Integrating Machine Learning in Clinical Practice for Characterizing the Malignancy of Solitary Pulmonary Nodules in PET/CT Screening.

The study investigates the efficiency of integrating Machine Learning (ML) in clinical practice for diagnosing solitary pulmonary nodules' (SPN) malignancy. Patient data had been recorded in the Department of Nuclear Medicine, University Hospital of Patras, in Greece. A dataset comprising 456 SPN characteristics extracted from CT scans, the SUVmax score from the PET examination, and the ultimate outcome (benign/malignant), determined by patient follow-up or biopsy, was used to build the ML classifier.

A Deep Learning Methodology for the Detection of Abnormal Parathyroid Glands via Scintigraphy with Tc-Sestamibi.

Background: Parathyroid proliferative disorder encompasses a wide spectrum of diseases, including parathyroid adenoma (PTA), parathyroid hyperplasia, and parathyroid carcinoma. Imaging modalities that deliver their results preoperatively help in the localisation of parathyroid glands (PGs) and assist in surgery. Artificial intelligence and, more specifically, image detection methods, can assist medical experts and reduce the workload in their everyday routine.

Applications of Generative Adversarial Networks (GANs) in Positron Emission Tomography (PET) imaging: A review.

Purpose: This paper reviews recent applications of Generative Adversarial Networks (GANs) in Positron Emission Tomography (PET) imaging. Recent advances in Deep Learning (DL) and GANs catalysed the research of their applications in medical imaging modalities. As a result, several unique GAN topologies have emerged and been assessed in an experimental environment over the last two years.

Automatic classification of solitary pulmonary nodules in PET/CT imaging employing transfer learning techniques.

Early and automatic diagnosis of Solitary Pulmonary Nodules (SPN) in Computed Tomography (CT) chest scans can provide early treatment for patients with lung cancer, as well as doctor liberation from time-consuming procedures. The purpose of this study is the automatic and reliable characterization of SPNs in CT scans extracted from Positron Emission Tomography and Computer Tomography (PET/CT) system. To achieve the aforementioned task, Deep Learning with Convolutional Neural Networks (CNN) is applied.

Advanced fuzzy cognitive maps: state-space and rule-based methodology for coronary artery disease detection.

According to the World Health Organization, 50% of deaths in European Union are caused by Cardiovascular Diseases (CVD), while 80% of premature heart diseases and strokes can be prevented. In this study, a Computer-Aided Diagnostic model for a precise diagnosis of Coronary Artery Disease (CAD) is proposed. The methodology is based on State Space Advanced Fuzzy Cognitive Maps (AFCMs), an evolution of the traditional Fuzzy Cognitive Maps.

Y-microsphere radioembolization: The method, clinical evidence and perspective.

The current review unfolds the procedural steps and the clinical evidence for yttrium-90 (Y)-microspheres radioembolization. Radioembolization is part of the loco-regional therapeutic spectrum for liver malignancy and involves the invasive, intra-arterial delivery of microspheres carrying β-emitter isotopes in order to destroy cancerous tissue via ionizing radiation. The main steps of the therapeutic process are selection of eligible patients, angiographic workup, simulation scintigraphy, pre-treatment dosimetry, actual treatment and post-treatment imaging/dosimetry.

Automatic characterization of myocardial perfusion imaging polar maps employing deep learning and data augmentation.

Objective: To investigate a deep learning technique, more specifically state-of-the-art convolutional neural networks (CNN), for automatic characterization of polar maps derived from myocardial perfusion imaging (MPI) studies for the diagnosis of coronary artery disease.

Subjects And Methods: Stress and rest polar maps corresponding to 216 patient cases from the database of the department of Nuclear Medicine of our institution were analyzed. Both attenuation-corrected (AC) and non-corrected (NAC) images were included.

The impact of transmission-emission misregistration on the interpretation of SPET/CT myocardial perfusion studies and the value of misregistration correction.

