Asia Oceania Journal of Nuclear Medicine and Biology最新文献

Gastroparesis, characterized by delayed gastric emptying in the absence of mechanical obstruction, is a challenging condition to diagnose and treat in children due to limited pediatric-specific data. This case report presents a 15-month-old girl with recurrent and chronic vomiting since infancy, which worsened upon the introduction of solid foods. Initial diagnostic evaluations, including esophagogastroduodenoscopy (EGD) and upper gastrointestinal contrast study, ruled out structural abnormalities. A gastric emptying scintigraphy (GES) with ^99mTc DTPA confirmed significant gastric retention, leading to a diagnosis of idiopathic gastroparesis. Endoscopic intra-pyloric botulinum toxin injection (IPBI) was performed and resulting in significant symptom improvement. Post-procedure assessments revealed improved gastric emptying, with reduced retention at 60 and 180 minutes and a markedly decreased half-time (t_1/2) was shown following the procedure. These findings highlight that IPBI may be a promising therapeutic option for pediatric idiopathic gastroparesis unresponsive to standard treatments. Further research is warranted to refine treatment protocols and evaluate long-term outcomes.

This case report presents a case of unusual diffuse cardiac uptake (Peruguni 3: uptake greater than rib uptake) on a ^99mTc-methylene diphosphonate bone scan in an 83-year-old patient with metastatic prostate cancer which is almost resolved (Peruguni 1: uptake less than rib uptake) on a follow up bone scan about 4.4 months later. Laboratory values and imaging were negative for cardiac amyloidosis and a thorough review of the patient's medical chart did not reveal any other possible causes, pharmacologic or otherwise, thus deeming the uptake non-specific. While increased non-specific cardiac ^99mTc-diphosphanate uptake has been previously reported in elderly prostate cancer patients, possibly attributable to asymptomatic atherosclerosis, this explanation is unlikely considering that the uptake almost resolved within a relatively short period of time. It is clinically important to rule out amyloidosis in patients with increased cardiac uptake on bone scans. However, we believe that clinicians should also consider the possibility of non-specific uptake as a cause for cardiac uptake on bone scan, which would only require follow-up rather than medical intervention.

Objectives: Sudden death in multiple system atrophy (MSA) is caused by decreased serotonergic innervation, but there is no routine test method for this decrease. In addition to dopamine transporters, iodine-123-labelled N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl) nortropane (¹²³I-FP-CIT) binds serotonin transporters (SERTs). We noted a binding potential to quantify the total quantity of ¹²³I-FP-CIT binding to its receptors.Following Mintun's binding-potential concept, this study aimed to evaluate the relationship between the specific binding ratio (SBR) and total SERT tissue amount, but not SERT binding, and to develop an SBR imaging method to measure brain-stem SERT. We sought to establish a binding-potential imaging procedure using SBR images to examine differences in the brain-stem SERT distribution between healthy subjects and MSA patients.

Methods: Single-photon emission computed tomography (SPECT) and T1-weighted magnetic resonance (MR) images were aligned. The MR (T1) images were used to set a reference site for the occipital-lobe SBR in each subject, and measurements were made from the SPECT image at the same position. The pixel values and accumulation ratios compared with the occipital lobe were calculated, and a regional SBR distribution image was created. We identified areas with SERT accumulation above a certain level.

Results: The SERT accumulation site was visualised as an SBR value on MR images. The accumulation distribution (SERT distribution) on the SBR images significantly differed between the healthy subjects and patients with MSA.

Conclusion: SERT accumulation was noted in the brain-stem region, indicating that SBR imaging was useful for viewing and quantifying SERT accumulation.

We present two patients with a history of paroxysmal atrial fibrillation who developed pulmonary vein stenosis (PVS) following atrial fibrillation (AF) ablation. Case 1 involved a female patient in her 50s who was asymptomatic for pulmonary symptoms but was found to have a high degree of left superior PVS 15 months after AF ablation. This was demonstrated using contrast-enhanced computed tomography (CE-CT) and supported by findings of perfusion defects on ventilation-perfusion (V/Q) scan. Case 2 was a male patient in his 60s who developed progressive left superior PVS nine months after AF ablation, evidenced by serial CE-CT and V/Q scans. PVS is a rare but well-known complication of pulmonary vein ablation for the treatment of AF that can lead to severe complications if left untreated. V/Q scans effectively assess the functional significance of PVS by detecting abnormal blood flow segments. Although a V/Q mismatch characterized by reduced perfusion defects is more commonly used in evaluating pulmonary embolism, PVS should not be disregarded as a differential diagnosis. Few studies emphasize the utility of V/Q scans in managing PVS and highlight V/Q mismatch as a notable finding. This case report aimed to highlight their significance.

