Teaching cases

Teaching points:

• Therapy with 177Lutetium DOTA TATE can be useful for inoperable, metastatic GEP NETs.
• The rate of complete responses obtained by Kwekkeboom et al was only 2% in patients treated with 177Lu-DOTA TATE. They reported partial responses, minor responses, stable disease and progressive disease, respectively, in 26%, 19%, 35% and 15% of their patients.
• Treatment tolerance was good, significant reduction of symptoms was obtained and 2-yr survival rate was 76 ± 16%.
• Predictors of good response include: high uptake of lesions in somatostatin receptor scintigraphy and Karnofky’s performance status > 70%.
• Predictors of poor prognosis include: massive liver involvement, bone metastases and Karnofky’s index 70%.

Teaching points:

Causes of I-131 Unrelated to Thyroid Cancer

• Choroid plexus salivary glands, gastric mucosa, urinary tract; contamination by physiological sections.

• Ectopic gastric mucosa, other gastrointestinal abnormalities, urinary tract abnormalities, mammary abnormalities.
• Serous cavities and cysts.
• Inflammation and infection.
• Nonthyroidal neoplasms.
• Unexplained causes.
• Choroid plexus salivary glands, gastric mucosa, urinary tract; contamination by physiological sections.
• Ectopic gastric mucosa, other gastrointestinal abnormalities, urinary tract abnormalities, mammary abnormalities.
• Serous cavities and cysts.
• Inflammation and infection.
• Nonthyroidal neoplasms.
• Unexplained causes.

Case presentation:

• Female.
• 66 y.o.
• Recurrence of multinodular goiter (MNG) with intra-thoracic extension.
• History of mild, intermittent asthma and chronic hypertension treated with ACEI, with no cardiovascular symptoms.
• Her MNG was discovered 33 years before, treated with subtotal thyroidectomy, with benign changes on pathology examination.
• Seven years ago she had a thyroid scintigram performed using 99mTc pertechnetate which revealed significant residual thyroid tissue extending to mediastinum, with globally decreased uptake.
• She received no treatment at that time.
• Two years later she presented with large MNG recurrence, surgery being contraindicated because of anatomic considerations.
• Radiometabolic treatment was performed with 30 mCi of 131I in an attempt to reduce gland volume.

Teaching points:

• Recombinant human TSH (rhTSH)-stimulated iodine scintigraphy is an effective and safe alternative to thyroid hormone withdrawal,to be used during the post-surgical follow-up of papillary and follicular thyroid cancer.
• Its clinical efficiency for the detection of persistent and recurrent disease is similar to that of thyroid hormone withdrawal.
• As a novel clinical application, compressive goiters with benign changes and low uptake of 131I can be efficiently treated with the use of rhTSH.
• Recombinant human TSH-stimulated radioiodine therapy of nodular goiter allows major reduction of the radiation burden with retained efficacy.

Case presentation:

• Male
• 48 y.o.
• Health screeening CTA, no symptoms.
• Hyperlipidemia.
• Physical exam.
• Normal CVS findings.
• BP 145/78.
• 78kg weight.
• Ht 172 cm.

Case presentations:

• Female.
• 66 y.o.
• No known risk factors for CAD.
• Asthmathic, atypical chest pain.
• Chronic LBBB. -Had bronchospasm when submitted for MPS with dipyridamole, so she was switched to exercise.

Teaching points:

• Regadenoson is a pharmacologic agent approved by the FDA in 2008 as an agent for use in stress testing and can also be used in combined protocols with exercise.
• Regadenoson produces maximal hyperemia quickly after IV injection as a bolus and maintains it for an optimal duration, practical for myocardial perfusion imaging.
• Regadenoson is an agonist with low affinity for the A2A adenosine receptor, and at least a 10-fold lower affinity for the A1 adenosine receptor. In addition, it has relatively weak affinity for the A2B and A3 adenosine receptors.
• Coronary vasodilation and an increase in coronary blood flow (CBF) results from activation of the A2A adenosine receptor by regadenoson.

Case presentation:

• Male.
• 58 y.o.
• Diabetic.
• Smoker.
• Hypertension (poorly controlled).
• Admitted for episode of chest pain 72 hs ago (resolved).
• ECG: Inferior Q waves, dynamic changes lateral wall.
• Echo: Mild LVH, inferior hypokinesis, LVEF ~40%.
• Myocardial perfusion with dipyridamole requested.

