Imaging of Bone Anatomical Variants Around the Foot and Ankle.

Different anatomical variants can be found in the ankle and foot, generally as occasional findings, although they can be the cause of diagnostic pitfalls and difficulties, especially in radiographic interpretation in trauma. These variants include accessory bones, supernumerary sesamoid bones, and accessory muscles. In most cases, they represent developmental anomalies found in incidental radiographic findings. This review discusses the main bony anatomical variants, including accessory and sesamoid ossicles, most commonly found in the foot and ankle that can be a cause of diagnostic challenges.

MR Imaging of the Lower Limb: Pitfalls, Tricks, and Tips.

The purpose of this article is to discuss most common diagnostic pitfalls of the lower limb with specific attention to the knee, ankle, and foot joints. The knowledge of normal anatomic variants, correlation with age, symptoms, and medical history together with these potential MR imaging pitfalls is fundamental for an accurate interpretation of the imaging findings of the lower limb.

CT-Guided RFA for Management of Surgical Relapses of Giant Cell Tumour of Bone.

OBJECTIVES: This retrospective study describes a pilot experience in CT-guided RadioFrequency Ablation (RFA) treatment of 5 Giant Cell Tumour of the bone (GCT) recurrences after surgery. METHODS: After biopsy to confirm the diagnosis of GCT recurrences, all patients were treated with RFA in a single session. A close follow-up was scheduled with contrast-enhanced MRI starting 1 months after treatment. RESULTS: Five lesions were treated in 5 patients. The length of the observation period was between 4 and 100 months. One lesion relapsed 4 months after the RFA treatment, and the patient underwent a second surgical treatment which included the en-block resection and prosthetic implant. No complications were recorded. CONCLUSIONS: The management of GCT relapses with RFA could be an interesting and innovative field. However, the results of this limited series need to be confirmed by further investigations of larger patient cohorts.

Diagnostic yield of CT-guided lung biopsies: how can we limit negative sampling?

OBJECTIVES: To investigate whether lesion imaging features may condition the outcome of CT-guided lung biopsy (CTLB) and to develop a scoring system of biopsy outcome prediction. METHODS: This is a single center retrospective study on 319 CTLBs that were performed in 319 patients (167 males/152 females, mean age 68 ± 12.2). Uni- and multivariate analysis were performed aiming to assess the imaging features that are likely to be correlated to a negative biopsy outcome and patients were stratified in groups accordingly. RESULTS: Technical success was 100%. 78% of the biopsies (250/319) led to a concrete histology report (218 malignant/32 benign). The remaining lesions led to concrete histology at a second attempt that occurred on a later time. Multivariate analysis revealed increased risk of inconclusive result for nodules with low fludeoxyglucose uptake [odds ration (OR) = 2.64, 95% confidence interval (CI) 1.4-4.97; p = 0.003], for nodules with diameter smaller than 18 mm (OR = 2.03, 95% CI 1.14-3.62; p = 0.017) and for nodules that are located in one of the lung bases (OR = 1.96, 95% CI 1.06-3.62; p = 0.033). Three different groups of patients were identified accordingly with low (<30%), medium (30-50%) and high (>50%) probability of obtaining an inconclusive biopsy sample. CONCLUSION: This study confirms that percutaneous CT-guided biopsy in nodules that are either small in diameter or present low positron emission tomography-fludeoxyglucose uptake or are in one of the lung bases may lead to inconclusive histology. This information should be factored when planning percutaneous biopsies of such nodules in terms of patient informed consent and biopsy strategy. ADVANCES IN KNOWLEDGE: Inconclusive histology after lung biopsy may be subject to factors irrelevant to technical success. Lung biopsy histology outcomes may be predicted and avoided after adequate planning.

Basics in Magnetic Resonance guided Focused Ultrasound: technical basis and clinical application. A brief overview.

