Congenital Anomalies of the Upper Urinary Tract: A Comprehensive Review.

The upper urinary tract is the most common human system affected by congenital anomalies. Congenital anomalies of the kidneys and ureters comprise a wide spectrum of disorders ranging from simple variants with no clinical significance to complex anomalies that may lead to severe complications and end-stage renal disease. They may be classified as anomalies of renal form, which are subclassified as structural anomalies (eg, persistent fetal lobulation, hypertrophied column of Bertin, and dromedary hump) and fusion anomalies (eg, horseshoe kidney and pancake kidney); anomalies of renal position (eg, renal malrotation, simple renal ectopia, and crossed renal ectopia) and renal number (eg, renal agenesis and supernumerary kidney); and abnormalities in development of the urinary collecting system (eg, pyelocaliceal diverticulum, megacalycosis, ureteropelvic junction obstruction, duplex collecting system, megaureter, ectopic ureter, and ureterocele). US is usually the first imaging modality used because of its low cost, wide availability, and absence of ionizing radiation. Intravenous urography and voiding cystourethrography are also useful, mainly for characterization of the collecting system and vesicoureteral reflux. However, intravenous urography has been replaced by CT urography and MR urography. These imaging methods not only allow direct visualization of the collecting system but also demonstrate the function of the kidneys, the vascular anatomy, adjacent structures, and complications. Comprehension of congenital anomalies of the upper urinary tract is crucial for an accurate diagnosis and correct management. The authors discuss the spectrum of these anomalies, with emphasis on embryologic development, imaging findings, clinical manifestations, and complications. Online supplemental material is available for this article. ©RSNA, 2021.

Emergency CT for assessment and management of blunt traumatic splenic injuries at a Level 1 Trauma Center: 13-year study.

PURPOSE: To determine the relationship between multidetector computed tomography (MDCT) findings, management strategies, and ultimate clinical outcomes in patients with splenic injuries secondary to blunt trauma. MATERIALS AND METHODS: This Institutional Review Board-approved study collected 351 consecutive patients admitted at the Emergency Department (ED) of a Level I Trauma Center with blunt splenic trauma between October 2002 and November 2015. Their MDCT studies were retrospectively and independently reviewed by two radiologists to grade splenic injuries according to the American Association for the Surgery of Trauma (AAST) organ injury scale (OIS) and to detect intraparenchymal (type A) or extraparenchymal (type B) active bleeding and/or contained vascular injuries (CVI). Clinical data, information on management, and outcome were retrieved from the hospital database. Statistical analysis relied on Student's t, chi-squared, and Cohen's kappa tests. RESULTS: Emergency multiphase MDCT was obtained in 263 hemodynamically stable patients. Interobserver agreement for both AAST grading of injuries and vascular lesions was excellent (k = 0.77). Operative management (OM) was performed in 160 patients (45.58% of the whole cohort), and high-grade (IV and V) OIS injuries and type B bleeding were statistically significant (p < 0.05) predictors of OM. Nonoperative management (NOM) failed in 23 patients out of 191 (12.04%). In 75% of them, NOM failure occurred within 30 h from the trauma event, without significant increase of mortality. Both intraparenchymal and extraparenchymal active bleeding were predictive of NOM failure (p < 0.05). CONCLUSION: Providing detection and characterization of parenchymal and vascular traumatic lesions, MDCT plays a crucial role for safe and appropriate guidance of ED management of splenic traumas and contributes to the shift toward NOM in hemodynamically stable patients.

Enhancement of abdominal structures on MRI at 1.5 and 3 T: a retrospective intraindividual crossover comparison.

