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1.
Beer M Machann W Sandstede J Buchner S Lipke C Köstler H Lorenz R Harre K Spindler M Hahn D 《European radiology》2007,17(5):1275-1283
To evaluate multivoxel 31P-MR spectroscopy (MRS) for assessment of energy metabolism in patients with myocardial infarction (MI) in correlation to
left ventricular (LV) wall thickness and the outcome of revascularization. Thirty patients with subacute anterior myocardial
infarction and planned revascularization were enrolled. 3D–chemical shift imaging was applied to determine PCr/ATP ratios
in two areas: infarcted/anterior and noninfarcted/septal myocardium. MRI was used to evaluate LV function and wall thickness,
and was repeated 6 months after revascularization to assess myocardial viability. Fifteen volunteers were controls. Fifteen
patients showed normalization of wall motion abnormalities after revascularization (Group 1; viable), 15 not (Group 2; non-viable).
Regarding infarcted/anterior myocardium, Group 2 had lower PCr/ATP ratios (0.81 ± 0.60 vs 1.17 ± 0.25), and PCr/ATP ratios
were reduced in both groups compared to controls (1.45 ± 0.29). Regarding noninfarcted/septal myocardium, again Group 2 had
lower ratios (0.93 ± 0.53 vs 1.31 ± 0.38); however, compared to controls (1.51 ± 0.32) a reduction of PCr/ATP ratios was only
found in Group 2. For both myocardial regions, no correlations between PCr/ATP ratios and LV wall thickness were detected.
The more severe energetic alteration in irreversibly damaged myocardium is not an effect of differences of wall thinning.
Additional alterations of noninfarcted, adjacent myocardium can be detected. 相似文献
2.
Mamoru Okada Kenichi Mitsunami Toshiro Inubushi Masahiko Kinoshita 《Magnetic resonance in medicine》1998,39(5):772-782
Although both aging and hypertrophy are extremely important factors for cardiac performance, their influence on cardiac metabolism, especially that of high-energy phosphates, has not been fully elucidated as yet. Quantitative measurements of high-energy phosphates were attempted by comparing myocardial 31P NMR spectra with an external reference using depth-resolved surface-coil spectroscopy. The voxel size of the region of interest (ROI) was disk-shaped with 15-cm diameter and 25-mm thickness, but the left ventricular weight actually involved in the ROI was estimated to be between 22 and 66 g using MRI. Myocardial phosphocreatine (PCr) content and adenosine triphosphate (ATP) content for the 30 normal volunteers showed significant age dependence since both decreased in relation to increasing age. Myocardial PCr content and ATP content in patients with hypertension did not differ significantly from the age-matched control group. PCr content (6.1 ± 2.2 μmol/g wet tissue, n=10) and ATP content (4.1 ±1.3 μmol/g wet tissue) in patients with hypertrophic cardiomyopathy were less than the age-matched control group (n = 15; PCr: 9.7 ± 2.5 μmol/g wet tissue, P <0.01; ATP: 6.4 ±1.8 μmol/g wet tissue, P <0.05), respectively. These results indicate that quantitative 31P MRS may be valuable in the assessment of changes in high-energy phosphate metabolism caused by aging or hypertrophy. 相似文献
3.
Ko Higuchi Michinobu Nagao Yoshio Matsuo Takeshi Kamitani Masato Yonezawa Mikako Jinnouchi Yuzo Yamasaki Koichiro Abe Shingo Baba Yasushi Mukai Taiki Higo Kenji Sunagawa Hiroshi Honda 《Japanese journal of radiology》2013,31(2):123-132
Purpose
To investigate myocardial viability in chronic ischemic heart disease by myocardial perfusion and regional contraction analysis using 256-slice MSCT coronary angiography (CCTA).Methods
In 30 patients with prior myocardial infarction (MI), CCTA with retrospective ECG-gating and stress-redistribution thallium-201 SPECT were performed. Using the same raw data as used for CCTA, myocardial perfusion imaging (CT-MPI) was reconstructed at four phases during the cardiac cycle. Mean myocardial attenuation and wall thickness at end-systole and end-diastole were measured in the MI areas depicted by SPECT, and they were compared between viable and non-viable segments categorized by SPECT.Results
End-systolic thickness was significantly greater for viable than for non-viable segments (12.0 ± 3.2 vs. 9.6 ± 3.5 mm, p = 0.0017). There was no difference in end-diastolic thickness. Myocardial attenuation was significantly higher for viable than for non-viable segments in the subendocardium (62 ± 13 vs. 70 ± 11 HU, p = 0.003) and the epicardium (65 ± 13 vs. 80 ± 15 HU, p = 0.0002).Conclusion
The systolic wall thinning and epicardial low-attenuation areas were the indicative findings of CT-MPI for non-viable segments in the prior MI. 相似文献4.
