Perfusion scanning

About: Perfusion scanning is a research topic. Over the lifetime, 9496 publications have been published within this topic receiving 223860 citations. The topic is also known as: perfusion imaging.

Can pretreatment CT perfusion predict response of advanced squamous cell carcinoma of the upper aerodigestive tract treated with induction chemotherapy

Abstract: BACKGROUND AND PURPOSE: Treatment of advanced stage squamous cell carcinoma of the upper aerodigestive tract with nonsurgical organ preservation protocols demonstrates improved cure rates with fewer comorbidities compared with surgery and radiation. The purpose of this study was to prospectively assess whether pretreatment evaluation of the primary site with quantitative CT perfusion measurements predicted response to induction chemotherapy and to create a prediction model to predict the response to induction chemotherapy in future patients. METHODS: Seventeen patients who were enrolled in a prospective trial assessing surgical intervention versus a nonsurgical protocol underwent a pretreatment CT perfusion followed by direct laryngoscopy. After induction chemotherapy, tumor response was determined by the surgeon’s estimate of tumor volume. The CT perfusion parameters were correlated with the clinical response using a Wilcoxon rank-sum analysis. A logistic regression model was used to create a prediction based on the most significant CT perfusion parameter. RESULTS: Elevated values of blood volume (P = .004) and blood flow (P = .03) were significantly correlated with >50% reduction in tumor volume after chemotherapy. A prediction model based on tumor blood volume demonstrated 91.7% sensitivity and 80.0% specificity, with an area under the receiver operating characteristic curve of 0.95. CONCLUSION: Our preliminary data imply that tumors with elevated blood volume and blood flow were statistically associated with response to induction chemotherapy. These results suggest that pretreatment CT perfusion may be able to identify patients who will successfully respond to induction chemotherapy, which could potentially eliminate this step for subsequent patients when deciding on the appropriate treatment regimen.

A quantitative approach to technetium-99m hexamethylpropylene amine oxime

Abstract: A non-invasive, simple method for the quantitative evaluation of brain perfusion is presented using intravenous radionuclide angiography with technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO). Graphical analysis was employed for the evaluation of the unidirectional influx constant (ku of the tracer from the blood to the brain. The ku values were standardized to provide objective and comparable values, brain perfusion indices (BPI), among studied subjects by setting the ratio of ROIbrain size to ROIaorta size at 10. The wholebrain BPI values for the normal control subjects showed a significant negative correlation with advancing age (r = -0.632, P =0.0204, n =13). The mean of the wholebrain BPI of 7.0 (SD =1.4) in 20 patients with cerebrovascular disorders was significantly lower than that of 10.6 (SD =1.5) in 13 normal control subjects. The BPI measurements showed only minimal intra- and interobserver variability. Changes of the ratio of ROIaorta size and ROIbmin size did not significantly influence the BPI values. Hemispherical BPI values in 19 subjects (n =38) showed highly significant correlations with the hemispherical mean cerebral blood flow values obtained from Xenon-133 single photon emission tomography (SPET) (r =0.926, P =0.0001 for the early picture method and r =0.932, P =0.0001 for the sequential picture method). This technique is easy to apply as an adjunct to SPET and may be helpful in the quantitative evaluation of brain perfusion in routine clinical studies.

Repeatability and reproducibility of phase analysis of gated single-photon emission computed tomography myocardial perfusion imaging used to quantify cardiac dyssynchrony.

Abstract: Background A novel method to quantify dyssynchrony has been developed using phase analysis of gated single-photon emission computed tomography perfusion imaging. We report on the effect of variability in image reconstruction on the phase analysis results (repeatability) and on the interobserver and intraobserver reproducibility of the technique.

Is a lung perfusion scan obtained by using single photon emission computed tomography able to improve the radionuclide diagnosis of pulmonary embolism

Abstract: Planar pulmonary scintigraphy is still regularly performed for the evaluation of pulmonary embolism (PE). However, only about 50-80% of cases can be resolved by this approach. This study evaluates the ability of tomographic acquisition (single photon emission computed tomography, SPECT) of the perfusion scan to improve the radionuclide diagnosis of PE. One hundred and fourteen consecutive patients with a suspicion of PE underwent planar and SPECT lung perfusion scans as well as planar ventilation scans. The final diagnosis was obtained by using an algorithm, including D-dimer measurement, leg ultrasonography, a V/Q scan and chest spiral computed tomography, as well as the patient outcome. A planar perfusion scan was considered positive for PE in the presence of one or more wedge shaped defect, while SPECT was considered positive with one or more wedge shaped defect with sharp borders, three-plane visualization, whatever the photopenia. A definite diagnosis was achieved in 70 patients. After exclusion of four 'non-diagnostic' SPECT images, the prevalence of PE was 23% (n =15). Intraobserver and interobserver reproducibilities were 91%/94% and 79%/88% for planar/SPECT images, respectively. The sensitivities for PE diagnosis were similar for planar and SPECT perfusion scans (80%), whereas SPECT had a higher specificity (96% vs 78%; P =0.01). SPECT correctly classified 8/9 intermediate and 31/32 low probability V/Q scans as negative. It is concluded that lung perfusion SPECT is readily performed and reproducible. A negative study eliminates the need for a combined V/Q study and most of the 'non-diagnostic' V/Q probabilities can be solved with a perfusion image obtained by using tomography.