scispace - formally typeset
Search or ask a question

Showing papers on "Perfusion scanning published in 2007"


Journal ArticleDOI
TL;DR: In studies with high disease prevalence, stress cardiac MRI, using either technique, demonstrates overall good sensitivity and specificity for the diagnosis of CAD.

546 citations


Journal ArticleDOI
TL;DR: In patients with known or suspected coronary artery disease, my cardiac ischemia detected by MRP and DSMR can be used to identify patients at high risk for subsequent cardiac death or nonfatal myocardial infarction.
Abstract: Background— Adenosine stress magnetic resonance perfusion (MRP) and dobutamine stress magnetic resonance (DSMR) wall motion analyses are highly accurate for the detection of myocardial ischemia. However, knowledge about the prognostic value of stress MR examinations is limited. We sought to determine the value of MRP and DSMR, as assessed during a single-session examination, in predicting the outcome of patients with known or suspected coronary artery disease. Methods and Results— In 513 patients (with known or suspected coronary disease, prior coronary artery bypass graft, or percutaneous coronary intervention), a combined single-session magnetic resonance stress examination (MRP and DSMR) was performed at 1.5 T. For first-pass perfusion imaging, the standard adenosine stress imaging protocol (140 μg · kg−1 · min−1 for 6 minutes, 3-slice turbo field echo–echo-planar imaging or steady-state free precession sequence, 0.05 mmol/kg Gd-DTPA) was applied, and for DSMR, the standard high-dose dobutamine/atropin...

506 citations


Journal ArticleDOI
TL;DR: Assessment of perfusion data alone by visual or quantitative SPECT MPI analysis underestimates the magnitude of left main coronary artery disease, and the combination of perfusions and nonperfusion abnormalities on gated MPI identifies high risk in most patients with left main CAD.

318 citations


Journal ArticleDOI
TL;DR: This phase 3 trial shows that regadenoson provides diagnostic information comparable to a standard adenosine infusion, and there were no serious drug-related side effects, and regadenoon was better tolerated than adenoine.

314 citations


Journal ArticleDOI
TL;DR: Results suggest that CT perfusion is a feasible and, from the limited data, reproducible technique for quantifying tumor vascularity and angiogenesis in advanced HCC.
Abstract: Purpose: To prospectively assess computed tomographic (CT) perfusion for evaluation of tumor vascularity of advanced hepatocellular carcinoma (HCC) and to correlate CT perfusion parameters with tumor grade and serum markers. Materials and Methods: The study was HIPAA compliant and was approved by the institutional review board. Patients provided informed consent. Thirty patients (22 men, eight women; mean age, 60 years; range, 28–79 years) with unresectable or metastatic HCC were studied. Dynamic first-pass CT perfusion was performed in primary (n = 25) and metastatic (n = 5) HCCs after intravenous injection of contrast medium. Data were analyzed to calculate tissue blood flow, blood volume, mean transit time, and permeability–surface area product. Repeat examination was performed in four patients within 30 hours to test reproducibility of CT perfusion. CT perfusion parameters were compared among tumors of different grades, with presence or absence of portal vein invasion, with presence or absence of cirr...

301 citations


Journal ArticleDOI
TL;DR: There is growing and consistent evidence that gated myocardial perfusion PET also provides clinically useful risk stratification and this integrated platform for assessing anatomy and biology offers a great potential for translating advances in molecularly targeted imaging into humans.
Abstract: The field of nuclear cardiology is witnessing growing interest in the use of cardiac PET for the evaluation of patients with coronary artery disease (CAD). The available evidence suggests that myocardial perfusion PET provides an accurate means for diagnosing obstructive CAD, which appears superior to SPECT especially in the obese and in those undergoing pharmacologic stress. The ability to record changes in left ventricular function from rest to peak stress and to quantify myocardial perfusion (in mL/min/g of tissue) provides an added advantage over SPECT for evaluating multivessel CAD. There is growing and consistent evidence that gated myocardial perfusion PET also provides clinically useful risk stratification. Although the introduction of hybrid PET/CT technology offers the exciting possibility of assessing the extent of anatomic CAD (CT coronary angiography) and its functional consequences (ischemic burden) in the same setting, there are technical challenges in the implementation of CT-based transmission imaging for attenuation correction. Nonetheless, this integrated platform for assessing anatomy and biology offers a great potential for translating advances in molecularly targeted imaging into humans.

