Molecular Imaging and Radionuclide Therapy最新文献

Objectives: The aim of this study was to analyze the systolic part of the left ventricular (LV) volume curve obtained by gated myocardial perfusion imaging with the formula used in exponential decay and to investigate the clinical value of the results.

Methods: One hundred fifty eight patients were retrospectively enrolled in the study. The study group was divided into three groups as normal, ischemia, and infarct. The systolic portion of the LV volume curve was also analyzed using the exponential decay formula. The scintigraphic parameter obtained using this formula is called the ejection constant (Ec).

Results: The Ec results were 1.8±0.8, 2.7±0.9, 3.5±1 in infarct, ischemia, and normal groups, respectively, and the difference in Ec results between the groups was statistically significant (p≤0.001).

Conclusion: It appears that Ec may play a clinical role as a scintigraphic parameter in the evaluation of systolic functions of the left ventricle.

A 7-year-old boy with known diagnosis of hereditary spherocytosis and ulcerative colitis was referred for ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography after detection of a 28 mm lesion suspicious for malignancy in spleen on upper abdomen magnetic resonance imaging (MRI). As an incidental finding, a moderately increased uptake of ¹⁸F-FDG was observed in periportal region with no definable mass. MRI revealed compatible findings with "periportal cuffing" as described on ultrasonography.

A 61-year-old male patient, who had undergone radical prostatectomy, underwent ⁶⁸Ga labeled prostate-specific membrane antigen (PSMA) positron emission tomography/computerized tomography (PET/CT) for evaluation of suspected biochemical recurrence of prostate cancer (PCa). PET/CT scan showed increased ⁶⁸Ga PSMA expressions in hypodense mass lesions in both adrenal gland localizations. An adrenal gland tru-cut biopsy was performed for the right side, which showed poor-differentiated carcinoma metastases associated with the patient's high-grade PCa. As far as we could determine based on an extensive literature search, this is the second case in which isolated adrenal metastasis was detected by ⁶⁸Ga PSMA PET/CT study in a patient with PCa.

Rectal neuroendocrine carcinomas constitute <1% of all neuroendocrine carcinomas and <1% of all gastrointestinal tract malignancies. Cutaneous metastases of rectal neuroendocrine carcinoma are rarer than visceral metastases. We represent a 71-year-old man who was diagnosed with neuroendocrine tumor grade 3 originating from the rectum 1 year ago. He was referred for ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography for restaging after 6 cycles of chemotherapy and radiotherapy. Intensely increased ¹⁸F-FDG uptake in the right cutaneous inguinal region was consistent with neuroendocrine carcinoma metastasis with biopsy from the same region.

The fever of unknown origin (FUO) represents a complex diagnostic challenge due to the wide range of etiologies that could cause it, including neoplastic, infectious, rheumatic/inflammatory, and miscellaneous disorders. Several nuclear medicine techniques have proven to be valuable tools for guiding etiologic diagnosis in the setting of FUO. One of these is technetium-99m (Tc-99m)-hexamethylpropylene amine oxime (HMPAO)-labeled leukocyte scintigraphy, which is a diagnosis method that allows in most cases the localization and evaluation of the extension of an occult infection. This paper presents an uncommon case of pseudomembranous colitis without diarrhea as etiology of FUO diagnosed by Tc-99m-HMPAO-labeled leukocytes.

Neuroendocrine tumors are slow-growing tumors originating from neuroendocrine cells and capable of metastasis. Most of them are found in the gastrointestinal tract; however, they can also be rarely seen in other organs. Testicular neuroendocrine tumors account for less than 1% of all testicular neoplasms. They may present as primary testicular or secondary tumors from extratesticular sources. Jejunal neuroendocrine tumor metastasis to the testis is extremely rare. We present the case of a 61-year-old man with a jejunal neuroendocrine tumor and metastases to bilateral testicles revealed on Gallium-68-DOTATATE positron emission tomography/computed tomography.

Bone scintigraphy with Tc-99m-diphosphonate analogs are widely used in staging, restaging, and monitoring the therapy effectiveness of various cancer types. Bone-seeking agents are excreted through urination, resulting in the visualization of either anatomical abnormalities or pathological conditions of the kidneys and bladder. We present a case of a 63-year-old man with urinary bladder carcinoma depicted on whole body planar and single-photon emission computed tomography/computed tomography images.

Intravenous tumor extension is a well-recognized phenomenon occurring in various malignancies but is a relatively rare entity in thyroid carcinoma. In patients with poorly differentiated thyroid cancer (pDTC), I-131 avid superior vena cava tumor (SVC) thrombus at initial presentation is infrequent and potential life threatening. Tumor thrombus can form either due to direct vascular extension of the primary mass or by hematogenous spread. Hybrid nuclear imaging can differentiate the two entities, which can impact the treatment plan of the patient. We present images of an interesting case of evolution of SVC thrombus in a 46-year-old woman with diagnosed pDTC over the span of two years.

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.

Fibrous dysplasia (FD) is a rare congenital benign bone disease that manifests as a defect in the bone remodeling process, affecting the function, differentiation, and maturation of osteoblasts. This process is located in the bone marrow, where the normal marrow tissue is replaced with immature bone islands and fibrous stroma. The etiology is unclear so far, but it is known to be connected with a point mutation of the gene that encodes Gs α protein at the time of embryogenesis, and because of that, all of the affected somatic cells become dysplastic. It is important to determine whether the mutation occurred earlier in the process of embryogenesis so that there will be more mutant cells and the disease will appear in a more severe form. The clinical presentation of FD is variable, so there are plenty of potential differential diagnoses. The most common include Paget disease, non-ossifying fibroma, osteofibrous dysplasia, aneurysmal bone cyst, adamantinoma, giant cell tumor, fracture callus, and low-grade central osteosarcoma.