Explore the vast range of titles available.

Objective The aim of this study was (1) to investigate the application of texture analysis of choline PET/CT images in prostate cancer (PCa) patients and (2) to propose a machine-learning radiomics model able to select PET features predictive of disease progression in PCa patients with a same high-risk class at restaging. Material and methods Ninety-four high-risk PCa patients who underwent restaging Cho-PET/CT were analyzed. Follow-up data were recorded for a minimum of 13 months after the PET/CT scan. PET images were imported in LIFEx toolbox to extract 51 features from each lesion. A statistical system based on correlation matrix and point-biserial-correlation coefficient has been implemented for features reduction and selection, while Discriminant analysis (DA) was used as a method for features classification in a whole sample and sub-groups for primary tumor or local relapse (T), nodal disease (N), and metastatic disease (M). Results In the whole group, 2 feature (HISTO_Entropy_log10; HISTO_Energy_Uniformity) results were able to discriminate the occurrence of disease progression at follow-up, obtaining the best performance in DA classification (sensitivity 47.1%, specificity 76.5%, positive predictive value (PPV) 46.7%, and accuracy 67.6%). In the sub-group analysis, the best performance in DA classification for T was obtained by selecting 3 features (SUVmin; SHAPE_Sphericity; GLCM_Correlation) with a sensitivity of 91.6%, specificity 84.1%, PPV 79.1%, and accuracy 87%; for N by selecting 2 features (HISTO = _Energy Uniformity; GLZLM_SZLGE) with a sensitivity of 68.1%, specificity 91.4%, PPV 83%, and accuracy 82.6%; and for M by selecting 2 features (HISTO_Entropy_log10 - HISTO_Entropy_log2) with a sensitivity 64.4%, specificity 74.6%, PPV 40.6%, and accuracy 72.5%. Conclusion This machine learning model demonstrated to be feasible and useful to select Cho-PET features for T, N, and M with valuable association with high-risk PCa patients’ outcomes. Key Points • Artificial intelligence applications are feasible and useful to select Cho-PET features. • Our model demonstrated the presence of specific features for T, N, and M with valuable association with high-risk PCa patients’ outcomes. • Further prospective studies are necessary to confirm our results and to develop the application of artificial intelligence in PET imaging of PCa.

The widespread use of imaging examinations has increased the detection of incidental adrenal lesions, which are mostly benign and non-functioning adenomas. The differentiation of a benign from a malignant adrenal mass can be crucial especially in oncology patients since it would greatly affect treatment and prognosis. In this setting, imaging plays a key role in the detection and characterization of adrenal lesions, with several imaging tools which can be employed by radiologists. A thorough knowledge of the imaging features of adrenal masses is essential to better characterize these lesions, avoiding a misinterpretation of imaging findings, which frequently overlap between benign and malignant conditions, thus helping clinicians and surgeons in the management of patients. The purpose of this paper is to provide an overview of the main imaging features of adrenal masses and tumor-like conditions recalling the strengths and weaknesses of imaging modalities commonly used in adrenal imaging.

BackgroundLacrimal gland (LG) involvement in patients with Graves ophthalmopathy (GO) has been considered as a potential cause of the associated GO symptoms and different studies demonstrated the LG involvement in patients with GO than healthy controls. The aim of this study was to evaluate LG involvement, through measurement of its herniation, using a magnetic resonance imaging (MRI) index, in patients with different GO activities.MethodsThirty-two consecutive Caucasian patients affected by GO were enrolled and grouped in group A (16 with inactive GO, CAS < 3) and B (16 with active GO, CAS ≥ 3) according to their GO activity. All patients underwent clinical-endocrinological assessment, a complete ocular evaluation, and orbital MRI examination.ResultsNo difference was found between the hormonal parameters, thyroid ultrasound-derived parameters, and thyroid-stimulating hormone (TSH) receptor (TSH-R) antibodies (TRAb) levels in group B and those in group A. The LG herniation (LGH) measurement evaluated by MRI was significantly higher in group B for both right (10.1 (7.3–17) vs. 7 (0–3.4) mm; p = 0.004) and left (8.5 (6.6–13) vs. 5.8 (0–12) mm; p = 0.026) eye than group A. A positive correlation was found between TRAb and LGH herniation (Rho 0.462, p = 0.009).ConclusionsMeasurement of LGH seems to be a good marker of the disease and GO activity.Key Points• Lacrimal gland herniation is a simple index related to disease activity• Lacrimal gland herniation is correlated to TRAb levels• Lacrimal gland evaluation could be useful to differentiate active from inactive Graves ophthalmopathy in an early stage of disease