283 citations


Journal ArticleDOI
TL;DR: The findings of the study show that the peak height and the percentage of signal intensity recovery derived from the ΔR2* curve of DSC perfusion MR imaging can differentiate GBM and MET.
Abstract: BACKGROUND AND PURPOSE: Glioblastoma multiforme (GBM) and single brain metastasis (MET) are the 2 most common malignant brain tumors that can appear similar on anatomic imaging but require vastly different treatment strategy. The purpose of our study was to determine whether the peak height and the percentage of signal intensity recovery derived from dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion MR imaging could differentiate GBM and MET. MATERIALS AND METHODS: Forty-three patients with histopathologic diagnosis of GBM ( n = 27) or MET ( n = 16) underwent DSC perfusion MR imaging in addition to anatomic MR imaging before surgery. Regions of interest were drawn around the nonenhancing peritumoral T2 lesion (PTL) and the contrast-enhancing lesion (CEL). T2* signal intensity-time curves acquired during the first pass of gadolinium contrast material were converted to the changes in relaxation rate to yield T2* relaxivity (ΔR2*) curve. The peak height of maximal signal intensity drop and the percentage of signal intensity recovery at the end of first pass were measured for each voxel in the PTL and CEL regions of the tumor. RESULTS: The average peak height for the PTL was significantly higher ( P = .04) in GBM than in MET. The average percentage of signal intensity recovery was significantly reduced in PTL (78.4% versus 82.8%; P = .02) and in CEL (62.5% versus 80.9%, P < .01) regions of MET compared with those regions in the GBM group. CONCLUSIONS: The findings of our study show that the peak height and the percentage of signal intensity recovery derived from the ΔR2* curve of DSC perfusion MR imaging can differentiate GBM and MET.

245 citations


Journal ArticleDOI
TL;DR: Higher overall scar burden, a larger number of severely scarred segments, and greater scar density near the LV lead tip portend an unfavorable response to CRT in ICM patients.

241 citations


Journal ArticleDOI
TL;DR: ASL perfusion and perfusion-based functional MRI methods have been applied in many clinical settings, including acute and chronic cerebrovascular disease, CNS neoplasms, epilepsy, aging and development, neurodegenerative disorders, and neuropsychiatric diseases.

217 citations


Journal ArticleDOI
TL;DR: vance in voxel-based statistical analysis has markedly enhanced the value of brain perfusion SPECT in diagnosing early AD at the stage of MCI and offers a prediction of the conversion from mild cognitive impairment to AD.
Abstract: Structural MRI and functional imaging by SPECT as well as 18F-FDG PET are widely used in the diagnosis of Alzheimer9s disease (AD). Metabolic and perfusion reductions in the parietotemporal association cortex are recognized as a diagnostic pattern for AD. Outstanding progress in the diagnostic accuracy of these modalities has been achieved with statistical analysis on a voxel-by-voxel basis after anatomic standardization of individual scans to a standardized brain volume template instead of visual inspection or a volume-of-interest technique. In a very early stage of AD, this statistical approach revealed losses of gray matter in the entorhinal and hippocampal areas and hypometabolism or hypoperfusion in the posterior cingulate cortex and precuneus. This statistical approach also offers a prediction of the conversion from mild cognitive impairment (MCI) to AD. The presence of hypometabolism or hypoperfusion in parietal association areas and entorhinal atrophy at the MCI stage have been reported to predict a rapid conversion to AD. A recent advance in voxel-based statistical analysis has markedly enhanced the value of brain perfusion SPECT in diagnosing early AD at the stage of MCI.