Teaching points:

• In patients with no known coronary artery disease, MPS adds prognostic information and risk-stratifies patients beyond clinical data.
• Semiquantitative information obtained by MPS provides important measurements of disease extent and severity, however visual analysis is able to depict high-risk patients in most cases.
• In patients with 3-vessel disease, perfusion defects can be restricted to only one or two arterial territories, because due to the fundamentals on which nuclear images are based, the region with relative ‘best perfusion’ can appear ‘normal’ (like the lateral wall in this particular case, despite a lesion in the Cx artery).

Case presentation:

• Female.
• 75 y.o.
• Hypertension, moderate overweight, dyslipidemia.
• Asymptomatic, pre-op evaluation (gynecological).
• Medication: ACEI, B-blockers.
• ECG: Atrial fibrillation (AF), average HR 80 bpm, otherwise normal.
• Echo: LVEF 48%, no WMA. - Referred for MPS w/ pharmacologic stress.
• Dipyridamole + rest (2-day protocol); no symptoms, no ECG changes other than previously known AF, BP 135/80 mmHg.

 Teaching points:

• QC data is important info when interpreting gated perfusion studies.
• AF and other arrhythmias can cause false EF values.
• Before considering TID, look at HR during acquisition.
• Changes above 10 bpm between acquisitions can cause difference in LV volume calculation.

Case presentation:

• Female.
• 66 y.o.
• Presented with typical chest pains (NSTEMI), NYHA II.
• Hyperlipidemia.
• Hypertension.
• Type II Diabetes.
• Medically stabilized & sent for coronary revascularization on 2nd day of admission.

Case presentation:

• Male.
• 65 y.o.
• Acute coronary syndrome, no evidence of MI by ECG or enzymes.
• Echo with WM abnormalities. -Submitted for myocardial perfusion study (MPS) with pharmacologic test.
• Dipyridamole (0.56 mg/Kg) + rest in 2-day protocol with 99mTc-MIBI.

Teaching points:

• Post-stress decrease in LVEF and/or increase in ESV are strong predictors of cardiac events.
• Transient ischemic dilation (TID) of the LV and a relative drop in post-stress LVEF may represent myocardial stunning.
• In this patient, these findings were associated with 2-vessel disease (including 90% LAD stenosis).
• LV volumes should be considered when interpreting a gated SPECT study. However, abnormal volumes should be reported with caution since significant differences could be obtained using different software packages.

Case presentation:

• Male.
• 81 y.o.
• Dyslipemia, stress, overweight, family history.
• Asymptomatic with positive exercise test.
• Aortic stenosis. - EKG: synus rythm 75 bpm, mild repolarization changes.
• The patient underwent a dipyridamole/rest myocardial perfusion gated SPECT study with 99mTc-MIBI Teaching points
• Myocardial perfusion imaging is useful for identifying multivessel disease, since most patients have perfusion abnormalities indicative of ischemia.
• In few cases, balanced ischemia can produce “normal” perfusion images but frequently showing myocardial stunning with transient LV dilation and lower post-stress LVEF.
• High risk studies indicate the need for aggressive management.

Case presentation:

• Male.
• 65 y.o.
• Previous MPI 1 year ago, told “no major problems”.
• Hypertension.
• Hyperlipidemia.
• New onset chest discomfort.
• Pharmacologic MPI

Case presentation:

• Male.
• 60 y.o.
• Poorly controlled type II diabetes mellitus (DM).
• Presents at the Emergency Department (ED) with chest pain at rest with radiation to right shoulder, lasting for about 45 min but relapsing several times during the last 24 hours, with no other symptoms.
• At admission, BP is 140/90 mmHg, regular cardiac rhythm of 70 bpm, physical examination otherwise unremarkable.
• Troponin I and CPK MB within normal limits.

Teaching points:

• In the absence of previous MI, or in patients with no previous history of CAD, rest MPS can depict ACS with high accuracy.
• Rest MPS are class IA indication for ED imaging in patiens with chest pain and nondiagnostic ECG, serum markers and enzymes, according to the ACC/AHA/ASNC Guidelines.
• The use of MPS to guide admission can result in unnecessary hospitalizations and in reduction of inappropriate discharges from the ED; this is also true for patients with DM (ERASE Chest Pain Trial).

