Nuclear - Image interpretation Flashcards by Dustin Hill

Describe the findings and cause of the patients symptoms

62 yo male with increasing SOB and LE edma
Projection image in the LAO position from the stress portion of a 1-day-rest/stress Tc99m SPECT MPI study is shown

Pulmonary Hypertension

marked RV hypertrophy and enlargement
relative paucity of lung uptake of Tc99m suggests possible COPD (frequent cause of pulmonary hypertension and RVH)

How well did you know this?

Not at all

Perfectly

What is the cause of increased lung uptake when using Tl201 with stress?

severe ischemia
causes an increase in the lung-to-heart ratio
Caused by increased PCWP –> extravasation of Tl201 from intravascular space to the interstitial space
- not reported with Tc99m agents

How well did you know this?

Not at all

Perfectly

Based on the stress and rest projection images, which radioisotope imaging protocols was most likely use

1-day rest / stress Tc99m

based on grainy quality of the rest images (low count statistics) –> 1-day study using low-dose rest and high-dose stress
distribution consistent with Tc99m –> GI track and Liver

How well did you know this?

Not at all

Perfectly

Desribe the findings and most likely cause of SOB:

COPD

marked thickening of the diaphragm recognized as a lucency starting fom the patient’s right abdominal wall and extending all the way to the heart
Dark appearance of diaphragm muscle between vascular lungs and liver
- marked hypertrophy of diaphragm in COPD patients
- *

How well did you know this?

Not at all

Perfectly

Describe the findings:

67 year old male with atypical chest pain
abnormal baseline EKG
Exercise SPECT MPI at 13.5 METS without anginal symptoms

Scaling artifact

circumferential decrease in counts that is most prominent on the short-axis slices relative to resting images
caused by a very hot apical anterior hot spot
incorrect scaling –> decreases subendocardial counts and may give the appearance of TID

How well did you know this?

Not at all

Perfectly

Describe the findings and next step:

60-year old female presents with chest pain to the ER
Exercise SPECT MPI is performed

Discharge for outpatient follow-up

normal study by visual and quantitative analysis

How well did you know this?

Not at all

Perfectly

Describe the findings:

58 year old female with progressive chest pain
Stress MPI is performed

coronary angiography

large area of severe ischemia involving the apex, septum, anterior and lateral walls
TID of the cavity
High risk scan consistent with:
- proximal LAD or LM disease
- severe MVCAD

How well did you know this?

Not at all

Perfectly

Describe the findings:

75 year old male with remote MI and atypical chest pain
Rb82 vasodilator PET study is performed

severe lateral wall ischemia and apical infarction

large area of severe lateral wall ischemia extending fom the apex to the base
apical infarction most prominent on the HLA and VLA images

How well did you know this?

Not at all

Perfectly

Describe the findings, which artery is likely to be causing the symptoms in this patient?

RCA

How well did you know this?

Not at all

Perfectly

Describe the findings:

39 year old female with BMI 45 being evaluated for intestinal bypass surgery
PMH: HTN, DM, dyslipidemia
Pharmacologic SPECT MPI is performed (without AC) –> severe chest pain without EKG changes

uniform breast attenuation

images were acquired with a small filed of view camera with the patient sitting upright in a chair with the chest pressed against a stabilizing bar
raw projection image shows –> large left breast covering the entire heart –> uniformattenuation of the heart and not the focal decrease on the perfusion images seen in the anterior wall when there is only partial coverage of the heart by breast tissue
Right breast is seen on the right with a bright area in between due to liver and lung background that has less attenuation
Rotating projection images should be reviewed in cine mode on a workstation as part of QC for every study interpreted

How well did you know this?

Not at all

Perfectly

Describe the findings and next step:

85 year old female with multiple prior MI’s and CABG presents with worsening heart failure despite optimal medical therapy
SPECT MPI is performed

PET assessment of hibernation

extensive and severe areas of absent perfusion on the resting SPECT MPI involving the LAD and RCA territories with only the lateral wall showing perfusion
No evidence of ischemia

How well did you know this?

Not at all

Perfectly

Describe the findings:

46 year old female for pre-operative risk assessment
PMH: DM, HTN, dyslipidemia, obesity (5ft 8-inches tall, 434 pounds)
Pharmacologic 1-day rest/stress Tc99m perfusion studie with CT AC performed

Normal study

Apical defect –> apical thinning
- recognized variant in obese patients with large BMI
- due to overrepresentation of counts due to close proximity throughout the 180-degree acquisition is corrected
Multiple defects in this study (both attenuation –> confirmed by normal motion on gated images)
- uniform breast attenuation
- inferior wall diaphragmatic attenuation

How well did you know this?

