRT). 10 patients (6 female, 4 male) were examined by CT and MRT pre- and postoperatively. Preoperatively there is a clear thickening of the dermis and subcutaneous field. In addition, the area around the achilles tendon is thickened, the fasciae are enlarged and the muscles of the lower leg show an increase of fatty tissue. A decrease of the cutaneous and subcutaneous thickening is seen postoperatively. The fasciotomy split is visible in most patients.

Adipose Tissue↗