Radiomics in the characterization of lipid-poor adrenal adenomas at unenhanced CT: time to look beyond usual density metrics.

OBJECTIVES: In this study, we developed a radiomic signature for the classification of benign lipid-poor adenomas, which may potentially help clinicians limit the number of unnecessary investigations in clinical practice. Indeterminate adrenal lesions of benign and malignant nature may exhibit different values of key radiomics features. METHODS: Patients who had available histopathology reports and a non-contrast-enhanced CT scan were included in the study. Radiomics feature extraction was done after the adrenal lesions were contoured. The primary feature selection and prediction performance scores were calculated using the least absolute shrinkage and selection operator (LASSO). To eliminate redundancy, the best-performing features were further examined using the Pearson correlation coefficient, and new predictive models were created. RESULTS: This investigation covered 50 lesions in 48 patients. After LASSO-based radiomics feature selection, the test dataset's 30 iterations of logistic regression models produced an average performance of 0.72. The model with the best performance, made up of 13 radiomics features, had an AUC of 0.99 in the training phase and 1.00 in the test phase. The number of features was lowered to 5 after performing Pearson's correlation to prevent overfitting. The final radiomic signature trained a number of machine learning classifiers, with an average AUC of 0.93. CONCLUSIONS: Including more radiomics features in the identification of adenomas may improve the accuracy of NECT and reduce the need for additional imaging procedures and clinical workup, according to this and other recent radiomics studies that have clear points of contact with current clinical practice. CLINICAL RELEVANCE STATEMENT: The study developed a radiomic signature using unenhanced CT scans for classifying lipid-poor adenomas, potentially reducing unnecessary investigations that scored a final accuracy of 93%. KEY POINTS: • Radiomics has potential for differentiating lipid-poor adenomas and avoiding unnecessary further investigations. • Quadratic mean, strength, maximum 3D diameter, volume density, and area density are promising predictors for adenomas. • Radiomics models reach high performance with average AUC of 0.95 in the training phase and 0.72 in the test phase.

Cone Beam Computed Tomography Image Fusion with Cross Sectional Images for Percutaneous Renal Tumor Ablation: Preliminary Data.

PURPOSE: Percutaneous ablative treatments in the kidney are now standard options for local cancer therapy. Multimodality image guidance, combining two 3D image sets, may improve procedural images and interventional strategies. We aimed to assess the value of intra-procedural cone beam computed tomography (CBCT) with magnetic resonance (MR) or CT imaging fusion technique in the guidance of percutaneous microwave ablation (MWA) of renal neoplasms. MATERIALS AND METHODS: Fifteen patients (eight males, seven females, median age 65 years, median lesion size 20 mm) underwent percutaneous MWA for 15 renal tumors. All the procedures were performed in a dedicated angiography room setting; CBCT ablation planning capabilities included multimodality image fusion. Preoperative contrast-enhanced CT was available in 12 patients, whereas magnetic resonance imaging in the remaining. All patients were considered inoperable due to comorbidities, advanced age, and/or refusal to undergo surgery. Exclusion criteria were: tumors visible at unenhanced CBCT, metastatic disease, and uncorrected coagulopathy. Technical success and technical effectiveness were calculated. Procedural time, complications and recurrences were registered. RESULTS: MWA under CBCT-guidance with fusion technique was technically successful in 14 out of 15 cases (93%). The median procedural time was 45 min. No procedure-related complications were reported. No enhancing tissue was visualized in the area of ablation at 1-month follow-up. All 15 cases were recurrence-free at last follow-up assessment (median follow-up of 12 months); no cancer-specific deaths were registered. CONCLUSION: CBCT-CT/MR image fusion is technically feasible and safe in achieving correct targeting and complete ablation of renal lesions. This approach bears the potential to overcome most of the limitations of unenhanced CBCT guidance alone; larger series are needed to validate this technique.

Rhenium Radioisotopes for Medicine, a Focus on Production and Applications.