216 citations


Journal ArticleDOI
TL;DR: In this paper, the diagnostic accuracy of cardiovascular magnetic resonance (CMR) perfusion imaging at 3-Tesla (T) in suspected coronary artery disease (CAD) was established.

Journal ArticleDOI
TL;DR: Correlation between PCT/CTA and MRI was excellent for infarct size, cortical involvement, and internal cerebral artery occlusion and substantial for penumbra/infarct ratio.
Abstract: Forty-two stroke patients successively underwent perfusion CT (PCT)/CT angiography (CTA) and MRI examinations within 3 to 9 hours following symptom onset; 14 would have been suitable candidates for reperfusion treatment based on MRI findings. Correlation between PCT/CTA and MRI was excellent for infarct size, cortical involvement, and internal cerebral artery occlusion and substantial for penumbra/infarct ratio. Relying on MRI or PCT/CTA would have led to the same treatment decisions in all cases but one.

Journal ArticleDOI
TL;DR: Straight DHCA without adjunctive perfusion suffices as a sole means of cerebral protection and stroke and seizure rates are low, especially for straightforward ascending/arch reconstructions.

Journal ArticleDOI
TL;DR: Despite an excellent negative predictive value, CTA is a poor discriminator of patients with myocardial ischemia, and potentially complementary roles of CT and perfusion imaging in the evaluation of Patients with suspected CAD are suggested.

Journal ArticleDOI
TL;DR: Perfusion CT has potential for monitoring the effects of combined neoadjuvant chemotherapy and radiation therapy and predicting the response of rectal cancer to such therapy.
Abstract: Purpose: To prospectively monitor changes in rectal cancer perfusion after combined neoadjuvant chemotherapy and radiation therapy with perfusion computed tomography (CT) and to evaluate whether perfusion CT findings correlate with response to therapy. Materials and Methods: The study was approved by the institutional ethics committee of the European Institute of Oncology; written informed consent was obtained from all participants before the study. Twenty-five patients with rectal adenocarcinoma (18 men, seven women; age range, 42–72 years; mean age, 61.3 years) underwent perfusion CT; all of them underwent neoadjuvant chemotherapy and radiation therapy, followed by surgery. In 19 patients, perfusion CT was repeated after chemotherapy and radiation therapy. Dynamic perfusion CT was performed for 50 seconds after intravenous injection of contrast medium (40 mL, 370 mg iodine per milliliter, 4 mL/sec). Blood flow (BF), blood volume (BV), mean transit time, and permeability–surface area product (PS) were co...

Journal ArticleDOI
TL;DR: Combining PWI and MRS with conventional MR imaging increases the accuracy of the attribution of malignancy to glial neoplasms and the best performing parameter was found to be the perfusion level.
Abstract: Diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI) and MR spectroscopy (MRS) provide useful data for tumor evaluation To assess the contribution of these multimodal techniques in grading glial neoplasms, we compared the value of DWI, PWI and MRS in the evaluation of histologically proven high- and low-grade gliomas in a population of 105 patients Independently for each modality, the following variables were used to compare the tumors: minimum apparent diffusion coefficient (ADC) and maximum relative cerebral blood volume (rCBV) normalized values between tumor and healthy tissue, maximum Cho/Cr ratio and minimum NAA/Cr ratio in tumor, and scored lactate and lipid values in tumor The Mann-Whitney and Wilcoxon tests were employed to compare DWI, PWI and MRS between tumor types Logistic regression analysis was used to determine which parameters best increased the diagnostic accuracy in terms of sensitivity, specificity, and positive and negative predictive values ROC curves were determined for parameters with high sensitivity and specificity to identify threshold values to separate high- from low-grade lesions Statistically significant differences were found for rCBV tumor/normal tissue ratio, and NAA/Cr ratio in tumor and Cho/Cr ratio in tumor between low- and high-grade tumors The best performing single parameter for group classification was the normalized rCBV value; including all parameters, statistical significance was reached by rCBV tumor/normal tissue ratio, NAA/Cr tumor ratio and lactate From the ROC curves, a high probability for a neoplasm to be a high-grade lesion was associated with a rCBV tumor/normal tissue ratio of >116 and NAA/Cr tumor ratio of <044 Combining PWI and MRS with conventional MR imaging increases the accuracy of the attribution of malignancy to glial neoplasms The best performing parameter was found to be the perfusion level

