抄録
The usefulness of scanning for detecting a lung lesion has been extended by developing radiopharmaceuticals (i. e. MAA and 113mIn iron hydroxide) and scintillation camera, The attractiveness of the scintillation camera was enable to investigate both perfusion and ventilation of the lung quantitatively with 133Xe.
As above mentioned, merit of the lung scanning as a function test could be obtained in easy detecting imbalance of perfusion and ventilation.
Author examined 186 cases of diseases of the lung in the Division of Radioisotope at the Ilnd Tokyo National Hospital, from Jan, through Aug., 1970, and we observed the lung scintiphotography in 101 cases who showed well defined clinical courses.
The scintiphotographs were made by scintillation camera with Aloca XYS-203. After 5 min. intravenous administration of 200 μCi 131I-MAA on the supine position, minute quantities in every scintiphotographs of the lung was estimated. This procedure was repeated on the prone and lateral position. 133Xe was measured by Hisada's method, in which using a close circuit with O2 inhalation, when the highest lung uptake value were observed after one shot of intravenous administration of 133Xe solution, the scintiphotos and regional quantities were obtained (perfusion scan), Then expired 133Xe gas was inspirated again with a close circuit (inhalation scan). Thereafter, we checked up the deposition in the lung by wash-outing uuder a open circuit (wash-out scan). Quantitative interpretation could be performed by the value of these 3 stages.
As compared with the pulmonary angiography and bronchospirometry the pulmonary lesion could be detected easily, early, visibly, repeatedly and safely by the scintillation camera, on the other hand resolution and quantitation are slightly inferior to the others.
Author revealed 6 scintigraphic patterns of lung perfusion scan, which are as followings.
I Normal
II Hypoactivity without definite cold areas
a) partial area
b) a single lung area
III Uneven distribution of radioactivity with cold zones
a) patchy defcets
b) clear-cut cold area less than or over one third of a single lung area
IV Cold zone is occupied a single lung area
According to this classification, pulmonary hilar cancer is associated with absent pulmonary arterial perfusion in the corresponding territories, and bronchiectasis can be detected with IIIa pattern; this findings may be reflected by the chronic inflammation and bullous emphysema. In the detection of multiple pulmonary microembolism two-fold scintigraphic pattern consisting of 1) decreased radioactivity along the interlobar fissure (fissural visualization) and 2) apparent diminution in the size of involved lobes (shrunken lobe) is presented peculiarly. Various kinds of scintiphotographic findings in lung fibrosis may be considered as emphysematous bullosis and chronic inflammation. In general, scintiphotograph in aged person is various, so it can't be represented complete patho-physiological states. Although congenital bronchial stenosis revealed IIb pattern, it should be investigated by bronchospirometry or 133Xe, because scintiphotographs with MAA would be limited to representation of the lung lesions.
The application of 133Xe to scintillation camera seems to be excellent, for this technique is used together with perfusion scan, ventilation scan and washout scan.
Seven scintiphotographic patterns are described; complete bronchial obstruction, partial bronchial obstruction, bronchiolar obrtruction, anatomical changes in the pulmonary parenchyma, obstructive pulmonary emphysema, intrapulmonary shunt and anatomical and functional pulmonary obstruction.
Pulmonary scintiphotography does not indicate the cause of pulmonary lelions, but it points out existence and localization of pathological processes of the lung, so it becomes the indicator to