In recent decades, the use of alpha; pure beta; or beta/gamma emitters in oncology, endocrinology, and interventional cardiology rheumatology, has proved to be an important alternative to the most common therapeutic regimens. Among radionuclides used for therapy in nuclear medicine, two rhenium radioisotopes are of particular relevance: rhenium-186 and rhenium-188. The first is routinely produced in nuclear reactors by direct neutron activation of rhenium-186 via 185Re(n,γ)186Re nuclear reaction. Rhenium-188 is produced by the decay of the parent tungsten-188. Separation of rhenium-188 is mainly performed using a chromatographic 188W/188Re generator in which tungsten-188 is adsorbed on the alumina column, similar to the 99Mo/99mTc generator system, and the radionuclide eluted in saline solution. The application of rhenium-186 and rhenium-188 depends on their specific activity. Rhenium-186 is produced in low specific activity and is mainly used for labeling particles or diphosphonates for bone pain palliation. Whereas, rhenium-188 of high specific activity can be used for labeling peptides or bioactive molecules. One of the advantages of rhenium is its chemical similarity with technetium. So, diagnostic technetium analogs labeled with radiorhenium can be developed for therapeutic applications. Clinical trials promoting the use of 186/188Re-radiopharmaceuticals is, in particular, are discussed.

Nothing but lung and bones: Longitudinal evolution and quantitative analysis in a case of idiopathic diffuse pulmonary ossification.

A 77-year-old Caucasian man, a former surveyor in a chemical company, underwent a chest X-ray (CXR) as a follow-up exam for a melanoma of the back, surgically removed. CXR showed interstitial thickening in both lower lobes; then, a high-resolution computed tomography of the chest (HRCT) was performed to further investigate these findings, revealing multiple small, calcified nodules with branching appearance at both lung bases. Clinical examination and exposure history were negative, except for a decrease in diffusing capacity for carbon monoxide resulting from pulmonary function tests. Surgical lung biopsy was performed; histology revealed numerous nodules and branching tubules of bone tissue, some of which with marrow elements. After multidisciplinary discussion of the case, a diagnosis of idiopathic diffuse pulmonary ossification (DPO) was considered. Clinical status of the patient was stable over time, despite the increase in extent of calcifications. DPO is an uncommon condition that should be considered in different clinical-radiological settings; multidisciplinary discussion is essential for the final diagnosis.

90Y/177Lu-DOTATOC: From Preclinical Studies to Application in Humans.

The PRRT (Peptide Receptor Radionuclide Therapy) is a promising modality treatment for patients with inoperable or metastatic neuroendocrine tumors (NETs). Progression-free survival (PFS) and overall survival (OS) of these patients are favorably comparable with standard therapies. The protagonist in this type of therapy is a somatostatin-modified peptide fragment ([Tyr3] octreotide), equipped with a specific chelating system (DOTA) capable of creating a stable bond with ß-emitting radionuclides, such as yttrium-90 and lutetium-177. In this review, covering twenty five years of literature, we describe the characteristics and performances of the two most used therapeutic radiopharmaceuticals for the NETs radio-treatment: [90Y]Y-DOTATOC and [177Lu]Lu-DOTATOC taking this opportunity to retrace the most significant results that have determined their success, promoting them from preclinical studies to application in humans.

Diffuse panbronchiolitis as parathymic syndrome in a Caucasian man previously treated for thymoma.

Diffuse panbronchiolitis (DPB) is a rare disease characterized by bronchiolitis and chronic sinusitis. Being largely restricted to East Asia, its actual incidence in Caucasian patients is probably underestimated. DPB has been described in association with thymic neoplasms, mainly arising as a consequence of immune dysregulation. We present a rare case of DPB diagnosed in a 69-year-old Caucasian man who had undergone surgery for stage 2A thymoma a year before. The patient came to our hospital complaining of exertional dyspnea and productive cough, with a persistent lung consolidation described at chest X-rays. High resolution computed tomography (CT) showed diffuse centrilobular micronodules and solid nodules, tree-in-bud opacities, peripheral consolidations and cylindrical bronchiectasis. Sinus disease was also demonstrated by CT. Analysis of bronchoalveolar lavage showed marked granulocyte inflammation and allowed the isolation of Haemophilus Influenzae. Consequently, the diagnosis of DPB was reached by integrating clinical, and radiological data. Long-term therapy with azithromycin was prescribed, and was found to be effective in controlling symptoms and reducing radiological abnormalities at 6-month clinical and CT follow-up. Confidence with the radiological presentation and clinical significance of DPB is necessary, since the condition is responsive and reversible to long-term macrolide treatment, the effect of which is mainly attributed to an anti-inflammatory, and immunoregulatory action.

