General Information
Bone scintigraphy is more colloquially known as ___ ___
Bone scan
Technetium is combined with an appropriate bone-imaging agent. 99MDP (methylene diphosphate) and 99MAA (macroaggregated albumin) are examples of such radiopharmaceutical agents. True or False?
True
Combining gallium with technetium provides more information than the gallium alone. True or False?
True
Upon binding to cytoplasmic components of the white blood cell membrane, destruction follows. Name one of two organs in the human body that lights up as a result. You may name both of them if you would like.
Spleen, Liver
Which is NOT well suited as a podiatric indication for bone scintigraphy? Two answers are correct.
A) Osteomyelitis
B) Rheumatoid arthritis
C) Trauma
D) Nonspecific pain
E) Osteochondroma
F) Individual who is pregnant
G) Stress fracture
H) Achilles tendonitis
F) Individual who is pregnant & H) Achilles tendonitis
Bone scintigraphy has poor _____ and has good _______.
A) sensitivity, specificity
B) specificity, sensitivity
B) specificity, sensitivity
A 65-year-old type 2 diabetic patient presents with chronic, non-healing wounds on the lower extremities. Patient complains that there is cramping present upon ambulation. Which of the following is appropriate to order?
A) Tc-99MAA
B) Tc-99MDP
C) Both A & B
A) Tc-99MAA
Gallium 67-citrate binds to white blood cells, plasma, proteins, siderophores, and iron-binding proteins. Name one of three iron-binding proteins that gallium binds to. You may name all of them if you would like.
Acceptable Answers: Transferrin, Ferritin, Lactoferritin
A 50-year-old female patient presents redness, swelling, warmth, and pain with ascending red streaks, suggesting lymphangitis, post-injury to her first toenail after a nail trim. She states the symptoms commenced an hour ago, but she lacked transportation until now to arrive to the ED. You decide to order place orders for imaging modalities as you are concerned it is a deeper, more complex infection. Before you order Indium-111, what are some scans that you should consider? Name at least two.
X-ray, MRI, CT, Ultrasound
In a Combined Tc and Ga bone scan, which conditions can be ruled in and ruled out?
A) Osteomyelitis
B) Chronic Osteomyelitis
C) Cellulitis
D) Osteoarthropathy
E) Stress fracture
F) All of the above
F) All of the above
___ spots indicate areas of high radiopharmaceutical uptake.
Hot spots
Which phase in a four phase scan is best useful to delineate cellulitis versus osteomyelitis?
A) Phase one
B) Phase two
C) Phase three
D) Phase four
Phase three/ Delayed image/ Bone-imaging phase
Which statement is accurate regarding Gallium-67 citrate?
A) Half-life is short, so radiation dose is small
B) Half-life is short, so radiation dose is high
C) Half-life is long, so radiation dose is small
D) Half-life is long, so radiation dose is high
D) Half-life is long, so radiation dose is high
Which type of granulocyte is taken up predominantly by the Indium-111?
A) Basophils
B) Neutrophils
C) Eosinophils
Neutrophils
A 55-year-old diabetic patient presents with a painful, swollen left foot. The patient reports that the pain has been progressively exacerbating the past fortnight. On physical examination, the left foot is erythematous and warm to the touch. There is some notable fluctuance in certain areas, suggesting possible abscess formation. The patient has a history of recurrent foot ulcers, and recent lab results show 12,000 WBC count and 55 mm/hr ESR. Plain radiographs of the foot show soft tissue swelling; however, there are no clear signs of OM. Given the clinical picture and the need to evaluate for possible OM or soft tissue infection, which imaging study would be the most appropriate next step?
A) Order Gallium-67 Citrate (Ga-67)
B) Order Thallium-201 (Ti-201)
C) Order a Combined Tc and Bone Scan
D) Order Indium-111 (In-111)
A) Order Gallium-67 Citrate (Ga-67)
One of the steps involves utilizing and positioning a scintillation probe or detector over the target. In the process, photons are emitted. Which type of high frequency and energy waves on the electromagnetic spectrum are emitted?
Gamma
Match each phase of the four phase scan (i.e. delayed image/bone-imaging phase, radionuclide angiogram/ blood flow phase, blood pooling images) with appropriate times images are taken. NOTE: only use three answer choices out of the four answer choices listed to match accordingly.
1) 2 to 4 hours
2) 3 to 10 minutes
3) 1 to 3 seconds
4) Varying times
First phase/ Radionuclide Angiogram/ Blood Flow Phase: Images taken 1 to 3 seconds
Second phase/ Blood pooling images: Images taken 3 to 10 minutes post injection
Third phase/ Delayed image/ Bone-imaging phase: Images taken 3 to 4 hours post injection
Fourth phase: Images taken at 24 hours
Gallium-67 citrate takes more time to perform for a patient with chondrosarcoma, for example, than for a patient with osteomyelitis secondary to a diabetic foot ulcer, for instance. If family members of both patients are anxiously waiting to receive reports in the waiting room, which family/ families will receive the news first?