Objectives: IQ-SPECT technology uses cardiac-specific SMARTZOOM(TM) collimator that can reduce the time required to acquire myocardial perfusion images to half (14 seconds/view) of a standard SPECT procedure. This study aimed to further shorten the scan acquisition time (7 seconds/view) using the SMARTZOOM(TM) collimator without compromising the image quality.

Methods: This prospective observational study involved 50 patients (39 men and 11 women) who underwent myocardial perfusion studies using the SMARTZOOM(TM) collimator. The scans were acquired in 7 seconds/view (Group A) and 14 seconds/view (Group B). Attenuation-corrected (AC), non-attenuation-corrected (NAC), and polar maps were generated for both groups using the QGS/QPS software. The groups were qualitatively and quantitatively compared in terms of image quality, relative uptake score, summed scores, total perfusion deficit, and left ventricular ejection fraction (LVEF).

Results: The image quality of both groups was comparable in the AC studies, whereas Group B was superior to Group A in the NAC studies. All images exhibited an image quality score of ≥3, which suggested adequate image quality. The mean LVEF values were 62.16 and 64.34 in Groups A and B, respectively (p-value 0.326). A strong positive correlation was observed between the two datasets (Pearson's r=0.59). The mean summed score in the AC images was 7.5 in both groups (p-value 0.49), and in the NAC images, the scores were 7.68 in Group A and 7.46 in Group B (p-value 0.46). The mean total perfusion deficits calculated using the 17-segment models were 11% and 16% in Group A and Group B, respectively, for the AC images (p-value 0.143) and 11.2% and 16.5% in Group A and Group B, respectively, for the NAC images (p-value 0.135). Significant differences were not noted in the calculation of the relative uptake score in segments 1- 17 for the AC and NAC images in Groups A and B.

Conclusion: The findings from this study indicate that further shortening of the scan acquisition time to 7 seconds/view is possible in myocardial perfusion imaging using the SMARTZOOM(TM) collimator without compromising the scan quality and the results, thus improving patient comfort.

Rasmussen encephalitis (RE) is a rare condition characterized by a chronic inflammatory disorder due to unilateral inflammation of the cerebral cortex. Typically, it involves one cerebral hemisphere and manifests through intractable epileptic seizures. Its occurrence in adults is infrequent. We present a case of a 28-year-old woman who was brought to the emergency room due to the sudden onset of uncontrolled seizures. The use of 2-[¹⁸F]-FDG PET/CT (FDG-PET) helped in the differential diagnosis between autoimmune seronegative encephalitis and Rasmussen encephalitis. Even though FDG-PET is not a mandatory diagnostic criterion in the clinical evaluation of RE patients, the presented case and the available literature suggest its usefulness as a valuable diagnostic tool in patients with uncertain diagnosis, emphasizing its potential as a reliable adjunct in challenging diagnostic scenarios and for patient follow-up.

Objectives: Measurement of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO₂) by positron emission tomography (PET) with oxygen-15 labeled gases is widely used for investigation into the pathophysiology of occlusive cerebrovascular disease. However, all methods for quantification of CBF, CBV, OEF, and CMRO₂ by PET with oxygen-15 labeled gases require invasive arterial blood sampling. The present study developed a reference region-based method for quantification of CBF, CBV, OEF, and CMRO₂ using PET and oxygen-15 labeled gases based on the steady-state method without invasive arterial blood sampling.

Methods: The CBF, CBV, OEF, and CMRO₂ were measured in patients with occlusive cerebrovascular disease by PET using ¹⁵O-labeled gases, C¹⁵O₂, C¹⁵O, and ¹⁵O₂, with the steady-state method. In the present method, the ratios of values in a brain region to the reference region for CBF, CBV, OEF, and CMRO₂ were calculated without invasive arterial blood sampling.

