ABSTRACT: In this note, we aim to present a patient with a known case of prostate cancer with widespread metastasis to the skeleton and liver who has undergone several cycles of chemoradiotherapy. The patient received 2 doses of 177 Lu-prostate-specific membrane antigen therapy, in which several zones of uptake were detected on the thoracic wall compatible with cutaneous metastatic lesions of prostate cancer.
Prostate , Prostatic Neoplasms, Castration-Resistant , Radioisotopes , Male , Humans , Prostate/pathology , Prostate-Specific Antigen , Prostatic Neoplasms, Castration-Resistant/pathology , Dipeptides/therapeutic use , Lutetium/therapeutic use , Heterocyclic Compounds, 1-Ring/therapeutic use , Treatment Outcome , Neoplasm Metastasis
In this note, it was aimed to describe a 66-year-old patient for ischemia evaluation following the episodes of chest discomfort using dipyridamole stress-rest myocardial perfusion single-photon emission computed tomography (SPECT). Invasive coronary angiography demonstrated a total occlusion of the right coronary artery (RCA) and prominent RCA intracoronary collateral (Kugel's artery) associated with nonviable, infarcted myocardium in the inferior wall of left ventricular LV on myocardial perfusion SPECT. Thus, recanalization of RCA was not performed in our patient. It is concluded that performing complementary imaging modalities for assessing myocardial perfusion like SPECT for the prediction of viability to sole reliance on angiographic data in decision making for revascularization is encouraged.
Objectives: To investigate the added diagnostic value of delayed imaging at 3 and 4 h compared to 2 h imaging as well as scanning up to 4 h compared to 3, and by this means, diagnosis reclassification or changes in diagnosis across various time points. Methods: Seventeen patients clinically suspected of gastroparesis, 8 (47.1%) men and 9 (52.9%) women, according to the standard procedural guidelines, underwent gastric emptying scintigraphy after ingesting a standard meal. One-minute static images in anterior and posterior projections were acquired immediately after ingestion and then at 1-, 2-, 3- , and 4 h time points. For image analysis, a manual region-of-interest was drawn, and then, count of stomach in each projection was used to calculate geometric mean for each time point. Decay correction was applied. At 2-, 3- and 4 h time points, percentage of retained activity was compared to standard values; therefore, each patient was labeled as normal or delayed. Results: Pairwise correlation between time points was statistically significant. Value of hour 3 shows an extremely strong correlation with the value of hour 4 (r=0.951, p<0.001). In hour 2, of 17 participants, 11 (64.7%) were diagnosed as normal and 6 (35.3%) as delayed. In hour 3, the diagnosis made as delayed rose to 9 (52.9%), whereas normal was 8 (47.1%). Finally, in hour 4, results were 10 (58.8%) as delayed and 7 (41.2%) as normal. All subjects who were labeled as delayed in hour 3 remained with the same diagnosis and 1 out of 8 subjects categorized as normal in hour 3 changed to delayed. For testing agreement, coefficient of kappa was computed between each pair. Agreement between diagnosis in hour 2 with hours 3 or 4 was not strong (kappa <0.6 for both pairs). However, a strong agreement was found between diagnosis in hours 3 and 4 (kappa: 0.881). Conclusion: Because of excellent correlation between values of hours 3 and 4 and strong agreement between the diagnosis in those time points, extending acquisition from 3 to 4 h adds little to the final dai gnosis and may not be noticeably meaningful, especially in the clinical setting.
OBJECTIVE: To assess the effect of software-simulated "bouncing" motion on left ventricle (LV) perfusion and function indices concerning three main determinants of motion (duration, magnitude and time) by evaluating the sole effect and interaction of these attributes in a statistical model. METHODS: Twenty-nine gated myocardial perfusion SPECT scans were selected for the study and then, "bounce" motion pattern was simulated manually regarding three main attributes of motion including duration (short versus long), magnitude (2 versus 4 pixels) and time (early versus late), all in upward vertical direction. All SPECT images are reconstructed and filtered with an identical method (OSEM algorithm) and same parameters. Indices of LV myocardial perfusion and function are derived using QGS package of Cedars-Sinai software in original and simulated-motion images and are then compared with each other. Two- and three-way Repeated Measure Within-Subjects ANOVA tests are conducted to evaluate the main effect of each variable or attribute and the interaction between them. RESULTS: Summed scores increase roughly exponentially from "no motion" to short bounce and then, to long bounce. In long 4-pixel bounce, perfusion defects are remarkable. All comparisons of defect extent (DE) and total perfusion deficit (TPD) are statistically significant. Mean difference between short bounce motion patterns with "no motion" is small even in 4-pixel movements (almost 3% or lower). In contrast, mean difference between long bounce motion patterns with "no motion" is higher than 5%. Using a paired-sample t-test, in all pairs, mean difference for ejection fraction (EF) is less than 4% which all are statistically significant. Value of end-diastolic volume (EDV) and end-systolic volume (ESV) are consistently decreased based on duration (from short to long) and magnitude (from 2 to 4 pixels). Using Within-Subjects ANOVAs, in long bounce, main effect of magnitude and interaction of magnitude and time, but not time solely, were statistically significant. In 2-pixel magnitude, none of variables and their interaction were significant, but in 4-pixel magnitude, EF showed statistical significance with duration. CONCLUSION: The perfusion parameters are to a higher extent involved by motion particularly in long bounce with a 4-pixel displacement. In short bounce, the effect is negligible, and therefore, no need to repeat the scan. Parameters of function are much less vulnerable to be affected by motion. Thus, contrary to current recommendations, there may be less need to repeat the scan in short 2-pixel bounce.
