WHAT IS THIS IMAGE?
WHAT IS THIS IMAGE? 2017: IMAGE 1 RESULT
Incidental detection of RIB fractures
with Tc-99m pyrophosphate scanning
A 77-year-old man with history of atrial ﬁbrillation
and hepatocellular carcinoma with a prior liver transplant
developed pneumonia and suffered an in-hospital hypoxic
respiratory arrest requiring 3 minutes of CPR with return
of circulation. Two weeks after discharge, he presented
with dyspnea, bilateral pleural effusions, and lower
extremity edema. He was treated for heart failure, and an
echocardiogram demonstrated normal ejection fraction
with left ventricular hypertrophy. An electrocardiogram
demonstrated low-voltage QRS complexes in the inferior
leads. Amyloidosis was suspected, and a Tc-99m
pyrophosphate scan was conducted (Figure 1).
Figure 1 shows a Tc-99m pyrophosphate scan,
where no myocardial uptake of tracer was seen. Thus,
the likelihood of ATTR amyloidosis as a cause of this
Tc-99m pyrophosphate scan demonstrating radiotracer uptake in the
mid sternum and on lateral aspects of the ribs. These coincide with the bony
stress points from CPR.
patient’s heart failure is low. However isotope uptake
was noted in the sternum and several ribs. CT imaging
performed immediately post arrest showed evidence of
rib fractures (Figure 2), but an intact sternum (Figure 3).
Osteoblastic activity involves the active deposition of
pyrophosphate into bone matrix. Radionuclide scintigraphy
with Tc-99m PYP scanning is an extremely sensitive marker
of bone remodeling.
Stress or ‘hairline’ fractures can also be
detected by this method. Fractures between 24 hours and 6
months are generally PYP avid, with 90% not showing PYP
uptake after 2 years.
There is considerable heterogeneity in
the patterns of bone tracer uptake by the sternum.
There were 52 responses of which 54% were correct.
Other responses included leukemia, metastatic lesions,
amyloidosis, sarcoidosis, strontium breakthrough image
following rubidium-82 MPI, osteomyelitis, and PET
J Nucl Cardiol 2017;24:1131–2.
Copyright Ó 2017 American Society of Nuclear Cardiology.