Guidelines for radiology and nuclear medicine procedures taking call on nights and weekends: gastrointestinal bleeding, hepatobiliary and lung scans. It is interactive, e.g. using Keynote presentation software. PowerPoint

1. •GI bleed
•Hepatobiliary
•Ventilation/perfusion (V/Q) lung

2. 80-y.o. female with profuse rectal bleeding

3. 80 y.o. woman with profuse rectal
bleeding.
What is the diagnosis?
1. Normal
2. Technical problem
3. Large bowel bleed
4. Small bowel bleed
5. None of the above
0%
20%
40% 40%
0%
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%

4. Large bowel bleed, likely splenic
flexure, with some retrograde motion.
Blood stimulates peristalsis.

5. Large bowel bleed, likely splenic flexure, with some
retrograde motion. Blood stimulates peristalsis.

6. •Indication: GI bleed.
•Radiopharmaceutical: Tc-99m labeled
autologous red blood cells, 30 mCi. (In
vitro method for best tagging.)
•Image anterior abdomen:
•Flow: 1 sec/frame for 60 sec
•Function: 60 sec/frame for 60 min.
•Additional imaging may be needed.

7.  More sensitive than angiography. Rates of
the order of 0.2 -0.3 mL/min or less are
detected (angiography--~1 mL/min).
 Problem is that bleeding is intermittent.
 The main purpose is to identify the site.
This can aid in decisions re selective
angiography and surgical intervention.
 Most bleeding sites show a focus that
increases and changes position and/or
configuration with time.
 Sites seen in delayed imaging are uncertain
as to origin.
 Normal findings may include bladder urine
and male genitalia.

8. 67-y.o. male with black tarry stool
and decreasing hematocrit

9. 67-y.o. male with tarry stool and
decreasing hematocrit.
What is the diagnosis?
1. Normal
2. Technical problem
3. Large bowel bleed
4. Small bowel bleed
5. None of the above
44%
11% 11%
22%
11%
0%
10%
20%
30%
40%
50%

10. Normal. There can be variation in ap-
pearance of vascular compartment

11. 60-y.o. male with brb per rectum:

12. 62-y.o. male with brb per rectum

13. 62-.o. male with bright red blood
per rectum
What is the diagnosis?
1. Normal
2. Technical problem
3. Large bowel bleed
4. Small bowel bleed
5. None of the above
12%
38%
25%
0%
25%
0%
5%
10%
15%
20%
25%
30%
35%
40%

14.  This is more likely a technical problem than a
gastric bleed, because of bright red blood.
(Could be checked with gastroscopy.)
 Specifically, it is likely due to a poor tag and
free pertechnetate, which is taken up by the
stomach. A very inadequate tag may lead to a
false negative. Typically, pertechnetate is
taken up by thyroid and salivary glands, but
beware of absent or nonfunctioning thyroid.

16. 27-y.o female, RUQ pain.

17. RUQ pain
What should we do now?
1. Report normal study
2. Report acute
cholecystitis
3. Report other
abnormality
4. Administer sincalide
5. Administer
morphine
43%
14%
0% 0%
43%
0%
10%
20%
30%
40%
50%

18.  When the GB is not visualized
during 1 hour of imaging,
morphine, 0.04 mg/kg (max 5
mg) may be administered to
tighten the sphincter of Oddi
and make the cystic duct the
path of least resistance. Image 0.5
h.

19.  Morphine may be inadvisable or
contraindicated with hyperamylasemia (or
pancreatitis), narcotic addiction, history of
adverse reaction to morphine, respiratory
depression, increased intracranial pressure in
children, or if there is no bowel activity seen.

