Chapter 1: The science and the scan
"Boring, But Necessary"
- Hybrid Imaging System
- Anatomic & Functional Exam
- The Machine
- “Whole Body” vs. “Skull Base to Mid-Thigh”
- Three Sets of Images
Produced
- Glucose Analog
- Malignancy & Glucose Metabolism
- Mechanisms for Increased Intracellular Glucose
- Why 18F-FDG Works
- Whole Body Assessment
- The “You’re Kidding Me!” Effect
- Post-Therapeutic Scar vs. Active Malignancy
- Detecting Malignancy
- Staging Malignancy
- Assess Response to Therapy
- Detecting Recurrence
- Not All Cancer is FDG-Avid
- Normal FDG-Uptake vs. Pathologic Uptake
- Technical Limitations
- Poor Patient Preparation
- Misregistration
- Brown Fat Activation
- SUV Problems
- Fields of View Discrepancy
- PET/CT Artifacts
- Timing of Exam After Therapy
- CT Images
- Non-Attenuation Corrected Images
- Attenuation Corrected Images
- Maximum Intensity Projection (MIP)
- Fusion of Images
- All Images Viewed in 3 Planes
7. Contrast Media: Oral & I.V.
- Who Gets Oral Contrast?
- Who Gets IV Contrast?
- Oral Contrast “Cocktail” Recipe
8. What the Patient Should Expect
- Documenting Height & Weight
- Private Resting Room
- Drinking PO Contrast
- FDG Injection
- Delay Between Injection & Scan
9. Safety Concerns with PET/CT Imaging
- Radiation Exposure to Patient
- Radiation Exposure to Patient’s Contacts
- Patient Contact with Pregnant Women
- Breastfeeding
Chapter 2: PET/CT Problems Which Limit Interpretation
"Something just doesn't seem right here"
- Optimizing Glucose & Insulin Levels
- Fasting Prior to Exam
- Diabetic Patients
- Low Carbohydrate Diet
- Hydration
- Strenuous Exercise
- Voiding Prior to Exam
- Patient Instruction Sheet
- Definition
- Distribution / Appearance
- Don’t Miss the Hidden Nod
- Reporting Language
- Prevention
3. Timing of PET/CT Exam After Therapy
- “Rule of 3”
- Chemotherapy: 1 month
- Surgery: 2 months
- Radiation: 3 months
- Etiology: Hybrid Imaging
- Patient Movement
- Respiratory Motion
- Breathing Techniques
- Bowel Peristalsis
- False Positives
- False Negatives
- Reporting Language
- Beam Hardening
- Diaphragmatic Mismatch
- Linear Hand Motion
- Attenuation Correction
- Differing Fields of View
- Poor Patient Preparation
- FDG Extravasation
- Extensive Brown Fat
- Metformin-Induced Bowel Uptake
- Marked Reactive Marrow Uptake
- Extensive Tumor Uptake in
- Different Types of SUV Measurements
- Factors that Influence SUV Measurements
- What SUV Number Indicates Malignancy?
- What Percent Change in SUV on a Follow Up Exam is Significant?
- How to Compare Exams With Very Different Background Metabolic Activities?
Chapter 3: The Standardized Uptake Value (SUV)
"The good, the bad & the ugly"
1. What is the SUV & Why Used?
- Quantitative vs. Qualitative Assessment
- Unitless Measurement
- Formula
- SUV = ?
- Patient Preparation
- Time Between FDG Injection & Scan
- Partial Volume Effects
- Extravasation
- Patient Weight
- Size & Position of ROI
- Attenuation Correction Artifacts
- Consensus?
- Body Weight
- Lean Body Mass
- Ideal Body Weight
- Body Surface Area
- Maximum vs. Mean
- Average SUV’s by Organ
4. Interpreting the SUV: Threshold Values, “Oncologic Plausibility” & Relative Uptake
- Precise Threshold Values?
- “Oncologic Plausibility”