Journal Article
TL;DR: It is indicated that 11C-ABP688 has suitable characteristics and is a promising PET ligand for imaging mGluR5 distribution in humans and could be of great value for the selection of appropriate doses of clinically relevant candidate drugs that bind to mGLUR5 and for PET studies of patients with psychiatric and neurologic disorders.
Abstract: 3-(6-Methyl-pyridin-2-ylethynyl)-cyclohex-2-enone-O-11C-methyl-oxime (11C-ABP688), a noncompetitive and highly selective antagonist for the metabotropic glutamate receptor subtype 5 (mGluR5), was evaluated for its potential as a PET agent. Methods: Six healthy male volunteers (mean age, 25 y; range, 21–33 y) were studied. Brain perfusion (15O-H2O) was measured immediately before each 11C-ABP688 PET scan. For anatomic coregistration, T1-weighted MRI was performed on each subject. Arterial blood samples for the determination of the arterial input curve were obtained at predefined time points, and 11C-ABP688 uptake was assessed quantitatively using a 2-tissue-compartment model. Results: An initial rapid uptake of radioactivity followed by a gradual clearance from all examined brain regions was observed. Relatively high radioactivity concentrations were observed in mGluR5-rich brain regions such as the anterior cingulate, medial temporal lobe, amygdala, caudate, and putamen, whereas radioactivity uptake in the cerebellum and white matter, regions known to contain low densities of mGluR5, was low. Specific distribution volume as an outcome measure of mGluR5 density in the various brain regions ranged from 5.45 ± 1.47 (anterior cingulate) to 1.91 ± 0.32 (cerebellum), and the rank order of the corresponding specific distribution volumes of 11C-ABP688 in cortical regions was temporal > frontal > occipital > parietal. The metabolism of 11C-ABP688 in plasma was rapid; at 60 min after injection, 25% ± 0.03% of radioactivity measured in the plasma of healthy volunteers was intact parent compound. Conclusion: The results of these studies indicate that 11C-ABP688 has suitable characteristics and is a promising PET ligand for imaging mGluR5 distribution in humans. Furthermore, it could be of great value for the selection of appropriate doses of clinically relevant candidate drugs that bind to mGluR5 and for PET studies of patients with psychiatric and neurologic disorders.

Journal ArticleDOI
TL;DR: In this paper, the authors used the Alberta Stroke Program Early CT Score (ASPECTS) to predict the infarct size in the absence of major neurologic improvement.
Abstract: BACKGROUND AND PURPOSE: Qualitative CT perfusion (CTP) assessment by using the Alberta Stroke Program Early CT Score (ASPECTS) allows rapid calculation of infarct extent for middle cerebral artery infarcts. Published thresholds exist for noncontrast CT (NCCT) ASPECTS, which may distinguish outcome/complication risk, but early ischemic signs are difficult to detect. We hypothesized that different ASPECTS thresholds exist for CTP parameters versus NCCT and that these may be superior at predicting clinical and radiologic outcome in the acute setting. MATERIALS AND METHODS: Thirty-six baseline acute stroke NCCT and CTP studies within 3 hours of symptoms were blindly reviewed by 3 neuroradiologists, and ASPECTS were assigned. Treatment response was defined as major neurologic improvement when a ≥8-point National Institutes of Health Stroke Scale improvement at 24 hours occurred. Follow-up NCCT ASPECTS and 90-day modified Rankin score (mRS) were radiologic and clinical reference standards. Receiver operating characteristic curves derived optimal thresholds for outcome. RESULTS: Cerebral blood volume and NCCT ASPECTS had similar radiologic correlations (0.6 and 0.5, respectively) and best predicted infarct size in the absence of major neurologic improvement. A NCCT ASPECT threshold of 7 and a cerebral blood volume threshold of 8 discriminated patients with poor follow-up scans ( P P = .0001) and mRS ≤2 ( P = .001 and P P = .02). Interobserver agreement was substantial (intraclass correlation coefficient, 0.69). Cerebral blood volume ASPECTS sensitivity, specificity, positive predictive value, and negative predictive value for clinical outcome were 60%, 100%, 100%, and 45%, respectively. No patients with cerebral blood volume ASPECTS CONCLUSION: Cerebral blood volume ASPECTS is equivalent to NCCT for predicting radiologic outcome but may have an additional benefit in predicting patients with major neurologic improvement.