Not at all

Perfectly

What does a I-mIBG 123 study evaluate?

When is this study utilized?

myocardial sympathetic innervation

abnormal in heart failure syndromes and may be a marker of future cardiac events (including life-threatening arrhythmia and cardiac death)

How well did you know this?

Not at all

Perfectly

What I-mIBG 123 finding is associated with the highest risk of cardiac events in heart failure patients?

mIBG heart-to-mediastinum ratio

calculated as:
- the ratio of counts in a region of interest drawn over the heart
- to the counts in a 7x7 pixel mediastinal reference region
uptake ratio < 1.60 correlated with increased time to first occurrence:
- NYHA functional class progression
- Arrhythmia (life-threatening)
- Cardiac death

How well did you know this?

Not at all

Perfectly

What are quantiative parameters obtained from I-mIBG 123 imaging studies?

mIBG washout rate
- measure of retention of the tracer in the myocardium
mIBG heart-to-mediastinum ratio

How well did you know this?

Not at all

Perfectly

Describe the findings and next step:

62 year old female with atypical chest pain
no PMH
EKG and Troponin are negative
Exercise Tc99m SPECT MPI
- 10:30 (12 METS) with no chest pain or ischemic changes on EKG
- BP stable
- EF 67%, TID 0.86

Low-risk abnormal SPECT MPI

Perfusion images:
- mid and distal, inferolateral wall reversible defects
SDS 4 –> 7% of myocardium affected
- 10% is generally considered the threshold for high-risk or severe ischemia
Duke treadmill score + 10.5 (low risk)
*

Describe the findings:

Severely abnormal study

moderate-severe reversible perfusion defects involving the septum and apex (consistent with LAD disease)
TID ratio 2.00

***MVCAD –> CABG

What is the benefit of rest-only imaging studies

When can it be utilized effectively?

Simple and rapid protocol
Cost effective
Low-Moderate risk acute chest pain
Normal perfusion study with radiotracer injected during active chest pain
- virtually excludes acute MI
- cannot exclude chronic stable ischemic heart disease

In what patient’s is rest-only imaging not-applicable?

prior MI

acute myocardial ischemia or infarction cannot be distinguished from an old MI

What are limitations of rest-only imaging protocols?

Prior MI
- cannot distinguish acute myocardial ischemia/infarction cannot be distinguished from an old MI
Attenuation artifact cannot be distinguished from myocardial ishcemia
- normal wall motion does not definitively differentiate attenuation from abnormal perfusion (non-transmural infarction can still demonstrate normal wall motion)
Limited value in identifying acute ischemia after chest pain resolution

What is the timing cut-off for rest-only imaging?

Active chest pain
ischemic symptoms resolved shortly ( < 3 hours) before testing

Describe the findings:

55 yo AA male presents after a syncopal event (fatigue, SOB, orthopnea, PND and weight gain)
EKG with complete heart block
CXR with cardiomegaly and hilar fullness
Echo: LVEF 35% with global hypokinesis
LHC: normal coronaries
N13 / F18-FDG PET is shown

Mismatch of the anteroseptum

decreased perfusion involving the basal and mid anterior, anteroseptum and inferoseptum with corresponding increased F18-FDG in the same distribution

What is the sarcoidosis spectrum of disease on PET/CT?

Normal
- normal perfusion / negative FDG
Non-specific
- normal perfusion / diffuse FDG
Early disease
- normal perfusion / focal increase of FDG
Mismatch pattern
- abnormal perfusion / focal increase in FDG
Scar
- abnormal perfusion / no FDG uptake

Describe the findings/diagnosis:

75 year old AA male with complaints of SOB and fatigue
PMH: HTN, dyslipidemia, CKD
Echo: LV thickening, grade 2 diastolic dysfunction, biatrial enlargement
Tc99m pyrophosphate imaging is shown

ATTR Amyloidosis

Both semi-quantitative visual scoring and
- grade 2-3 myocardial uptake
Heart to contralateral ratio (H/CL) are used in clinical practice
- H/CL > 1.5
- H/CL > 1.6 –> associated with worse survival

Describe the findings/diagnosis:

**Pericardial Effusion** * photopenic area seen circumferential to the heart

Describe the findings/diagnosis: * 55 year old female presents to the ED with chest pain * PMH: HTN and dyslipidemia * EKG: deep T wave inversions throughout the anterior leads * Troponin negative * Exercise SPECT MPI is performed

**Apical hypertrophic cardiomopathy** * characteristic **"solar polar" map** pattern * results from increased apical counts at rest secondary to LVH * stress --\> significant decrease in the apical counts with "relative" apical ischemia, even in the absence of CAD

What are high-risk features on SPECT MPI?

