Purpose: Cardiac 2-deoxy-2-[F-18]fluoro-D-glucose positron emission tomography (FDG PET) is widely used to assess myocardial viability in patients with ischemic heart disease. While sufficient glucose uptake is a prerequisite for accurate interpretation of cardiac viability, there are a lack of data on which clinical variables have the most significant impact on myocardial glucose metabolism. Therefore, this study was designed to evaluate several clinical variables that could affect myocardial glucose metabolism. Methods: A total of 214 consecutive cases were retrospectively enrolled in this study. All subjects received 250 mg of acipimox and underwent glucose loading as preparation for cardiac FDG PET/CT. Three-dimensional regions of interest (ROIs) were drawn on PET/CT fusion images. Myocardial glucose uptake ratio (MGUR = SUVmax of LV myocardium/SUVmean of liver) was then calculated. Multiple clinical variables including body mass index (BMI), blood glucose levels at different times, administered insulin dosage, lipid profiles, and ejection fraction were measured and analyzed for correlation with myocardial glucose uptake. After dichotomizing the subjects based on a BMI of 25, each group’s MGUR was compared. Results: Myocardial uptake showed significant correlations with BMI (r = −0.162, p = 0.018), HbA1c (r = −0.150, p = 0.030), and triglyceride levels (r = −0.137, p = 0.046). No other clinical variables showed a significant correlation with myocardial glucose uptake. After multiple linear regression analysis, BMI (p = 0.032) and HbA1c (p = 0.050) showed a correlation with MGUR. In group analysis, after dividing patients based on BMI, the obese group showed significantly lower myocardial uptake than the non-obese group (3.8 ± 1.9 vs. 4.4 ± 2.1, p = 0.031). Conclusions: Among several clinical variables, BMI and HbA1c levels were related to myocardial glucose uptake. A prospective study would be needed to examine whether a protocol that additionally considers BMI and HbA1c levels is necessary for the current cardiac FDG PET protocol.

Objective Cardiac 2-deoxy-2-[F-18]fluoro-D-glucose positron emission tomography (FDG PET) is widely used to assess myocardial viability in patients with ischemic heart disease. While sufficient glucose uptake is a prerequisite for accurate interpretation of cardiac viability, there is a lack of data on which clinical variables have the most significant impact on myocardial glucose metabolism. Therefore, this study was designed to evaluate several clinical variables that could affect myocardial glucose metabolism. Methods Between May 2018 and November 2022, a total of 214 consecutive cases were retrospectively enrolled in this study. All subjects were fasted for at least 8 hours. They received 250 mg of acipimox and underwent glucose loading as preparation for cardiac FDG PET/CT. Three-dimensional regions of interest (ROI) were drawn on PET/CT fusion images. SUV ratio (SUVmax of LV myocardium/SUVmean of liver) was then calculated. Clinical variables of age, sex, height, weight, body mass index (BMI), fasting blood glucose level, administered insulin dosage, blood glucose level at FDG injection, total cholesterol, high-density lipoprotein, low-density lipoprotein, cardiac markers, creatinine, hemoglobin A1c, and ejection fraction were measured and analyzed for correlation with myocardial glucose uptake. Participants were divided into an obese group and a non-obese group based on a BMI of 25. Whether there was a difference in myocardial glucose uptake between the two groups was then determined. Pearson correlation coefficient and Student’s t-test were used for statistical analysis. Results Myocardial uptake showed significant correlations with BMI (r = -0.162, p = 0.018), HbA1c (r = -0.150, p = 0.030), and triglyceride levels (r = -0.137, p = 0.046). No other clinical variables showed a significant correlation with myocardial glucose uptake. In group analysis, after dividing patients based on BMI, the obese group showed significantly lower myocardial uptake than the non-obese group (3.8 ± 1.9 vs. 4.4 ± 2.1, p = 0.031). Conclusions Among several clinical variables, BMI, HbA1c, and triglyceride levels exhibited negative correlations with myocardial glucose uptake. Patients with higher BMI, HbA1c, and triglyceride levels might require more thorough preparation or consideration during cardiac FDG PET exams to ensure optimal glucose uptake.

