Diagnosis of Fungal Infection (Candida albicans) After Heart Transplantation in a Pediatric Case with Fever of Unknown Origin: Role of 99mTc-UBI SPECT/CT and 18F-FDG PET/CT.

The diagnosis of patients with fever of unknown origin (FUO) in pediatric heart transplantation is a challenging medical problem. The physician should differentiate between rejections, infections, malignancy, adrenal insufficiency, and drug fever. Immunosuppressive therapy in these patients exposes them to a high risk of developing a post-transplantation fungal infection. In this case, we discuss the diagnostic contribution of the 99mTc-UBI scan and 18F-FDG PET scan for diagnosis of fungal infection causing FUO in these patients.

Incidental osteonecrosis in the distal left femur in a case of beta-thalassemia with COVID-19: Role of [99mTc]Tc-MDP whole-body bone scan.

Secondary anemia in hemoglobinopathies like thalassemia can cause expansion of the bone marrow cavities because of compensatory marrow hyperplasia. This case demonstrates spontaneous osteonecrosis of the distal left femur in a patient with ß-thalassemia that may be secondary to ischemic infarction secondary to occlusion of the microvasculature within the expanded cancellous bone. This subject was referred to Hazrat Rasool Akram Hospital because of fever, cough, and bone pain. In the CT scan she had scattered peripheral CGO in both lungs due to COVID-19 with two paravertebral masses due to extramedullary hematopoiesis. The patient had also generalized bone pain so the physician asked for a whole-body bone scan and incidentally, we found a cold lesion with a rim of increased uptake in the distal left femur that with bone biopsy it was consistent with osteonecrosis. This case illustrates the importance of performing a whole-body bone scan in ß-thalassemia for the management of patients and diagnosis of occult osteonecrosis.

Extensive Venous Tumor Thrombi in a Case of Malignant Melanoma: Role of 18F FDG PET/CT.

The 18F-FDG PET/CT imaging is a non-invasive modality for diagnosis and staging of metastatic melanoma. Venous thromboembolism (VTE) is a common complication of cancers, which needs anticoagulant therapy. Tumor thrombosis (TT), on the other hand, is an infrequent complication of solid malignancies that may need aggressive management. Accurate diagnosis of TT and its differentiation from VTE may change patient management and avoid unnecessary anticoagulation treatment. The objective of this case is to introduce a patient with malignant melanoma presenting with extensive venous tumor thrombi with intense FDG uptake.

A Rare Case of Coexistence Ectopic Lingual Thyroid and Thyroglossal Cyst with Tc 99 m Thyroid Scintigraphy.

Lingual thyroid is a very rare anomaly and is usually incidentally found in patients that have hypothyroidism or mass in throat. This case however had another mass in the submandible with diagnosis of thyroglossal cyst. Thyroglossal duct cyst is the most common congenital neck mass. About 50% of cases present before the age of 10 and second group age present in young adulthood. We present a 27-year-old man who presented with sub-mental mass. The patient had also hypothyroidism. A CT scan was performed to confirm the diagnosis. The CT scan confirmed submental cyst and incidentally discovered lingual thyroid along with absence of thyroid tissue in its normal pretracheal position. The patient had symptoms of hypothyroidism and he was treated with levothyroxin. Our case report highlights a rare and unusual situation because of the coexistence of a thyroglossal cyst and a partially functional lingual thyroid.

Role of Technetium-99m-Ethylenedicysteine in the Calculation of Differential Renal Function: A Comparison Study with Dimercaptosuccinic Acid Renal Scintigraphy.

PURPOSE OF THE STUDY: The aim of our study was to compare the technetium-99m (Tc-99m)-ethylenedicysteine (EC) renography calculation of differential renal function (DRF) with this measurement using Tc-99m-dimercaptosuccinic acid (DMSA) scintigraphy. MATERIALS AND METHODS: Patients referred to our department were included in our study, and both DMSA and EC scans were performed for each patient according to the standard imaging protocols. A checklist was filled for each patient. Statistical analysis was performed using correlation and regression methods. RESULTS: Forty-two patients (mean age: 3.6 ± 3.4 years), including 32 boys and 10 girls, participated in our study. The results of EC scintigraphy were significantly correlated with the values of DMSA scintigraphy (P < 0.001). Performing linear regression, EC renography significantly (P < 0.001) predicted the DRF as it was calculated by DMSA scintigraphy (R 2 = 0.92, P < 0.001). This test was significant in both male and female subgroups (P < 0.001). CONCLUSIONS: Overall, our study findings were similar to the reported results in the other reviewed studies, showing that Tc-99m-EC can be considered as an alternative for DMSA scintigraphy, providing interchangeable results.

Assessment of LV diastolic dysfunction in myocardial perfusion imaging: a correlative study with transthoracic echocardiography.