Leonardo Pace Pasquale Perrone-Filardi PierPaolo Mainenti Mariella Prastaro Pasquale Vezzuto Andrea Varrone Teresa Crisci Alberto Cuocolo Santo Dellegrottaglie Federico Piscione Massimo Chiariello Marco Salvatore 《European journal of nuclear medicine and molecular imaging》1998,25(7):744-750
The purpose of this study was to evaluate whether combined evaluation by discriminant analysis of rest-redistribution thallium-201
tomography and low-dose dobutamine echocardiography enhances the accuracy in identifying viable myocardium in patients with
chronic coronary artery disease. Rest-redistribution 201Tl has high sensitivity but low specificity in identifying viable myocardium, while the opposite is true for low-dose dobutamine
echocardiography. Forty-six patients underwent low-dose dobutamine echocardiography and rest-redistribution 201Tl tomography on the same day. Rest echocardiography was repeated at least 30 days (mean 40±20) after myocardial revascularization.
Discriminant analysis was applied to the results of 201Tl tomography and dobutamine echocardiography to classify a/dyskinetic segments as viable or non-viable. In 92 a/dyskinetic
segments that were revascularized, rest-redistribution 201Tl tomography yielded an accuracy of 75%, while the accuracy of dobutamine echocardiography was 70% (P<0.05). When discriminant analysis was used, the combined evaluation gave an accuracy of 83% (P<0.05 vs both tests). These findings demonstrate that low-dose dobutamine echocardiography and 201Tl imaging are useful and complementary techniques for identifying viable myocardium in patients with chronic coronary artery
disease. Combined evaluation by discriminant analysis significantly improves accuracy, although the cost-effectiveness of
such an approach remains to be determined.
Received 13 January and in revised form 16 March 1998 相似文献
5.
Sorrentino AR Acampa W Petretta M Mainolfi C Salvatore M Cuocolo A 《European journal of nuclear medicine and molecular imaging》2007,34(4):558-562
Purpose We compared the prognostic value of 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) after nitrate administration and positron emission tomography
(PET) with 18F-fluorodeoxyglucose (FDG) in patients with ischaemic left ventricular (LV) dysfunction.
Methods Eighty-nine patients with previous myocardial infarction and LV dysfunction (LV ejection fraction 33 ± 10%) underwent 99mTc-tetrofosmin SPECT under control conditions (baseline) and after sublingual administration of 10 mg of isosorbide dinitrate
(nitrate). Within 1 week, all patients underwent PET imaging with 18F-FDG. Four patients were excluded because of inadequate FDG uptake caused by severe diabetes. Follow-up data were obtained
by phone contact with patients and by review of hospital or physicians’ records. Cardiac death, myocardial infarction and
late revascularisation for unstable angina were considered as events. Follow-up data were not available in three patients.
Follow-up was 96% complete at a mean period of 29 ± 19 months.
Results At baseline SPECT, 59 (72%) patients had evidence of viable myocardium, while 23 did not. Of these latter patients, 12 (52%)
demonstrated viable myocardium after nitrate and 13 (56%) had preserved metabolic activity. Cardiac events (cardiac death,
myocardial infarction and late revascularisation for unstable angina) occurred in 24 (29%) patients. Event-free survival was
similar in patients with and patients without viable myocardium at baseline SPECT (p = 0.8). In contrast, event-free survival was lower in patients with viable myocardium at nitrate SPECT and PET compared to
those without viable myocardium (both p<0.05).
Conclusion In patients with ischaemic LV dysfunction, the prognostic value of SPECT imaging after nitrate is comparable to that of PET
metabolic imaging. 相似文献
6.
Alberto Cuocolo Mario Petretta Emanuele Nicolai Leonardo Pace Domenico Bonaduce Marco Salvatore Bruno Trimarco 《European journal of nuclear medicine and molecular imaging》1997,25(1):60-68
The role of coronary revascularization of dysfunctional myocardium with preserved thallium-201 uptake in determining the
prognosis in patients after myocardial infarction remains to be defined. This study was designed to evaluate the effects of
successful revascularization on survival and left ventricular (LV) function in patients with previous myocardial infarction
and evidence of dysfunctional but still viable myocardium at rest-redistribution 201Tl imaging. Seventy-six consecutive patients with LV dysfunction related to previous myocardial infarction and evidence of
viable myocardium at rest-redistribution 201Tl tomography were followed for 17±8 months. LV ejection fraction (EF) was assessed by radionuclide angiography at baseline
and after 13±2 months. Thirty-nine patients were revascularized (group A) and 37 treated medically (group B). During the follow-up
there were nine cardiac deaths. Survival rate was 97% in group A and 66% in group B (P<0.01). By Cox multivariate analysis, the extent of viable myocardium was the best predictor of cardiac death (χ2=8.67, P<0.01) and provided additional information to clinical and functional data (P<0.01). The inclusion of revascularization as a variable improved the global χ2 of the model from 14.1 to 21.9 (P<0.01). At follow-up, EF had improved by ≥5% in 16 patients. By multivariate logistic analysis, the extent of viable myocardium
was the best predictor of EF improvement (χ2=15.49, P<0.001) and provided additional information to clinical and functional data (P<0.01). The inclusion of revascularization as a variable improved the global χ2 of the model from 16.8 to 22.5 (P<0.01). These results demonstrate that the total extent of dysfunctional myocardium with preserved 201Tl uptake is the strongest predictor of cardiac death in patients after myocardial infarction. Successful revascularization
of dysfunctional but viable myocardium improves survival and LVEF in such patients.