OBJECTIVE: To quantitatively compare the extent of enhancement of abdominal structures on MRI in an intraindividual fashion at 1.5 and 3 T. METHODS: HIPAA-compliant, retrospective, longitudinal, intraindividual, crossover study, with waived informed consent, of consecutive individuals scanned at both 1.5 and 3 T closed-bore magnets using gadobenate dimeglumine during different phases of enhancement at tightly controlled arterial phase timing. Quantitative ROI measurements and qualitative sub-phase arterial phase assignments were independently performed by two radiologists. Qualitative discrepancies were resolved by a senior radiologist. RESULTS: Final population included 60 patients [41 female and 19 male; age, 49.35 ± 18.31 years (range 16-81); weight, 78.88 ± 20.3 kg (range 44.5-136)]. Similar enhancement peak patterns were noted at both field strengths. Interobserver agreement of quantitative evaluations was substantial. Significantly higher amplitudes of enhancement peaks were noted for all abdominal solid organs during all phases at 3 T, except for the pancreas (p = 0.17-0.30). Significantly higher amplitudes of enhancement peaks of the abdominal aorta at 1.5 T were noted. CONCLUSION: Similar peak patterns of enhancement for abdominal structures were observed at 1.5 and 3 T, with solid abdominal organs showing a higher percentage enhancement at 3 T, while unexpectedly higher aortic higher percentage enhancement was observed at 1.5 T. KEY POINTS: • Similar enhancement peak patterns at both field strengths for studied abdominal structures. • Significantly higher percentage enhancement of most abdominal organs at 3 T. • Non-statistically significant trend of higher pancreatic percentage enhancement at 3 T. • Significantly lower abdominal aortic percentage enhancement at 3 T.

Bone Metastases of Hepatocellular Carcinoma: Appearance on MRI Using a Standard Abdominal Protocol.

OBJECTIVE: The purpose of this study is to describe the MRI features of hepatocellular carcinoma (HCC) bone metastases. MATERIALS AND METHODS: Thirty-three consecutive patients were included. Two radiologists performed qualitative and quantitative analysis. The coordinator searched for clinical and epidemiologic features related to patients and their primary liver tumors. Earlier MRI studies were also reviewed to determine whether bone metastases were already present and prospectively identified. Descriptive statistics and the Lin concordance correlation coefficient were used. RESULTS: Chronic hepatitis C virus infection was the most common cause of liver disease (20/32; 62.5%), and diffuse and multifocal HCC were the most frequent types of liver HCCs (28/33; 84.8%). Most lesions were located at the spine (109/155; 70.3%), with high signal intensity on fat-suppressed T1-weighted (54/62; 87.1%) and T2-weighted (53/62; 85.5%) images. Bone metastases were predominantly nodular (48/62; 77.4%), confined to the vertebral body (40/60; 66.7%), and best visualized at the arterial phase (40/62; 64.5%). The ring pattern of enhancement was present in 23 of 62 lesions, and the remaining lesions showed diffuse enhancement. Thirty-five of 62 (56.4%) bone metastases showed arterial peak of enhancement. In 13 of 33 (39.9%) patients, bone metastases were not prospectively reported. CONCLUSION: Most patients with bone metastases had chronic hepatitis C virus infection and diffuse or multifocal HCC. Metastases are most commonly appreciated as hypervascular focal moderately intensely enhancing nodular masses on the hepatic arterial dominant phase images, with concomitant moderately high signal intensity on fat-suppressed T1- and T2-weighted images.

A comprehensive exploration of gallbladder health: from common to rare imaging findings.

This comprehensive review explores a wide range of imaging findings associated with the gallbladder (GB), from anatomic variants to rare diseases. Through an in-depth review of diagnostic modalities including ultrasound, magnetic resonance cholangiopancreatography, CT, and MRI, we aim to highlight the crucial role of imaging techniques in diagnosing GB disorders, as congenital anomalies, inflammatory diseases, neoplasms, and surgical complications. Employing a detailed analysis and comparison of imaging findings across various modalities, this review seeks to improve diagnostic accuracy for GB-related pathologies, facilitating optimal patient management.

Diffuse and focal liver fat: advanced imaging techniques and diagnostic insights.