Diagnostic Contribution of Contrast-Enhanced CT as Compared with Unenhanced Low-Dose CT in PET/CT Staging and Treatment Response Assessment of 18F-FDG-Avid Lymphomas: A Prospective Study.

The aim of this study was to assess the added diagnostic value of contrast-enhanced CT (CECT) as compared with unenhanced CT (UECT) in PET/CT staging and treatment response assessment of 18F-FDG-avid lymphomas. Methods: 170 PET/UECT scans followed by CECT scans were prospectively performed for staging (n = 85) and for treatment response assessment (n = 85) of 18F-FDG-avid lymphomas, during a single session using an integrated 64-slice PET/CT scanner. CECT and UECT images were evaluated separately by 2 radiologists, whereas PET images were evaluated by 2 nuclear physicians. Nodal and extranodal UECT and CECT findings were classified according to the Lugano criteria and were successively compared with PET/CT results, considered the gold standard. In the analyzed groups, the agreement rate with the disease status determined via PET was calculated separately for UECT and CECT using the McNemar test on paired data. The added value of the contrast medium was shown by the agreement between the PET and CECT results and the lack of agreement between UECT and PET. Results: CECT enabled the identification of additional extranodal lesions (hepatic, muscular, and gastric) in only 3 staging group cases (3.5%), indicating different stages as compared with UECT, whereas there was absolute agreement between CECT and UECT in terms of treatment response assessment. The added diagnostic value of CECT was lower than the established threshold for clinical relevance (15%). The McNemar test indicated no statistical significance in either group. The incidental findings detected by CECT but not UECT were important for clinical management but not sufficient to alter lymphoma treatment strategy. Conclusion: According to our results, it might be possible to exclude CECT examination of 18F-FDG-avid lymphoma from staging and treatment response assessment, with the consequent advantages of reducing radiation exposure and potential contrast-related risks.

Uterine Myomas: Extravascular Treatment.

Uterine fibroids are common benign tumors that affect the female reproductive tract. They are responsible for considerable morbidity and deterioration of life quality. The main advantages offered by mini invasive techniques are low grade of invasiveness and short times of hospitalization. The most diffuse technique is uterine artery embolization (UAE). Common concerns with UAE include postprocedural pain, postembolization syndrome, and risk of infection. Image-guided thermal ablation techniques like radiofrequency ablation, percutaneous microwave ablation, and imaging-guided high-intensity focused ultrasound were introduced to overcome the side effects related to UAE and surgery. The aim of this review is to briefly analyze the ablative procedures and their role in the management of symptomatic fibroids, and to describe the safety profile and outcomes of these modalities.

The potential role of MR based radiomic biomarkers in the characterization of focal testicular lesions.

How to differentiate with MRI-based techniques testicular germ (TGCTs) and testicular non-germ cell tumors (TNGCTs) is still under debate and Radiomics may be the turning key. Our purpose is to investigate the performance of MRI-based Radiomics signatures for the preoperative prediction of testicular neoplasm histology. The aim is twofold: (i), differentiating TGCTs and TNGCTs status and (ii) differentiating seminomas (SGCTs) from non-seminomatous (NSGCTs). Forty-two patients with pathology-proven testicular neoplasms and referred for pre-treatment MRI, were retrospectively enrolled. Thirty-two out of 44 lesions were TGCTs. Twelve out of 44 were TNGCTs or other histologies. Two radiologists segmented the volume of interest on T2-weighted images. Approximately 500 imaging features were extracted. Least Absolute Shrinkage and Selection Operator (LASSO) was applied as method for variable selection. A linear model and a linear support vector machine (SVM) were trained with selected features to assess discrimination scores for the two endpoints. LASSO identified 3 features that were employed to build fivefold validated linear discriminant and linear SVM classifiers for the TGCT-TNGCT endpoint giving an overall accuracy of 89%. Four features were employed to build another SVM for the SGCT-SNGCT endpoint with an overall accuracy of 86%. The data obtained proved that T2-weighted-based Radiomics is a promising tool in the diagnostic workup of testicular neoplasms by discriminating germ cell from non-gem cell tumors, and seminomas from non-seminomas.

Outcomes following minimally invasive imagine-guided percutaneous ablation of adrenal glands.

