UNCORRECTED PROOF Nonosseous, Nonurologic Uptake on Bone Scintigraphy: Atlas and Analysis Lionel S. Zuckier, MD,* and Leonard M. Freeman, MD † Uptake in nonosseous, nonurologic tissues is occasionally found in the performance of bone scintigraphy. Proper interpretation of these cases depends on identifying the involved organs and appreciating the significance of the uptake. Because of the rarity of these findings and a relative de-emphasis of planar imaging in radiologic imaging, current era trainees may exhibit difficulty in identifying organs on planar projections. The first section of this work consists of an image atlas depicting uptake by various nonosseous, nonuro- logic organs on planar scintigraphy. In the second section, we discuss the etiologies of soft-tissue uptake, organized according to mechanisms of accretion: (1) metastatic calci- fication, (2) dystrophic calcification, (3) metabolic uptake, and (4) compartmental seques- tration. Spurious or artifactual uptake represents a fifth category of apparent soft-tissue uptake which will also be reviewed. Causes of organ uptake span the gamut of trivial and artifactual to those reflecting serious malignant and systemic disorders. Clues as to etiology may be gleaned from grouping of abnormalities. Semin Nucl Med xx:xxx © 2010 Published by Elsevier Inc. B one scintigraphy with the use of 99m Tc-labeled radiophar- maceuticals is a cornerstone of the practice of nuclear medicine and has remained a standard clinical technique for more than 4 decades. New technology, such as single-photon emission computed tomography-computed tomography, has helped bone scintigraphy remain relevant in the era of cross- sectional imaging. 1 The intended purpose of bone scintigra- phy is to portray areas of new bone formation within the skeleton, and it has proved to be a highly useful technique for this purpose, depicting reaction of bone to tumor, 2-4 frac- ture, 5 and infection. 6 Because approximately one half of the administered radiopharmaceutical is excreted via renal filtra- tion, abnormalities of the urinary system also frequently are noted during bone scintigraphy. 7-9 In this article we will re- view findings and significance in a third realm, uptake of bone scintigraphy radiopharmaceuticals by nonosseous, nonurologic organs and tissues. Rarely, abnormally increased uptake is observed in struc- tures other than bone and urinary tract, reflecting an atypical interaction between the radiopharmaceutical and patient. In such cases, to reach an accurate diagnosis, the interpreting physician must first recognize which structures are involved and then the significance of uptake. The exact location of uptake may be difficult to discern because of the unexpected nature of the finding. Furthermore, current-era trainees, pri- marily schooled in the intricacies of cross-sectional imaging, are less facile with planar imaging and may experience diffi- culty in identifying organs on various projections. The first section of this review will therefore consist of an image atlas depicting uptake by various nonosseous, nonurologic organs on planar scintigraphy. In the second section, we will discuss the etiologies of soft-tissue uptake, organized according to mechanisms of accretion. This review is meant to comple- ment several earlier treatments of this topic, 10-18 including multiple “Gamuts,” 19-31 which have appeared in this publica- tion. *New Jersey Medical School, University of Medicine and Dentistry, New Jersey, Newark, NJ. †Department of Nuclear Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY. Address reprint requests to: Lionel Zuckier, Department of Radiology, Uni- versity Hospital, H-125 150 Bergen Street, Newark, NJ. E-mail: Zuckier@umdnj.edu. 1 0001-2998/10/$-see front matter © 2010 Published by Elsevier Inc. doi:10.1053/j.semnuclmed.2010.02.003 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 tapraid2/zs1-snuc/zs1-snuc/zs199908/zs12135d08z nairre S=1 4/8/10 Art: 50292