Received 22 June and in revised form 15 September 1997 相似文献
7.
Hans Jürgen Gallowitsch Oliver Unterweger Peter Mikosch Ewald Kresnik Josef Sykora Georg Grimm Peter Lind 《European journal of nuclear medicine and molecular imaging》1999,26(5):459-466
The aim of this study was to determine the influence of attenuation-corrected thallium-201 stress/redistribution/reinjection
single-photon emission tomography (SPET) on the number of viable segments in patients with previous myocardial infarction
and dysfunctional myocardium. Fifty-one patients with previous myocardial infarction and left ventricular dysfunction were
included in the study. In all patients, 201Tl non-corrected (NC) and attenuation-corrected (AC) SPET was performed using a stress/redistribution/reinjection protocol
followed by coronary angiography. A semiquantitative analysis was performed using polar maps for NC and AC stress, redistribution
and reinjection short-axis and vertical long-axis (apex) slices. Severe (perfusion defect below 50%/maximal count rate: PD<50), mild and moderate persistent defects for redistribution and reinjection were evaluated for both NC and AC studies. A total
of 1581 segments were evaluated by semiquantitative segmental analysis for both NC and AC studies for each redistribution
and reinjection map. In the redistribution maps, NC revealed a total of 352 segments and AC a total of 222 segments with impaired
perfusion below 50% of the maximal count rate (PD<50). The mean number of affected segments was 6.9±5.5 in the case of NC and 4.4±4.8 in the case of AC (P<0.001). In the reinjection maps, NC revealed a total of 263 non-viable segments (PD<50) and AC a total of 169 non-viable segments. The mean number of affected segments was 5.2±5.3 in the case of NC and 3.3±4.2
in the case of AC (P<0.001). Recovery of function was better predicted by AC than by NC in 20% of patients in the follow-up group. Therefore,
the use of attenuation correction influences the extent of viable segments by showing more viable segments in either redistribution
or reinjection maps. 201Tl imaging without attenuation correction may underestimate the extent of tissue viability, which may contribute to the lower
sensitivity compared to fluorine-18-fluorodeoxyglucose positron emission tomography, where attenuation correction is a routinely
performed procedure.
Received 26 October and in revised form 23 December 1998 相似文献
8.
Assessment of reperfused myocardium using a new ischaemia-avid imaging agent, technetium-99m HL91: comparison with myocardial glucose uptake 总被引:3,自引:0,他引:3
Kazuki Fukuchi Hideo Kusuoka Kenji Yutani Shinji Hasegawa Tsunehiko Nishimura 《European journal of nuclear medicine and molecular imaging》1998,25(4):361-366
We evaluated the efficacy of a new ischae-mia-avid imaging agent, technetium-99m labelled 4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione
dioxime (99mTc- HL91) as a marker of myocardial viability in ischaemic and reperfused myocardium. The left coronary artery of rats was
ligated for 15 or 60 min and released. The myocardium was reperfused for 60 min [stunned myocardium, or acute myocardial infarction
(MI)] or 7 days (subacute MI). Thereafter, 99mTc-HL91 and carbon-14 2-deoxyglucose (DG) were co-injected 30 min before sacrifice. We evaluated the myocardial accumulation
of 99mTc-HL91 and DG by dual-tracer ex vivo autoradiography. The uptake of each tracer in the myocardial region was normalized by
that in the septum (control), and expressed as percent uptake (%HL or %DG, respectively). Individual hearts were also histopathologically
examined. The %HL in the stunned myocardium (n = 8) and in the septum were identical (101%±15%, mean±SD, P = ns), whereas the %DG was significantly increased (149%±27%, P<0.05) compared with that in the septum. These results suggest that 99mTc-HL91 cannot visualize stunned myocardium, whereas DG can. In acute MI (n = 7), the %HL (423%±96%, P<0.005) and the %DG (318%±91%, P<0.001) in the non-infarcted area at risk were significantly augmented compared with those in the septum. The %DG (181%±17%)
in the infarcted area was also augmented (P<0.001), whereas the %HL (106%±25%) in the infarcted area was identical to that in the septum (P = ns). These results indicate that 99mTc-HL91 detected viable myocardium in the area at risk. In subacute MI (n = 8), the%HL in the infarcted area (101%±45%) and in the septum was identical, whereas %DG (292%±57%) was significantly higher
than that in the non-infarcted risk area or the septum (P<0.0001). These findings suggest that DG detected viable myocardium in the area at risk, but that 99mTc-HL91 was not retained. We conclude that 99mTc-HL91 is a potent marker of myocardial viability when used during the early acute phase after reperfusion.