The fatty liver disease represents a complex, multifaceted challenge, requiring a multidisciplinary approach for effective management and research. This article uses conventional and advanced imaging techniques to explore the etiology, imaging patterns, and quantification methods of hepatic steatosis. Particular emphasis is placed on the challenges and advancements in the imaging diagnostics of fatty liver disease. Techniques such as ultrasound, CT, MRI, and elastography are indispensable for providing deep insights into the liver's fat content. These modalities not only distinguish between diffuse and focal steatosis but also help identify accompanying conditions, such as inflammation and fibrosis, which are critical for accurate diagnosis and management.

Practical Guide for Radiological Diagnosis of Primary and Secondary Sclerosing Cholangitis.

Sclerosing cholangitis comprises a group of conditions that lead to chronic cholestatic disease of the bile ducts, characterized by inflammation, fibrosis, and segmental strictures of the intrahepatic and/or extrahepatic ducts, and can be classified as primary sclerosing cholangitis or secondary sclerosing cholangitis. In this review, we follow a logical step-by-step appraisal of the clinical and radiological findings of the main secondary sclerosing cholangitis groups, finally arriving at the exclusion diagnosis, which is primary sclerosing cholangitis. At the end, a practical guide is provided, aiming to facilitate the radiological approach to this complex group of diseases.

Evaluating inflammatory activity in Crohn's disease by cross-sectional imaging techniques.

The evaluation of inflammatory bowel activity in patients with Crohn's disease has traditionally been a challenge, mainly because of the difficulty in gaining endoscopic access to the small bowel. Historically, barium-based contrast studies were the only option for the evaluation of inflammatory activity in Crohn's disease. They were gradually replaced by cross-sectional imaging techniques, computed tomography enterography (CTE) and magnetic resonance enterography (MRE) now being the modalities of choice for such evaluations. Those two imaging methods have provided important information regarding intestinal wall involvement and extra-intestinal manifestations of Crohn's disease, not only assessing lesion characteristics and complications but also quantifying inflammatory bowel activity. The objective of this article is to review the main technical aspects of CTE and MRE, together with their indications, contraindications, and limitations, as well as the CTE and MRE imaging characteristics of inflammatory activity in Crohn's disease.

Hepatic neuroendocrine neoplasm: imaging patterns.

Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors with distinct morphological and biological manifestations, the liver being the main organ affected by its metastases. However, primary hepatic involvement is quite rare. Hepatic NENs can have a variety of radiological presentation forms and can therefore mimic other lesions, making their diagnosis challenging. Nonetheless, certain imaging aspects allow NENs to be included among the main differential diagnoses of hepatic lesions and can guide the search for an extrahepatic primary site when the probable diagnosis is metastases.

As neoplasias neuroendócrinas (NNEs) são um grupo heterogêneo de tumores com manifestações morfológicas e biológicas distintas, sendo o fígado o principal órgão acometido por suas metástases. Por outro lado, o acometimento primário deste órgão é muito raro. Podem-se observar as mais diversas formas de apresentação radiológica das NNEs hepáticas primária e secundária e, em razão dessa variedade e por mimetizar outras lesões, o seu diagnóstico pode se revelar um desafio. No entanto, alguns desses aspectos permitem incluir as NNEs entre os principais diagnósticos diferenciais de lesões hepáticas e, nos casos de metástases, orientar na busca de um eventual sítio primário extra-hepático.

Non-neoplastic cholangiopathies: an algorithmic approach.

Cholangiopathies are chronic diseases that affect the bile ducts, comprising a heterogeneous group of progressive and potentially fatal entities. The diagnosis of these diseases is a great challenge for radiologists because of the overlapping of their clinical, biochemical, and imaging findings. Nevertheless, identifying the precise etiology is crucial, given that the therapeutic options are distinct and influence the prognosis of the patient. The purpose of this review article is to discuss some of the non-neoplastic causes of cholangiopathies and to provide a useful diagnostic algorithm.