Journal ArticleDOI
TL;DR: 3D SPECT/CT image fusion is feasible, reproducible and allows correct superposition of SPECT segments onto cardiac CT anatomy.
Abstract: Combining the functional information of SPECT myocardial perfusion imaging (SPECT-MPI) and the morphological information of coronary CT angiography (CTA) may allow easier evaluation of the spatial relationship between coronary stenoses and perfusion defects. The aim of the present study was the validation of a novel software solution for three-dimensional (3D) image fusion of SPECT-MPI and CTA. SPECT-MPI with adenosine stress/rest 99mTc-tetrofosmin was fused with 64-slice CTA in 15 consecutive patients with a single perfusion defect and a single significant coronary artery stenosis (≥50% diameter stenosis). 3D fused SPECT/CT images were analysed by two independent observers with regard to superposition of the stenosed vessel onto the myocardial perfusion defect. Interobserver variability was assessed by recording the X, Y, Z coordinates for the origin of the stenosed coronary artery and the centre of the perfusion defect and measuring the distance between the two landmarks. SPECT-MPI revealed a fixed defect in seven patients, a reversible defect in five patients and a mixed defect in three patients and CTA documented a significant stenosis in the respective subtending coronary artery. 3D fused SPECT/CT images showed a match of coronary lesion and perfusion defect in each patient and the fusion process took less than 15 min. Interobserver variability was excellent for landmark detection (r = 1.00 and r = 0.99, p < 0.0001) and very good for the 3D distance between the two landmarks (r = 0.94, p < 0.001). 3D SPECT/CT image fusion is feasible, reproducible and allows correct superposition of SPECT segments onto cardiac CT anatomy.

Journal Article
Meng Law1, Robert J. C. Young1, James Babb1, Erica Pollack1, Glyn Johnson1 
TL;DR: In this paper, the authors compared histogram analysis with region-of-interest (ROI) measurements of relative cerebral blood volume (rCBV) for the grading of glial neoplasms.
Abstract: BACKGROUND AND PURPOSE: Histogram analysis can be applied to dynamic susceptibility contrast (DSC) perfusion MR imaging datasets and can be as effective as traditional region-of-interest (ROI) measurements of relative cerebral blood volume (rCBV), an operator-dependent method. We compare the routine ROI method with histogram analysis in the grading of glial neoplasms. MATERIALS AND METHODS: Ninety-two patients underwent conventional and DSC MR imaging. Routine rCBV (rCBVmax) measurements were obtained from ROIs of the maximal abnormality within the glioma. Histogram analysis rCBVT was performed with an ROI drawn around the maximal tumor diameter. Spearman rank correlations measured associations among glioma grade, rCBVmax, and histogram measures. Mann-Whitney tests compared grade with respect to rCBV and histogram measures. Logistic regression and McNemar test compared the utility of rCBVmax and histogram measures for detecting high grade gliomas. RESULTS: Routine rCBVmax analysis showed significant correlation with grade (r = 0.734, P CONCLUSION: rCBVT histogram analysis is as effective as rCBVmax analysis in the correlation with glioma grade. Inexperienced operators may obtain perfusion metrics using histogram analyses that are comparable with those obtained by experienced operators using ROI analysis.

