Non-invasive diagnosis of liver fibrosis: A review of current imaging modalities.

Hundreds of millions of patients are suffering from cirrhosis and other chronic liver diseases worldwide, and this public health problem continues to grow. It has been proven that liver fibrosis is reversible after the elimination of the etiology, especially in the early stage. Thus, early diagnosis of liver fibrosis is of vital importance for clinical treatment. Liver biopsy remains the gold standard for both diagnosis and staging of fibrosis, but is suboptimal, due in large parts to its invasive nature and sundry associated complications. To overcome this, a number of non-invasive diagnosis based on serum biomarkers or imaging modalities have been developed. While diagnosis based on serum biomarkers is cheaper and more acceptable to patients, almost none developed to date are liver-specific, and may engender a false positive error. The imaging modalities have evolved rapidly and are taking on more and more important roles in the diagnosis of liver fibrosis.

Diagnosing pulmonary embolisms: the clinician's point of view. / Diagnóstico de la embolia pulmonar. El punto de vista del médico clínico.

Pulmonary thromboembolism is common and potentially severe. To ensure the correct approach to the diagnostic workup of pulmonary thromboembolism, it is essential to know the basic concepts governing the use of the different tests available. The diagnostic approach to pulmonary thromboembolism is an example of the application of the conditional probabilities of Bayes' theorem in daily practice. To interpret the available diagnostic tests correctly, it is necessary to analyze different concepts that are fundamental for decision making. Thus, it is necessary to know what the likelihood ratios, 95% confidence intervals, and decision thresholds mean. Whether to determine the D-dimer concentration or to do CT angiography or other imaging tests depends on their capacity to modify the pretest probability of having the disease to a posttest probability that is higher or lower than the thresholds for action. This review aims to clarify the diagnostic sequence of thromboembolic pulmonary disease, analyzing the main diagnostic tools (clinical examination, laboratory tests, and imaging tests), placing special emphasis on the principles that govern evidence-based medicine.

Radiological description of cystic pancreatic tumors. / Descripción radiológica de las neoplasias quísticas pancreáticas.

Although most cystic pancreatic lesions are pseudocysts, it is important to do a thorough differential diagnosis with true cystic tumors because cystic tumors are potentially malignant. Sometimes computed tomography and magnetic resonance imaging cannot establish the definitive diagnosis, making it necessary to perform other imaging tests such as endoscopic ultrasound, which in addition to morphological information, can also enable cytologic and biochemical analysis of the lesion through puncture and aspiration of its contents. Combining all these findings nearly always provides enough diagnostic information to allow the appropriate approach in each case. This article describes the specific morphological characteristics for each cystic pancreatic tumor on computed tomography, magnetic resonance imaging, and endoscopic ultrasound and reviews the guidelines for managing these types of lesions.

Nontraumatic head and neck emergencies: a clinical approach. Part 1: cervicofacial swelling, dysphagia, and dyspnea. / Urgencias no traumáticas de cabeza y cuello. Aproximación desde la clínica. Parte 1: tumefacción cervicofacial, disfagia y disnea.

Nontraumatic emergencies of the head and neck represent a challenge in the field of neuroradiology for two reasons: first, they affect an area where the thorax joins the cranial cavity and can thus compromise both structures; second, they are uncommon, so they are not well known. Various publications focus on nontraumatic emergencies of the head and neck from the viewpoints of anatomic location or of particular diseases. However, these are not the most helpful viewpoints for dealing with patients in the emergency department, who present with particular signs and symptoms. We propose an analysis starting from the four most common clinical presentations of patients who come to the emergency department for nontraumatic head and neck emergencies: cervical swelling, dysphagia, dyspnea, and loss of vision. Starting from these entities, we develop an approach to the radiologic management and diagnosis of these patients.

Supra- and infra-torcular double occipital encephalocele.

An encephalocele is a protrusion of the brain and/or meninges through a defect in the skull that is closed or covered with skin. Occipital encephaloceles are the most frequent type in North America and Western Europe, where about 85% of encephaloceles take this form. To the best of our knowledge, there are only three other reported cases of double occipital encephaloceles in the literature. The current study reports a double and both supra- and infra-torcular occipital encephalocele in a neonate and discusses the importance of preoperative neuroimaging studies to optimize the outcome. The patient was a 1-day-old male child who was identified by prenatal ultrasound to have two occipital encephaloceles. The patient underwent a closure of the occipital encephalocele on the second postnatal day. The infant tolerated the procedure well and was extubated on the first postoperative day. The child continues to do well during follow-up.

