Diagnostic approach to focal liver lesions at cross-sectional imaging: a primer for beginners.

Liver imaging encompasses a broad spectrum of diseases in different clinical backgrounds. The available literature is vast and reported data often lacks standardization. Because of all these issues, the differential diagnosis and the characterization of liver lesions can be challenging for the beginner. The aim of this narrative review is to provide the basics for an algorithm approach to liver lesions on cross-sectional imaging. First, some tips for the optimization of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) protocols will be provided. Liver Imaging Reporting and Data System (LI-RADS, version 2018) working group is proposing the adoption of their standardized lexicon beyond the original target population of LI-RADS (i.e., liver cirrhosis). Thus, the main imaging findings will be defined following the LI-RADS lexicon. Since the contrast study is the most important for lesion characterization, this narrative review separates the lesions into avascular, hypovascular, and hypervascular, with a focus on chronic liver disease (CLD) and hepatocellular carcinoma (HCC).

Technological advances in body CT: a primer for beginners.

Many technological advances have entered the clinical routine of Computed Tomography (CT) imaging. The new CT scanners have specific solutions in gantry design to bear the mechanical solicitations. The X-ray tubes have been improved for faster acquisitions at low radiation exposure, while the innovations in CT detectors provide a better image quality. The optimization of image quality and contrast, and the reduction of radiation dose, cannot be achieved without the implementation of adequate reconstruction software, such as Iterative Reconstructions (IR) and Artificial Intelligence (AI). In recent years, dual-energy (DECT) technology has expanded the indications of CT. In this narrative review, a panoramic overview of the technological novelties in CT imaging will be provided for optimal utilization of CT technology.

Degenerative and inflammatory musculoskeletal disorders: updates and hot topics in diagnostic and interventional imaging.

OBJECTIVE: The purpose of this review is to present the latest innovations and current topics in musculoskeletal diagnosis and interventional imaging, with a focus on degenerative and inflammatory diseases. MATERIALS AND METHODS: In this study, the search was conducted through the online databases PubMed and Google Scholar, including articles published in English in the past 15 years, in order to find existing studies, clinical cases, and reviews on the latest innovations and current topics in degenerative and inflammatory musculoskeletal pathologies. RESULTS: Imaging plays a pivotal role in the diagnosis and treatment of MSK degenerative and inflammatory disease. In the last few years continuous innovations and technological advances have allowed new clinical applications in the management of MSK disorder. Advanced magnetic resonance techniques, the introduction of fusion imaging techniques and new approaches to infiltrative medicine are revolutionizing the clinical and therapeutic approach to degenerative and inflammatory pathologies. Artificial intelligence also increasingly seeks to be applied in all fields of medicine and radiology with increasingly promising results. CONCLUSIONS: Imaging modalities undergo continuous innovations and revolutions due to technological advances, with direct repercussions on clinical applications and new therapeutic potential through interventional radiology techniques. In recent years, there have been particular innovations in the context of musculoskeletal imaging of degenerative and inflammatory diseases, both for diagnosis and intervention.

Non-traumatic non-cardiovascular thoracic emergencies: role of imaging.

Patients presenting to the emergency with thoracic symptoms could have a wide variety of causes, even if the traumatic and vascular causes are excluded. Therefore, the diagnosis is often a challenge for emergency physicians. Anamnesis, physical examination and laboratory testing need to be integrated with imaging to get a rapid diagnosis and to distinguish among the potential causes. This review discusses the role of diagnostic imaging studies in the emergency setting in patients with non-traumatic non-cardiovascular thoracic symptoms. The use of chest x-ray, bedside lung Ultrasound and Computed Tomography in the diagnosis and care of these patients have been reviewed as well as the common findings on imaging.

Optimization of CT protocol in polytrauma patients: an update.