Journal Article
TL;DR: Because an eZ IS can use a common normal data base by converting site-specific SPECT data to the core data, the eZIS was useful for automated diagnosis of very early AD in routine studies in multiple institutions.
Abstract: BACKGROUND AND PURPOSE: In Alzheimer disease (AD), a peculiar regional cerebral blood flow (rCBF) abnormality has been reported in the posterior cingulate gyri and precunei, even at a very early stage. We performed a multicenter brain perfusion single-photon emission tomography (SPECT) study to evaluate the discrimination ability of an easy Z-score imaging system (eZIS) with a common normal data base between patients with very early AD at the stage of mild cognitive impairment and age-matched healthy controls. MATERIALS AND METHODS: For a multicenter study, SPECT images of 40 patients with AD and 40 healthy volunteers were acquired from 4 gamma camera systems in 4 different institutions. Systematic differences of SPECT images between gamma cameras were corrected by using conversion maps calculated from the SPECT images of the same brain phantom. Receiver operating characteristic (ROC) analysis was performed to discriminate patients and controls by using a Z-score in the volume of interest (VOI), which had been defined as a region related to AD in subjects other than those in a multicenter study. RESULTS: Bilateral posterior cingulate gyri, precunei, and parietal cortices were defined as a VOI showing rCBF reduction in very early AD. A new indicator of rCBF abnormality in the VOI provided 86% accuracy for distinction of AD and healthy controls in the multicenter study. The area under the ROC curve was 0.934. CONCLUSION: Because an eZIS can use a common normal data base by converting site-specific SPECT data to the core data, the eZIS was useful for automated diagnosis of very early AD in routine studies in multiple institutions.

Journal ArticleDOI
TL;DR: A systematic evaluation of the empirical data concerning deficits in mental ability, brain perfusion, and cerebral functioning due to chronically low blood pressure suggests that more attention should be allocated to chronic hypotension in both research and clinical practice.
Abstract: This review article includes a systematic evaluation of the empirical data concerning deficits in mental ability, brain perfusion, and cerebral functioning due to chronically low blood pressure. A number of studies have provided strong evidence for reduced cognitive performance in hypotension, particularly in the domains of attention and memory. EEG studies have demonstrated that the hypotension-related poorer mental ability is also reflected in diminished cortical activity. Contrary to convention, more recent research has suggested a deficient regulation of cerebral blood flow in persons with low blood pressure. In addition to reduced tonic brain perfusion, studies demonstrated insufficient adjustment of blood flow to cognitive requirements. Altogether, these findings suggest that more attention should be allocated to chronic hypotension in both research and clinical practice.

Journal ArticleDOI
TL;DR: Isolated focal swelling identifies penumbral tissue and parenchymal hypoattenuation identifies infarct core, and although this has prognostic implications when assessing patient suitability for thrombolytic therapy, the majority of acutely hypoperfused regions appear normal on noncontrast CT.
Abstract: Objectives: To correlate the two types of early ischemic change on noncontrast CT (NCCT) (parenchymal hypoattenuation [PH] and isolated focal swelling [IFS]) with concurrent assessment of cerebral perfusion and to compare their rates of progression to infarction Methods: We assessed cortical regions on NCCT for early ischemic change Quantitative perfusion values were calculated for cortical regions from acute CT perfusion (CTP) maps of cerebral blood volume (CBV), blood flow (CBF), and mean transit time (MTT) Reperfusion and presence of infarction were determined from follow-up MRI Results: We studied 40 patients with sub-6 hour anterior circulation ischemic stroke; 19 received IV recombinant tissue plasminogen activator Of the 202 regions acutely hypoperfused on CTP, 123 were normal on NCCT, 58 had PH, and 21 had IFS Acute CBV was low in PH regions, and elevated in IFS regions Acute CBF was reduced in IFS regions, but more so in PH regions Progression to infarction occurred in virtually all PH regions, but IFS regions had much lower rates of infarction with major reperfusion Acute CBV in hypoperfused normal NCCT regions ranged from reduced to elevated, with substantially differing risk of infarction Conclusions: Isolated focal swelling identifies penumbral tissue and parenchymal hypoattenuation identifies infarct core Although this has prognostic implications when assessing patient suitability for thrombolytic therapy, the majority of acutely hypoperfused regions appear normal on noncontrast CT Perfusion CT can stratify the level of risk of subsequent infarction for normal-appearing regions on noncontrast CT