Objective: Previous studies indicate that the quality of single photon emission tomography/computed tomography (SPET/CT) myocardial perfusion imaging (MPI) is degraded by even mild transmission-emission misregistrations. The purpose of the current study was to investigate the impact of SPET/CT misalignment on the interpretation of MPI and examine the value of a commercial software application for registration correction.

Subjects And Methods: A total of 255 technetium-99m ((99m)Tc)-tetrofosmin stress/rest MPI examinations in 150 patients were reviewed for SPET/CT misalignment.

Assessment of absolute Tc-99m tetrofosmin retention in the myocardium as an index of myocardial blood flow and coronary flow reserve by gated-SPECT/CT: a feasibility study.

Objective: Estimation of myocardial blood flow (MBF) and coronary flow reserve (CFR) by SPECT myocardial perfusion imaging (MPI) remains challenging. Our aim was to approximate MBF and CFR by quantifying the absolute Tc-99m tetrofosmin retention in the myocardium via gated-SPECT/CT MPI.

Methods: Tracer retention was calculated on the basis of the microsphere kinetic model and served as an index of MBF at stress and rest (sMBFi, rMBFi).

Tc-99m depreotide SPECT/CT for lymph node staging of non-small-cell lung cancer.

Objective: To investigate the potential role of Tc-99m depreotide (Tc-DEPR) in the preoperative lymph node (N) staging of non-small-cell lung cancer (NSCLC).

Methods: Sixty-one patients with NSCLC at the potentially operable stage were enrolled and underwent scintigraphy before surgery (n=56) or mediastinoscopy (n=5). Imaging was performed with a hybrid single photon emission computed tomography/computed tomography (SPECT/CT) system.

Bone scintigraphy depicts bilateral atypical femoral stress fractures with metachronous presentation, long before a complete fracture occurs.

Atypical femoral fractures (AFF), although rare, are recognized more often during the last decade. They are located in the subtrochanteric region or the femoral shaft, may be bilateral, can evolve to complete fractures after bone overload or minimal trauma and have specific radiological features. The complete fractures have horizontal or slightly oblique configuration accompanied by a medial spike, are non-comminuted, and extend to both cortices.

CT-based attenuation correction in Tl-201 myocardial perfusion scintigraphy is less effective than non-corrected SPECT for risk stratification.

Background: Previous studies advocate the use of attenuation correction in myocardial perfusion scintigraphy (MPS) for patient risk stratification.

Methods: Six-hundred and thirty-seven unselected patients underwent Tl-201 MPS by a hybrid SPECT/CT system. Attenuation-corrected (AC) and non-corrected (NAC) images were interpreted blindly and summed stress scores (SSS) were calculated.

Atypical bilateral stress fractures of the femoral shaft diagnosed by bone scintigraphy in a woman with osteoporosis.

Recent case series have identified the presence of atypical insufficiency fractures at the diaphyseal femur of osteoporotic patients, which are possibly related to the long-term use of biphosphonates. We present images of a 72-year-old woman with a history of colon cancer and osteoporosis referred for bone scintigraphy because of bilateral thigh pain. No trauma or intense exercise was reported.

(99m)Tc sestamibi as a prognostic factor of response to first-line therapy and outcome in patients with malignant lymphoma.

Introduction: Resistance to chemotherapy poses a major problem in cancer patients. Although of multifactorial origin, some of the implicated mechanisms also interfere with (99m)Tc-MIBI uptake and retention in cancer cells. The aim of the current study was to investigate the prognostic value of baseline (99m)Tc-MIBI imaging in lymphoma.

Is there a role for Nuclear Medicine in diagnosis and management of patients with primary aldosteronism?

Primary aldosteronism (PA) is the most common cause of secondary hypertension. The diagnosis of PA is of clinical importance for choosing the appropriate treatment, meaning, surgery for the unilateral disease, and inclusion of aldosterone antagonists in the antihypertensive treatment for the bilateral disease. Current diagnostic approaches showed that the prevalence of PA is much higher than previously estimated.