A) Family of patient with chondrosarcoma
B) Family of patient with OM secondary to a DFU
C) There is a very slim chance that both families could find out respective reports at the 24 hour mark
D) Families of both patients will find out at the same time as imaging is taken at the same time
E) A & C
F) B & C
F) B & C
The patient's family member would like to understand the process at large for how Indium-111 works. You, as the podiatry attending, explain that instead of simply injecting the radiopharmaceutical as performed for other scans, the process is a bit more laborious. You further state, "After the blood of the patient is drawn, it is isolated with just WBCs that are labeled with In-111". You then ask the student doctor what the last step is based on the following multiple choice answers, with which she answers correctly. Which one is accurate?
A) Discard the labeled WBCs after solely imaging the isolated WBCs that are labeled
B) Reintroduce the labeled WBCs back into the bloodstream for imaging
C) Freeze the labeled WBCs for later use in multiple scans
D) Inject the labeled WBCs directly into the site of infection for precise targeting
B) Reintroduce the labeled WBCs back into the bloodstream for imaging
A 70-year-old male patient with a history of peripheral arterial disease (PAD) and diabetes mellitus presents with non-healing ulcers on the toes of his left foot. The ulcers have been present for several months despite conservative treatment, including local wound care and antibiotics. The patient complains of intermittent claudication and rest pain in his left leg. On physical examination, the left foot appears pale and cool to the touch, with weak dorsalis pedis and posterior tibial pulses. ABI is 0.6. Given the need to evaluate the perfusion of the foot to guide further treatment, which imaging study would be the most appropriate next step?
A) Order a Combined Tc and Bone scan
B) Order Indium-111 (In-111)
C) Order Thallium-201 (Ti-201)
D) Order Gallium-67 Citrate (Ga-67)
32-year-old male athletic patient presents to clinic complaining of dull, aching pain in the second metatarsal with no noticeable swelling localized to the right foot. It is aggravated by physical activity (e.g. walking and running). There is tenderness noted. The attending would like to place an order for bone scintigraphy, however, he is aware that a diagnosis of this type of fracture takes AT LEAST how many hours post injury for an early diagnosis?
A) 5 hours
B) 6 hours
C) 7 hours
D) 8 hours
C) 7 hours
A foot and ankle radiologist received a phone call from a podiatrist at the 24 hour mark to obtain the reading for the scan of the last phase of the four phase scan. He states to the podiatrist that the report is inconclusive for osteomyelitis, stating that the ratio has increased more than one whole number compared with the third phase using the soft-tissue-to-bone ratio. Is the radiologist correct or incorrect, & why or why not?
Radiologist is incorrect. The ratio that is always used in place is the the bone-to-soft-tissue ratio. In this case, he meant to say "increased more than one whole number compared with the third phase". Because of the increase in more than one whole number for the ratio, patient is positive for OM.
Gallium-67 citrate is similar to Tc-99m MDP in that the radiopharmaceutical agents are excreted by kidneys. What is important to relay to the patient for pre-preparation based on the above information with regard to minimizing radiation exposure?
Adequate hydration/ voiding is imperative in order to decrease radiation exposure to the bladder wall.
Which roman numeral(s) is/are best fitting for accurately assessing Indium-111?
I. Order if there is a subacute infection
II. Order if there is an acute infection
III. Order if there is a chronic infection
A) I
B) II
C) III
D) I & II
E) I & III
F) II & III
G) I, II, & III
B) II
A 65-year-old female patient with a history of diabetes mellitus presents with a chronic, non-healing ulcer on the plantar aspect of the right foot. The ulcer has been present for the past several months and has not responded to standard wound care and antibiotic therapies. The patient reports a sharp, persistent pain and swelling in the area. On examination, the ulcer appears deep, with exposed bone, and the surrounding tissue is erythematous and warm to the touch. Laboratory tests show 18,000 WBC count and CRP 50.0 mg/mL. Plain x-ray read reveals osteopenia and potential early signs of OM, though the findings are inconclusive. Given the need to evaluate both bone involvements and the presence of infection, which imaging study would be the most appropriate next step?
A) Order Gallium-67 Citrate
B) Order Indium-111 (In 111)
C) Order Thallium-201 (Ti-201)
D) Order a Combined Tc and Bone scan
D) Order a Combined Tc and Bone scan