Received 9 September and in revised form 17 December 1997 相似文献
9.
Chia‐Ying Liu Alban Redheuil Ronald Ouwerkerk Joao A. C. Lima David A. Bluemke 《Magnetic resonance in medicine》2010,63(4):892-901
Proton MR spectroscopy (1H‐MRS) has been used for in vivo quantification of intracellular triglycerides within the sarcolemma. The purpose of this study was to assess whether breath‐hold dual‐echo in‐ and out‐of‐phase MRI at 3.0 T can quantify the fat content of the myocardium. Biases, including T1, T*2, and noise, that confound the calculation of the fat fraction were carefully corrected. Thirty‐four of 46 participants had both MRI and MRS data. The fat fractions from MRI showed a strong correlation with fat fractions from MRS (r = 0.78; P < 0.05). The mean myocardial fat fraction for all 34 subjects was 0.7 ± 0.5% (range: 0.11–3%) assessed with MRS and 1.04 ± 0.4% (range: 0.32–2.44%) assessed with in‐ and out‐of‐phase MRI (P < 0.05). Scanning times were less than 15 sec for Dixon imaging, plus an additional minute for the acquisition used for T*2 calculation, and 15‐20 min for MRS. The average postprocessing time for MRS was 3 min and 5 min for MRI including T*2 measurement. We conclude that the dual echo method provides a rapid means to detect and quantifying myocardial fat content in vivo. Correction/adjustment for field inhomogeneity using three or more echoes seems crucial for the dual echo approach. Magn Reson Med 63:892–901, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
10.
Giovagnoni A Ligabue G Rossi R Muia N Modena MG Romagnoli R 《La Radiologia medica》1999,98(6):482-489
PURPOSE: Dobutamine cine MRI is a new diagnostic imaging technique in the pretreatment (revascularization) assessment of myocardial infarction patients. We report the results of a comparative study of the diagnostic yield of dobutamine cine MRI with that of stress echocardiography in the assessment of viable myocardium. We also propose a new method for analysis of cine MR images, employing digital subtraction, aimed at decreasing subjectivity in the quantitative assessment of myocardial wall thickening. MATERIAL AND METHODS: Twenty-six patients (21 men and 5 women) with a history of myocardial infarction who were scheduled for revascularization were submitted to stress echocardiography and dobutamine cine MRI to evaluate contractile recovery of the segments considered akinetic or hypokinetic at baseline echocardiography. Dobutamine was administered in growing doses (5, 10, 15 gamma/kg/min). We considered 16 segments of the left ventricle in each patient. We performed a quantitative analysis of systolic wall thickening on individual cine MR frames both by manual measurements and by digital subtraction. RESULTS: In the 416 segments studied, we found 307 normokinetic, 64 scarred and 45 viable segments with stress echocardiography, versus 302 normokinetic, 83 scarred and 31 viable segments with dobutamine MRI. Wall thickening analysis on Cine MR images showed 268 normal, 68 scarred and 80 viable segments, versus 274 normal, 58 scarred and 84 viable segments with digital subtraction. Three months after revascularization 15 patients were examined to check contractile recovery of the segments considered as viable. Echocardiography had 79% sensitivity and 97% specificity, while cine MRI had 96% and 86%, respectively. Quantitative assessment of systolic wall thickening by cine MRI and digital subtraction had 96% sensitivity and 91% specificity, with no statistically significant differences between the two techniques. In patients with anteroseptal wall myocardial infarction stress echocardiography had 75% sensitivity and 97% specificity. In the subgroup of 13 patients with diaphragmatic or inferior wall infarction echocardiography sensitivity dropped to 68%, versus 96% of cine MRI, but its specificity was higher, namely 97 versus 86%. CONCLUSIONS: In anteroseptal infarction, echocardiography permits to distinguish viable myocardium and scarred myocardial tissue with good sensitivity and specificity, but cine MRI performs better. In inferolateral or diaphragmatic infarction, cine MRI has much higher sensitivity than stress echocardiography and thus makes the technique of choice to evaluate viable myocardium in these sites. The digital subtraction technique is as accurate as manual measurements, but reduces the error rate and permits quicker evaluation, particularly in subendocardial thickening. 相似文献
11.