Contrast-enhanced CT is not routinely indicated in uncomplicated urinary infections, but it may be necessary in patients with specific risk factors (i.e., diabetes, immunocompromised patients, history of stones, or prior renal surgery) or in patients not responding to antibiotics and in detecting complications of pyelonephritis. CT is the gold standard for imaging assessment of pyelonephritis severity. Imaging appearance of acute pyelonephritis, including focal (i.e., wedge-shaped zones of decreased attenuation or hypodense mass) and diffuse (i.e., global enlargement, poor parenchymal enhancement, lack of excretion of contrast, fat stranding) forms, needs to be differentiated from renal infarction, renal lymphoma, and interstitial nephritis. Chronic pyelonephritis—which appears as focal polar scars with underlying calyceal distortion, global atrophy, and hypertrophy of residual tissue—may mimic at imaging lobar infarcts. This pictorial essay reviews the CT imaging appearance of acute and chronic pyelonephritis, their uncommon subtypes, and their complications, with key features for early diagnosis. Their knowledge is crucial for emergency and abdominal radiologists to avoid misdiagnosis with malignancy and to guide the clinician towards the appropriate medical or surgical treatment.

Abdominopelvic vascular compression syndromes include a variety of uncommon conditions characterized by either extrinsic compression of blood vessels by adjacent anatomical structures (i.e., median arcuate ligament syndrome, nutcracker syndrome, May-Thurner syndrome) or compression of hollow viscera by adjacent vessels (i.e., superior mesenteric artery syndrome, ureteropelvic junction obstruction, ureteral vascular compression syndromes, portal biliopathy). These syndromes can be unexpectedly diagnosed even in asymptomatic patients and the predisposing anatomic conditions can be incidentally discovered on imaging examinations performed for other indications, or they can manifest with atypical abdominal symptoms and acute complications, which may lead to significant morbidity if unrecognized. Although computed tomography (CT) is an accurate noninvasive technique for their detection, the diagnosis remains challenging due to the uncommon clinical presentation and often overlooked imaging features. Dynamic imaging may be performed in order to evaluate patients with inconstant symptoms manifesting in a specific position. The purposes of this paper are to review the CT imaging findings of abdominopelvic vascular compression syndromes, correlating with anatomical variants and to provide key features for the noninvasive imaging diagnosis.

Endovascular aneurysm repair (EVAR) is a minimally invasive treatment proposed as an alternative to open repair in patients with abdominal aortic aneurysms. EVAR consists in a stent-graft placement within the aorta in order to exclude the aneurysm from arterial circulation and reduce the risk of rupture. Knowledge of the various types of devices is mandatory because some stents/grafts are more frequently associated with complications. CT angiography is the gold standard diagnostic technique for preprocedural planning and postprocedural surveillance. EVAR needs long-term follow-up due to the high rate of complications. Complications can be divided in endograft device-related and systemic complications. The purpose of this article is to review the CT imaging findings of EVAR complications and the key features for the diagnosis.