[Key aspects in interpreting clinical trials in radiology]. / El ensayo clínico en Radiología: claves para su interpretación.

A clinical trial is an experimental study to evaluate the efficacy and safety of a treatment or diagnostic technique in human beings. To ensure the methodological quality of a clinical trial and the validity of its results, various checklists have been elaborated to identify biases that could invalidate its conclusions. This article focuses on the points we need to consider in the critical evaluation of a clinical trial. We can usually find this information in the "materials and methods" and "results" sections of articles. Randomization, follow-up (or analysis of losses), blinding, and equivalence between groups (apart from the intervention itself) are some key aspects related to design. In the "results" section, we need to consider what measures of clinical efficacy were used (relative risk, odds ratio, or number needed to treat, among others) and the precision of the results (confidence intervals). Once we have confirmed that the clinical trial fulfills these criteria, we need to determine whether the results can be applied in our environment and whether the benefits obtained justify the risks and costs involved.

[Critical reading of articles about diagnostic tests (part II): Analyzing results]. / Lectura crítica de artículos de pruebas diagnósticas II: análisis de resultados.

A new diagnostic test needs to be validated through comparison with a reference standard in an appropriate spectrum of patients. Diagnostic tests are not perfectly accurate; on the contrary, there can be false-positive and false-negative findings. A good diagnostic test is that which provides an acceptable proportion of positive results when a determinate condition is present in patients and an acceptable proportion of negative results when it is absent. The best measure of the usefulness of a diagnostic test is the likelihood ratio, which informs us to what degree a particular result is more likely in a person in whom a condition is present than in a person in whom the condition is absent. The present article discusses the fundamental statistical concepts necessary to interpret the results section of an article about a diagnostic test; however, the approach is clearly oriented toward clinical practice, with emphasis on concepts rather than mathematics.

[Patterns of pulmonary vascularization on plain-film chest X-rays]. / Los patrones de vascularización pulmonar en la radiografía simple de tórax.

Plain chest films are a fundamental tool in the practice of medicine. The apparent simplicity of plain chest films sometimes leads us to forget that interpreting them correctly can provide very valuable information, especially if the interpretation is grounded in key clinical information. To interpret a plain chest film, it is important to pay attention to the pulmonary vascularization. This article reviews the normal shape and distribution of the pulmonary vessels on plain chest films and the most common pathologic vascular patterns, including those seen in pulmonary hypertension, hyperemia, hypovascularization, and alternative perfusion.

[The six steps necessary in elaborating critically appraised topics]. / Los 6 pasos necesarios para elaborar Critically Appraised Topics.

Different types of critically appraised topics (CATs) can be elaborated in diagnostic imaging: comparison of diagnostic tests, evaluation of techniques for early detection (screening), economical analyses, or therapeutic aspects, among others. Their design will vary in function of the question they aim to answer. For example, for treatment evaluation, clinical trials are the best, but if there are secondary studies (systematic reviews or meta-analyses) that synthesize information from several studies, the results will be more important and the scientific conclusions will be more relevant. Regardless of the study design used, the elaboration of a CAT will involve six steps: 1) question; 2) systematic and efficient bibliographic search; 3) levels of evidence (choosing the articles that have the best level); 4) critical reading of the articles chosen; 5) applying conclusions to the context, and 6) recommendations. In this article, we will describe these steps and the nuances for different types of studies in each step.

Update in imaging tests used for the localization of parathyroid pathology.

Preoperative localization of parathyroid pathology, generally a parathyroid adenoma, can be difficult in some cases due to the anatomical variants that these glands present. The objective of this review is to analyse the different imaging techniques used for preoperative localization of parathyroid pathology (scintigraphy, ultrasound, CT, MRI and PET). There is great variability between the different tests for the preoperative localization of parathyroid pathology. The importance of knowing the different diagnostic options lies in the need to choose the most suitable test at each moment and for each patient for an adequate management of primary hyperparathyroidism (PHP) with surgical criteria.

[Critically appraised topics (CATs): a new publishing opportunity in Radiología]. / Critically Appraised Topics: una nueva oportunidad de publicación en Radiología.

Physicians need fast access to quality information about the best diagnostic tests and treatments in each case. To meet this need, a new publishing format has emerged. Critically appraised topics (CATs) are elaborated following the five steps of evidence-based medicine. CATs are structured summaries of research articles that deal with a specific clinical query, presenting a critical evaluation of the best evidence available to support the validity of the available options. CATs have proven useful in teaching evidence-based radiology and this publishing format is becoming more common. Radiology CATs can be found on medical websites and in journals, including those dedicated to general medicine as well as those specifically dedicated to radiology. Radiología encourages the publication of CATs because we consider that they can be useful for daily decision making.