First applications of high focused ultrasound as intracranial ablative therapy were firstly described in early 50'. Since then, the technological innovations have shown an increasingly safe and effective face of this technique. And in the last few years, Magnetic Resonance (MR) guided Focused Ultrasound (gFUS) has become a valid minimally invasive technique in the treatment of several diseases, from bone tumors to symptomatic uterine fibroids or essential tremors. MR guidance, through the tomographic view, offers the advantage of an accurate target detection and treatment planning. Moreover, real-time monitoring sequences allow to avoid non-target ablation. An adequate knowledge of FUS is essential to understand its clinical effectiveness. Therefore, this brief review aims to debate the physical characteristics of US and the main fields of clinical application.

Radiomics and functional imaging in lung cancer: the importance of radiological heterogeneity beyond FDG PET/CT and lung biopsy.

PURPOSE: [18F]-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (FDG PET/CT) has a central role in the lung nodules' characterization even if, with SUV < 2.5, percutaneous CT-guided Lung Biopsy (CTLB) is needed to assess nodule nature. In that scenario, CT Texture Analysis (CTTA) could be a non-invasive imaging biomarker. Our purpose is to test CTTA ability in differentiating malignant from benign nodules. METHOD: Patients that underwent FDG PET/CT followed by CTLB between January 2013 and December 2018 were retrospectively enrolled. Were included patients with lung nodule SUV < 2.5 and histological diagnosis. EXCLUSION CRITERIA: nodules SUV > 2.5, patients who refused CTLB or received oncological treatment before CTLB, indeterminate pathology report, CT motion artifacts. Two radiologists in consensus performed CTTA, drawing a volumetric Region of Interest of nodule with a dedicated first order TA software with and without spatial scaling filters, on preliminary CT performed for CTLB. Statistics included a comparison between malignant and benign neoplasms distribution (2-tailed T-test or Mann-Whitney test according to normal/non-normal data distribution), P-values < 0.05 were considered statistically significant. CTTA accuracy was tested with Receiver Operating Characteristics (ROC) curve. RESULTS: Form an initial population of 1178, 46 patients encountered inclusion criteria. Pathologist reported 27/46 (59%) malignant and 19/46 (41%) benign nodules. In malignant lesions CTTA showed lower Kurtosis' and higher Skewness' values (all P ≤ 0.0013 and all filtered TA P < 0.024, respectively). ROC curve showed significant Area Under the Curve for Kurtosis and Skewness (0.654 and 0.642, P < 0.001) at medium filtration. CONCLUSIONS: CTTA is a promising radiological tool to characterize benign and malignant lung nodules, even in those cases without an altered glucose metabolism.

Aspiration Thrombectomy with the Indigo System for Acute Lower Limb Ischemia: Preliminary experience and analysis of parameters affecting the outcome.

BACKGROUND: The purpose of our study is to assess the short-term technical success and the safety of the Indigo System in a series of patients undergoing vacuum-assisted catheter direct thrombus aspiration (IS-CDTA) for acute lower limb ischemia (ALLI) and to evaluate which parameters may affect the outcome. METHODS: All procedures using the IS-CDTA for ALLI, performed in a single-centre Interventional Radiology Unit from February 2016 to March 2020, were retrospectively analysed. Technical success was defined as the achievement of nearly-complete or complete revascularization (TIPI grade 2/3) and considered as a good outcome. Variables potentially correlated with the IS-CDTA outcome were analysed. RESULTS: 33 procedures were performed in 29 patients. Mean age was 69 years old (range 47 - 88), 24 males (83%) and 5 females (18%). The technical success was 70%. Catheter-directed thrombolysis following IS-CDTA was performed in 23 cases and the overall technical success increased from 70% to 90%, afterwards. The median time between symptoms insurgency and IS-CDTA was significantly shorter in patients with good outcome (10 hours; IQR 2.75-48) compared to those with poor outcome (168 hours; IQR 36-336) (P = 0.003). No statistically significant differences were found between the two groups regarding ATK vs. BTK (P = 0.34), native vessel vs. graft (P = 0.25), occlusion nature P = 0.28) or Rutherford score (P = 0.80). CONCLUSION: IS-CDTA is a valid option for a rapid and percutaneous treatment of ALLI. Our experience indicates that the time elapsing from the symptoms insurgency and the endovascular procedure is the best positive predictor of the outcome.