* perfusion defects in multiple vascular territories * increased Tl-201 lung uptake * LVEF \< 40% * extensive hypoperfusion in one vascular territory * increased end-systolic and end-diastolic volumes * TID of LV cavity during stress

Describe the findings and most common use

**Equilibrium radionuclide angiocardiography (RNA) / MUGA** **Effects of Chemotherapy**

What is RNA best utilized for?

**Ventricular function (gold standard)** * LV function * RV function * Chamber size * Dyssynchrony

What is the next best step?

**Exercise MPI** * MPI added due to LVH with TWI --\> may reduce specificity of the test * additional risk stratification provided by MPI would provide: * prognostic information * guidance for revascularization decisions

Describe the findings and next step: * 58 year old female admitted with worsening DOE and heart failure * PMH: HTN and DM * Echo: mid-distal anterior, septal and apical akinesis with mild MR, and LVEF 30% * Vasodilator Tc99m SPECT: fixed, medium size, severe intensity perfusion defect involving mid to apical anterior, apical septal, mid anteroseptal, and LV walls * LHC: MVCAD with moderate-severe lesions in mid LAD, proximal RCA, mid-OM2 * N13 / F18-FDG/CT is shown below

**CABG - viable myocardium in LAD territory** * Oragne --\> viable myocardium * Green --\> non-viable myocardium

Describe the findings and next step: * 68 year old man with progressive DOE and exertional CP, left hip pain limits exercise capacity * PMH: obesity, hyperlipidemia, HTN * Vasodilator N13 PET/CT is performed * CFR = 1.1

**coronary angiography** * TID + CFR \< 1.5 = * suggestive of significant epicardial disease involving the LM, proximal LAD or MVCAD * alternatively microvascular dysfunction

What is her estimated annual risk of all-cause mortality?

**High risk ( \> 3%)** * **blunted heart rate response (HRR) during a regadenoson MPI study** --\> significantly increases risk of subsequent death or adverse CV outcomes

What is the annualized risk of death with a blunted HRR during MPI study?

* Abnormal MPI + blunted HRR * **9.6%** * Normal MPI + blunted HRR * **7.5% annualized risk of death (high)** * Normal MPI + Normal HRR * 1.7% if normal HRR

What is the most appropriate next step?

**ICD placement** * FDG PET / SPECT MPI performed after 2 meals with no carbohydrates + high fat content + prolonged fasting --\> **usual protocol to identify inflmmation** * Classic Sarcoidosis imaging findings: * reduced perfusion and increased FDG uptake * Focal perfusion defect + abnormal FDG uptake --\> increased risk of death/VT

What is the cardiac event rate associated with TID (abnormal study)?

**1.8%** vs. 0.7%

Describe the findings and next step: * 50 year old male with burning, substernal chest discomfort that started 2 hours ago * PMH: obesity, HTN, HLD, GERD, tobacco abuse * EKG: NSR, nonspecific ST depression * Troponin negative * Rest Tc99m tetrofosmin MPI is performed

**coronary angiography** * acute rest perfusion imaging: * large perfusion defect in the inferior/inferolateral wall --\> consistent with myocardial ischemia * abnormal acute rest MPI --\> high probability of ACS * NPV --\> 99-100% * NPV --\> exclude cardiac events in medium-term follow up --\> 97%

Why is acute resting MPI a useful test in the ER setting?

**NPV --\> 99-100%** * abnormal acute rest MPI --\> high probability of ACS --\> LHC * NPV 97% --\> exclude cardiac events in medium-term follow up * ensures safe discharge for stress testing to be completed a a later time

What are findings on EKG that will preclude use of acute rest MPI?

**Q waves --\> prior MI** * likely to have resting myocardial perfusion defects --\> repeat MPI during a chest pain free period to distinguish **new ischemia from old infarct**