Esophageal tumors: The keys to diagnosis by pneumo-computed tomography.

OBJECTIVE: To review and describe the most characteristic radiological findings of the most frequent esophageal tumor lesions, with emphasis on the esophago-gastric distention technique pneumo-computed tomography performed in our institution. To know the main advantage of this distension technique. CONCLUSION: Malignant tumor lesions (predominantly squamous cell carcinoma in the mid esophagus and adenocarcinoma in the distal esophagus) present as asymmetric wall thickening, mucosal irregularity, or mass extending into adjacent organs with lymph node involvement. Benign tumors (mainly leiomyoma being the most frequent and others such as lipoma) present as endoluminal growth, with defined borders and homogeneous attenuation. Post-contrast enhancement is scarce or moderate. The technique of computed tomography pneumotomography technique achieves an additional distension of the esophageal lumen in all cases. It allows delimiting the superior and inferior borders of the lesions, helping the surgeon to define the therapeutic strategy.

Correlation between imaging findings and hormonal markers at the onset of puberty in girls.

INTRODUCTION: This study aimed to determine the diagnostic performance of transabdominal pelvic ultrasonography and bone age in identifying the onset of puberty in girls at the Clínica Las Américas in Medellín, Colombia. METHODS: We included girls aged ≤11 years referred to our clinic between March 2016 and March 2019 for signs of puberty. We compared the findings on pelvic and breast ultrasonography and bone age versus the baseline measurement of luteinizing hormone (LH) in serum, used as the reference standard for identifying the onset of puberty. We calculated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive and negative likelihood ratios, analyzing subgroups of patients of different ages. RESULTS: We analyzed 43 patients. Ultrasound assessment of breast development had the highest sensitivity (94.1%) of all the imaging parameters evaluated, but its specificity was low. However, characteristics such as the length of the body of the uterus >3.0 cm and the presence of endometrial echoes were highly specific for identifying the onset of puberty, particularly in patients aged ≤8 years. CONCLUSION: Pelvic ultrasonography, ultrasonographic assessment of Tanner stage of breast development, and the evaluation of bone age are useful tools for the imaging confirmation of the onset of puberty. The results of this study support the use of these techniques in clinical practice in the workup for pubertal disorders in girls.

Diagnostic accuracy of imaging compared to histology in congenital lung malformations.

INTRODUCTION: The aim of this study was to evaluate the accuracy of imaging tests (prenatal ultrasound [US] and postnatal computed tomography [CT]) in comparison to histology for diagnosis of congenital lung malformations (CLMs). MATERIAL AND METHODS: Retrospective study of patients with a prenatal diagnosis of CLM whose postnatal follow-up included thoracic CT scan and histological examination of the lesion. We collected data on demographic variables, gestational age at diagnosis, US findings and the history of multiple gestation. We used the kappa coefficient to determine the level of agreement between the findings of prenatal US and postnatal tests (CT and histology).We analysed paired data on the size of the lesion, its location and the presence or absence of systemic arterial vascularization. RESULTS: The sample included 56 patients with 57 lesions. The mean gestational age at diagnosis was 22.42 weeks (SD, 3.94) and 57% were male. Malformations most frequently involved the left lung and the lower lobes. The agreement between CT and histology in the detection of cystic lesions was moderate (κ = 0.55) but stronger compared to the agreement between US and histology (κ = 0.10). The agreement between CT and histology was substantial (κ = 0.66) in the detection of systemic vascularization of the lesion and stronger compared to the agreement between US and histology. Both imaging methods were highly accurate in the identification of the location of the pulmonary lesions. CONCLUSIONS: postnatal CT offers a substantial concordance with histological findings, especially in the detection of systemic vascularization, and an accurate prediction of the anatomy of the lesion.

Cardiac tomography-echocardiography imaging fusion: a new approach to congenital heart disease.