- Relative Uptake
- Assessing Nodes in Lymphoma Cases
- Assessing Nodes in Non-Lymphoma Cases
- Potential Lesions in Solid Organs
- Pulmonary Nodules
5. What % Change in SUV on a Follow Up Exam is Clinically Significant?
- The Problem
- Current Recommendations
6. How to Compare Sequential Exams With Very Different Background Activities?
- Differing Background Metabolic Activities
- When Qualitative Assessment is Required
- Reporting Language
7. Should We Just Abandon the SUV?
- Pros & Cons
- “Qualitative” Definitions
- Mild
- Moderate
- Intense
- Final Recommendations
Chapter 4: Our Systematic Approach to Reading a PET/CT
"Eat your vegetables"
1. Reading Station & Reading Software
- Reading Station
- Monitor Set-Up
- PET/CT Reading Software
- Hanging Protocol
- Reading in Context (“Oncologic Plausibility”)
- Measure Size on CT, Not on PET Images
- Abnormality Seen Only on First PET Image
- Assess the Patient’s Main Pathology Last
- Beware the Ureter
3. Excellent Views: The MIP, Coronal & Sagittal Images
- 3-D Rotating MIP & Coronal “Quick MIP”
- Coronal PET
- Sagittal PET
4. Written Annotations While Reading
- Numbers, Numbers & More Numbers
- Size & SUV Annotation System
- Sample Annotation Sheet
- Goals of Reporting
- Lawyers, Lawyers & Lawyers
- Sample PET/CT Report
- Negative Exam
- Positive Exam
- Patient Questionnaire
- Technologist’s Data Sheet
- Huge Exam: Requires Systematic Approach
- Our “12-Step Reading System”
- “The Read” in Action: Sample Case (Video)
- Annotations for Sample Case
- Final Report for Sample Case
Chapter 5: Normal Physiologic Distribution of FDG
"The essentials"
- To Locate Cancer, First Eliminate:
- Normal FDG-Avid “Structures”
- Benign FDG-Avid “Findings”
Chapter 6: Benign FDG-Avid "Findings" & Common Diagnostic Challenges
"Separating the Expert from the Not-So-Expert"
3. Chest
- Inflammatory Lymph Nodes
- Thymic Rebound
- Pleura: Talc Pleurodesis vs. Malignancy vs. Inflammation
-
Radiation-Induced Lung Disease
- Radiation Pneumonitis
- Radiation Fibrosis
- "Post-Therapeutic Inflammatory Changes" / Scarring of the Lung
- Atelectasis / Infiltrate
- Lipomatous Hypertrophy of the Inter-Atrial Septum
- Elastofibroma Dorsi
- Site of Prior Chest Port
- Esophagitis vs. Neoplasm
- Subcutaneous & Intramuscular Medical Injections
- Injected FDG-Blood Clot
4. Abdomen & Pelvis
- The Heterogeneous Liver
- Liver Ablation
- Hypermetabolic Geographic Fatty Infiltration
- Hypermetabolic Hepatic Adenoma
- FDG-Avid Adrenal Gland Algorithm
- Therapy-Induced Splenic Activation
- Peritoneal Carcinomatosis
- Pre-Sacral Soft Tissue After Rectal Surgery
- Gallbladder: Cholecystitis vs. Malignancy
- Inguinal Herniorraphy
- Bladder in Inguinal Canal
- Uterine Fibroid
- Tampon
5. Miscellaneous (continued)
-
Vascular Uptake
- Atherosclerosis
- Vasculitis
- Vascular Grafts
-
Value of NAC PET Images
- Resolving AC Artifacts
- Lung Nodule Identification
-
Non-Malignant, Yet Clinically Significant, FDG-Avid CT Abnormalies
- Acute Diverticulitis
- Colitis
- Cholecystitis
- Pneumonia
- Abscess
- Pancreatitis
- Skeletal Abnormalities [See Chapter 7]
Chapter 7: The Bones
"...is connected to the..."
Chapter 8: The Cancers
"Putting it all together"
The Language of Reporting
FIGURES 1-4 ARE TYPES REPORTS. THEY NEED TO OPEN VERY LARGE (LIKE THE REFERNECES SECTION)…
Goals of Reporting:
Identifying abnormalities, reporting sizes and calculating SUV’s are the easy parts of PET/CT reading. The challenge and the real art of PET/CT reading are to meaningfully interpret these findings for the clinician.
Simply reporting that there are “several enlarged and moderately-avid nodes” without concluding with a meaningful interpretation of their significance is unhelpful and irresponsible.
The patient has been sent to us to answer a few simple questions:
Initial Exam:
- Is there active malignancy?
- What is the tumor burden and where is it located?
Follow Up Exam:
- What has happened in the interim (response to therapy)?
- Complete metabolic response? Partial? No change? Disease progression?
If these questions are not specifically answered in our report, we have simply not done our job.
Lawyers, Lawyers & Lawyers:
It would be naïve and a bit disingenuous to not acknowledge that balanced against
our noble goal of helping patients is a realistic need to also protect ourselves from excessive litigation.
Old, dumb joke:
Q: What’s a radiologist’s favorite plant?
A: The hedge.
While finding the proper balance between helping and hedging is often difficult, PETCTMD has worked very hard – with both clinicians and attorneys –to develop very precise reporting language that best finds this balance.
As we proceed throughout our teaching cases, we will suggest very specific reporting language that we believe achieves this goal.
Sample PET/CT Reports:
Until you develop your own reporting style, here are two sample reports (a negative report & a positive one) to give you a feel for the degree of specificity expected in a PET/CT report.
- Negative Report [Fig. 1]
- Positive Report [Fig. 2]
Patient & Technologist’s Sheets:
Detailed patient history is essential to accurate PET/CT interpretation. This includes not only the type of cancer the patient may have, but any recent treatments (surgery, chemotherapy, radiation) that may dramatically influence exam interpretation.
Depending on the center or hospital you might read for, access to patient history may be extremely limited. For this reason, our patients and our technologists each fill out a single page document, listing the information most relevant to PET/CT interpretation.
Not infrequently, these forms are the only patient history the radiologist will receive.
- Patient Questionnaire [Fig. 3]
- Technologist’s Data Sheet [Fig. 4]




