CONCLUSION
SPECT bone scanning of the knee is superior to planar
imaging in detecting ACL injury and is a sensitive examination
in a population of patients predominantly with chronic ACL
tears. Sensitivity may be dependent on the chronicity of
symptoms although acute tears and both partial and complete
tears can be identified.
Focal activity at either end of the ACL attachments may be
seen, but the more common appearance is of a single, focal
abnormality in the medial aspect of the posterior, lateral femoral
condyle. This pattern has not been previously reported in
patients with acute tears and may therefore occur more fre
quently in those with chronic symptoms.
SPECT imaging of the knee may be a valuable examination
in suspected ACL injury particularly if MRI is not available, if
MRI is equivocal or if the clinical signs do not support a
diagnosis of ACL tears detected by MRI. In addition, knee
SPECT is able to localize other areas of injury within the knee
associated with ACL tears.
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Pediatrie Gastric Emptying: Value of Right Lateral
and Upright Positioning
Javier Villanueva-Meyer, Leonard E. Swischuk, Fernando Cesani, Seham A. Ali and Elma Briscoe
Sections of Nuclear Medicine and Pediatrie Radiology, Department of Radiology, University of Texas Medical Branch,
Galveston, Texas
Gastroesophageal reflux and gastric emptying are usually assessed
simultaneously with a 1-hr procedure. After ingestion of radiolabeled
formula sequential images are gathered when the infant is in the
supine position. This position is adequate for gastroesophageal
reflux assessment, but delays gastric emptying. Methods: We
studied 48 children, 1 wk to 2 yr of age, who presented with vomiting
or failure to thrive. They received 99mTc-sulphur colloid in formula.
After completing 1 hr supine imaging we obtained additional ab
dominal views after changing the position of the infant to right lateral
for 30 min, and upright for another 30 min. Results: The percent of
gastric emptying at 60 min in the supine position was 35% ±19%.
At 90 min, in the right lateral decubitus, the percent gastric emptying
was 60% ±25%. At 120 min, after an upright period, the gastric
emptying was 73% ±20%. In the supine position 19 of 48 patients
showed significant emptying (defined as >40% emptying). This
increased to 41 of 48 normal studies considering the right lateral
position and to 45 of 48 normal studies considering the infant
upright position. Conclusion: Many patients with delayed gastric
emptying show significant emptying just by changing position. We
routinely complement gastric emptying studies with delayed views
in the right lateral and upright position.
Key Words: delayed gastric emptying; pediatrie gastric emptying;
gastroesophageal reflux; technetium-99m-sulphur colloid
J NucÃ-Med 1996; 37:1356-1358
A concern in infants with recurrent pulmonary infections,
failure to thrive and vomiting is the presence of gastroesopha
geal reflux or delayed gastric emptying. Gastroesophageal
reflux is routinely assessed with radionuclide scintigraphy or
Received May 22, 1995; revision accepted Sept. 7, 1995.
For correspondence or reprints contact: Javier Villanueva-Meyer, MD, Section of
Nuclear Medicine, UTMB, Galveston, TX 77555-0793.
pH probing (1,2). The pH probe is the most sensitive method
but the radionuclide method, although less sensitive, is thought
to be more physiologic and is widely used (3). The association
of gastroesophageal reflux and delayed gastric emptying is
questionable (4-6) but it still is desirable to evaluate both in
one study. Many methods have been proposed to measure
gastric emptying: ultrasonic examination (7); epigastric imped
ance (8) and dual-isotope with combined solid and liquid meal
(9); and either liquid or formula (/ ). Of all these, the milk scan
is the most physiologic, allowing evaluation of gastroesopha
geal reflux and delayed gastric emptying in one setting. With
this procedure formula labeled with 99mTc-sulphur colloid
(99mTc-SC) is administered to the infant and images in the
posterior projection are gathered every minute seeking the
presence of gastroesophageal reflux. During the 1-hr acquisi
tion, the infant is in the supine position and gastric emptying is
assessed with the results reported as percent emptying or
retention at 1 hr or halftime emptying. The variability of these
results has been considerable and has cast doubt on the clinical
utility of the test in small infants (3-6,10-12).
In addition we encountered many discrepancies between
radiologie upper gastrointestinal series and nuclear gastric
emptying studies. We explored this discrepancy and decided
that positioning was a problem. The standard position in upper
gastrointestinal studies is right anterior oblique, with the right
side of the infant down, this enhances gastric emptying. Also,
this is more physiologic because babies are fed in the right
lateral semi-upright position.
In this study, at the end of 60 min supine imaging, we
gathered two additional views: one after changing the infant to
the right lateral decubitus, and another after holding the infant
1356 THEJOURNALOFNUCLEARMEDICINE•Vol. 37 •No. 8 •August 1996