20. post morphine

21. Post-morphine images
What is the diagnosis?
1. Normal study
2. Acute cholecystitis
3. Chronic gallbladder
disease
4. Bile leak
5. Other abnormality
44%
11%
33%
11%
0%
0%
10%
20%
30%
40%
50%

22.  Chronic cholecystitis.

23.  Indication: Usually suspicion of acute
cholecystitis.
 Radiopharmaceutical: Tc-99m mebrofenin
(Choletec) IV, 5 mCi (10 with
hyperbilirubinemia). It is excreted in bile,
somewhat like bilirubin.
 Patient should be NPO 4-24 h, preferably no
opiods 4 h.
 Flow 1 sec/frame for 60 frames
 Function: 60 sec/frame for 60 min; 90 min if
for suspected biliary leak

24.  Sincalide =Kinevac= CCK-8.
 Physiologically active C-terminal octapeptide
of the polypeptide hormone cholecystokinin
(CCK). It produces gallbladder contraction and
sphincter of Oddi relaxation.
 Often called CCK, as in “Please do a HIDA
scan with CCK.”

25. Two basic uses of sincalide
 1. To avoid false positives
(nonvisualization of GB), “prime”
with 0.02 µg/kg in 50 ml normal
saline over 20 min, if patient has
been NPO > 24 h or on TPN,
conditions that cause GB distension
with viscous bile, and begin the
study 30 min later (time for GB to
relax).

26. Sincalide, continued
2. For the evaluation of upper
abdominal pain thought to be
biliary in origin, with
ultrasonographically normal
appearing gallbladder. After initial
imaging reveals GB visualization,
give 0.02 mcg/kg in normal saline
over 60 min. Image 60 sec/frame
during the full time of infusion.

27.  False positives may occur in hospitalized or
acutely ill patients because of their acute illness
and/or medications like morphine and other
opiates , benzodiazepenes, ethanol, octreotide,
nicotine, nifedipine, pirenzepine, progesterone,
theophylline (partial list).

28. Normal hepatobiliary scan
 Rapid uptake into the hepatic
parenchyma, rapid clearance of the
cardiac blood pool, followed by activity
in ductal system, GB and small bowel, all
within 1 h.
 Acute cholecystitis is diagnosed when
there is nonvisualization to 4 h or 30 min
after morphine. The hallmark of acute
cholecystitis is cystic duct obstruction,
hence nonvisualization of the GB.

29. 32-y.o. female with RUQ pain.

30. Sincalide administered for GBEF

31. Normal GBEF. Current normal for
1-h study is ≥38%

32. GBEF
 Usually ordered as such, nonemergently.
 May be appended to a normal inpatient
study (with provider’s authorization) for
chronic suspicious symptoms. Caution
recommended.
 “[The report of a positive result]
generally should conclude with a
statement…such as ‘In the appropriate
clinical setting, this is consistent with
functional gallbladder disorder’

33.  What is the condition we are
diagnosing? Various terms have
been used: gallbladder dyskinesia,
chronic acalculous gallbladder
dysfunction, acalculous biliary
disease, chronic acalculous
cholecystitis or biliary dyskinesia. To
prevent confusion, the authors have
proposed the term “functional
gallbladder disorder.”

34. 40-yo woman, RUQ pain, prior
adverse reaction to morphine

35. Images at 90 min and 4 h

36. Rim sign: A rim of activity above the GB fossa
indicating a high probability of acute cholecystitis with
complications like perforated or gangrenous GB. Likely
surgical emergency.

38. Bile leak, biloma. In leaks,
activity may be free in abdomen,
e.g. paracolic gutters or
outlining bowel loops.

39. 52-year-old female with a history of
rising bilirubin

40. 90 and 120 min delays

41. 52-year-old female with a history of
rising bilirubin
What is the diagnosis?
1. Normal study
2. Acute cholecystitis
3. Chronic gallbladder
disease
4. Bile leak
5. Other abnormality
12%
0%
12%
0%
75%
0%
10%
20%
30%
40%
50%
60%
70%
80%

42. Other abnormality
 Impaired liver function with poor clearance
of cardiac blood pool.
 Delayed visualization of GB rules out acute
cholecystitis, but does not demonstrate
chronic cholecystitis. Delayed imaging is
needed in such cases.
 Transit to bowel is also seen, but not quickly.

43. 52-year-old female with a history of
rising bilirubin

44.  It is preferable to wait 4-6 hours after opiates
like morphine before a biliary scan.
 Sincalide after morphine may give false
positive EF.
 Morphine is OK after sincalide (short half-life).
 Contraindications to sincalide are known
allergic reaction, intestinal obstruction and
pregnancy.