Radiologists play a key role in the management of trauma patients. With the improvement of computed tomography (CT), radiologist makes an important contribution to the timely diagnosis of trauma-related findings and the choice of the most suitable treatment, improving patient outcomes. It is important to select the most appropriate imaging technique, which in the trauma patient is CT, and especially the most appropriate CT protocol, to correctly characterize trauma injuries. Currently, there is no agreement on what the optimal protocol is, acquisition times and number of contrast enhanced phases are not standardized. This is a review of the most recent literature on optimizing the CT protocol in polytrauma, with the intent of giving a useful tool for radiologists in the management of trauma patients.

Diagnostic protocols in oncology: workup and treatment planning. Part 1: the optimitation of CT protocol.

The increase in oncology knowledge and the possibility of creating personalized medicine by selecting a more suitable therapy related to tumor subtypes, as well as the patient's management with cancer within a multidisciplinary team has improved the clinical outcomes. Early detection of cancer through screening-based imaging is probably the major contributor to a reduction in mortality for certain cancers. Nowadays, imaging can also characterize several lesions and predict their histopathological features and can predict tumor behaviour and prognosis. CT is the main diagnostic tool in oncologic imaging and is widely used for the tumors detection, staging, and follow-up. Moreover, since CT accounts for 49-66% of overall patient radiation exposure, the constant reduction, optimization, dose inter- and intraindividual consistency are major goals in radiological field. In the recent years, numerous dose reduction techniques have been established and created voltage modulation keeping a satisfactory image quality. The introduction of CT dual-layer detector technology enabled the acquisition of spectral data without additional CT x-ray tube or additional acquisitions. In addition, since MRI does not expose the body to radiation, it has become a mainstay of non-invasive diagnostic radiology modality since the 1980s.

Diagnostic protocols in oncology: workup and treatment planning. Part 2: Abbreviated MR protocol.

Magnetic resonance imaging (MRI) is a non-invasive imaging technique (non-ionizing radiation) with superior soft tissue contrasts and potential morphological and functional applications. However, long examination and interpretation times, as well as higher costs, still represent barriers to MRI use in clinical routine. Abbreviated MRI protocols have emerged as an alternative to standard MRI protocols. Abbreviated MRI protocols eliminate redundant sequences that negatively affect cost, acquisition time, patient comfort. However, the diagnostic information is generally not compromised. Abbreviated MRI protocols have already been utilized for hepatocellular carcinoma, for prostate cancer detection, and for nonalcoholic fatty liver disease screening.

Structured reporting of chest CT in COVID-19 pneumonia: a consensus proposal.

OBJECTIVES: The need of a standardized reporting scheme and language, in imaging of COVID-19 pneumonia, has been welcomed by major scientific societies. The aim of the study was to build the reporting scheme of chest CT in COVID-19 pneumonia. METHODS: A team of experts, of the Italian Society of Medical and Interventional Radiology (SIRM), has been recruited to compose a consensus panel. They used a modified Delphi process to build a reporting scheme and expressed a level of agreement for each section of the report. To measure the internal consistency of the panelist ratings for each section of the report, a quality analysis based on the average inter-item correlation was performed with Cronbach's alpha (Cα) correlation coefficient. RESULTS: The overall mean score of the experts and the sum of score were 3.1 (std.dev. ± 0.11) and 122 in the second round, and improved to 3.75 (std.dev. ± 0.40) and 154 in the third round. The Cronbach's alpha (Cα) correlation coefficient was 0.741 (acceptable) in the second round and improved to 0.789 in the third round. The final report was built in the management of radiology report template (MRRT) and includes n = 4 items in the procedure information, n = 5 items in the clinical information, n = 16 in the findings, and n = 3 in the impression, with overall 28 items. CONCLUSIONS: The proposed structured report could be of help both for expert radiologists and for the less experienced who are faced with the management of these patients. The structured report is conceived as a guideline, to recommend the key items/findings of chest CT in COVID-19 pneumonia.

A closer look to the new frontier of artificial intelligence in the percutaneous treatment of primary lesions of the liver.