Whilst surgery represents the gold standard for the treatment of adrenal primary malignant tumors, metastatic involvement of the adrenal glands is generally approached conservatively; however, surgery for local control has been controversial, and several reports have described the utility of surgical removal in terms of prolonged survival in selected patients. Different techniques, including radiofrequency ablation (RFA), microwave ablation (MWA), laser induced thermal therapy (LITT), cryoablation (CRA), and chemical ablation, are employed in percutaneous image-guided ablation for primary and metastatic malignancies of the adrenal glands, in case of patients with multiple comorbidities or who refuse surgery. Technical success, clinical success and safety were analysed and discussed in this systematic review. Tumor size was found a significant determinant for local disease control; histology of the primary malignancy and coexistence of tumor elsewhere were correlated with prognosis. These procedures resulted to be feasible and safe, with hypertensive crisis representing the most common complication. Although there is lack of evidence in the literature concerning outcomes compared with surgery, percutaneous ablation may represent a useful therapeutic option for controlling unresectable adrenal metastases, offering patients opportunities for improved survival.

Pitfalls in the embolisation of a thyrocervical trunk bleeding: a case report.

INTRODUCTION: An intrathoracic bleeding from the thyrocervical branch is not common in blunt trauma, but an interventional radiologist should be aware of the risks in order to prevent complications. CASE PRESENTATION: A 30-year-old male presented with a right pneumo-haemothorax due to active bleeding revealed at contrast-enhanced CT, as a consequence of a fall occurred in the previous week. The patient was treated with endovascular embolisation in an angiographic room with coils placement, since the right thyrocervical artery was found to be supplying the pneumo-haemothorax. A radiculo-medullary branch rose from the thyrocervical trunk, impeding the proximal embolization with microparticles and needing selective isolation of the bleeding artery with the catheter to avoid spinal cord injuries. The treatment had a successful result and the following CT control showed signs of recovering, without any complication. CONCLUSION: Our paper presents a rare contingency, warning the operator to bear in mind the presence of arteries feeding the spinal cord. This crucial detail precludes the use of microparticles embolisation to prevent neurologic sequelae, whereas the use of endovascular coils for embolization should be mandatory. Moreover, this case reminds that the post-traumatic bleeding deriving from a cervical trauma may also occur later.

Percutaneous microwave ablation therapy of renal cancer local relapse after radical nephrectomy: a feasibility and efficacy study.

Renal cell carcinoma (RCC) local recurrence after radical nephrectomy is uncommon. When feasible, surgical removal remains the primary treatment strategy; nevertheless, local RCC relapse management is controversial, and less invasive procedures may represent an attractive option to achieve oncologic control. The aim of our study was to assess the feasibility, safety, and clinical outcomes of image-guided percutaneous microwave ablation (MWA) for RCC local recurrence in patients initially treated with nephrectomy with curative intent. 10 consecutive patients underwent CT-guided percutaneous MWA of a total of 10 retroperitoneal nodules. Inclusion criteria were: histologically verified retroperitoneal metastases, previous radical nephrectomy, lesion no larger than 3 cm, no other metastatic site elsewhere. All the procedures were performed under moderate sedation choosing the most favorable patient decubitus. If deemed necessary, pneumodissection was induced before ablation. After the antenna placement inside the target lesion, thermal ablation was achieved by maintenance of a power of 100 W for a total time between 2 and 4 min. All patients were observed overnight and discharged the following day if clinically stable. Technical success was obtained in 100% of patients. One patient was re-treated to complete oncologic response with repeat MWA. No major complications were observed. No patients demonstrated local recurrence at a mean follow-up of 26 months. MWA is a safe and effective treatment strategy for loco-regional relapse of RCC following radical nephrectomy. This technique may represent a valuable approach for patients who are not eligible for surgery.

Current concepts in ablative procedures for primary benign liver lesions: a step forward to minimize the invasiveness of treatment when deemed necessary.