Hirofumi Aoki Ichiro Matsunari Yusuke Nomura Wataru Fujita Ryoko Komatsu Yoshiharu Miyazaki Stephan G. Nekolla Kouji Kajinami 《Annals of nuclear medicine》2013,27(6):523-531
Objective
The purpose of this study was to investigate the relationship between sympathetic innervation, contractile function, and the oxidative metabolism of the non-infarcted myocardium in patients with prior myocardial infarction.Methods
In 19 patients (14 men, 5 women, 65 ± 9 years) after prior myocardial infarction, sympathetic innervation was assessed by 11C-hydroxyephedrine (HED) positron emission tomography (PET). Oxidative metabolism was quantified using 11C-acetate PET. Left ventricular systolic function was measured by echocardiography with speckle tracking technique.Results
The 11C-HED retention was positively correlated with left ventricular ejection fraction (LVEF) (r = 0.566, P < 0.05), and negatively with peak longitudinal strain in systole in the non-infarcted myocardium (r = ?0.561, P < 0.05). Kmono, as an index of oxidative metabolism, was significantly correlated with rate pressure product (r = 0.649, P < 0.01), but not with 11C-HED retention (r = 0.188, P = 0.442). Furthermore, there was no significant correlation between Kmono and LVEF (r = 0.106, P = 0.666) or peak longitudinal strain in systole (r = ?0.256, P = 0.291) in the non-infarcted myocardium. When the patients were divided into two groups based on the median value of left ventricular end-systolic volume index (LVESVI) (41 mL), there were no significant differences in age, sex, and rate pressure product between the groups. However, the large LVESVI group (>41 mL) was associated with reduced 11C-HED retention and peak longitudinal strain in systole, whereas Kmono was similar between the groups.Conclusions
This study indicates that remodeled LV after myocardial infarction is associated with impaired sympathetic innervation and function even in the non-infarcted myocardial tissue. Furthermore, oxidative metabolism in the non-infarcted myocardium seems to be operated by normal regulatory mechanisms rather than pre-synaptic sympathetic neuronal function. 相似文献12.
Sheng-Ting Li Xiu-Jie Liu Zong-Liang Lu Rong-Fang Shi Xiao-Dong Zhu Wen-Qi Chen Qing-Wen Wu Yun-Zhong Liu 《Journal of nuclear cardiology》1996,3(6):457-463
Background
Assessment of viable myocardium in territories of hypoperfused myocardium is important for predicting functional recovery after revascularization. This study was designed to evaluate quantitative analysis of 99mTc-labeled 2-methoxyisobutyl isonitrile (MIBI) myocardial perfusion imaging combined with isosorbide dinitrate (ISDN) infusion to detect myocardial viability in patients with chronic coronary artery disease before and after revascularization.Methods and Results
Twenty-seven consecutive patients with previous myocardial infarction and left ventricular dysfunction (left ventricular ejection fraction 35.2%±13.5%) referred for coronary artery bypass (CABG) were studied with 99mTc-labeled MIBI single-photon emission computed tomograpy at rest and during ISDN infusion before CABG followed by resting imaging after CABG. Quantitative analysis was performed with circumferential profiles. Left ventricular function (global and regional) was assessed by radionuclide ventriculography before and after CABG. Out of 212 abnormal perfusion segments with resting 99mTc-labeled MIBI SPECT, 99 segments (47%) showed improved uptake of 99mTc-labeled MIBI during ISDN infusion. The mean ratio of myocardial uptake was 0.58±0.25 (resting 0.53±0.23; p<0.05). After CABG, of 212 segments with hypoperfusion, 108 segments (51%; p>0.05 vs ISDN) showed improved uptake of 99mTc-labeled MIBI. The mean ratio of myocardial uptake was 0.60±0.26 (resting 0.53±0.23; p<0.05). The concordance between the improvement of post-CABG wall motion and that of pre-CABG ISDN perfusion imaging was 83%, between the improvement of wall motion and perfusion imaging after CABG 94%, and between the improvement of pre-CABG ISDN and post-CABG perfusion imaging 83%, respectively.Conclusion
ISDN infusion can improve the uptake of 99mTc-labeled MIBI in hypoperfused myocardium and increase the efficiency of 99mTc-labeled MIBI in the detection of viable myocardium in patients with previous myocardial infarction and left ventricular dysfunction. 相似文献13.