The purpose of thermal ablation is induction of tumor death by means of localized hyperthermia resulting in irreversible cellular damage. Ablative therapies are well-recognized treatment modalities for HCC lesions and are considered standard of care for HCC nodules < 3 cm in diameter in patients not suitable for surgery. Effective lesion treatment rely on complete target volume ablation. Technical limitations are represented by large (> 3 cm) or multicentric nodules as well as complex nodule location and poor lesion conspicuity. Artificial Intelligence (AI) is a general term referred to computational algorithms that can analyze data and perform complex tasks otherwise prerogative of Human Intelligence. AI has a variety of application in percutaneous ablation procedures such as Navigational software, Fusion Imaging, and robot-assisted ablation tools. Those instruments represent relative innovations in the field of Interventional Oncology and promising strategies to overcome actual limitations of ablative therapy in order to increase feasibility and technical results. This work aims to review the principal application of Artificial Intelligence in the percutaneous ablation of primary lesions of the liver with special focus on how AI can impact in the treatment of HCC especially on potential advantages on the drawbacks of the conventional technique.

Pediatric musculoskeletal injuries: role of ultrasound and magnetic resonance imaging.

Pediatric musculoskeletal system is particularly prone to traumatic and sports-related injuries, both acute and chronic, i.e., overuse injuries, because of inherent conditions of weakness, such as the open physis, representing the weakest aspect within the bone, the ligamentous supports and changing biomechanics. Being aware that a quick diagnosis is essential to preserve the good functionality of the limb involved, it is mandatory for the radiologist to recognize the most common patterns of these injuries, identifying those requiring a prompt surgery, as well as be confident with the technique performed, and be supported by an important background experience and knowledge skills.

Neonatal adrenal masses: do we have reliable criteria for differential diagnosis and expectant management?

AIM: Differential diagnosis of neonatal adrenal masses (NAM) is often based on empirical criteria. Expectant management relies on spontaneous regression, described either for NB as for adrenal hemorrhage (AH). Histology was available for biopsied cases only. Aim of the study was to correlate clinical, laboratory and imaging data of a series of NAM, to final diagnosis. METHODS: Records of 23 NAM, diagnosed before or after birth, were reviewed, collecting data about: obstetrical history, clinical features, imaging, laboratory data, surgical findings, outcome. RESULTS: M/F ratio was 1.6/1. Size of the lesion ranged from 17 to 50 mm.. Doppler sonography (PD) showed no flow in 14/23. Urinary catecholamines (UCM) were elevated in 5/23. Reduction in a mean time of 3 months occurred in 14/23. MIBG and CT scans resulted positive in 8 and 9 cases among 16 NAM, unvaried or increased at one month. Three cases developed as IV S NB; diagnosis was confirmed by CT guided biopsy; regression occurred within 20 months. Surgery was decided for 6 unchanged/increasing NAM after 3-6 months; they were all NB. Predictive value for NB was high for MIBG and CT scan and was lower for high UCM level and positive PD findings. CONCLUSION: Clear criteria to differentiate AH from NB are still missing. Despite spontaneous regression is thought to indirectly confirm a non neoplastic lesion, benign evolution has also been documented for NB. As histology is available only in operated or biopsied cases, we still lack a reliable set of signs for early differentiation and to reduce repeated, invasive investigations.

Dual-source CT coronary angiography: prospective versus retrospective acquisition technique.

PURPOSE: The aim of our work was to compare image quality and radiation dose in a group of patients who underwent cardiac dual-source computed tomography (DSCT) with prospective electrocardiographic (ECG) gating with those of a control group studied with retrospective gating. MATERIALS AND METHODS: Sixty patients were randomly assigned to two groups of 30 individuals each. Patients with heart rates >70 bpm and body mass index (BMI) >30 kg/m(2) were excluded. Group A was examined with prospective ECG gating and group B with retrospective gating. The dose-length product (DLP) was recorded to calculate the radiation dose, whereas the effective dose was normalised to a standard 12-cm scan of the heart. RESULTS: Applying the best reconstruction interval, 98.6% of segments in the prospective group and 99.3% in the retrospective group were diagnostic. No significant difference (p>0.05) in image quality was observed between groups. Mean normalised radiation dose was 4.91 ± 0.4 mSv in the prospective-gating group and 14.62 mSv ± 4.36 in the retrospective-gating group (p<0.01). CONCLUSIONS: Coronary CT with prospective ECG gating, a standard feature on new scanners, allows for a significant reduction in radiation dose without causing any significant decrease in image quality or in the number of segments assessed. The prospective technique is thus recommended for patients with heart rates £70 bpm and BMI £30 kg/m(2).

