Journal of nuclear medicine technology最新文献

The recent emergence of text-to-image generative artificial intelligence (AI) diffusion models such as DALL-E, Firefly, Stable Diffusion, and Midjourney has been touted with popular hype about the transformative potential in health care. This hype-driven, rapid assimilation comes with few professional guidelines and without regulatory oversight. Despite documented limitations, text-to-image generative AI creations have permeated nuclear medicine and medical imaging. Given the representation of medical imaging professions and potential dangers in misrepresentation and errors from both a reputation and community harm perspective, critical quality assurance of text-to-image generative AI creations is required. Here, tools for evaluating the quality and fitness for purpose of generative AI images in nuclear medicine and imaging are discussed. Generative AI text-to-image creation suffers quality limitations that are generally prohibitive of mainstream use in nuclear medicine and medical imaging. Text-to-image generative AI diffusion models should be used within a framework of critical quality assurance for quality and accuracy.

Gated equilibrium radionuclide angiography (ERNA), or multigated acquisition scanning, is a well-established technique to monitor left ventricular ejection fraction (LVEF) in patients treated with potentially cardiotoxic chemotherapy. To determine the results of a true change in LVEF, low inter- and intrareader variability is important. The aim of this study was to investigate inter- and intrareader variability in LVEF measurements using 2 different commercially available software packages with cardiac MR (CMR) as a reference standard. Methods: In 46 ERNA scans, LVEF was measured by 2 experienced nuclear medicine technologists, using the 2 software packages Xeleris and Corridor4DM. All patients had CMR performed within 1.5 h from ERNA. CMR-derived LVEF was measured by a cardiologist using cvi42 software. Eight patients were reanalyzed to investigate intrareader variability. Bland-Altman analysis was used to assess agreement between readers and software. Repeated-measures ANOVA was used to assess interactions between readers and software. Differences in mean LVEF were compared using a t test. The Lin concordance correlation coefficient (CCC) was used to test LVEF agreement between software packages and readers and the reference CMR results. Results: Corridor4DM had a significantly higher mean LVEF than did Xeleris. No significant interreader difference was observed within the same software. ANOVA found that readers did not influence LVEFs. The CCC between software packages was similar for both readers, at 0.409 for reader 1 and 0.418 for reader 2. Both software packages showed a significant LVEF bias compared with CMR (4% for Xeleris vs. 11% for Corridor4DM). For both readers, the CCC for correlation with MRI was higher for Xeleris (0.438/0.572) than for Corridor4DM (0.257/0.244). Conclusion: A high degree of variability was found between the 2 different software packages for the calculation of LVEF. No significant difference in LVEF was found between readers using the same software. Corridor4DM gave higher LVEF estimates than did Xeleris. Our findings suggest that different software programs for assessing LVEF in ERNA examinations are not interchangeable. The utmost caution is recommended if switching between different types of software.

This study aimed to validate the effectiveness of MotionFree (MF) in the abdominal region using 2 different PET/CT scanners to determine how to use MF efficiently. Methods: All 198 patients underwent respiratory-gated ¹⁸F-FDG PET/CT with MF. Imaging was performed using Discovery MI (DMI) and Discovery IQ (DIQ) PET/CT scanners, and all data were divided into 2 groups in each category (abdominal: upper and lower abdomen, lesion size, <20 mm and ≥20 mm; scanner group: DMI and DIQ). A physician assessed whether the respiratory motion artifacts were reduced with MF. The SUV change rate (ΔSUV) of 80 measurable lesions with and without MF was calculated. The relationship between the ΔSUVs and these groups was compared. Results: Motion artifacts were reduced in 62 of 198 patients (31.3%) in the upper abdomen, in 1 of 198 patients (0.5%) in the lower abdomen, in 51 of 98 patients (52.0%) in the DMI, and in 12 of 100 patients (12.0%) in DIQ with MF. ΔSUVs were significantly higher in the upper abdomen than in the lower abdomen. ΔSUV was up to 58.3% in DMI and up to 47.6% in DIQ. ΔSUVs of lesions with a size of less than 20 mm were significantly higher than those with a lesion size of 20 mm or greater. Although DMI was more effective than DIQ in terms of motion artifacts, both DMI and DIQ have the potential to increase the SUV with MF. MF significantly reduced the respiratory motion artifacts and increased the SUV for lesions smaller than 20 mm in the upper abdomen. Conclusion: MF reduced the motion artifacts in higher-spatial-resolution PET/CT images. In both PET/CT scanners, SUVs in lesions smaller than 20 mm and lesions in the upper abdomen increased significantly with MF. To use MF without increasing the acquisition time, it may be useful to apply it to the upper abdomen.