Case presentation: -Male. -63 y.o. - Knee osteoarthritis limiting exercise capacity. - Hypertension (BP 145/90 mmHg under medication). - Family history of CAD (father had sudden death at 53). - Total Cholesterol = 223; HDL = 45; LDL = 128, Gluc = 0.97. Teaching points - CAC provides independent incremental information in addition to traditional risk factors in the prediction of allcause mortality. - The principal difference between MPS and Ca scoring is that the former is an excellent tool for assessing shortterm risk, guiding decisions on revascularization.  - In contrast, atherosclerosis imaging methods like CAC provide greater long-term risk assessment, and are more useful in defining the need for aggressive medical prevention.

Case presentation:

• Male.
• 67 y.o.
• Exertional shortness of breath, orthopnoea, paroxysmal nocturnal dyspnoea.
• Hypertension.
• Type II DM.
• Hyperlipidemia.
• Referred for further evaluation.
• Able to exercise, TMX-MPI decided upon.

Case presentation:

• Female.
• 70 y.o.
• Hypertension, Hyperlipidemia, NIDDM.
• Presents with atypical chest discomforts on exertion (stairs) and rest.
• TMX performed in Yangon.

Case presentation:

• Male.
• 63 y.o.
• Hypertension.
• Dyspnea and chest pain when exercising, progressive.
• Normal rest ECG. - Stress echo: poor acoustic window, technically suboptimal.
• Myocardial perfusion study with exercise (99mTc-sestamibi). -Stress test: Chest pain, mild ECG changes, drop in SBP.

Teaching points:

• Post-stress increased RV uptake has prognostic implications and can reflect RV pressure overload due to postischemic LV dysfunction.
• Post-stress increased RV activity can be also an indicator of stress-induced RV:LV perfusion imbalance associated with severe CAD (e.g., high-grade left main stenosis with less severe proximal right CAD stenosis).
• The amount of inducible ischemia, transient dilation of the LV, LVEF post-stress & rest, and reversible regional wall motion abnormalities are other major indicators of poor prognosis (predictive parameters of cardiac events).

Case presentation:

• Female.
• 45 y.o.
• Atypical chest pain, that has lasted for about 3 hours, stable.
• She complains of fatigue and palpitations when exercising, however with no chest pain.
• Smoker since 23 y.o.
• Non diabetic.
• Normal levels of blood pressure and cholesterol.
• No history of CAD.
• BMI 27, HR 78 bpm, BP 145/90 mmHg, normal chest examination, other wise unremarkable.
• Basal EKG: pre-excitation syndrome. Cardiac enzymes including serum Troponine levels are within normal limits.
• Basal echocardiogram: mild mitral valve prolapse, with preserved global and regional ventricular function.

Teaching points:

• Attenuation is a common artifact in myocardial perfusion imaging, being present in 20-30% of cases, mimicking the presence of MI.
• Breast attenuation causes pseudo-defects on the anterior wall of the left ventricle, and is more evident in women with lage breasts. However, it can be also significant in women with small but dense breasts. In men, diaphragmatic attenuation is more common, affecting the inferior wall - especially in obese patients.
• Attenuation correction is possible using external sources or CT, but these are expensive solutions. Prone imaging can be used mainly for inferior wall artifacts.
• Gated SPECT provides information about regional wall motion and thickening, which would be affected by infarction but preserved when attenuation is present.
• Visualization of raw data can also aid in depicting attenuation.

Case presentation:

• Male.
• 52 y.o.
• Hypertension, Hyperlipidemia. 
• Presents with chest discomforts on exertion (stairs) and occasionally at rest. 
• Clinical Exam NAD.
• Baseline ECG normal.

Case presentation:

• Male.
• 51 y.o.
• 185cm Ht.
• CAD risk (Hyperlipidemia).
• Smoker.
• 3/7 after acute cardiac event.
• Study: adenosine/ sestamibi.

Teaching points:

• Myocardial perfusion imaging (MPI) is useful in acute coronary syndromes to:Confirm / rule out MI.Evaluate extension of ischemia / scar. Identify the culprit vessel.

Case presentation:

• Female
• 83 y.o.
• No coronary risk factors. No previous history of CAD.
• Episode of chest pain at rest, with normal EKG and enzymes. The symptoms resolved spontaneously, and the patient was discharged.
• Since the patient was unable to exercise, the cardiologist ordered a myocardial perfusion study (MPS) with pharmacologic stress.

Teaching points:

• MPS is safe and has prognostic incremental value in elderly patients and may influence medical decisions.
• High risk features like TID, ESV increase and LVEF decrease during stress, indicate the need for intervention rather than medical treatment.
• Women with severely abnormal scan results are at increased risk for hard cardiac events than are men with same results.
• Ischemia in the LAD territory could be predicted by the result of the test.