Alberto Cuocolo Wanda Acampa Emanuele Nicolai Leonardo Pace Mario Petretta Marco Salvatore 《Journal of nuclear cardiology》2000,7(1):8-15
Background This study was designed to determine the most effective quantitative threshold for thallium-201 and technetium 99m sestamibi
uptake on tomographic imaging after rest injection for the detection of myocardial viability in patients with chronic myocardial
infarction.
Methods and Results Thallium and sestamibi cardiac tomography at rest was performed in 43 patients with chronic myocardial infarction and impaired
left ventricular (LV) function undergoing coronary revascularization. In all patients, echocardiography and radionuclide angiography
were performed at baseline and repeated 12 months later to evaluate recovery of regional LV function and LV ejection fraction,
respectively. Optimal threshold cutoff points to separate reversible from irreversible dysfunction were determined by receiver
operating characteristic analysis. When all dysfunctional segments were considered, the best cutoff point in the identification
of reversible LV dysfunction for both thallium and sestamibi activity was 67%. When only akinetic or dyskinetic segments were
considered, the best cutoff point in the identification of reversible LV dysfunction was 58% for thallium and 55% for sestamibi.
In these segments, the area under the receiving operating characteristic curves constructed for thallium and sestamibi activity
were 0.74±0.05 and 0.75±0.04, respectively (P=not significant). LV ejection fraction was 33%±7% at baseline and increased to 37%±7% after revascularization (P<.0001). A significant relation between the number of akinetic or dyskinetic but viable myocardial segments and revascularization-induced
changes in LV ejection fraction was observed for both thallium (r=0.60, P<.0001) and sestamibi (r=0.64, P<.0001) imaging.
Conclusions In patients with chronic myocardial infarction, quantitative analysis of thallium and sestamibi activity on tomographic imaging
at rest predicts recovery of regional and global LV dysfunction after revascularization procedures. The most effective quantitative
threshold for detecting reversible LV dysfunction is comparable for thallium and sestamibi tomographic imaging. However, the
optimal cutoff point is different for both tracers when all dysfunctional segments are considered or when the analysis is
focused only on segments with more severe functional impairment (ie, akinetic or dyskinetic segments). 相似文献
14.
Heyne JP Rzanny R Hansch A Leder U Reichenbach JR Kaiser WA 《European radiology》2006,16(8):1796-1802
Hypertensive heart disease (HHD) causes structural changes (e.g., fibrosis) that result in diastolic and systolic myocardial dysfunction. Alterations of 31P metabolism and cardiac energy impairments were assessed in patients with HHD by MR spectroscopy (MRS) and correlated with left ventricular systolic function. Thirty-six patients with HHD and 20 healthy controls (mean age 35.2±10.7 years) were examined with 31P-MRS at 1.5 T by using an ECG-gated CSI sequence. Twenty-five patients (mean age 64.3±9.3 years) had diastolic dysfunction, but preserved systolic function (HHD-D), whereas 11 patients (62.3±11.4 years) suffered from additional impaired systolic function (HHD-S). In both patient groups, the PCr/γ-ATP ratio was lower than in the controls (controls: 2.07±0.17; P<0.001), and in HHD-S was lower than in HHD-D (1.43±0.21 vs. 1.65±0.25; P=0.012). PCr/γ-ATP ratios were linearly correlated with LVEF (Pearson's r: 0.39; P=0.025). In the HHD-S group, the PDE/γ-ATP ratio was significantly lower (0.56±0.36) than in the controls (1.14±0.42; P=0.001). In contrast to the group of HHD-D patients, whose slightly decreased PCr/γ-ATP ratios compared to controls may be explained by age differences, the more distinct changes observed in HHD-S patients indicate an altered energy metabolism. The observed metabolic changes were related to functional impairments, as indicated by a reduced LVEF. Reduced PDE/ATP ratios indicate changes in the phospholipid metabolism. 相似文献
15.