Preliminary experience with abdominal dual-energy CT (DECT): true versus virtual nonenhanced images of the liver.

PURPOSE: The aim of this work was to compare the quality and noise of true non-enhanced (TNE) and virtual non-enhanced (VNE) images in patients undergoing dual-energy computed tomography (DECT) of the liver. MATERIALS AND METHODS: Twenty consecutive patients (mean age 54.7±19.9 years) prospectively underwent abdominal DECT to assess the liver using a triphasic protocol consisting of precontrast, arterial-phase and portal-phase acquisitions. Exclusion criteria were allergy to iodinated contrast material, impaired renal function and a body mass index (BMI) >35 kg/m(2). The DE portal-phase acquisition was performed with automatic dose modulation (CARE Dose 4D). Nonionic iodinated contrast material (Iomeron 400) was administered at 0.625 gI/kg with a flow rate of 3.5 ml/s. Axial VNE images were reconstructed based on the portal data set using a collimation and an increment of 5 mm and were compared with TNE images reconstructed with the same parameters. The average image quality and noise were analysed by two radiologists in separate reading sessions. RESULTS: No statistically significant difference (p>0.05) in image quality was observed between VNE (4.00±0.85) and TNE images (4.35±0.58). A sufficient diagnostic quality was found in 95.0% (19/20) of VNE images and in 100% of TNE images. No statistically significant difference (p<0.05) was observed in the average image noise of VNE (9.5±0.7) and TNE (12.3±1.1) images. CONCLUSIONS: Abdominal DECT allows acquisition of liver VNE images with similar image quality and lower noise than TNE. Nevertheless, a few technical limitations related to the small field of view of the second detector in patients with a high BMI and heterogeneous iodine subtraction restrict the application of this technique to selected patients only.

The risk of associated urological abnormalities in children with pre and postnatal occasional diagnosis of solitary, small or ectopic kidney: is a complete urological screening always necessary?

OBJECTIVE: Voiding cystourethrogram (VCUG) and radionuclide scan is recommended for patients with solitary (secondary to aplasia or multicystic dysplasia), hypoplasic or single ectopic kidney, to detect associated anomalies (vesicoureteric reflux, obstructive uropathies). With the increase of occasional diagnosis, mainly by fetal ultrasound (US), the possibility of an unjustified extension of diagnostic work up must be prevented. Aim of this paper was to estimate the incidence of associated anomalies in asymptomatic cases without associated US signs of hydronephrosis. MATERIALS AND METHODS: Among 158 Patients examined there were 81 solitary kidneys (26 multicystic dysplasia), 27 small kidneys, 50 single ectopic kidneys); prenatal diagnosis was recorded in 86%. Incidence of associated anomalies was compared with figures resulting when symptomatic cases or with hydronephrosis were excluded. RESULTS: Vesicoureteral reflux or obstruction were found in 17% of solitary kidneys, 70% of hypoplasic kidneys and 2% of single ectopic kidneys. Among those (120 cases) without infection or hydronephrosis, incidence decreased, respectively to 5, 60 and 0%. CONCLUSIONS: Associated anomalies are reported to affect up to 48% of solitary kidneys and about 30% of single ectopic; 80% of severe reflux are usually associated to small kidneys. In our series of solitary and ectopic kidneys incidence of abnormalities was significantly less and fell to negligible values when occasionally detected, undilated cases were considered. On this basis, indiscriminate urological screening simply based on the occasional pre or postnatal detection of undilated solitary or ectopic kidney appears to be unjustified. Small kidneys deserve special attention and VCUG is always indicated.

Second-generation sonographic contrast agents in the evaluation of renal trauma.