As colangiopatias são doenças crônicas que afetam as vias biliares, constituindo um grupo heterogêneo de doenças progressivas e potencialmente fatais. O seu diagnóstico configura um grande desafio para os radiologistas, uma vez que seus aspectos clínicos, laboratoriais e de imagem se sobrepõem. Apesar disso, a busca etiológica é crucial, tendo em vista que as opções terapêuticas são distintas e influenciam o prognóstico do paciente. O objetivo deste artigo de revisão é discutir algumas das causas não neoplásicas de colangiopatias e fornecer um algoritmo útil na abordagem diagnóstica.

Unenhanced magnetic resonance angiography as an accurate alternative in the preoperative assessment of potential living kidney donors with contraindications to computed tomography angiography and to contrast-enhanced magnetic resonance angiography.

OBJECTIVE: To evaluate the accuracy of steady-state free precession (SSFP) unenhanced magnetic resonance angiography (MRA) at 1.5 T for the identification of multiple renal arteries, using computed tomography angiography (CTA) as the reference standard. MATERIALS AND METHODS: This was a prospective study involving 39 patients (26 males; mean age, 62.6 years) who underwent CTA and unenhanced MRA to evaluate the proximal and middle segments of the renal arteries. The analysis was performed in two phases: the quality of unenhanced MRA images was classified as diagnostic or nondiagnostic for the presence of multiple renal arteries by two independent readers; two other independent readers then evaluated the images previously classified as being of diagnostic quality. The sensitivity, specificity, and overall accuracy of unenhanced MRA were calculated, CTA being used as the reference standard. The kappa statistic was used in order to calculate interobserver agreement. RESULTS: The image quality of unenhanced MRA was considered diagnostic in 70-90% of the extrarenal arterial segments. The CTA examination revealed 19 multiple renal arteries (8 on the right and 11 on the left). The accuracy of unenhanced MRA for the identification of multiple renal arteries was greater than 90%, with a sensitivity of 72.7-100% and a specificity of 96.3-100%. CONCLUSION: Unenhanced MRA provides high quality imaging of the extrarenal segments of renal arteries. This method may be used as an alternative for the evaluation of the renal arteries, given that it has an accuracy comparable to that of CTA.

OBJETIVO: Avaliar, prospectivamente, a acurácia da angiografia por ressonância magnética (angio-RM) sem contraste, com a sequência steady-state free precession (SSFP) 1,5 T, para a identificação de artérias renais múltiplas, usando para isso a angiografia por tomografia computadorizada (angio-TC) como padrão de referência. MATERIAIS E MÉTODOS: Trinta e nove pacientes (26 do sexo masculino; idade média de 62,6 anos) foram submetidos a angio-TC e angio-RM para avaliação dos segmentos proximais e médios das artérias renais. A análise dividiu-se em duas partes: inicialmente, a qualidade das imagens de angio-RM foi classificada como diagnóstica ou não diagnóstica por dois avaliadores independentes; posteriormente, outros dois avaliadores analisaram as imagens consideradas diagnósticas quanto à presença de múltiplas artérias renais. Sensibilidade, especificidade e acurácia da angio-RM foram calculadas utilizando-se a angio-TC como referência. Estatística kappa foi utilizada para cálculo da concordância interobservador. RESULTADOS: A qualidade das imagens de angio-RM foi considerada diagnóstica em 70-90% dos segmentos arteriais extrarrenais. A angio-TC revelou 19 artérias renais múltiplas (8 direitas e 11 esquerdas). A acurácia da angio-RM para identificação de artérias renais múltiplas foi maior que 90%, com sensibilidade variando de 72,7% a 100% e especificidade variando de 96,3% a 100%. CONCLUSÃO: A angio-RM sem contraste proporciona imagens de alta qualidade dos segmentos extrarrenais das artérias renais. Este método pode ser alternativamente utilizado para avaliação renal, com acurácia comparável à da angio-TC.

The many faces of primary and secondary hepatic lymphoma: imaging manifestations and diagnostic approach.

