No abstract available.
Kidney* ; Perfusion* ; Radionuclide Imaging*

Scince 201Tl was introduced as a myocardial perfusion imaging agent in the early 1970s, scintigraphic evaluation of myocardial perfusion for the diagnosis of coronary artery disease is a valuable noninvasive diagnostic imaging modality. Stress radionuclide myocardial perfusion imaging is widely accepted to have high diagnostic and prognostic use in the assessment of patients with known or suspected coronary artery disease. With wise use of this nonivasive imaging technique, more patients are referred for stress perfusion imaging. Until now various protocols for stress testing and myocardial imaging were developed and used in worldwide. This article presented various protocols of stress testing and myocardial imaging for clinical use.
Coronary Artery Disease ; Diagnostic Imaging ; Exercise Test ; Humans ; Myocardial Perfusion Imaging ; Perfusion ; Perfusion Imaging

BACKGROUND: Traditional visual reading of patch-test reactions is a rather subjective method, lacking the sensitivity and reproducibility needed in experimental studies. Recently the laser Doppler perfusion imaging (LDPI) has been used to measure objectively the increase in superficial blood flow which results in the appearance of erythema. OBJECTIVE: We designed this study to examine the relationship between the LDPI measurement and visual reading after patch test to several different irritants. METHODS: In this study, reading of erythema in experimentally-induced irritant contact dermatitis was performed visually and by laser Doppler perfusion imaging (LDPI). In addition, we investigated whether the LDPI measurement was appropriate in the routine patch test clinic. RESULTS: A close correlation was shown between the 2 methods (r=0.9046, p<0.001) and the LDPI producing mean adjusted perfusion values (APVs) was able to discriminate between the different visual grades. CONCLUSION: LDPI is a valuable instrument to objectively assess intensity of irritant patch-test reaction, and is indeed one of the few methods which overcomes the inter-individual variations in visual reading, but this instrument is not appropriate to use routinely in patch test clinic because of unacceptably long measurement time.
Dermatitis, Contact ; Erythema ; Irritants ; Methods ; Patch Tests ; Perfusion Imaging* ; Perfusion*

PURPOSE: The aim of this study is to better understand the pattern and nature of reverse redistribution (RR) in myocardial perfusion imaging. MATERIALS AND METHODS: In consecutive 20 acute myocardial infarction (MI) patients, frequency of RR was correlated with that of subendocardial MI that was detected by myocardial contrast echocardiography (MCE). RR was judged to be present when there was more than one grade of worsening in perfusion at 24 hr delayed images compared with the initial rest images. MCE evaluated the significant lack of opacification in the subendocardial myocardium relative to the subepi-cardial myocardium to suggest the subendocardial MI. Kendall's nonparametric correlation coefficiency was calculated. RESULTS: Concordant cases were 15 of 20 (75%) and correlation was statistically significant (p=0.0285). CONCLUSION: Our results suggested that RR was correlated with MCE-detected nontransmural MI.
Echocardiography* ; Humans ; Myocardial Infarction* ; Myocardial Perfusion Imaging ; Myocardium ; Perfusion

PURPOSE: To compare the results of harmonic ultrasound (US) renal perfusion imaging using 99mTc-DTPA as contrast agent with those obtained when a microbubble contrast medium was used. MATERIALS AND METHODS: Twenty rabbits underwent harmonic US renal perfusion imaging using 99mTc-DTPA as contrast agent, and the imaging procedure was then repeated using a microbubble contrast medium. Three different concentrations of contrast media (200, 300 and 400 mg/ml) and two different scanning techniques (intermittent and continuous) were used, and the images obtained were assessed using six different methods. By means of a computer program, the images were converted to a renal perfusion curve and Tpeak values were calculated. Images obtained after use of the two different contrast media were compared. RESULTS: Tpeak at renal perfusion imaging using 99mTc-DTPA was 6.3+/-0.9 sec, and where microbubble contrast agent was used, the findings were was as follows: 13.8+/-1.6 sec (method 1), 6.5+/-1.1 sec (method 2), 14.8+/-1.7 sec (method 3), 6.6+/-1.0 sec (method 4), 15.2+/-2.0 sec (method 5), 6.4+/-0.7 sec (method 6). Method 6 had the highest correlation coefficients. CONCLUSION: In conclusion, the harmonic ultrasound renal perfusion images acquired using 99mTc-DTPA were similar to those obtained using microbubble contrast agent. Continuous scanning techniques showed correlation.
Contrast Media ; Microbubbles ; Perfusion Imaging ; Perfusion* ; Rabbits ; Ultrasonography*