Nobukazu Takahashi Yoshio Ishida Masakazu Maeno Yoshiaki Hirose Shigeo Kawano Shyuji Fukuoka Kohei Hayashida Sachio Kurbayashi Seiki Hamada Naoaki Yamada Makoto Takamiya Katuro Shimomura Tohru Ohe 《Annals of nuclear medicine》1997,11(3):233-241
We examined the feasibility of myocardial123I-MIBG,201TlCl, magnetic resonance imaging (MRI) and ultrafast computed tomography (UFCT) for the early detection of left ventricular involvements in 15 patients with arrhythmogenic right ventricular dysplasia (ARVD). Radionuclide ventriculography (RNV) and myocardial imaging with123I-MIBG,201TlCl, MRI and UFCT were performed in all 15 patients and in 10 normal subjects. The patients’ scans were visually interpreted by two nuclear medicine physicians taking into consideration the extent score (ES) and severity score (SS) calculated by using the bull’s-eye view in relation to normal data derived from the normal subjects. The left ventricular ejection fraction (LVEF) was measured by RNV. Fourteen (93%) patients showed regional123I-MIBG defects, while 12 (80%) patients showed regional201TlCl defects. The ES and SS were higher in123I-MIBG than201TlCl (ES: 31.5± 18.5 vs. 17.5+18.2, p < 0.01, SS: 34.8±42.2 vs. 16.9±37.5, p< 0.01). Abnormal UFCT and MRI findings suggesting fatty involvements of the LV myocardium were demonstrated in 7 patients (Group B), while 7 patients showed regional123I-MIBG defects without abnormal UFCT and MRI findings (Group A).123I-MIBG was significantly more sensitive than UFCT and MRI (p< 0.05), although one patient, an exception, showed abnormal UFCT findings for the apex of the LV myocardium without abnormal123I-MIBG and MRI findings. The LVEF, as a measure of LV systolic function, was better preserved in Group A than in Group B (59.3±3.6 vs. 45.8±5.8, p< 0.01). The present findings indicated that myocardial imaging with123I-MIBG sensitively detects myocardial damage in patients with ARVD in the early stage when cardiac systolic function is still preserved. 相似文献
16.
Saskia G.C. van Elderen MD Joost Doornbos PhD Einar H.R. van Essen MD Herman H.P.J. Lemkes MD J. Antonie Maassen PhD Jan W.A. Smit MD Albert de Roos MD 《Journal of magnetic resonance imaging : JMRI》2009,29(1):127-131
Purpose
To investigate high‐energy phosphate metabolism in striated skeletal muscle of patients with Maternally Inherited Diabetes and Deafness (MIDD) syndrome.Materials and Methods
In 11 patients with the MIDD mutation (six with diabetes mellitus [DM] and five non‐DM) and eight healthy subjects, phosphocreatine (PCr) and inorganic phosphate (Pi) in the vastus medialis muscle was measured immediately after exercise using 31P‐magnetic resonance spectroscopy (MRS). The half‐time of recovery (t1/2) of monoexponentially fitted (PCr+Pi)/PCr was calculated from spectra obtained every 4 seconds after cessation of exercise. A multiple linear regression model was used for statistical analysis.Results
Patients with the MIDD mutation showed a significantly prolonged t1/2 (PCr+Pi)/PCr after exercise as compared to controls (13.6±3.0 vs. 8.7±1.3 sec, P = 0.01). No association between the presence of DM and t1/2 (PCr + Pi)/PCr was found (P = 0.382).Conclusion
MIDD patients showed impaired mitochondrial oxidative phosphorylation in skeletal muscle shortly after exercise, irrespective of the presence of DM. J. Magn. Reson. Imaging 2009;29:127–131. © 2008 Wiley‐Liss, Inc. 相似文献17.
The identification of myocardial viability in the setting of left ventricular (LV) dysfunction is crucial for the prediction of functional recovery following revascularization. Although echocardiography, positron emission tomography (PET), and nuclear imaging have validated roles, recent advances in cardiac magnetic resonance (CMR) technology and availability have led to increased experience in CMR for identification of myocardial viability. CMR has unique advantages in the ability of magnetic resonance spectroscopy (MRS) to measure subcellular components of myocardium, and in the image resolution of magnetic resonance proton imaging. As a result of excellent image resolution and advances in pulse sequences and coil technology, magnetic resonance imaging (MRI) can be used to identify the transmural extent of myocardial infarction (MI) in vivo for the first time. This review of the role of CMR in myocardial viability imaging describes the acute and chronic settings of ventricular dysfunction and concepts regarding the underlying pathophysiology. Recent advances in MRS and MRI are discussed, including the potential for dobutamine MRI to identify viable myocardium and a detailed review of the technique of delayed gadolinium (Gd) contrast hyperenhancement for visualization of viable and nonviable myocardium. 相似文献
18.
Massimo Ciavolella Cesare Greco Rosanna Tavolaro Gaetano Tanzilli Francesco Scopinaro Pietro Paolo Campa 《Journal of nuclear cardiology》1998,5(2):128-133
Background Trimetazidine is an antiischemic drug protecting the myocardium from ischemic damage through the preservation of mitochondrial
oxidative metabolism, without any hemodynamic effect. 99mTc-sestamibi is accumulated by myocytes according to mitochondrial function. As mitochondrial metabolism is thought to be
present in hibernating myocardium, the aim of the study was to investigate trimetazidine effects on infarcted and eventually
hibernating myocardial areas by means of 99mTc-sestamibi perfusional scintigraphy, comparing them to postoperative recovery of wall motion.
Methods and Results Twelve patients with previous myocardial infarction underwent 2 perfusion imaging tomographic studies at rest with 99mTc-sestamibi, receiving placebo or trimetazidine (60 mg orally), and subsequently underwent revascularization procedures.