Journal ArticleDOI
TL;DR: Many patients with MVD show no perfusion defect in zones supplied by arteries with total occlusion or a FFR<0.75, suggesting MPI underestimates ischemic burden and FFR may be better at guiding revascularization decisions than perfusion imaging in patients withMVD.
Abstract: We hypothesized that myocardial perfusion imaging (MPI) would fail to identify all vascular zones with the potential for myocardial ischemia in patients with multivessel coronary disease (MVD). MPI is based on the concept of relative flow reserve. The ability of these techniques to determine the significance of a particular stenosis in the setting of MVD is questionable. Fractional flow reserve (FFR) can determine the significance of individual stenoses. Thirty-six patients with disease involving 88 arteries underwent angiography, FFR, and MPI. FFR was performed using a pressure wire with hyperemia from intracoronary adenosine. Myocardial perfusion images were analyzed quantitatively and segments assigned to a specific coronary artery. The relation between FFR and perfusion was determined for each vascular zone. Of the 88 vessels, the artery was occluded (n = 20) or had an abnormal FFR ≤0.75 (n = 34) in 54 of 88 (61%). MPI showed no defect in 51 zones (58%). Concordance between angiography, FFR, and MPI was seen in 61 of 88 zones (69%). Discordance was seen in the remaining 27 zones (31%) and was predominantly from the finding of a FFR

Journal Article
TL;DR: It is suggested 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.
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.

Journal ArticleDOI
TL;DR: Perfusion CT parameters can be used for preoperative grading of gliomas and can provide valuable complementary information about tumor hemodynamics, not available with conventional imaging techniques.
Abstract: BACKGROUND AND PURPOSE: Perfusion imaging using CT can provide additional information about tumor vascularity and angiogenesis for characterizing gliomas. The purpose of our study was to demonstrate the usefulness of various perfusion CT (PCT) parameters in assessing the grade of treatment-naive gliomas and also to compare it with conventional MR imaging features. MATERIALS AND METHODS: PCT was performed in 19 patients with glioma (14 high-grade gliomas and 5 low-grade gliomas). Normalized ratios of the PCT parameters (normalized cerebral blood volume [nCBV], normalized cerebral blood flow [nCBF], normalized mean transit time [nMTT]) were used for final analysis. Conventional MR imaging features of these tumors were assessed separately and compared with PCT parameters. Low- and high-grade gliomas were compared by using the nonparametric Wilcoxon 2-sample tests. RESULTS: Mean nCBV in the high- and low-grade gliomas was 3.06 ± 1.35 and 1.44 ± 0.42, respectively, with a statistically significant difference between the 2 groups (P = .005). Mean nCBF for the high- and low-grade gliomas was 3.03 ± 2.16 and 1.16 ± 0.36, respectively, with a statistically significant difference between the 2 groups (P = .045). Cut points of >1.92 for nCBV (85.7% sensitivity and 100% specificity), >1.48 for nCBF (71.4% sensitivity and 100% specificity), and 1.92 or nCBF of >1.48 improved the sensitivity and specificity to 92.9% and 100%, respectively. The sensitivity and specificity for diagnosing a high-grade glioma with conventional MR imaging were 85.7% and 60%, respectively. CONCLUSIONS: PCT can be used for preoperative grading of gliomas and can provide valuable complementary information about tumor hemodynamics, not available with conventional imaging techniques. nCBV was the single best parameter correlating with glioma grades, though using nCBF when nCBV was 1.92 was found to identify the high-grade gliomas.