PURPOSE: The purpose of this study was to define the indications, diagnostic accuracy and limitations of second-generation sonographic contrast agents in the evaluation of patients with renal trauma. MATERIALS AND METHODS: Between March 2004 and April 2005, 277 patients with blunt abdominal trauma were evaluated. Twenty-eight out of 277 patients had renal lesions, the severity of which was graded according to the organ injury severity scale of the American Association for the Surgery of Trauma (AAST). All the patients enrolled in the study had minor trauma and were evaluated with baseline ultrasound (US), contrast-enhanced US after injection of a second-generation contrast agent (SonoVue) and, if positive, with multiphasic multidetector computed tomography (MDCT). RESULTS: Five out of 28 traumatic parenchymal lesions with perirenal fluid collection were identified at baseline US. All 28 renal parenchymal lesions, with or without perirenal or retroperitoneal haematoma, were identified at contrast-enhanced US. Multiphase MDCT confirmed all the cases that were positive at contrast-enhanced US and demonstrated the integrity of the urinary tract in the delayed phase. CONCLUSIONS: Our experience confirmed the diagnostic accuracy of second-generation sonographic contrast material both for diagnosis and for appropriate patient management. In particular, contrast-enhanced sonography proved to be a reliable technique for the evaluation and follow-up of low-grade renal injuries. Its main advantage is reduced radiation exposure, as fewer MDCT examinations are needed, whereas its limitation is the high cost of the technique if used in unselected patients.

[Natural history of prenatally diagnosed hydronephrosis: possible recurrence of dilatation after spontaneous reduction, in cases with pelvic diameter larger than 20 mms, recommends long term follow-up]. / Evoluzione naturale delle idronefrosi a diagnosi prenatale: rischio di ricomparsa, dopo riduzione spontanea, delle dilatazioni con DAP superiore a 20 mm ed indicazioni per un follow-up a lungo termine.

BACKGROUND: Long term follow-up of a prenatally diagnosed hydronephrosis usually extends no longer than the first two years of life. During this period spontaneous reduction occurs in most of the dilatations, not sustained by obstruction or reflux. Late recurrence of hydronephrosis is considered to be unusual. The aim of the present work has been to verify the risk of recurrent hydronephrosis long time after reduction and to identify factors associated to recurrence. MATERIALS AND METHODS: In a seven years period (1992-99) 276 patients with hydronephrosis unrelated to reflux, duplex kidney, megaureter or vesical obstruction have been observed. Among them, 231 were referred after prenatal diagnosis. Hydronephrosis of grade III or more was recorded in 73/231 with a pelvic diameter > or = 15 mms at ultrasonography (US) and a normal counter-lateral kidney. Surgical treatment was elected in 39 cases on the basis of a separate function < 40%, deterioration during follow-up, or occurrence of clinical symptoms. Thirthy four cases were treated conservatively and four were lost at follow. Among the remaining 30 cases, 14 had a pelvic diameter lager than 20 mms. They were followed for a mean of 16.6 months (range 7-26) and spontaneous significant reduction of pelvic dilatation was recorded in all of them. RESULTS: Patients were recalled after a mean of 32.1 months from the last US. In 3 cases among 14 with a pelvic diameter larger than 20 mms a recurrent severe hydronephrosis was found respectively at 39, 56, and 68 months. In two of them, isotopic scans documented a reduced separate function. The third case reported recurrent symtpoms. A pyeloplasty was performed in all cases. CONCLUSIONS: Spontaneous reduction in most of the prenatally detected cases of neonatal hydronephrosis within the first two months of life make follow-up beyond this term controversial, whenever complete disappearance of pelvic dilatation has been documented. The Authors report three cases with severe hydronephrosis (pelvic diameter > 20 mms) among a group of patients treated conservatively. Long time after spontaneous reduction, recurrent hydronephrosis was documented in all by US, associated to deterioration of separate function and symptoms. Long term follow-up is recommendable in severe cases of prenatally detected hydronephrosis cases, even after reduction, to warrant from recurrence and renal damage.

[Intramural esophageal bronchogenic cyst: an unusual cause of dysphagia in pediatric patients. Report of a case]. / Quiste broncogénico de la pared esofágica: un caso inusual de disfagia en un paciente pediátrico.