Extragonadal choriocarcinoma in men is an extremely rare and highly aggressive malignancy. Inconclusive biopsies due to a high necrotic component often delay diagnosis. Here is such a case, in which suggestive imaging findings on [¹⁸F]FDG PET/CT, a raised level of serum β-human chorionic gonadotropin, and gynecomastia clinched the diagnosis.

Various techniques have been used in attempts to reduce interfering gastrointestinal activity in myocardial perfusion imaging (MPI); however, these approaches have yielded inconsistent results. The goal of this study was to investigate the efficacy of monitored walking, a previously unexplored technique, in reducing subdiaphragmatic activity-related artifacts during pharmacologic stress ^99mTc-tetrofosmin MPI with SPECT to improve the overall image quality. Methods: The study included patients who underwent MPI with pharmacologic stress. They were given a step counter immediately after the radiotracer injection and were randomized into a group A, with a request to walk at least 1,000 steps before imaging, and a group B, with no specific instructions about walking. The reconstructed SPECT images were assessed visually. Moderate and severe levels of subdiaphragmatic tracer activity were considered relevant for the interpretation of the scans. Additionally, myocardial and abdominal activity was semiquantitatively assessed on raw planar images, and the mean myocardium-to-abdomen count ratios were calculated. Results: We enrolled 199 patients (95 patients in group A and 104 patients in group B). Clinical characteristics did not differ significantly between the 2 groups. Patients in group A walked more steps than patients in group B (P < 0.001), but there were no differences in the proportion of accepted scans between the 2 groups (P = 0.41). Additionally, there were no differences in the proportion of relevant subdiaphragmatic activity between the groups (P = 0.91). The number of steps did not impact the acceptance rate (P = 0.29). Conclusion: A higher number of steps walked during the waiting period between pharmacologic stress and acquisition does not affect subdiaphragmatic activity-related artifacts or the proportion of accepted scans after pharmacologic stress. However, pedometer use and clear instructions motivate patients to walk while awaiting imaging. Larger studies are required to compare a higher-step-count group with a sedentary control group to assess the influence of walking on gastrointestinal artifacts in MPI.

An ectopic kidney is often found inadvertently during CT, ultrasonography, MRI, or urologic physical examination. Ectopic kidneys usually occur in the pelvis. A pelvic ectopic kidney may be misinterpreted for a pelvic tumor by less experienced physicians and surgeons. We present an extremely rare case of ectopic kidney in the deep subcutaneous region of the abdominal wall and associated with the additional abnormality of spina bifida. MRI found an ectopic kidney but failed to identify ureteropelvic drainage. Diuretic renography with ^99mTc-diethylenetriaminepentaacetic acid showed normal functioning and identified nonobstructive ureteropelvic drainage of the ectopic subcutaneous kidney.

Hepatic metastases of cranial meningiomas are rare, particularly when they present as a delayed, solitary metastasis, which poses a challenge for imaging-based diagnosis. [¹⁸F]FDG PET/CT facilitates diagnosis and posttreatment restaging, whereas somatostatin receptor-targeted PET demonstrates high sensitivity and specificity in the diagnosis of meningiomas and may potentially evaluate the viability of theranostics approaches, particularly for treatment-resistant meningiomas.

Oncocytic adenomas are rare benign tumors that typically originate in organs such as the kidneys, thyroid, parathyroid, salivary glands, or pituitary gland. Oncocytic adenoma of the adrenal gland is extremely rare. It often shows heterogeneous, nonspecific features on anatomic imaging, as well as high ¹⁸F-FDG avidity despite its benign nature. The definitive diagnosis relies on histopathologic examination, including immunohistochemistry. We present an incidentally detected benign adrenal oncocytic adenoma with intense ¹⁸F-FDG uptake mimicking sinister pathologies.

Effective clinical education relies on consistent terminology and clearly defined roles and expectations. This brief communication explores the complexities inherent in the nomenclature of clinical education, aiming to clarify and standardize the terms used across educational settings. Common roles in clinical education and instruction are defined; the roles of the clinical coordinator, affiliate education supervisor, and clinical instructor are discussed; and the key responsibilities and tasks of each clinical education role are explained. Understanding the nomenclature, roles, and responsibilities of those involved in clinical education helps standardize clinical education and provides a more efficient and effective clinical education process.