Epiploic appendagitis is a rare cause of acute abdominal pain, determined by a benign self-limiting inflammation of the epiploic appendages. It may manifest with heterogeneous clinical presentations, mimicking other more severe entities responsible of acute abdominal pain, such as acute diverticulitis or appendicitis. Given its importance as clinical mimicker, imaging plays a crucial role to avoid inaccurate diagnosis that may lead to unnecessary hospitalization, antibiotic therapy, and surgery. CT represents the gold standard technique for the evaluation of patients with indeterminate acute abdominal pain. Imaging findings include the presence of an oval lesion with fat-attenuation surrounded by a thin hyperdense rim on CT (“hyperattenuating ring sign”) abutting anteriorly the large bowel, usually associated with inflammation of the adjacent mesentery. A central high-attenuation focus within the fatty lesion (“central dot sign”) can sometimes be observed and is indicative of a central thrombosed vein within the inflamed epiploic appendage. Rarely, epiploic appendagitis may be located within a hernia sac or attached to the vermiform appendix. Chronically infarcted epiploic appendage may detach, appearing as an intraperitoneal loose calcified body in the abdominal cavity. In this review, we aim to provide an overview of the clinical presentation and key imaging features that may help the radiologist to make an accurate diagnosis and guide the clinical management of those patients.

COVID-19 has infected more than 2 million people in the world in less than 5 months outbreak. Chest imaging is recommended for triage of suspected cases of COVID-19 with moderate-severe clinical features and high pre-test probability of disease, and may help for patient follow-up and to identify patients at higher risk of disease worsening. This pictorial essay illustrates typical and uncommon imaging findings of COVID-19 pneumonia and the role of imaging for patient management.

Objectives The Liver Imaging Reporting and Data System algorithm allows category downgrade in the presence of ancillary features (AFs) favoring benignity, even in observations categorized as LR-5. This study aims to assess the role of AFs favoring benignity in LR-5 observations and their impact on category downgrade. Methods This study included high-risk patients with at least one LR-5 observation imaged with gadoxetate disodium MRI. Three readers with different experience levels independently evaluated the presence of AFs favoring malignancy (not hepatocellular carcinoma (HCC) in particular and HCC in particular) and AFs favoring benignity. Category downgrade was considered possible in the presence of ≥ 1 AF favoring benignity and no AF favoring malignancy. Correlation between observations size and number of AFs was assessed using Spearman’s rank correlation coefficient. Cohen’s kappa ( k ) test was used to assess inter-reader agreement. Results The final study cohort included 162 LR-5 (mean size: 23 ± 16 mm) in 119 patients. AFs favoring benignity were reported in 9 (5.6%), 20 (12.3%), and 10 (6.2%) LR-5 observations by reader 1, reader 2, and reader 3, respectively. Hepatobiliary phase isointensity was observed in 6 (3.7%), 2 (1.2%), and 7 (4.3%) observations, respectively. Category downgrade was considered possible in only one (0.6%) observation by reader 1 and reader 3. There was a significant correlation between observation size and number of AFs favoring malignancy ( p  < 0.001), not HCC in particular ( p  ≤ 0.010), and favoring HCC in particular ( p  < 0.001). Inter-reader agreement of AFs favoring benignity was poor to moderate ( k range: − 0.01, 0.43). Conclusions AFs favoring benignity are not uncommon in LR-5 observations, but category downgrade is exceptional. Key Points • Ancillary features favoring benignity are encountered in 5.6–12.3% of observations categorized as LR-5. • Category downgrade of LR-5 observations is very rare (0.6% of observations) in the presence of AFs favoring benignity due to the high prevalence (98–99%) of ancillary features favoring malignancy in LR-5 observations. • The inter-reader agreement of ancillary features favoring benignity is poor to moderate (k range: − 0.01, 0.43) in readers with different levels of experience.

Contrast-enhanced ultrasound (CEUS) represents a significant breakthrough in ultrasonography (US), and it is being increasingly used for the evaluation of focal liver lesions (FLLs). CEUS is unique in that it allows non-invasively assessment of liver perfusion in real time throughout the vascular phase, which has led to dramatic improvements in the diagnostic accuracy of US in the detection and characterization of FLLs, the choice of therapeutic procedures, and the evaluation of response. Currently, CEUS is included as a part of the suggested diagnostic work-up of FLLs, including in cirrhotic patients with hepatocellular carcinoma, resulting in better patient management and cost-effective delivery of therapy.