Lungs, imaging

The intravenous dose of albumin microspheres containing Tc 99m for lung imaging is equivalent of 4 mCi. Express this dose in terms of megabecquerels. 

FIG. 1. Fast 1 -min SPECT coronal-section lung images of a healthy subject after inhalation of normal saline aerosols containing TC-DTPA in large and small droplet sizes (7 im, top panel 3 pm, bottom panel) generated by air jet nebulizers. The difference in deposition between the two aerosols is clearly shown in these images. 

Figure 13 Applying the PET shell analysis program to the lung images. One transmission slice from each of the coronal, transaxial, and sagittal planes is illustrated. The number of shells will vary with the geometry (cross-sectional area) of the slice. The shell configurations, obtained for the transmission scan slices, are then superimposed on the emission scans, slice by slice, providing volume and activity information related to the distribution of drug within the lung.

Taplin GV, Chopra S, Yanda RL, et al. 1976. Radionuclidic lung-imaging procedures in the assessment of injury due to ammonia inhalation. Chest 69 582-586. 

Heck LL, Duley JW Jr (1974) Statistical considerations in lung imaging with Tc-99m-albumin particles. Radiology 113 675-679... 

S. Lam, C. MacAulay, J. Hung, et al. (1993). Detection of dysplasia and CIS with a lung imaging fluorescence endoscopy device. J. Thorac. Cardiovasc. Surg., 105, 1035-1040. 

Logus JW, Trajan, M Hooper HR, Lentle BC, Mann SFP. Single photon emission tomography of lungs imaged with Tc-labelled aerosol. J Can Assoc Radiol 1984 35 133-138. 

An example of the current state of the art is the HP xenon lung image in a rat shown in Fig. 19, which illustrates an impressive level of detail. The in-plane resolution of the 3D image is 0.39 x 0.39 mm, with a field of view of 5 cm. A 100 mL xenon/oxygen bolus was delivered over the course of 80 breaths, and the image was acquired using a radial projection encoding sequence. 

To date, clinical HP gas imaging is still awaiting FDA approval, largely because of concerns for respiratory safety. Because xenon is known to be an anesthetic, He is likely to be approved earlier. This coupled with He s higher sensitivity has made it the focus of most of the recent lung imaging studies. 

Figure 10.14 Bedside screen where the patient s lung images can be continually followed.

Specialize and find the most promising medical application (e.g., lung imaging at bedside). 

Particulate radiopharmaceuticals rely on a specific particle size to be effective. For example, technetium ( Tc )-macroaggregates of human serum albumin (MAA) (for use in lung imaging) have a particle size... 

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