With increased use of medical imaging, the incidental detection of benign solid liver tumors has become more frequent. Facing with benign disease, the indications for surgery are still object of discussion in light of the stable natural course of most lesions and obvious drawbacks of any surgical intervention; therefore, in most situations, a conservative approach is recommended, and surgery is mainly reserved for those cases with persistent or worsening symptoms, or who are at risk for complications as malignant transformation. The advent of ablative techniques has widened the range of treatment options available to these patients, presenting as a valid alternative to resection in terms of safety and efficacy in selected cases, particularly in patients who are considered poor surgical candidates and with smaller lesions. This review outlines the role of percutaneous ablative methods for benign solid liver tumors that are encountered in adults, providing a per histology analysis of the existing evidence. The up-to-date strategies for management of the most common benign solid tumors are recapitulated.

Percutaneous cervical discectomy: retrospective comparison of two different techniques.

AIM: To compare clinical success and patient satisfaction of percutaneous cervical nucleoplasty (PCN) and percutaneous cervical discectomy (PCD) in contained cervical disc herniation treatment. MATERIALS AND METHODS: We retrospectively identified 50 consecutive patients in our institution: 24 underwent the PCD treatment and 26 patients were treated by the PCN procedure. All patients complained of radicular pain with or without neck pain; diagnosis of contained cervical disc herniation was obtained by MRI; all patients had received conservative therapy which did not result in symptom improvement. Exclusion from our series consisted of patients who had undergone previous surgery at the indicated level, or those with myelopathy, or those in whom more than a sole herniation was treated in the same session. Overall procedure time, fluoroscopy time, radiation dose and complications were recorded. The MacNab scale score was used to assess clinical success in terms of pain relief at 2- and 6-month follow-up. After 4-6 months, a cervical MRI was obtained in 24 patients. RESULTS: Neither major nor minor complications were reported. Regarding patient satisfaction, overall median modified MacNab score was excellent both at 2 and 6 months after treatment. No significant statistical difference was found in mean modified MacNab score at 2 and 6 months among patients grouped by treatment choice (p = 0.319 and 0.847, respectively); radiation dose was inferior in PCN group than in PCD, with no significant statistical difference. CONCLUSION: PCD and PCN were found to be safe and effective in terms of pain relief in contained cervical herniation treatment.

NEP-Score Thresholds Predict Survival of Patients With Bronchial Carcinoids.

Survival prognostic markers are extremely needed to better define therapeutic strategies in patients with bronchial carcinoids (BC). We aim to verify the applicability of the NEP-Score in a homogeneous BC cohort and identify a derivative prognostic marker, the NEP-Score at diagnosis (NEP-D) that does not consider new metastases during follow-up. Sixty-four patients (38 females, and 26 males, mean age at diagnosis 58.9 ± 1.7 years) with BC were retrospectively evaluated. NEP-Score was calculated at the end of follow-up (NEP-T). A derivative score, the NEP-Score at diagnosis (NEP-D) that does not consider new metastases during follow-up, was then assessed. Patients were subdivided according to their living status at the end of follow-up. A NEP-Score threshold was investigated to predict survival. Mean NEP-T and mean NEP-D were significantly lower in live patients at end of follow-up. A NEP-T cut-off >138 significantly predicts survival. Atypical BC relapsed more frequently than Typical BC. Male gender and previous malignancy were negative prognostic factors for survival. We confirmed NEP-Score applicability in BC and NEP-D utility, being the latter a simple, quick, and cheap prognostic score that can help clinicians in decision making. The identified NEP-D threshold can predict NEN aggressiveness and may be used to define the best personalized therapeutic strategy. In this context, a validation study is needed.

Neck paraganglioma and follicular lymphoma: a case report.

BACKGROUND: Paragangliomas and pheochromocytomas are sympathetic or parasympathetic tumors derived from the paraganglia and the adrenal medulla, respectively. Paragangliomas and pheochromocytomas can be sporadic or familial, the latter frequently being multifocal and possibly due to succinate dehydrogenase complex genes mutations. In addition, 12% of sporadic paragangliomas are related to covered succinate dehydrogenase complex mutations. The importance of identifying succinate dehydrogenase complex mutations is related to the risk for these patients of developing multiple tumors, including non-endocrine ones, showing an aggressive clinical presentation. CASE PRESENTATION: We report the case of a 45-year-old Caucasian man with an indolent mass in his neck. Ultrasound of his neck, magnetic resonance imaging, and 1,4,7,10-tetraazacyclododecane-N(I),N(II),N(III),N(IIII)-tetraacetic acid(D)-Phe(1)-thy(3)-octreotide (68Ga-DOTATOC) positron emission tomography-computed tomography and endocrine work-up were consistent with a carotid body paraganglioma with concomitant nodal enlargement in several body regions, which turned out to be a follicular lymphoma at histology. He was found to carry a germline Succinate dehydrogenase subunit B gene (SDHB) mutation. CONCLUSION: It is crucial to look for a second malignancy in the case of a paraganglioma demonstrating succinate dehydrogenase complex germline mutations.