45. 31-y.o. female with dyspnea.

46. Continued

47. Suspect P.E.
We should report:
1. High probability of
P.E.
2. Low probability of
P.E.
3. Intermediate
probability of P.E.
4. Technical problem
5. None of the above
0%
62%
12%
0%
25%
0%
10%
20%
30%
40%
50%
60%
70%

48. None of the above.
 The study is normal, implying negligible
probability of P.E., regardless of
ventilation or chest x-ray.
 Note: Standard 8 views, A-P gradient
on perfusion (as in normal subjects
injected supine). Effect is less in
ventilation. Note some tracheal and
stomach activity crossing over to
perfusion scan.

49. Continued

50. Local protocol
 Indication: Usually suspicion of PE.
 Radiopharmaceuticals:
 40.0 mCi Tc-99m DTPA by aeorosol, 0.5-2 µm
droplets, patient supine or upright
 5.0 mCi Tc-99m MAA IV (~30 µm,vs 7-10µm of
capillaries , patient supine
 PA and lateral chest x-ray within 24 h (more current
if clinical picture is changing)
 Ventilation 200 kcts A, P, RAO, LPO, RL, LL,
RPO, LAO
 Then, perfusion 800 kcts, same views.

51. Summary/generalizations re diagnosis of PE
 The count rate of the perfusion study should be
3-4 times that of the ventilation study. Confirm
from total counts and time.
 A normal perfusion scan essentially excludes
clinically relevant PE.
 Typically, PE causes bilateral, multiple wedge-
shaped defects that extend to the periphery
that are unmatched (mismatched) with
ventilation.
 Other causes of perfusion defects are COPD,
pneumonia, asthma, tumor, etc., but they are
typically matched with ventilation. Reflex
vasoconstriction occurs secondary to hypoxia.
 Reverse mismatch does not indicate PE.

52. Classic high probability

54. UPMC consensus criteria: Mettler interpretation of
PIOPED data (Mettler and Guiberteau Table 7-5)
 Normal: No perfusion defects: neglible chance
of PE
 Very low probability (<10% chance)
 1. 3 or fewer small (<25% segment) defects, neg.
CXR.
 2. Non-segmental defects (large aortic knob, high
diaphragm).
 3. Triple match in upper to mid lung zone.
 4. Perfusion defect considerably smaller than CXR
opacity.
 5. Stripe sign (on all views).

55. Criteria (cont.)
 Low probability (10% to less than 20%
chance)
 1. Multiple matched defects with negative CXR.
 2. More than 3 small (<25% segment) defects, neg.
CXR
 3. Large matching effusion.
 Intermediate probability (20-80% chance)
 Triple match lower lung zone (opacity or small
pleural effusion)
 Single moderate segmental match, neg. CXR
 Single mismatch, moderate to large, two moderate or
one large/one moderate

56. Criteria, concluded
 High probability (greater than 80%)
 1. At least two large, or one large and two moderate,
or four moderate mismatches
 2. Large perfusion defect, considerably larger than
CXR abnormality

57. Probabilities of P.E. are best modified by
pretest probability.
The current SNM guidelines have 4
alternative interpretation schemes, and they
substitute the term likelihood ratio (LR),
which is independent of pre-test
probability. LR x pre-test probability = post-
test probability.

61. 71-y.o. male with dyspnea
We should report:
1. Normal
2. Very low
probability
3. Low probability
4. Intermediate
probability
5. High probability
0% 0%
100%
0% 0%
0%
20%
40%
60%
80%
100%
120%

62. Low probability
Based on multiple
matched defects with
negative CXR.

64. 58-y.o. Female with dyspnea, R-sided chest pain.

67. 58-y.o. female with dyspnea & right-
sided chest pain
We should report
1. Normal
2. Very low
probability
3. Low probability
4. Intermediate
probability
5. High probability
0% 0% 0% 0% 0%
0%
20%
40%
60%
80%
100%

68. Intermediate probability
 Based on triple match lower lung zone (opacity
or small pleural effusion)

69. 55-y.o. male with dyspnea.