Publications by authors named "Hoi Y Loi"

Desmoplastic small round cell tumor (DSRCT) is an exceptionally rare and highly aggressive primary peritoneal neoplasm predominantly seen in adolescents and young adults. Despite the availability of various treatment modalities, the prognosis remains grim due to the tumor's aggressive nature and tendency for widespread metastasis. Although imaging of DSRCT is frequently documented using computed tomography (CT), the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the initial diagnosis, staging, and particularly in the follow-up evaluation, is less explored.

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Article Synopsis
  • - The study investigates how effectively PET/MRI can predict treatment response in localized rectal cancer patients undergoing preoperative chemoradiotherapy (CRT), focusing on sensitivity and specificity of imaging parameters.
  • - Out of 31 recruited patients with rectal adenocarcinoma, 20 completed the study; results showed that 20% of patients were good responders to treatment, while 80% had a poor response based on histopathological assessments.
  • - Key imaging metrics like percent maximum thickness reduction and percent apparent diffusion coefficient (ADC) change demonstrated promising predictive values, suggesting their potential use in identifying good responders, highlighting the need for larger studies to validate these findings.
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Lymphoma typically manifests as lymphadenopathy, with or without solid organ involvement. Lymphomatous masses tend to respect anatomical structures, encasing rather than invading them. Tumor thrombus formation is a rare presentation in lymphoma that has been previously described in the liver and kidneys.

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Purpose: To compare the performances of machine learning (ML) and deep learning (DL) in improving the quality of low dose (LD) lung cancer PET images and the minimum counts required.

Materials And Methods: 33 standard dose (SD) PET images, were used to simulate LD PET images at seven-count levels of 0.25, 0.

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Background: Cardiac amyloidosis is a protein misfolding disorder involving deposition of amyloid fibril proteins in the heart. The associated fibrosis of the conduction tissue results in conduction abnormalities and arrhythmias. "Classical" electrocardiogram (ECG) findings in cardiac amyloidosis include that of low voltage complexes with increased left ventricular wall thickness on echocardiography.

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A 44-year-old woman presented with prolonged low-grade fever, bilateral upper limb weakness, and hyperesthesia. MRI showed hyperintense T2 signal and enhancement of the cervicothoracic spinal cord. F-FDG PET/CT was requested to investigate pyrexia of unknown origin.

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A 66-year-old woman with a known history of diffuse large B-cell lymphoma presented with left lower limb swelling following recent long-distance air travel. Ultrasound Doppler showed no evidence of deep vein thrombosis. In view of her medical history, an F-FDG PET/CT was ordered that found a soft tissue mass following the course of the femoral neurovascular bundle along the anteromedial aspect of the left thigh down to the popliteal fossa and the lateral calf muscle.

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Background: Increased somatostatin receptor (SSTR) expression in patients with undifferentiated nasopharyngeal carcinoma (NPC) has been demonstrated with receptor autoradiography, (111) In-Octreotide scintigraphy, and (68) Ga-DOTA-TOC positron emission tomography (PET)/CT imaging. We sought to compare and correlate the uptake of fluorodeoxyglucose (FDG) and DOTA-NOC in undifferentiated NPC to ascertain the possible role of (68) Ga-DOTA-NOC PET/CT as a new imaging biomarker and to assess whether targeted peptide receptor radionuclide therapy is a feasible treatment option.

Methods: After obtaining approval from our institutional review board, 4 patients with biopsy proven nonkeratinizing undifferentiated NPC who had just undergone routine staging/restaging (18) F-FDG PET/CT imaging were prospectively and consecutively recruited for (68) Ga-DOTA-NOC PET/CT imaging.

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Unlabelled: Evaluation of tumor heterogeneity based on texture parameters has recently attracted much interest in the PET imaging community. However, the impact of reconstruction settings on texture parameters is unclear, especially relating to time-of-flight and point-spread function modeling. Their effects on 55 texture features (TFs) and 6 features based on first-order statistics (FOS) were investigated.

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Unlabelled: A 61 years old man with a history of prostate cancer Gleason 3+4, treated with radical prostatectomy, underwent fluorine-18-fluorocholine positron emission tomography/computed tomography ((18)F-FCH PET/CT) imaging to investigate rising serum prostate specific antigen (PSA) levels. (18)F-FCH PET/CT showed a focus of linear increased uptake by a possible Meckel's diverticulum in the right hemi-pelvis, which was an incidental finding in this asymptomatic patient. Uptake of (18)F-FCH by Meckel's diverticulum has not been reported before and thus the mechanism of uptake has not been established.

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Purpose: To determine if first-order and high-order textural features on fluorine 18 ((18)F) fluorodeoxyglucose (FDG) positron emission tomography (PET) images of non-small cell lung cancer (NSCLC) (a) at baseline, (b) at 6 weeks, or (c) the percentage change between baseline and 6 weeks can predict response or survival in patients treated with erlotinib.

Materials And Methods: Institutional review board approval was obtained for post hoc analysis of data from a prospective single-center study for which informed consent was obtained. The study included 47 patients with NSCLC who underwent (18)F-FDG PET/computed tomography (CT) at baseline (n = 47) and 6 weeks (n = 40) after commencing treatment with erlotinib.

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Metastases to the larynx from prostate carcinoma are rare. We describe a case of asymptomatic prostate carcinoma metastasis to the right cricoid cartilage detected on 18F-fluorocholine PET/CT. This was histologically proven on open biopsy and the patient was offered local radiotherapy.

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Nephrogenic systemic fibrosis (NSF) has been linked to utilization of gadolinium-based contrast agents in patients with renal impairment. We present a 19-year-old female patient with end-stage renal failure presenting with joint pains and subcutaneous nodules. She had a prior gadolinium-enhanced magnetic resonance angiography when she was 14 years old.

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Pancreatic involvement by metastasis from other primaries is rare and accounts for approximately 2% to 4% of pancreatic tumors. In this article, we describe FDG-avid pancreatic involvement in a patient with diagnosis of breast cancer. We conclude that FDG PET can be a convenient noninvasive method of early detection of recurrence and in monitoring metastatic disease during follow-up in such patients.

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