OBJECTIVE: Myocardial perfusion imaging (MPI) by gated single-photon emission computed tomography (SPECT) is a feasible method in the evaluation of left ventricular perfusion and function. The purpose of this study was to determine the threshold and grading of left ventricular (LV) diastolic dysfunction (LVDD) using gated SPECT MPI. METHODS: A total of 149 patients were recruited in the study. All of the patients underwent a standard 2-day stress/rest gated MPI study and transthoracic echocardiography within 2 weeks. The reconstructed rest-only images were analyzed by Cedar-Sinai's quantitative gated SPECT and the LV diastolic parameters, including peak filling rate (PFR), time to PFR (TTPF) and secondary PFR (PFR2) to PFR ratio were provided and compared to echocardiographic data. RESULTS: 68 (45.6%) and 81 (54.4%) of patients were categorized in LVDD-absent and LVDD-present groups on the basis of LVDD evidence in echocardiography, respectively. receiver-operating-characteristic analysis for PFR and TTPF was performed, resulting in diagnostic sensitivities of 70 and 57% and specificities of 60 and 75% for PFR <2.6 end-diastolic volumes (EDV)/s and TTPF>160.5 ms, respectively. Applying our previously used thresholds of <1.70 EDV/s for PFR, >208 ms for TTPF and >1 for PFR2/PFR, sensitivities and specificities of 9.9 and 96.6%, 9.9 and 95.6% and 13.8 and 88% were resulted, respectively. Grading of LVDD on the basis of MPI-obtained diastolic parameters showed considerable overlapping data by interquartile range. CONCLUSION: Gated SPECT MPI can be used as a highly specific means for detection of LV diastolic dysfunction when compared to echocardiography. However, grading of severity of diastolic heart failure appears to be impracticable.

How reliable is the lacrimal scintigraphy report? An inter-observer agreement and reliability study.

AIM: To assess the inter-observer agreement and reliability as well as intra-observer repeatability for lacrimal scintigraphy (LS) reports with and without considering the irrigation test results. METHODS: A prospective, observational, cross sectional study. Two masked clinicians (lacrimal surgeon and nuclear medicine specialist) independently reported 100 LS images (50 patients of >6 years of age with unilateral anophthalmic socket) in a university hospital. The lacrimal surgeon performed a diagnostic irrigation test and repeated the report of the same LS images 2y after the first report (intra-observer agreement). A weighted Kappa analysis was performed to determine inter-observer agreement and reliability as well as intra-observer repeatability for the type (normal, partial and complete obstruction) and location (presac, preduct, and intraduct) of the obstruction. Subgroup analysis was also performed with consideration of irrigation test results. RESULTS: A significantly moderate agreement was found between lacrimal surgeon and nuclear medicine specialist for both the type (Kappa=0.55) and location (Kappa=0.48) of obstruction. Agreement values were higher for the type (Kappa=0.61 vs 0.41) and location (Kappa=0.56 vs 0.31) of obstruction in cases with normal than abnormal irrigation test. Strong and significant intra-observer (lacrimal surgeon) repeatability was found for both the type (Kappa=0.66) and location (Kappa=0.69) of obstruction. LS showed no to slight reliability based on irrigation test. CONCLUSION: A moderate agreement is found between lacrimal surgeon and nuclear medicine specialist regarding the interpretation of LS suggesting the importance of consensus groups among nuclear medicine specialists and lacrimal surgeons to create a common language for interpretation of LS. Intra-observer repeatability is strong for the lacrimal surgeon.

Artifacts in Quantitative analysis of myocardial perfusion SPECT, using Cedars-Sinai QPS Software.

Quantitative analysis of myocardial perfusion Single photon emission computerized tomography (SPECT) images is increasingly applied in modern nuclear cardiology practice, assisting in the interpretation of myocardial perfusion images (MPI). There are different extensively validated state-of-the-art software packages, including QPS (cedars-Sinai), Corridor 4DM (University of Michigan) and Emory cardiac toolbox (Emory university), providing highly accurate and reproducible data. However, these software packages may suffer from potential artifacts related to patient or technical factors. By recognizing the source of such artifacts, the interpreting physician can avoid misinterpretation of MPI study. In this review, we discuss some of technical pitfalls that may occur in Quantitative Perfusion SPECT software (QPS, cedars-Sinai Medical center).

The Effect of Milk, Water and Lemon Juice on Various Subdiaphragmatic Activity-Related Artifacts in Myocardial Perfusion Imaging.

BACKGROUND: Subdiaphragmatic activity can produce subdiaphragmatic-related artifacts, which can degrade the quality of myocardial perfusion imaging (MPI). OBJECTIVES: We examined the impact of drinking milk, water, and lemon juice on different subdiaphragmatic-related artifacts by using (99m)Tc-sestamibi myocardial single-photon emission computed tomography (SPECT) in order to determine a feasible method for improving the image quality. PATIENTS AND METHODS: A total of 179 patients (age 58 ± 9.6 years) were enrolled in this study. The patients were randomly divided into five groups. Ten minutes after injection of 740 MBq 99mTc-sestamibi in both pharmacologic stress and rest phases, the individuals in group 1 were given water and milk (125 mL of each); those in group 2 were given lemon juice (250 mL); group 3 was given milk (250 mL); and group 4 was given water (250 mL), whereas no intervention was performed in group 5. The study was double-blind for both subjects and data collectors. MPI was performed for all patients and image quality was controlled by 2 experienced nuclear physicians. Interfering activity was determined visually on reconstructed images and categorized as extracardiac normalization artifact, overlapping of activity, scattering of activity, and ramp filter artifact. RESULTS: There were significant differences in terms of interfering activity among the five groups; group 3 (milk) had significantly lower interfering activity than other groups had, as defined by overlapping of activity (on both stress and rest images), ramp filter artifact (stress images), and scatter artifact (rest images) (P < 0.05). Furthermore, there was a significant difference in the incidence of good-quality images, with no interfering activity in group 3 in the resting state compared with the other groups in the study (P < 0.05). CONCLUSIONS: Drinking 250 mL of milk in either the stress phase or the rest phase of imaging diminishes interfering subdiaphragmatic-related artifacts, particularly overlapping of activity in MPI SPECT, resulting in better-quality images.