Regional lung function evaluation with nitrogen-13

Ahluwalia, B.; Brownell, G.L.; Hales, Charles A.; Kazemi, Homayoun

doi:10.1007/bf00252802

Cited by 5 publications

(3 citation statements)

References 8 publications

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“…Molecular nitrogen labeled with N-13 has been utilized in evaluating regional pulmonary ventilation and perfusion. 22 Since it has a half-life of 10 min, serial studies can be performed. To evaluate whole lung function, a positron camera that images the entire lung has been used.…”

Section: Applicationsmentioning

confidence: 99%

New Imaging Modalities for Evaluating Pulmonary Disease

Frankel¹,

Coleman²

1983

Semin Respir Crit Care Med

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Several new imaging modalities that will be used clinically or in the research laboratory to study pulmonary diseases are being developed. These new techniques include single photon emission computed tomography (SPECT), positron emission tomography (PET), and nuclear magnetic resonance (NMR) imaging. These noninvasive techniques offer much promise for the development of quantitative metabolic, chemical, and blood flow studies of the pulmonary system.The early principles of tomographic imaging were developed for utilization in determining isotope distributions, 1 but the appropriate equations for quantitative studies were developed by Cormack 2 and applied by Hounsfield 3 to x-ray computed tomography. After x-ray computed tomography was developed, the new areas of PET and SPECT became possible. Although positron tomography has been discussed for many years, the development of the positron emission tomograph by Phelps, Ter-Pogossian, and Hoffman 4 permitted the field of positron tomography to develop. Positron emission tomography has been slow to develop in multiple centers owing to the necessity of having a cyclotron in addition to the positron tomograph. Furthermore, the chemistry for the development of appropriate radiopharmaceuticals has been developed only in the last few years. Since the chemistry has been simplified and smaller cyclotrons are becoming available to produce these radioisotopes, the techniques of positron tomography will be available to more centers in the future. PET studies can be used to gain additional information on pulmonary embolism, lung density changes, tumor metabolism, and possibly drug and hormone receptors and metabolism.Single photon emission computed tomography has developed along two lines: the scannerbased systems 5 and the camera-based systems. 6 An advantage of SPECT is that it can perform tomographic imaging of the radioisotopes available in nuclear radiology facilities. Studies with SPECT can be used to gain additional information in patients with pulmonary embolism and potentially to evaluate pulmonary metabolism and to quantitate pulmonary perfusion.The techniques of nuclear magnetic resonance have been utilized for many years by chemists. Recently these techniques have been applied to imaging of the body. 7 Although the initial studies have utilized information concerning hydrogen atoms (protons), a potential exists for doing quantitative metabolic studies such as phosphorus spectroscopy. 8 Nuclear magnetic resonance studies offer an advantage over the other techniques in that no ionizing radiation is utilized. There are no known effects from the large magnetic fields or the radiofrequency signals the patients are being exposed to. NMR will be applied to the determination of lung water and the evaluation and characterization of lung and mediastinal tumors.A discussion of the technical aspect of the three modalities is included in this review. Only a limited number of studies evaluating the pulmonary system have been performed with these new technologies. Many of the stud...

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Section: Applicationsmentioning

confidence: 99%

New Imaging Modalities for Evaluating Pulmonary Disease

Frankel¹,

Coleman²

1983

Semin Respir Crit Care Med

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“…8,9 Specifically, it has been part of routine preoperative evaluation for lung cancer resection or bullectomy in patients with chronic obstructive pulmonary disease and for assessment of pulmonary emboli in presence of chronic obstructive disease. 10 Mismatch between ventilation and perfusion is often observed in these disorders as a result of uneven pulmonary blood distribution. 10,11 We hypothesized that much greater pulmonary vasoconstriction would be induced by acute alveolar hypoxia in HAPE-s subjects compared with controls and that changes in pulmonary blood flow distribution could be demonstrated by ventilation-perfusion scintigraphy.…”

mentioning

confidence: 99%

“…10 Mismatch between ventilation and perfusion is often observed in these disorders as a result of uneven pulmonary blood distribution. 10,11 We hypothesized that much greater pulmonary vasoconstriction would be induced by acute alveolar hypoxia in HAPE-s subjects compared with controls and that changes in pulmonary blood flow distribution could be demonstrated by ventilation-perfusion scintigraphy. The present study was designed to examine ventilatory and pulmonary hemodynamic responses to acute hypoxia in HAPE-s subjects and to identify pathophysiological correlates of HAPE susceptibility.…”

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confidence: 99%

Hypoxia-Induced Pulmonary Blood Redistribution in Subjects With a History of High-Altitude Pulmonary Edema

Hanaoka

Tanaka

et al. 2000

Circulation

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Background-Pulmonary hypertension has been suggested to play an important role in development of high-altitude pulmonary edema (HAPE), and individual susceptibility has been suggested to be associated with enhanced pulmonary vascular response to hypoxia. We hypothesized that much greater pulmonary vasoconstriction would be induced by acute alveolar hypoxia in HAPE-susceptible (HAPE-s) subjects and that changes in pulmonary blood flow distribution could be demonstrated by radionuclide study. Methods and Results-We performed ventilation-perfusion scintigraphy in 8 HAPE-s subjects and 5 control subjects while each was in the supine position and acquired functional images of pulmonary blood flow and ventilation under separate normoxic and hypoxic (arterial oxygen saturation, 70%) conditions. We also measured acceleration time/right ventricular ejection time (AcT/RVET) with Doppler echocardiography under each condition in both groups. Moreover, we assayed human leukocyte antigen (HLA) alleles serologically in the HAPE-s group. Pulmonary blood flow was significantly shifted from the basal lung region to the apical lung region under hypoxia in HAPE-s subjects, although no significant change in regional ventilation was observed. With Doppler echocardiography, HAPE-s subjects showed increased pulmonary arterial pressure during hypoxia compared with control subjects. The magnitude of cephalad redistribution of lung blood flow was significantly higher in the HLA-DR6 -positive than in HLA-DR6 -negative HAPE-s subjects. Conclusions-These findings suggest that acute hypoxia induces much greater cephalad redistribution of pulmonary blood flow that results from exaggerated vasoconstriction in the basal lung in HAPE-s subjects. Furthermore, pulmonary vascular hyperreactivity to hypoxia may be associated with HLA-DR6.

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