A deep learning approach for virtual contrast enhancement in Contrast Enhanced Spectral Mammography.

Contrast Enhanced Spectral Mammography (CESM) is a dual-energy mammographic imaging technique that first requires intravenously administering an iodinated contrast medium. Then, it collects both a low-energy image, comparable to standard mammography, and a high-energy image. The two scans are combined to get a recombined image showing contrast enhancement. Despite CESM diagnostic advantages for breast cancer diagnosis, the use of contrast medium can cause side effects, and CESM also beams patients with a higher radiation dose compared to standard mammography. To address these limitations, this work proposes using deep generative models for virtual contrast enhancement on CESM, aiming to make CESM contrast-free and reduce the radiation dose. Our deep networks, consisting of an autoencoder and two Generative Adversarial Networks, the Pix2Pix, and the CycleGAN, generate synthetic recombined images solely from low-energy images. We perform an extensive quantitative and qualitative analysis of the model's performance, also exploiting radiologists' assessments, on a novel CESM dataset that includes 1138 images. As a further contribution to this work, we make the dataset publicly available. The results show that CycleGAN is the most promising deep network to generate synthetic recombined images, highlighting the potential of artificial intelligence techniques for virtual contrast enhancement in this field.

Contrast-Enhanced Mammography-Guided Biopsy: Preliminary Results of a Single-Center Retrospective Experience.

Background: CEM-guided breast biopsy is an advanced diagnostic procedure that takes advantage of the ability of CEM to enhance suspicious breast lesions. The aim pf this paper is to describe a single-center retrospective experience on CEM-guided breast biopsy in terms of procedural features and histological outcomes. Methods: 69 patients underwent the procedure. Patient age, breast density, presentation, dimensions, and lesion target enhancement were recorded. All the biopsy procedures were performed using a 7- or 10-gauge (G) vacuum-assisted biopsy needle. The procedural approach (horizontal or vertical) and the decubitus of the patient (lateral or in a sitting position) were noted. Results: A total of 69 patients underwent a CEM-guided biopsy. Suspicious lesions presented as mass enhancement in 35% of cases and non-mass enhancement in 65% of cases. The median size of the target lesions was 20 mm. The median procedural time for each biopsy was 10 ± 4 min. The patients were placed in a lateral decubitus position in 52% of cases and seated in 48% of cases. The most common approach was horizontal (57%). The mean AGD was 14.8 mGy. At histology, cancer detection rate was 28% (20/71). Conclusions: CEM-guided biopsy was feasible, with high procedure success rates and high tolerance by the patients.

A comparative analysis of thermal ablation techniques in the treatment of primary and secondary lung tumors: a single-center experience.

PURPOSE: To evaluate efficacy and safety of radiofrequency ablation (RFA) and microwave ablation (MWA) in unresectable lung malignancies. METHODS: Data regarding patients with primary and secondary lung tumors treated with RFA or MWA from 2008 to 2020 were reviewed retrospectively. Primary study objectives such as technical success, primary and secondary technique efficacy rates, local tumor progression (LTP) rate, LPT-free survival (LPTFS) and overall survival (OS) were assessed. Secondary study objectives were side effects and complications. RFA and MWA were compared using the Chi-square test for continuous variables. Kaplan-Meier curves were calculated for survival statistical analysis. RESULTS: A total of 113 patients with primary or secondary lung tumor underwent 74 RFA (48%) and 81 MWA (52%). Technical success rate was 151/155 (97%); primary and secondary technique efficacy rates were 123/155 (79%) and 129/155 (83%), respectively. During the entire study follow-up, 32 cases experienced disease progression (20%), of which 18 underwent repeat ablation (12%), in 6 cases with success (4%). Residual unablated tumor happened in 4/155 cases (3%). LTP occurred in 28/155 cases (17%). The only factor associated with poorer LTP-FS was lesion diameter ≥ 30 mm (P < 0.05). One-, 3- and 5-years LTP-FS was 83%, 82%, 82%, respectively. One-, 3- and 5-years OS of the entire population was 87%, 74%, 73%, respectively. Minor and major complication rates were 53/155 (34%) and 29/155 (19%), respectively. CONCLUSIONS: In conclusion, this study confirms the appropriateness of RFA and MWA for lung tumors treatment, in terms of safety and efficacy.

Augmented reality 3D navigation system for percutaneous CT-guided pulmonary ground-glass opacity biopsies: a comparison with the standard CT-guided technique.

Background: Augmented reality navigation system for percutaneous computed tomography (CT)-guided pulmonary biopsies has recently been introduced. There are no studies in literature about its use for ground glass lesions biopsies. The aim of this study is to evaluate the effectiveness of an augmented reality infrared navigation system performance on CT-guided percutaneous lung ground glass opacity (GGO) biopsy compared to a standard CT-guided technique. Methods: A total of 80 patients with lung GGO who underwent to a percutaneous CT-guided lung biopsy with an augmented reality infrared navigation system were retrospectively enrolled in the study. Comparison was performed with a group of 80 patients who underwent to lung biopsy with the standard CT-guided technique. Evaluation of maximum lesion diameter (MLD), distance between lesion and pleural surface (DPS), distance travelled by the needle (DTP), procedural time, validity of histological sample, procedural complications and the radiation dose to the patient's chest were recorded for each patient of both groups. In addition, each group was divided into two subgroups based on lesion size, according to a cut-off of 1.5 cm (<1.5 cm; ≥1.5 cm). Results: Augmented reality navigation system showed a significant reduction in procedural time, radiation dose administrated to patients and complications rate compared to a standard CT-guided technique. Technical success was achieved in the 100% of cases in both groups, but the diagnostical success was higher in the group where patients underwent to lung biopsies with the use of navigation system. We also found that using an augmented reality navigation system increases the diagnostical success rate for lesion <1.5 cm. MLD, DPS and DTP did not differ significantly between the two groups of patients. Conclusions: The use of an augmented reality navigation system for percutaneous CT-guided pulmonary GGO biopsies has demonstrated a lower incidence of post-procedural complications, a significantly reduction of the radiation dose administered to patients and a higher diagnostical success rate.

Different Treatments of Symptomatic Angiomyolipomas of the Kidney: Two Case Reports.

Development of more sensitive imaging techniques has caused an increase in the number of diagnosed small renal tumors. Approximately 2-3% of these lesions are proved to be angiomyolipomas (AML), a rare benign tumor of the kidney sometimes causing pain and hematuria. The most required approach is observation, but in the case of recurrent symptoms or larger tumors, which may cause bleeding, a more active treatment is required. We present two cases of symptomatic AML tumors of different sizes in the kidney: one treated with transarterial embolization (TAE), and the other with percutaneous cryoablation (CRA). The lesions were diagnosed on the basis of contrast-enhanced computed tomography (CT) scan and magnetic resonance imaging (MRI). Both treatments proved to be effective and safe for treating renal AMLs. A follow-up carried out, based on contrast-enhanced CT scan, confirmed complete treatment of AML and decreased lesion size. There are myriad minimally invasive approaches for the treatment of renal AMLs, and the preservation of renal function remains a priority. The most popular treatment option is the selective renal artery embolization. Owing to its limited invasiveness, CRA could be an attractive option for the preventive treatment of AML.