Investigation of the effectiveness of no-reference metric in image evaluation in nuclear medicine.

Background: In nuclear medicine, normalized mean square error (NMSE) is widely used for image quality evaluation and machine adjustment. However, evaluating clinical images in nuclear medicine using NMSE necessitates acquiring a reference image, which is time consuming and impractical. Therefore, it is necessary to explore no-reference metrics, such as perception-based image quality evaluator (PIQE) and natural image quality evaluator (NIQE), as alternatives for evaluating the quality of clinical images used in nuclear medicine.

[Development of Dose Management Software Using Visual Basic for Applications and Dose Evaluation in the Field of Nuclear Medicine].

Purpose: The purpose of this study was to develop software for smooth dose management based on the Japan diagnostic reference levels (DRLs 2020) in the field of nuclear medicine.

Method: Using the programming language Visual Basic for Applications (VBA), we implemented a function for calculating actual doses, a function for comparing doses at one's own facility with those of DRLs 2020, a function for calculating appropriate doses for pediatric nuclear medicine examinations, and so on. In addition, we evaluated actual doses before and after the software implementation.

Deep learning-based detection of parathyroid adenoma by Tc-MIBI scintigraphy in patients with primary hyperparathyroidism.

Objective: It is important to detect parathyroid adenomas by parathyroid scintigraphy with 99m-technetium sestamibi (Tc-MIBI) before surgery. This study aimed to develop and validate deep learning (DL)-based models to detect parathyroid adenoma in patients with primary hyperparathyroidism, from parathyroid scintigrams with Tc-MIBI.

Methods: DL-based models for detecting parathyroid adenoma in early- and late-phase parathyroid scintigrams were, respectively, developed and evaluated.

[Using Super Resolution to Denoise on PET Images].

A high-resolution display panel comes to practical use, but the resolution of the indicated contents does not change. The up-sampling processing is applied to indication of the low-resolution contents. In the up-sampling process, the super resolution enables an up-sampling process which estimates information of high frequency components lost by sampling while analyzing input images is noticed.

A Clinical Quantitative Evaluation of Hepatobiliary Transport of [C]Dehydropravastatin in Humans Using Positron Emission Tomography.

Various positron emission tomography (PET) probes have been developed to assess in vivo activities in humans of drug transporters, which aid in the prediction of pharmacokinetic properties of drugs and the impact of drug-drug interactions. We developed a new PET probe, sodium (3, 5)-3, 5-dihydroxy-7-((1 2, 6, 8)-6-hydroxy-2-methyl-8- ((1-[C]-()-2-methyl-but-2-enoyl) oxy) -1, 2, 6, 7, 8, 8-hexahydronaphthalen-1-yl) heptanoate ([C]DPV), and demonstrated its usefulness for the quantitative investigation of Oatps (gene symbol ) and Mrp2 (gene symbol ) in rats. To further analyze the species differences and verify the pharmacokinetic parameters in humans, serial PET scanning of the abdominal region with [C]DPV was performed in six healthy volunteers with and without an OATP1Bs and MRP2 inhibitor, rifampicin (600 mg, oral), in a crossover fashion.

[Scatter Correction of Septal Penetration for I-IMP Cerebral Blood Flow SPECT Adding Radioactivity from the Outside of Field of View-Comparison between Simulation-based and Multi-window Scatter Corrections].

Purpose: The N-Isopropyl-p-[123I] Iodoamphetamine (I-IMP) SPECT imaging reduces the image quality and quantitative accuracy due to scatter and septal penetration occurred by radioactive uptake from outside of the field of view such as the lungs. We evaluated the influence of scatter and septal penetration using phantom-simulated radioactivity from outside of the field of view, and subsequently compared the effect of scatter and septal penetration corrections between the simulation-based effective scatter source estimation (ESSE) method and the multi-window method (ellipse approximation method).

Methods: We used the phantom filled with 10 and 25 kBq/mL for the brain and lung parts corresponding to radioactive concentration in the clinical study.

Usefulness of standardized uptake value normalized by individual CT-based lean body mass in application of PET response criteria in solid tumors (PERCIST).

Our aim in this study was to verify the usefulness of the standardized uptake value (SUV) normalized by individual CT-based lean body mass (LBMCT) in application of PET response criteria in solid tumors (PERCIST).We retrospectively investigated 14 patients (4 male and 10 female) with malignant lymphoma who were undergoing chemotherapy. (18)F-FDG PET/CT examinations were performed before and after chemotherapy.

Validation of threshold method for myocardial control database by use of clinical data.

A database is an important factor in the statistical analysis of myocardial scintigraphy. Our aim in this study was to verify the validity of the threshold method using phantoms and to create a clinical database using this method. Since this method involves artificially excluding a low count area on a polar map, we created a myocardial phantom with defects.

Diagnostic ability of (99m)Tc-HSA-DTPA scintigraphy in combination with SPECT/CT for gastrointestinal bleeding.

Purpose: Gastrointestinal (GI) bleeding scintigraphy in combination with single-photon emission computed tomography/computed tomography (SPECT/CT) remains to be studied in detail. This study aimed to examine the diagnostic ability of this tool.

Methods: GI bleeding scintigraphy using (99m)Tc-human serum albumin-diethylenetriaminepentaacetic acid was performed for 38 patients with suspected GI bleeding.

[Bilateral filter applied to bone scintigraphy].

The aim of this study is to improve the image quality using a post process rather than a correction process at acquisition time. We used a smoothing filter that is widely used on a compact digital camera. Especially for nuclear medicine, when we use a short acquisition time, we will get images that have a large increase in statistical noise.

Subcutaneous Extravasation of Sr-89: Usefulness of Bremsstrahlung Imaging in Confirming Sr-89 Extravasation and in the Decision Making for the Choice of Treatment Strategies for Local Radiation Injuries Caused by Sr-89 Extravasation.

A male patient in his 20s presented at our clinic with pain caused by bone metastases of the primitive neuroectodermal tumor, and Sr-89 was administrated to palliate the pain. After receiving the injection, the patient complained of a slight burning pain at the catheterized area. Slight reddening and small circular swelling (diameter, 0.

Advantages of upright position imaging with medium-energy collimator for sentinel node lymphoscintigraphy in breast cancer patients.

Objective: To evaluate the advantage of upright position imaging with a medium-energy collimator for the detection of sentinel lymph node (SLN).

Methods: Thirty-four patients with operable breast cancer underwent sentinel node lymphoscintigraphy with 99mTc-tin colloid. Images were obtained in 5 different positions and paired images from the same patient were compared using side-by-side interpretation.

Usefulness of medium-energy collimator for sentinel node lymphoscintigraphy imaging in breast cancer patients.

Unlabelled: This study was performed to investigate the usefulness of a general-purpose medium-energy (ME) collimator for the accurate localization of the sentinel lymph node (SLN) in breast cancer patients.

Methods: We compared phantom images and lymphoscintigraphy images obtained under different conditions for a patient with breast cancer. Comparisons were performed between 2 cameras, between a low-energy high-resolution (LEHR) collimator and a general-purpose ME collimator, and between energy windows centered at 141 keV and at 146 keV.

[Usefulness of imaging method without using lead plate for sentinel lymph node scintigraphy].

Purpose: In scintigraphy of the sentinel lymph node, it is common to use a lead plate as a shield to reduce star artifact and scattered radiation in the portion surrounding the injected site of radioactive colloid. We have developed an imaging method without using a lead plate, and examined its usefulness in phantom and clinical imagings.

Methods, Results: Star artifact was eliminated using a medium energy collimator.