Dual-energy X-ray absorptiometry pitfalls in Thalassemia Major.

BACKGROUND: Low mineral mass and reduced bone strength with increased fracture risk are the main causes of morbidity in Thalassemia Major (TM). The pathogenesis is multifactorial and includes ineffective erythropoiesis with medullary expansion, multiple endocrine dysfunctions, direct iron bone deposition, deferoxamine-induced bone dysplasia, and reduced physical activity associated with disease complications. Dual-energy X-ray absorptiometry (DXA) is the "gold standard" for bone mineral density (BMD) assessment and for bone strength and quality evaluation. This method identifies patients at greater risk of fragility fractures, guiding treatment and monitoring response to therapy. In TM, DXA shows limitations concerning BMD calculation accuracy and fracture risk prediction. One of the main challenges in the assessment of bone health in patients with TM is the accurate interpretation of densitometric results. PURPOSE: This review investigates the major pitfalls in DXA implementation and interpretation in TM. METHODS: Available literature has been assessed. CONCLUSIONS: DXA shows limitations in assessing bone mineral "status" in TM, especially in the paediatric population, due to the peculiar characteristics of bone architecture and deformities associated with the disease. A radiological technique adjustment in this population is mandatory.

An Autopsy Case of Misdiagnosed Wernicke's Syndrome after Intragastric Balloon Therapy.

Intragastric balloon (IGB) therapy is a widely used technique to counter obesity, and it is known to be safe and effective. Although there can be a high rate of side effects following IGB therapy, most are self-healing and they are mainly accommodative in nature. Few cases of Wernicke's syndrome under IGB therapy have been described in the literature, and to the best of our knowledge, none have been fatal. We present here a case of a 51-year-old woman who underwent IGB therapy over 8 months. Late diagnosed Wernicke's syndrome that first appeared as lower limb neuropathy progressively immobilized the patient, until she required bed rest. Finally, a major complication of pneumonia caused her death. Wernicke's syndrome has been mainly related to bariatric surgery techniques, but it must also be linked to IGB therapy (and also to other restrictive weight-loss interventions). As the use of IGB therapy spreads, the literature must alert physicians to this complication. Wernicke's syndrome is a severe but reversible condition when diagnosed and treated early.

Imaging of the scrotum: beyond sonography.

The aim of this article is to describe the role of second-level imaging techniques after an initial ultrasonography evaluation in the assessment of scrotal diseases. While ultrasonography remains central as the primary imaging modality for the evaluation of pathologic conditions of the scrotum, the role of magnetic resonance imaging continues to evolve: it can actually be valuable as a problem-solving tool when sonographic findings are equivocal or inconclusive. Magnetic resonance imaging of the scrotum may provide accurate detection and characterization of scrotal diseases, well depicting the precise location of scrotal masses (intratesticular or extratesticular) and reliably characterizing benign conditions simulating neoplastic processes, thus preventing unnecessary radical surgery. Advanced magnetic resonance techniques, most of all diffusion weighted imaging and magnetic resonance spectroscopy, play in the meanwhile a more significant role in evaluating scrotal diseases. TEACHING POINTS: • Multiparametric ultrasonography usually represents the initial imaging modality for approaching scrotal diseases. • MRI is well established as a problem-solving tool for inconclusive sonographic findings. • Advanced MRI techniques can be successfully applied in scrotal pathology assessment. • MRI is valuable in differentiating benign conditions from neoplastic processes. • CT plays a role in trauma assessment and cancer staging alongside PET/CT.

Computed tomographic colonography in the evaluation of a case of giant colonic diverticulum.

The aim of this article was to present our experience with CT-colonography evaluation of a case of giant colonic diverticulum. Despite the high prevalence of diverticular disease in the Western world, giant colonic diverticula are rare entities, with fewer than 200 cases reported in literature.