Hepatic lymphoma can be divided into its primary and secondary forms. To be classified as primary hepatic lymphoma, the disease should be limited to the liver and hilar lymph nodes, with no distant involvement (to the bone marrow or other sites). Primary hepatic lymphoma is quite rare, accounting for less than 1% of all cases of non-Hodgkin lymphoma, whereas secondary hepatic lymphoma affects nearly half of such cases. Familiarity with the imaging features of hepatic lymphoma is important for its early diagnosis and appropriate management. In this essay, we aim to review the roles of computed tomography and magnetic resonance imaging in identifying and monitoring hepatic lymphomas, using sample cases to describe and illustrate the wide spectrum of imaging findings in the primary and secondary forms of this disorder.

O linfoma hepático pode ser dividido em primário e secundário. Para ser classificada como linfoma hepático primário, a doença deve estar limitada ao fígado e linfonodos hilares, sem acometimento de outros órgãos (incluindo a medula óssea). O linfoma hepático primário é muito raro, correspondendo a menos de 1% de todos os linfomas não Hodgkin. Já o envolvimento secundário do fígado ocorre em quase metade dos casos de linfoma não Hodgkin. O conhecimento dos aspectos de imagem do linfoma hepático é importante para o diagnóstico precoce e manejo adequado do paciente. Com base em imagens de casos, nosso objetivo é revisar o papel da imagem por tomografia computadorizada e ressonância magnética na identificação e segmento do linfoma hepático, ilustrando e descrevendo o amplo espectro de achados de imagem observados nas formas primária e secundária da doença.

The role of gadoxetic acid-enhanced magnetic resonance cholangiography in the evaluation of postoperative bile duct injury: pictorial essay.

Iatrogenic lesion of the bile ducts is a relatively common occurrence during liver surgery, increasing morbidity and mortality rates. T2-weighted magnetic resonance cholangiography and gadoxetic acid-enhanced functional magnetic resonance cholangiography (fMRC) with administration of hepatobiliary-specific contrast medium (gadoxetic acid) are fundamental to the diagnostic imaging approach in patients with such lesions. Here, we present a review of the literature and suggest an imaging approach to biliary tract injury, focusing on clinical cases in which fMRC had an impact on the decision-making process for the management of the affected patients.

The Mesenteric Organ: New Anatomical Concepts and an Imaging-based Review on Its Diseases.

The proposal of reclassifying the mesentery as an organ prompts clinicians and radiologists to reappraise their approach to it and to mesenteric diseases (mesenteropathies). Recent updates in mesenteric anatomy and the better comprehension of its structure constitute a basis to push forward the process of disease management and allow the development of less radical (including endoscopic, radiological, and pharmacotherapeutic) treatments. Radiological evaluation currently plays a pivotal role in the noninvasive characterization of abdominal diseases. Mesenteric-based radiological assessments form an essential component in planning radiological interventions and postoperative surveillance programs. The purpose of this article, therefore, is to provide an update on the new anatomical concepts related to the mesentery, also performing an imaging-based review of mesenteric diseases by categorizing them as primary and secondary.

Magnetic resonance imaging of the cirrhotic liver: diagnosis of hepatocellular carcinoma and evaluation of response to treatment - Part 1.

Magnetic resonance imaging (MRI) is the modern gold standard for the noninvasive evaluation of the cirrhotic liver. The combination of arterial phase hyperenhancement and delayed wash-out allows a definitive diagnosis of hepatocellular carcinoma (HCC) in patients with liver cirrhosis or chronic liver disease, without the requirement for confirmatory biopsy. That pattern is highly specific and has been endorsed in Western and Asian diagnostic guidelines. However, the sensitivity of the combination is relatively low for small HCCs. In this two-part review paper, we will address MRI of the cirrhotic liver. In this first part, we provide a brief background on liver cirrhosis and HCC, followed by descriptions of imaging surveillance of liver cirrhosis and the diagnostic performance of the different imaging modalities used in clinical settings. We then describe some of the requirements for the basic MRI technique, as well as the standard MRI protocol, and provide a detailed description of the appearance of various types of hepatocellular nodules encountered in the setting of the carcinogenic pathway in the cirrhotic liver, ranging from regenerative nodules to HCC.

