Diagnostic Performance of Machine Learning Models Based on 18F-FDG PET/CT Radiomic Features in the Classification of Solitary Pulmonary Nodules.

Objectives: This study aimed to evaluate the ability of 18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) radiomic features combined with machine learning methods to distinguish between benign and malignant solitary pulmonary nodules (SPN). Methods: Data of 48 patients with SPN detected on 18F-FDG PET/CT scan were evaluated retrospectively. The texture feature extraction from PET/CT images was performed using an open-source application (LIFEx). Deep learning and classical machine learning algorithms were used to build the models. Final diagnosis was confirmed by pathology and follow-up was accepted as the reference. The performances of the models were assessed by the following metrics: Sensitivity, specificity, accuracy, and area under the receiver operator characteristic curve (AUC). Results: The predictive models provided reasonable performance for the differential diagnosis of SPNs (AUCs ~0.81). The accuracy and AUC of the radiomic models were similar to the visual interpretation. However, when compared to the conventional evaluation, the sensitivity of the deep learning model (88% vs. 83%) and specificity of the classic learning model were higher (86% vs. 79%). Conclusion: Machine learning based on 18F-FDG PET/CT texture features can contribute to the conventional evaluation to distinguish between benign and malignant lung nodules.

Evaluation of the protective effect of agmatine against cisplatin nephrotoxicity with 99mTc-DMSA renal scintigraphy and cystatin-C.

BACKGROUND: The aim of the current study was to investigate whether agmatine (AGM) has a protective effect against cisplatin-induced nephrotoxicity. MATERIALS AND METHODS: Thirty-two rats were randomly divided into four groups: (1) Saline (control); (2) Cisplatin (CDDP; 7.5 mg/kg intraperitoneally); (3) Agmatine (AGM; 10 mg/kg intraperitoneally); (4) Cisplatin plus agmatine (CDDP + AGM). Agmatine was given before and two consecutive days after cisplatin injection. All the animals underwent renal scintigraphy with 99mTc-DMSA. The levels of serum creatinine, cystatin C, and blood urea nitrogen (BUN) were measured in addition to examination of the tissue samples with light microscopy. Acute renal injury was assessed with biochemical analyses, scintigraphic imaging, and histopathological evaluation. RESULTS: In the cisplatin group, the levels of BUN, creatinine, and cystatin C were significantly higher than that of the controls. Histopathological examination showed remarkable damage of tubular and glomerular structures. Additionally, cisplatin caused markedly decreased renal 99mTc-DMSA uptake. AGM administration improved renal functions. Serum creatinine, BUN, and cystatin C levels had a tendency to normalize and, scintigraphic and histopathological findings showed significantly less evidence of renal toxicity than those observed in animals receiving cisplatin alone. CONCLUSIONS: Our data indicate that AGM has a protective effect against cisplatin-induced nephrotoxicity. Therefore, it may improve the therapeutic index of cisplatin. In addition, the early renal damage induced by cisplatin and protective effects of AGM against cisplatin nephrotoxicity was accurately demonstrated with 99mTc-DMSA renal scintigraphy.

Bilateral generalised synovial chondromatosis of the knee: Bone scintigraphic demonstration with radiologic correlation.

A 67-year-old woman with a history of bilateral progressive knee pain and swelling was referred for (99m)Tc-methyl diphosphonate bone scintigraphy. Flow and blood pool images showed bilateral heterogeneous increased uptake and delayed phase revealed mass-looking lobulated heterogeneous increased activity in both of knees extending distal part of the femoral shaft, but no other pathologic uptake was found in rest of the body. A diagnosis of synovial chondromatosis was made when correlated with X-ray and computed tomography.(CT) images. This is a rare presentation of generalized synovial chondromatosis involving both knees which demonstrated on bone scintigraphy with X-ray and CT correlation.

Use of iodine-123 metaiodobenzylguanidine scintigraphy for the detection of amiodarone induced pulmonary toxicity in a rabbit model: a comparative study with technetium-99m diethyltriaminepenta acetic acid radioaerosol scintigraphy.

The purpose of the study was; (i) to determine whether 123I-MIBG scintigraphy is sensitive for detection of amiodarone induced pulmonary toxicity (AIPT) and (ii) to compare it with 99mTc-DTPA radioaerosol. Twelve white New Zealand rabbit with initial mean body weight 4.24 +/- 0.47 g were divided into two groups. AIPT group (n = 7) was administered amiodarone (20 mg/kg BW). The control group (n = 5) received the same amount of 0.9% saline. All animals underwent 123I-MIBG and 99mTc-DTPA radioaerosol scintigraphy at the end of the treatment period. 123I-MIBG static thorax images were obtained during 10 minutes at 15 minutes and 3-hours after intravenous injection of the radiopharmaceutical. Lung to heart ratios (LHR) and lung to mediastinum ratios (LMR), and retention index (LRI) of 123I-MIBG were determined. Two days after 123I-MIBG scintigraphy, 99mTc-DTPA radioaerosol scintigraphy was performed, and clearance from the lungs was measured for 10 min (1 min/frame) following termination of inhalation. 123I-MIBG lung retention index (LRI) was significantly higher in the AIPT group than the control (61 +/- 4.6 vs. 40 +/- 4.5, p = 0.01). Early LHR and LMR were significantly lower in the AIPT group than in the control group (p = 0.04, p = 0.01, respectively), whereas those of late LHR and LMR were not significantly different. T1/2 values of DTPA clearance were significantly increased in AIPT group according to the control group (55 +/- 7.2 vs. 86.6 +/- 18.5, p = 0.02). 123I-MIBG scintigraphy is a valuable tool for detecting AIPT in a rabbit model. Additionally, 99mTc-DTPA radioaerosol scintigraphy is an excellent comprehensive investigational tool for detecting AIPT with the added advantage of lower cost.