ST-segment depression during vasodilator stress is of minor clinical importance in women with normal myocardial perfusion imaging and low or intermediate risk of coronary artery disease.

Purpose: The prognostic value of electrocardiographic (ECG) ST-segment depression during vasodilator stress testing in patients with normal myocardial perfusion scintigraphy (MPS) is based on retrospective studies with controversial results. Moreover, the true incidence of obstructive coronary artery disease (CAD) in these patients is unknown.

Methods: During a 33-month period, all consecutive patients referred for MPS were prospectively evaluated for interpretable ST-segment depression ≥ 1 mm during vasodilator stress testing.

Imaging myocardial inflammation of various etiologies with 99mTc-depreotide SPET/CT.

Previous reports suggested the accumulation of technetium-99m-depreotide trifluoroacetate ((99m)Tc-D) at the sites of active infection or inflammation. Binding of depreotide to over-expressed somatostatin receptors in activated lymphocytes and macrophages probably accounts for the depiction of inflammation. We speculated that myocardial inflammation could also be illustrated by (99m)Tc-D scintigraphy.

Parametric images via dynamic 18F-fluorodeoxyglucose positron emission tomographic data acquisition in predicting midterm outcome of liver metastases secondary to gastrointestinal stromal tumours.

Purpose: (18)F-Fluorodeoxyglucose positron emission tomography (FDG PET) may underestimate viable tumour tissue in patients with gastrointestinal stromal tumours (GIST) treated with molecular targeted agents. The aim of the present study was to investigate the value of parametric images generated after dynamic data acquisition for the detection of active liver metastases.

Methods: The analysis included 65 dynamic FDG PET studies in 34 patients with liver metastases from GIST who were treated with imatinib or sunitinib.

Technetium-99m depreotide imaging by single photon emission tomography/low resolution computed tomography in malignant lymphomas: comparison with gallium-67 citrate.

Objective: Previous studies have demonstrated the feasibility of targeting lymphoma lesions with somatostatin receptor binding agents, mainly with In-111-pentetreotide. In the present work another somatostatin analog, Tc-99m depreotide, is investigated.

Methods: One-hundred and six patients, 47 with Hodgkin's (HL) and 59 with various types of non-Hodgkin's lymphoma (NHL), were imaged with both Tc-99m depreotide and Ga-67 citrate.

Tc-99m Depreotide SPECT/CT depicts myocardial involvement in a case of thrombotic thrombocytopenic purpura.

We report a case of thrombotic thrombocytopenic purpura (TTP) with cardiac involvement, imaged with Tc-99m depreotide. A 56-year-old man presented with fever, hematuria, and chest pain. Laboratory findings (angiopathic hemolytic anemia, thrombocytopenia, and uremia) were suggestive of TTP.

Comparison between 180 degrees and 360 degrees acquisition arcs with and without correction by CT-based attenuation maps in normal hearts at rest.

Objective: To investigate the effect of acquisition arc (180 degrees or 360 degrees ) and attenuation correction (AC), in artifact occurrence and image uniformity of myocardial perfusion SPECT studies in normal hearts.

Methods: Twenty male and 44 female patients with primary hyperparathyroidism and low probability of resting perfusion abnormalities were analysed. Tc-sestamibi myocardial perfusion studies were performed at rest with a hybrid SPECT/CT system.

Two cases of synovitis, acne, pustulosis, osteitis--SAPHO syndrome.

Synovitis, acne, pustulosis, osteitis (SAPHO) syndrome is rare with yet unknown prevalence. The difficulty in recognizing the syndrome is due to the very wide diversity of its signs and symptoms, the lack of skin manifestations in many cases and to confusion in medical terminology in describing this syndrome. In this paper, we present two cases with characteristic bone lesions in bone scan and in radiology images that are considered to be SAPHO syndrome.