Contrast echocardiography is broadly described as a variety of techniques whereby the blood pool on cardiac ultrasound is enhanced with encapsulated gas-filled microbubbles or other acoustically active nano- or microparticles. The development of this technology has occurred primarily in response to the need improve current diagnostic applications of echocardiography such as the need to better define left ventricular cavity volumes, regional wall motion, or the presence or absence of masses and thrombi. A secondary reason for the development of contrast echocardiography has been to expand the capabilities of echocardiography. These new applications include myocardial perfusion imaging for detection of ischemia and viability, perfusion imaging of masses/tumors, and molecular imaging. The ability to fill all of these current and future clinical roles has been predicated on the ability to produce robust contrast signal which, in turn, has relied on technical innovation with regards to the microbubble contrast agents and the ultrasound imaging paradigms. In this review, we will discuss the basics of contrast echocardiography including the composition of microbubble contrast agents, the unique imaging methods used to optimize contrast signal-to-noise ratio, and the clinical applications of contrast echocardiography that have made a clinical impact.
Contrast Media ; Echocardiography* ; Ischemia ; Microbubbles ; Molecular Imaging ; Myocardial Perfusion Imaging ; Perfusion Imaging ; Signal-To-Noise Ratio ; Ultrasonography

Arterial spin labeling is a noninvasive,quantitative method for perfusion imaging,which does not need any contrast media.This technique has been used in the renal perfusion analysis.In this article,we briefly introduced this technique and summarized its application in healthy volunteers,acute kidney injury,chronic kidney diseases,renovascular diseases,renal tumors,and renal transplantation.
Humans ; Kidney/diagnostic imaging* ; Magnetic Resonance Imaging ; Perfusion ; Perfusion Imaging ; Renal Insufficiency, Chronic ; Spin Labels

In this work practical considerations of a pulsed arterial spin labeling MRI are presented to reliable multi-slice perfusion measurements in the human brain. Three parameters were considered in this study. First, in order to improve slice profile and inversion efficiency of a labeling pulse a high power inversion pulse of adiabatic hyperbolic secant was designed. A 900o rotation of the flip angle was provided to make a good slice profile and excellent inversion efficiency. Second, to minimize contributions of a residual magnetization between interleaved scans of control and labeling we tested three different conditions which were applied 1) only saturation pulses, 2) only spoiler gradients, and 3) combinations of saturation pulses and spoiler gradients. Applications of both saturation pulses and spoiler gradients minimized the residual magnetization. Finally, to find a minimum gap between a tagged plane and an imaging plane we tested signal changes of the subtracted image between control and labeled images with varying the gap. The optimum gap was about 20 mm. In conclusion, in order to obtain high quality of perfusion images in human brain it is important to use optimum parameters. Before routinely using in clinical studies, we recommend to make optimizations of sequence parameters.
Brain* ; Humans* ; Magnetic Resonance Imaging* ; Perfusion*

No abstract available.
Extremities ; Ischemia ; Magnetic Resonance Imaging ; Oxygen ; Perfusion

OBJECTIVES: To identify diagnostically meaningful differences between Warthin's tumor and malignant masses in the parotid gland by dynamic susceptibility contrast (DSC) MR imaging. METHODS: Eleven malignant parotid tumors and 9 Warthin's tumors were included. MR imaging was performed on all patients. Signal intensity time curves of tumors were obtained by DSC MR imaging and dynamic susceptibility contrast percentages (DSC%) were calculated. RESULTS: No significant difference was observed between malignant tumors and Warthin's tumors (P = 0.437), although DSC% values tended to be higher for Warthin's tumors. CONCLUSIONS: Warthin's tumor tended to have higher DSC% values than malignant parotid tumors, but this difference was not significantly different.
Humans ; Magnetic Resonance Imaging ; Parotid Gland ; Perfusion