A ressonância magnética (RM) é o método padrão para a avaliação não invasiva do fígado cirrótico. A combinação de hiper-realce arterial e wash-out tardio permite um diagnóstico definitivo de carcinoma hepatocelular (CHC) em pacientes com cirrose hepática ou doença hepática crônica, sem a necessidade de biópsia confirmatória. Este padrão é altamente específico e tem sido utilizado por guidelines de diagnóstico ocidentais e asiáticas. No entanto, a sensibilidade desta combinação é relativamente baixa para CHCs pequenos. Neste artigo de revisão de duas partes, irá ser efetuada uma revisão do papel da RM na avaliação do fígado cirrótico. Na primeira parte, faremos uma breve revisão sobre cirrose hepática e CHC, seguido da vigilância da cirrose hepática por imagem e desempenho diagnóstico das diferentes modalidades de imagem utilizadas na prática clínica. Depois, descreveremos alguns dos requisitos técnicos básicos para RM, protocolos de RM e uma descrição detalhada do aparecimento dos diferentes nódulos hepatocelulares encontrados no contexto da via carcinogênica do fígado cirrótico, desde nódulos regenerativos a CHC.

Magnetic resonance imaging of the cirrhotic liver: diagnosis of hepatocellular carcinoma and evaluation of response to treatment - Part 2.

In the second part of this review, we will describe the ancillary imaging features of hepatocellular carcinoma (HCC) that can be seen on standard magnetic resonance imaging (MRI) protocol, and on novel and emerging protocols such as diffusion weighted imaging and utilization of hepatocyte-specific/hepatobiliary contrast agent. We will also describe the morphologic sub-types of HCC, and give a simplified non-invasive diagnostic algorithm for HCC, followed by a brief description of the liver imaging reporting and data system (LI-RADS), and MRI assessment of tumor response following locoregional therapy.

Na segunda parte desta revisão descreveremos os achados de imagem auxiliares para o diagnóstico de carcinoma hepatocelular (CHC) e que podem ser observados num protocolo de ressonância magnética (RM) padrão e em protocolos emergentes que incluem imagens de difusão e aplicação de contrastes hepatoespecíficos/hepatobiliares. Descreveremos também os subtipos morfológicos de CHC e um algoritmo diagnóstico não invasivo simplificado para o CHC, seguido de uma breve descrição do liver imaging reporting and data system (LI-RADS) e avaliação por RM após terapêutica locorregional.

Abdominal vascular syndromes: characteristic imaging findings.

Abdominal vascular syndromes are rare diseases. Although such syndromes vary widely in terms of symptoms and etiologies, certain imaging findings are characteristic. Depending on their etiology, they can be categorized as congenital-including blue rubber bleb nevus syndrome, Klippel-Trenaunay syndrome, and hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome)-or compressive-including "nutcracker" syndrome, median arcuate ligament syndrome, Cockett syndrome (also known as May-Thurner syndrome), and superior mesenteric artery syndrome. In this article, we aimed to illustrate imaging findings that are characteristic of these syndromes, through studies conducted at our institution, as well as to perform a brief review of the literature on this topic.

As síndromes vasculares abdominais englobam doenças raras, com sintomas e causas diversas, mas com achados de imagem característicos. Dividem-se em dois grupos distintos, a depender de sua origem, que pode ser congênita (síndrome de blue rubber bleb nevus, síndrome de Klippel-Trenaunay e telangiectasia hereditária hemorrágica/Rendu-Osler-Weber) ou compressiva (síndrome do "quebra-nozes", síndrome do ligamento arqueado, síndrome de Cockett ou May-Thurner e síndrome da artéria mesentérica superior). Neste artigo, o nosso objetivo é ilustrar achados de imagens determinantes dessas doenças, por meio de estudos adquiridos em nossa instituição, associando uma breve revisão da literatura.