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 160.5 ms, respectively. Applying our previously used thresholds of 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.

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 β-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 β-thalassemia for the management of patients and diagnosis of occult osteonecrosis. 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 β-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 β-thalassemia for the management of patients and diagnosis of occult osteonecrosis.

Background: Bone metastases are complications of many cancers, including colon cancer. Whole body bone scan is commonly used to detect bone metastases in these patients. Bone scan findings are sensitive for detecting metastases but with less experience and especially without the use of single photon emission computed tomography/computed tomography (SPECT/CT) images, they are less specific. This means that while bone scans are effective at identifying areas of abnormal bone activity, they may not always distinguish between bone metastases and other conditions, such as fractures, infections, or benign bone diseases such as a rare condition like osteopetrosis, leading to potential false positives. This 52-year-old male patient was referred for a whole-body bone scan for evaluation of bone metastasis. At first glance, the scan pattern with multiple foci of increased radiotracer uptake seemed to indicate bone metastases due to the patient’s colon cancer. However, upon closer inspection of the bone scan and careful attention to details such as bone deformities and cortical thickening, along with obtaining a more detailed patient history and reviewing other radiological records, the diagnosis of osteopetrosis was made. Conclusions: This case demonstrates the importance of carefully interpreting bone scan findings when diagnosing metastasis. It highlights that other benign diseases, including rare conditions such as osteopetrosis, can mimic the appearance of bone metastases on scans. Therefore, it is crucial to pay close attention to any abnormal patterns, like cortical thickening and bone deformity, and to thoroughly review the patient’s medical history and other relevant clinical data and imaging findings. This comprehensive approach helps avoid misdiagnosis and ensures accurate interpretation of the scan results. Keywords: osteopetrosis whole body bone scan bone metastasis colon cancer