Bronchogenic cyst a bronchopulmonary foregut malformation. An intramural esophageal localization has rarely been reported in respect to more common esophageal duplications or leiomyoma. The authors describe a case of bronchogenic cyst of the esophageal wall in a 3 years old girl. It was an misdiagnosed cause of dysphagia and was revealed by endoscopy and CT scan after two uneffective antireflux procedures performed in different institutions, which caused a worsening of symptoms. Complete excision of the lesion through a thoractomic approach and a redo of the antireflux procedure were followed by complete recovery.

[Neonatal asymptomatic and childhood symptomatic hydronephrosis: Are they different nosological entities?]. / Hidronefrosis neonatal asintomática e infantil sintomática: dos entidades nosológicas diferentes?

The authors reviewed two groups of patients with ureteropelvic junction obstructión divided by age and mode of presentation: patients with neonatal asymptomatic hydronephrosis diagnosed by prenatal ultrasonography and patients with symptomatic hydronephrosis. It was assumed that in these patients we are observing a continuous spectrum of the same pathology; nevertheless, some relevant differences were found between the two groups. Diuretic renograms did not show any change in postoperative renal function among prenatally detected cases while a significative improvement followed surgery among most of symptomatic cases. A possible explanation could be found in the obstructive mechanism which was responsible of obstruction in a significative proportion of these patients. Lower polar vessels produce a progressive symptomatic hydronephrosis in an healthy kidney in respect to intrinsic obstruction which are mainly found among prenatally detected cases and which are frequently associated to congenital renal damage unresponsive to surgery.

Functional outcome after pyeloplasty in children: impact of the cause of obstruction and of the mode of presentation.

OBJECTIVE: To compare functional outcome after pyeloplasty in two groups of patients affected by hydronephrosis, which had different modalities of diagnosis. The first, asymptomatic, detected by prenatal ultrasonography and the second referred later because of clinical symptoms. PATIENTS AND METHODS: 84 patients (54 prenatally detected and 30 symptomatic) among 339 observed with hydronephrosis, operated in a single centre for ureteropelvic junction obstruction, have been retrospectively studied. Seventeen cases with prenatal diagnosis had an early treatment and thirty-seven were operated on after an initial observation. Symptomatic cases were all operated on at diagnosis. Ultrasonographic and renographic assessment were made at diagnosis, before and after surgery. RESULTS: Renal function of prenatally detected cases was not influenced by early or delayed surgery. Insignificant functional loss was recorded among some cases operated after conservative management. Improvement in differential renal function (p<0.05) was recorded in symptomatic patients after pyeloplasty. A high percentage of obstructions secondary to lower polar crossing vessel were found among symptomatic cases (12 out of 30). Intrinsic obstructions were predominant among cases with in utero diagnosis (48 out of 54). Whenever the cause of obstruction is considered, postoperative functional improvement was limited to crossing vessels cases. CONCLUSIONS: Renal function among antenatally diagnosed obstructions is scarcely influenced by surgery; potential risk of further renal damage cannot be excluded when expectant management is decided. Later detected, symptomatic cases show a better functional response to surgery. This seems corresponding to distinct clinical entities based on different causes of hydronephrosis. A reversible renal damage seems to be associated to extrinsic obstructions from polar vessel, which are predominant among symptomatic, later detected cases. A congenital, irreversible loss of function accompanies intrinsic obstructions, typical of prenatally diagnosed cases.

Epithelial splenic cysts in children: surgical treatment by cyst-wall "peeling".

Primary splenic cysts are a rare finding. Some are large and require surgical removal. The epidermoid type has an epidermal lining, and prevention of recurrence is dependent on complete resection of the cyst wall, preserving the splenic tissue. Several open, laparoscopic, or percutaneous procedures have been proposed with or without splenic resection, but few give completely satisfactory results. Five consecutive splenic epithelial cysts in pediatric patients were treated by parenchyma-sparing complete removal of the cyst wall, which was gently peeled off the splenic tissue without major bleeding in all but one case. Long-term follow-up showed freedom from recurrence.