INTRODUCTION AND OBJECTIVES: Diagnosis, management, and surgical decision-making in children and adults with congenital heart disease are largely based on echocardiography findings. A recent development in cardiac imaging is fusion of different imaging modalities. Our objective was to evaluate the feasibility of computed tomography (CT) and 3-dimensional (3D) transthoracic echocardiography (TTE) fusion in children and adults with congenital heart disease. METHODS: We prospectively included 14 patients, 13 of whom had congenital heart disease, and who underwent both CT and 3D TTE as part of their usual follow-up. We described the steps required to complete the fusion process (alignment, landmarks, and superimposition), navigation, and image evaluation. RESULTS: Median age was 9.5 [2.7-15.7] years, 57% were male, and median body surface area was 0.9 m2 [0.6-1.7]. Congenital heart disease was classified as simple (n=4, 29%), moderate (n=4, 29%), or complex (n=6, 42%). 3D TTE-CT fusion was successful in all patients. Median total time to complete the fusion process was 735 [628-1163] seconds, with no significant difference according to the degree of complexity of the defects. Landmarks were significantly modified in complex congenital heart disease. CONCLUSIONS: We established the feasibility and accuracy of 3D TTE-CT fusion in a population of children and adults with a variety of congenital heart diseases. The simultaneous visualization of many intracardiac structures may help to understand the anatomical features of congenital heart disease without limitations regarding age, weight, or complexity of the congenital defects.

Bowel obstruction: signs indicating the need for urgent surgery.

Bowel obstruction is common in emergency departments. Obstruction is more common in the small bowel than in the large bowel. The most common cause is postsurgical adhesions. Nowadays, bowel obstruction is diagnosed with multidetector computed tomography (MDCT). MDCT studies for suspected bowel obstruction should focus on four points that need to be mentioned in the report: confirming the obstruction, determining whether there is a single transition point or whether the obstruction is found in a closed loop, establishing the cause of the obstruction, and seeking signs of complications. Identifying signs of ischemia is important in the management of the patient because it enables patients at higher risk of poor outcomes after conservation treatment who could benefit from early surgical intervention to avoid greater morbidity and mortality associated with strangulation and ischemia of the obstructed bowel loop.

Gastric adenocarcinoma: A review of the TNM classification system and ways of spreading.

Gastric cancer is the fifth most common cancer in the world. The most common histologic subtype is adenocarcinoma. Gastric adenocarcinomas are staged using the American Joint Committee on Cancer's 8th TNM classification. The perigastric ligaments, mesentery, omentum, and potential spaces between the parietal and visceral peritoneal linings play are important structures for staging. The spread of disease is influenced by the location of the tumor within the stomach, as well as by the anatomy related to the ligaments and lymph vessels. CT is the imaging modality of choice for the preoperative clinical staging of gastric cancer, and it is essential for planning treatment. To be able to do an adequate imaging workup, radiologists need to know the different pathways through which gastric cancer can spread: lymphatic, subperitoneal, direct invasion, transperitoneal, hematogenous, and extramural venous invasion.

Update on meningioma: Clinical-radiological and radio-pathological correlation.

Meningiomas are tumors that originate in the arachnoid villi and are the most common non-glial neoplasm in the central nervous system. The clinical manifestations associated with meningioma depend, fundamentally, on its location. The location in the cerebral convexity is the most frequent, especially in the frontal lobes, manifesting with headache, motor disturbances, seizures and even neurocognitive disorders. There are 15 histologic subtypes of meningioma and three histologic grades. Within these, grades two and three have a worse prognosis and a higher rate of recurrence, as well as a radiological behavior that is generally more aggressive. Although there are some imaging features that can suggest a specific subtype, the definitive diagnosis will always require histological/molecular confirmation.

Chest calcifications beyond the lung parenchyma-A review.

OBJECTIVE: Thoracic calcifications are frequently found in chest radiographs and CTs, occurring in a wide variety of disorders. Although most calcifications are harmless sequelae of previous disease, they provide important information to establish the diagnosis. This article reviews the different types of calcified lesions found in the chest, focusing on lesions outside the lung parenchyma. A location-based approach to the differential diagnosis is used, while providing the reader with diagnostic pearls and discussing the clinical importance of the different types of calcifications. CONCLUSION: Chest calcifications are a common finding in routine chest imaging. Understanding the different etiologies and radiologic manifestations provide the radiologist with the necessary tools to elaborate a differential diagnosis, as well as to correctly differentiate the findings that need further work-up from the ones that can be dismissed.

Urgent and unexpected findings in oncology and hematology patients: A practical approach to imaging.

Urgent and unexpected findings are very common in oncology and haematology patients. This article reviews the most important points included in the European Society of Radiology's guidelines and proposes a practical approach to reporting and communicating these findings more efficiently. This approach is explained with illustrative examples. Radiologists can provide added value in the management of these findings by helping referring clinicians reach the best decisions. To this end, it is essential to know the imaging manifestations of the most common findings that must be reported urgently, such as the specific toxicity of different treatments, the complications of tumours and catheters, infections, and thrombosis. Moreover, it is crucial to consider the individual patient's treatment, risk factors, clinical situation, and immune status.