Imaging of primary retroperitoneal neoplasms.

Retroperitoneal soft tissue tumors are frequently incidental findings on imaging tests as Computed tomography (CT) or Magnetic Resonance Imaging (MRI). Retroperitoneal soft tissue tumors are rare and therefore not common in daily radiological practice. Clinician and radiologist'skills to set retroperitoneal soft tissue tumors at presentation is crucial for a correct patient management. So far, several diagnostic algorithms have been proposed to assess retroperitoneal masses, which have not been validated by case histories (2-5). The aim of this article is to evaluate a new classification of retroperitoneal masses using CT and MRI. KEY WORDS: CT, Diagnosis, MRI, Retroperitoneum, Soft tissue sarcoma.

PET/CT in congenital hyperinsulinism: transforming patient's lives by molecular hybrid imaging.

Congenital hyperinsulinism (HI) is a life-threatening condition characterized by severe and recurrent episodes of hypoglycaemia due to defects in key genes involved in regulating insulin secretion. The delay in diagnosis and inappropriate management of HI lead to high risk of permanent hypoglycemic brain injury. The management of HI is challenging as each form of HI (focal, diffuse, and atypical) requires its own therapeutic strategy. In HI diagnostic work-up, integrated PET/CT scan is currently the first-line imaging technique allowing to differentiate between diffuse and focal form and, in the latter case, to localize the focus within the pancreas with high precision. Only in focal HI partial pancreatectomy is the treatment of choice and a curative surgical treatment means a real chance of transforming patient's lives and HI patient's future. The aim of this review is to discuss the role of PET/CT imaging in HI scenario, its technical advantages and limitations and how successful surgery is strongly dependent on accurate preoperative assessment (genetic analysis and PET/CT scan). A multidisciplinary approach in HI diagnosis and treatment inside a single team (involving different expertise) allows to manage children safely and properly, supporting their families in an organized care network.

Clinical application of 18F-DOPA PET/TC in pediatric patients.

The use 18F-DOPA PET/CT for oncologic and non-oncologic pediatric diseases is well consolidated in clinical practice. The indications include brain tumors, neuroendocrine malignancies and congenital hyperinsulinism. The number of papers involving pediatric subjects is steadily growing. However, literature still lacks clinical trials and large multicentric studies in contrast with the extensive literature available for adult patients. The aim of this review is to discuss the main clinical indications of 18F-DOPA in pediatric oncologic and nononcologic diseases and to analyze its role in diagnosis, staging, biopsy and surgical planning. The high resolution of PET/CT tomographs in addition to the high sensitivity and specificity of 18F-DOPA imaging exceeds the downsides linked to this nuclear medicine imaging modality. In fact, few potential limitations could discourage the use of PET/CT imaging. For example, similarly to MRI studies the long acquisition time of a PET/CT scan often requires sedation especially in infants. Moreover, the radiation exposure of a PET/CT scan may be high, but the clinical benefit deriving from nuclear medicine imaging outruns the risk connected to the use of ionizing radiations.

Gonioprobe, an Innovative Gamma-probe to Guide Parathyroid Radioguided Surgery: First Clinical Experiences with Navigator and Lock-ontarget Functions.

BACKGROUND: Radioguided surgery represents a validated technique for the detection and the excision of abnormal parathyroid glands responsible for primary hyperparathyroidism (PHPT). To date little attention has been paid as to how the characteristics of gamma-probes can influence surgical procedure and time, thus having an impact on postoperative morbidity, hospitalization and costs. METHODS: We designed a new prototype of gamma-probe, the Gonioprobe, and tested its clinical utility in the operating room. Gonioprobe, thanks to its 5 scintillating independent crystals, performs the dual function of Navigator and Lock-on-target. These characteristics allow the immediate guidance of the surgeon's hand towards the source with very high precision, and with a much higher spatial resolution than commercial probes. Gonioprobe was used during intervention to detect abnormal parathyroid tissue, and to ensure no radioactivity in surgery bed after adenoma removal. RESULTS: We tested our gamma-probe on parathyroid adenomas particularly difficult to identify at a visual inspection due to anatomy modifications from previous neck surgery and/or characterized by uncommon localization. Moreover, parathyroid adenomas were hardly removable due to the proximity to the esophagus, neck vessels and/or recurrent laryngeal nerve (RLN). An intraoperative nerve monitoring system was used to protect the recurrent laryngeal nerve from injuries. Parathyroid hormone (PTH) assay and frozen biopsy confirmed the successful excision of the adenomas. CONCLUSION: The intraoperative use of the innovative Gonioprobe along with the nerve monitoring system allowed an accurate and safe removal of parathyroid adenomas and offered a significant advantage by reducing surgical time and postoperative complications, as well as hospitalization and costs.