Heart Ventricles , Ventricular Dysfunction, Left , Humans , Heart Ventricles/diagnostic imaging , Tomography, Emission-Computed, Single-Photon/methods , Software , Perfusion
Artifacts originated from imaging hardware or instrumentation may be, on some occasions, confusing and peculiar to both physicians and technicians. Various artifacts from a variety of sources have been reported. In this note, we intend to describe a new one with an interesting pattern in whole-body scanning, which is strikingly different from its pattern in static spot view, in a patient presented for post-therapeutic 131I survey after total thyroidectomy.
INTRODUCTION AND BACKGROUND: The polarity status is one of the important items of specifications of trigger signal from cardiac trigger monitors with two options, either positive or negative. Some systems allow the user to set the polarity of trigger signal before imaging. Efforts should be made to set the polarity status according to the recommendations provided by the manufacturers. In case of inappropriate selection, changes in computation of end-systolic and end-diastolic volumes as well as ejection fraction may occur. OBJECTIVE: To investigate the effect of the polarity status of trigger signals in synchronization process during 8- and 16-frame gated SPECT imaging on the systolic and diastolic parameters of LV function. METHODS: Thirty-four patients referred for a myocardial perfusion SPECT were consecutively included in the study. The rest scan for each patient was performed with 8- and 16-frame gating simultaneously with positive trigger signal set by the operator in a cardiac trigger monitor and then repeated after manual selection of negative polarity. In total, the 4 imaging modes acquired were 8-frame/positive-trigger, 16-frame/positive-trigger, 8-frame/negative-trigger, and 16-frame/negative-trigger. All SPECT images were reconstructed and processed with the same values of parameters. Systolic and diastolic indices of LV function were derived in QGS of the Cedars-Sinai software and then were compared using various statistical tests, and a reliability analysis was also performed. RESULTS: The age of patients recruited in the study was 58.41 ± 8.94, and 16 (47.1%) males and 18 (52.9%) females. All the correlation coefficients between corresponding parameters in positive and negative trigger signals were statistically significant. The difference between the parameters of systolic function including EF, EDV, and ESV in positive and negative trigger signals was statistically significant in paired sample t test. Likewise, a statistically significant difference was also found between mean phase angle in scans with positive and negative trigger signals by a phase difference of 147.91 (41.0% of an average cardiac cycle) and 149 (41.3% of an average cardiac cycle) degrees in 8- and 16-frame gating modes, respectively. Strong agreement (according to high values of intra-class correlation coefficient) was found for all four pairs. According to Bland-Altman results, an offset of about 3 percentage units was found, both between imaging in 8-frame gating compared to 16-frame gating, higher value in favor of 16-frame gating, and also between imaging with positive polarity trigger compared to negative-polarity trigger, again higher value in favor of positive-polarity triggering. CONCLUSION: The status of the polarity of trigger signals or similar CTM-camera delays in synchronization process during 8- and 16-frame gated SPECT imaging can be considered as one of the factors that may influence systolic and diastolic indices of LV function.
Tomography, Emission-Computed, Single-Photon , Ventricular Function, Left , Electrocardiography , Female , Gated Blood-Pool Imaging/methods , Humans , Male , Perfusion , Reproducibility of Results , Stroke Volume , Tomography, Emission-Computed, Single-Photon/methods
A 62-year-old woman with a history of abdominal pain presented with multiple hepatic lesions and dilatation of portal, splenic and superior mesenteric veins on the magnetic resonance imaging referred for a 99mTc-octreotide scan. Accordingly, similar octreotide-avid lesions were found as well as an uptake in the epigastric region conforming to the anatomy of the portocaval venous system, compatible with a tumor thrombosis. Then, the patient underwent two cycles of therapy with 177Lu-DOTA-TATE, on that the same appearance was observed. The uptake in the tumor thrombus remained somewhat unchanged, but clinically, a significant improvement of the intractable ascites was achieved.
Prostate-specific membrane antigen (PSMA)-targeted imaging is now an effective tool for the evaluation of prostate cancer patients. Although salivary glands take up 68Ga-PSMA avidly, pathologies of these glands may be readily noticeable. Herein, we present a case of prostate cancer referred for 68Ga-PSMA positron emission tomography-computed tomography in whom an isolated aplasia of the submandibular salivary gland was incidentally found.