Results: Good correlations were observed for the ratios of values of the cerebral lesion to the reference brain region for CBF, CBV, OEF, and CMRO₂ calculated by the present method as compared with those obtained by the steady-state method with arterial blood sampling, indicating its validity. Simulation studies showed that errors in estimated values calculated by the present method were negligibly small for both conditions of misery perfusion and matched hypoperfusion.

Conclusion: A simple method for noninvasive quantification of CBF, CBV, OEF, and CMRO₂ using PET and oxygen-15 labeled gases could be developed based on the steady-state method. This method can be used to investigate the pathophysiology of occlusive cerebrovascular disease.

Craniopharyngioma is a rare, benign intracranial tumour that can present with solid, cystic, or mixed solid-cystic characteristics. This case report aims to discuss the follow up assessment of our patient after one year of the irradiation therapy for craniopharyngioma. A 43-year-old male who has underlying refractory cystic craniopharyngioma requiring two-weekly aspirations, complicated with visual impairment and panhypopituitarism, was referred to our department for intra-cavitary irradiation therapy. Initial diagnostic assessment with Tc-99m MAA followed by dose calculation using the Backlund formula were conducted prior to the therapy. The patient received 6.22 mCi (230.14 MBq) of Ytrrium-90 citrate colloid via the Ommaya reservoir to deliver a radiation dose of 300 Gy to the tumour. Positive outcomes were observed as signified by the reduction on the aspirated cystic frequency and volume, tumour volume, improvement on the visual function and stable hormonal level. Despite the complications, the intra-cavitary irradiation therapy has demonstrated a significant and valuable therapeutic option for our patient in the management of refractory cystic craniopharyngioma.

Objectives: Objectives: Ionizing radiation has the potential to change the pattern of DNA methylation and can cause oxidative damage that may impact DNA. In this prospective cohort study, the effect of ionizing radiation on Iraqi radiation workers has been estimated by investigating the malondialdehyde levels, DNA methylation, DNA fragmentation, as well as the karyorrhectic, differentiated, and basal cells in buccal tissue.

Methods: This work involved 80 participants, 40 hospital X-ray workers, and 40 control. Blood samples have been investigated using the NWLSS™ malondialdehyde assay, the gSYNC™ DNA extraction kit, and the comet assay.

Results: The mean values of malondialdehyde level, DNA methylation, and DNA fragmentation (%DNA in tai), in workers were found to be 3.00±0.53, 51.63±26.44, and 26.73±12.67, respectively, while in the control were found to be 0.67±0.11, 13.25±11.30, and 9.09±11.96, respectively. In buccal tissue, the mean values of karyorrhectic cells, differentiated cells, late differentiated cells, and early differentiated cells in workers were found to be 7.70±4.64, 8.98±5.44, 14.74±5.25, and 18.50±6.40, respectively, while in control group were found to be 0.15±0.43, 0.20±0.41, 3.45±1.30, 10.78±1.80, respectively. The level of basal cells in buccal tissue was lower in workers (49.33±18.77) compared to the control group (85.75±2.19).

Conclusions: The observed levels of biomarkers in radiation workers suggest adverse health consequences due to their occupational exposure to ionizing radiation. Controlling the exposure of hospital workers is the first step to improving the health of workers, thus decreasing economic and human costs.

Over the past decade, the role of ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in assessing treatment response for lymphoma patients undergoing immunotherapy has been extensively investigated. The advent of immunotherapy has challenged the utility of the established Lugano criteria, prompting the development of novel immunotherapy-specific response criteria now employed in clinical practice. Following ¹⁸F-FDG PET/CT evaluation after up to eight immunotherapy cycles, patients are typically transitioned to conventional imaging modalities if immunotherapy continuation is warranted. This case report illustrates the application of serial ¹⁸F-FDG PET/CT in monitoring a 67-year-old patient with Hodgkin lymphoma receiving immunotherapy, revealing complex, atypical response patterns unresolved by existing criteria. Notably, two episodes of pseudoprogression occurred at two distinct time points, one during cycle 5 and the other during cycle 22. Furthermore, an immunotherapy-enhanced abscopal effect was seen during radio-immunotherapy, leading to short-term disease remission. Our findings suggest that ¹⁸F-FDG PET/CT provides superior predictive value in delineating heterogeneous response patterns, thereby informing critical decisions regarding immunotherapy cessation or adjunctive therapeutic interventions.