In this presented case, a 77-year-old woman with an implanted prosthesis and ongoing knee pain underwent a bone scan using ^99mTc-hydroxydiphosphonate (HDP) in suspicion for bone infection. An incidental finding from this scan revealed diffuse cardiac uptake, necessitating further diagnostic procedures to exclude the possibility of cardiac amyloidosis. In the subsequent ^99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scan and SPECT images, no perceptible cardiac uptake was observed at all. Upon retrospective review of the patient’s medical records, she received 1000 mg of ferric carboxymaltose for iron-deficient anemia the day before the ^99mTc-HDP bone scan. Therefore, it was assumed that the diffuse and temporary cardiac activity was due to the transient iron overload. We present and share these bone scan images in order to avoid possible future misinterpretation of cardiac amyloidosis.

Distant metastasis of cholangiocarcinoma is most commonly diagnosed in the liver; however, it can also be found in the lungs, distant lymph nodes, bones, and brain. Distant lymph node metastasis outside the abdominal region without concurrent abdominal metastasis is exceedingly rare in extrahepatic cholangiocarcinoma. Herein, we present interesting ¹⁸F-FDG PET/CT images of a 49-year-old male patient with common bile duct cancer. In this case, the patient, who was scheduled for surgery, unexpectedly showed axillary lymph node metastasis on a preoperative ¹⁸F-FDG PET scan, which was subsequently confirmed via histological examination. Although such cases are exceptionally rare, this accurate diagnosis prompted a modification of the treatment plan, leading to a positive therapeutic response.

Purpose: To investigate whether the overall survival (OS) of patients with parkinsonism is associated with dopamine transporter activity in the striatum measured by ¹⁸F-N-(3-fluoropropyl)-2β-carbon ethoxy-3β-(4-iodophenyl) nortropane positron emission tomography (¹⁸F-FP-CIT PET). Methods: From March 2021 to December 2021, ¹⁸F-FP-CIT PET images from patients with Parkinsonism were retrospectively reviewed. Dopamine transporter activity in each striatal region was automatically measured as striatal binding ratio (BR) from PET DICOM files using AI-based quantification (BTXBrain, v1.1.1). Mortality data were obtained from the National Health Insurance system in South Korea. Independent t test was performed to compare regional BRs between nonsurvivor and survivor groups. OS was then compared between low BR and high BR groups for each brain region using Kaplan-Meier curves and the log-rank test. Both univariate and multivariate Cox regression analyses were conducted to calculate hazard ratios (HRs). Results: The final cohort comprised 125 patients (mean age: 73.1 ± 9.4 y) with a median follow-up period of 37 months (range: 31–41 mo). Twenty-six (20.8%) patients died during the follow-up period. Nonsurvivors showed significantly lower BRs in the dorsal striatum (p=0.03), caudates (p≤ 0.001), ventroanterior putamen (p=0.029), anterior pallidum (p=0.030), ventral striatum (p=0.002), and subthalamic nucleus (p=0.032). Patients with low caudate BR (≤1.63) demonstrated poorer OS than those with high caudate BR (>1.63) (HR: 5.48, 95% CI: 1.27–23.59, p<0.001). In multivariate analysis, old age (HR: 3.136; 95% CI: 1.356–7.251; p=0.008) and low caudate BR (HR: 5.360; 95% CI: 2.310–12.438; p<0.001) were significantly associated with higher mortality. Conclusions: In FP-CIT PET of patients with parkinsonism, the binding ratio of the caudate nucleus rather than that of the putamen can serve as a significant prognostic indicator for overall survival. Dopamine transporter activity of the caudate should receive more attention from a prognostic perspective, both in quantified data and visual analysis.