An echocardiographic study was carried out before and >3 months after revascularization. At polar map analysis of placebo
scan, infarcted vascular territories (wall motion score index: 2.65±0.31) showed 73.7%±10.4% of the territory with activity
<2.5 SD from the mean of normals, for a severity (expressed as the sum of the standard deviations below average normal values
in all abnormal pixels) of 833.8±345.7. Polar map analysis of the trimetazidine scan showed tracer uptake increased significantly
in 11 of them, by 8.2%±3.0% (p<0.001) and by 180.3±111.0 SD (p<0.001), respectively. Postoperative wall motion score index improved significantly in 9 of these territories (−0.9±0.4, p<0.001).
Conclusions Trimetazidine-associated increase in 99mTc-sestamibi uptake in infarcted but viable myocardial areas is probably related to an improvement in mitochondrial oxidative
metabolism that is essential to 99mTc-sestamibi retention. Additionally, coupling trimetazidine administration to 99mTc-sestamibi perfusional scintigraphy may represent a means of detecting viable myocardium. 相似文献
19.
Brodoefel H Klumpp B Reimann A Ohmer M Fenchel M Schroeder S Miller S Claussen C Kopp AF Scheule AM 《European radiology》2007,17(2):475-483
The purpose was to assess the practicability of low-dose CT imaging of late enhancement in acute infarction. Following temporary
occlusion of the second diagonal branch, seven pigs were studied by multislice computed tomography (MSCT) and magnetic resonance
imaging (MRI). Thus, 64-slice CT was performed at 3, 5, 10 and 15 min following the injection of contrast medium according
to a bolus/low-flow protocol. Standard parameters of 120 kV and 800 mAs were compared with 80 kV and 400 mAs in various combinations.
Infarct volumes were assessed as percentage of the ventricle for both MSCT and MR images. CT density values for viable and
infarcted myocardium were obtained and image quality assessed. Mean infarct volume as measured by MRI was 12.33±7.06%. MSCT
achieved best correlation of volumes at 5 and 10 min. Whilst lowering of tube current resulted in poor correlation, tube voltage
did not affect accuracy of infarct measurement (r
2=0.92 or 0.93 at 5 min, 800 mAs and 80 or 120 kV). In terms of image quality, greater image noise with 80 kV was compensated
by significantly better contrast enhancement between viable and non-viable myocardium at lower voltage. Myocardial viability
can accurately be assessed by MSCT at 80 kV, which ensures higher contrast for late enhancement and yields good correlation
with MRI.
A.F. Kopp and A.M. Scheule contributed equally to this study 相似文献
20.
The objective of this study was to determine and compare if MR contrast agents distributed into various compartments can
provide estimation of fractional distribution volume (FDV) in normal and infarcted myocardium using inversion recovery echo-planar
MR imaging (IR EPI). Three different types of MR agents were investigated: (a) an extracellular agent, GdDTPA-BMA (0.1 mmol/kg);
(b) an intravascular agent, GdDTPA-albumin (0.025 mmol/kg); and (c) an intracellular agent, manganese chloride (0.025 mmol/kg).
The null point was determined from a series of IR EPI images in which TI was varied. Temporal changes in ΔR1 (ΔR1 = 1/T1post-1/T1pre) were measured during the initial 29–59 min after administration. Rats (n = 24) were subjected to 1-h coronary artery occlusion/reperfusion. Histochemical staining confirmed the presence and location
of infarction. GdDTPA-BMA caused increase in ΔR1 of infarction < blood < < normal myocardium. ΔR1 ratios were 1.55 ± 0.08
for infarction and 0.33 ± 0.03 for normal myocardium, consistent with FDV of 0.82 ± 0.04 and 0.18 ± 0.01. The fractional distribution
of this agent in normal myocardium approximated the extracellular space of myocardium. GdDTPA-albumin caused increase in ΔR1
of blood < < infarction < < normal myocardium. ΔR1 ratio in normal, but not infarcted, myocardium was constant at 0.10 ± 0.02
and approximated fractional blood volume. MnCl2 caused equivalent increase in ΔR1 of normal and infarcted myocardium. ΔR1 of normal myocardium did not change overtime, whereas
ΔR1 of blood rapidly decreased, leading to overestimation of FDV in normal and infarcted myocardium. In conclusion, extracellular,
intravascular and intracellular MR contrast agents exhibited different T1-relaxation kinetics in both normal and infarcted
myocardium. Constant ΔR1 ratio (myocardium/blood) after administration of MR contrast agent is a prerequisite for estimation
of FDV of MR contrast agent in myocardium.
Received: 22 December 1998; Revised: 7 April 1999; Accepted: 18 May 1999 相似文献