Journal ArticleDOI
TL;DR: CT perfusion measurements enable differentiation and better discrimination, in comparison with morphologic criteria, between cancer and diverticulitis.
Abstract: Purpose: To determine whether computed tomographic (CT) perfusion measurements in prospectively recruited patients can be used to differentiate between diverticulitis and colorectal cancer and to compare this discrimination with that of standard morphologic criteria. Materials and Methods: After institutional review board approval and written informed consent were obtained, 60 patients (24 men, 36 women; mean age, 69 years; range, 33.5–90.4 years; 20 patients with cancer, 20 with diverticulitis, and 20 with inactive diverticular disease) underwent CT perfusion imaging at the level of the colonic abnormality, and perfusion parameters were calculated. Analysis of variance was used to investigate any differences in perfusion between the patient groups. Two independent observers also analyzed an abdominopelvic CT study obtained immediately after the CT perfusion study and noted standard morphologic criteria for differential diagnosis. The sensitivity and specificity of CT perfusion measurements for determinin...


Journal ArticleDOI
TL;DR: This review will discuss the role of structural imaging using computed tomography and magnetic resonance imaging and physiological imaging using CT perfusion, 131Xe CT, MRI and spectroscopy, and positron emission tomography in the assessment, management, and prediction of outcome after head injury.
Abstract: Head injury remains an important cause of death and disability in young adults. This review will discuss the role of structural imaging using computed tomography (CT) and magnetic resonance imaging (MRI) and physiological imaging using CT perfusion, 131 Xe CT, MRI and spectroscopy (MRS), single photon emission computed tomography, and positron emission tomography (PET) in the assessment, management, and prediction of outcome after head injury. CT allows rapid assessment of brain pathology which ensures patients who require urgent surgical intervention receive appropriate care. Although MRI provides greater spatial resolution, particularly within the posterior fossa and deep white matter, a complete assessment of the burden of injury requires imaging of cerebral physiology. Physiological imaging techniques can only provide ‘snap shots’ of physiology within the injured brain, but they can be repeated, and such data can be used to assess the impact of therapeutic interventions. Perfusion imaging based on CT techniques (xenon CT and CT perfusion) can be implemented easily in most hospital centres, and provide quantitative perfusion data in addition to structural images. PET imaging provides unparalleled insights into cerebral physiology and pathophysiology, but is not widely available and is primarily a research tool. MR technology continues to develop and is becoming generally available. Using a complex variety of sequences, MR can provide data concerning both structural and physiological derangements. Future developments with such imaging techniques should improve understanding of the pathophysiology of brain injury and provide data that should improve management and prediction of functional outcome.

Journal ArticleDOI
TL;DR: Function-guided IMRT planning appears to be effective in preserving functional lung in locally advanced-stage NSCLC patients.
Abstract: Purpose: To assess quantitatively the impact of incorporating functional lung imaging into intensity-modulated radiation therapy planning for locally advanced non-small cell lung cancer (NSCLC) Methods and Materials: Sixteen patients with advanced-stage NSCLC who underwent radiotherapy were included in this study Before radiotherapy, each patient underwent lung perfusion imaging with single-photon-emission computed tomography and X-ray computed tomography (SPECT-CT) The SPECT-CT was registered with simulation CT and was used to segment the 50- and 90-percentile hyperperfusion lung (F50 lung and F90 lung) Two IMRT plans were designed and compared in each patient: an anatomic plan using simulation CT alone and a functional plan using SPECT-CT in addition to the simulation CT Dosimetric parameters of the two types of plans were compared in terms of tumor coverage and avoidance of normal tissues Results: In incorporating perfusion information in IMRT planning, the median reductions in the mean doses to the F50 and F90 lung in the functional plan were 22 and 42 Gy, respectively, compared with those in the anatomic plans The median reductions in the percentage of volume irradiated with >5 Gy, >10 Gy, and >20 Gy in the functional plans were 71%, 60%, and 51%, respectively, for F50 lung, and 117%, 120%,more » and 68%, respectively, for F90 lung A greater degree of sparing of the functional lung was achieved for patients with large perfusion defects compared with those with relatively uniform perfusion distribution Conclusion: Function-guided IMRT planning appears to be effective in preserving functional lung in locally advanced-stage NSCLC patients« less