Seminal Vesicle Urinary Reflux After TURP Mimicking Vesicular Invasion From Prostate Cancer on 18F-Choline PET/CT.

Seminal vesicles are paired secretory glands located posterior to the bladder in men that produce seminal fluid to maintain sperm. Seminal vesicle reflux into the prostatic ducts may be associated with prostatitis in older patients or may represent a very rare complication of transurethral prostate resection in patients with prostatic cancer. This condition is frequently accidentally diagnosed on excretory urography and/or retrograde urethrogram. Clinical presentation includes pain, fever, recurrent epididymitis-prostatitis, and post void dribbling.

Early 18 F-FDG PET/CT in COVID-19.

We report the case of who has been hospitalized complaining about fever in the last 4 days. Laboratory data revealed lymphocytopenia and leucopenia with an elevation of C-reactive protein and positive real-time reverse transcription-polymerase chain reaction (RT-PCR). Six days before this hospitalization, when the patient was asymptomatic, 18 F-FDG PET/CT images were performed for the therapeutic control of liver metastases of colorectal cancer. Lung abnormality findings at 18 F-FDG PET/CT images, unrelated to cancer metastases, but suspicious for viral infection, may suggest the presence of COVID-19 disease in its early phase before symptoms onset. Since PET/CT is more sensitive than CT scan in detecting host's reaction, the added value of this technique could be monitoring disease progression and could be used as a biomarker of lung disease activity and therefore as an important tool for a better understanding of the factors that contribute to the progression of lung disease.

PET/CT in pediatric oncology.

The use of PET/CT in adult oncology has been consolidated by several and authoritative multicentric studies, metanalyses and systematic reviews. International guidelines help everyday nuclear medicine specialists, oncologists and radiologists in choosing the most suitable diagnostic path for each patient. Classifications based on traditional imaging and PET/CT findings define the most appropriate treatment and can predict the outcome for different types of malignancies. However, compared to adult patients the use of PET/CT in pediatric oncology is often burdened by lack of systematic and large multicentric studies and consequently accurate and precise guidelines. The cause of this shortage of large trials may be attributed to the rarity of these neoplasms and to the fear of long-term radiation effects on this peculiar category of patients. The aim of this article is to review the applications of PET/CT for imaging the most common pediatric neoplasms.

Evaluation of the basal ganglia in neurofibromatosis type 1.

PURPOSE: Alterations of the brain microstructure and metabolism have been identified in patients with neurofibromatosis type 1 (NF1). In this study, we analyzed the basal ganglia of NF1 subjects without cognitive delay throughout a combined approach with magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) in order to better define the metabolic and microstructural characteristics of these regions and, furthermore, to verify if metabolic and microstructural abnormalities may be present in normally developed NF1 patients. METHODS: A 3-T MRI with multivoxel MRS and DTI was performed in 14 NF1 patients and eight controls. N-acetyl-aspartate (NAA), choline (Cho), creatine (Cr) values and ratios, fractional anisotropy, and apparent diffusion coefficient (ADC) were calculated, for a total of four regions of interest (ROI) for each hemisphere. RESULTS: NF1 patients, compared to healthy controls, showed (a) decreased NAA in all the four ROI, (b) increased Cho and decreased Cr in three of the four ROI, (c) decreased NAA/Cho ratio in three ROI, and (d) increased ADC in all the four ROI. A trend of increased ADC was present in three of the four ROI of NF1 patients with unidentified bright objects (UBOs) and younger than 18 years. CONCLUSION: These data confirm the presence of neuroaxonal damage with myelin disturbances in NF1 patients. We showed that metabolic and microstructural anomalies can be present in the same time in NF1 patients without developmental delay or cognitive deficits. Relations between brain anomalies, UBOs, and cognitive functions need further studies.