Anatomy and Imaging of Accessory Liver Lobes: What Radiologists Should Know.

Although the liver may present a range of congenital anomalies, often involving shape irregularities or the number of lobules, less common variations include the presence of accessory liver lobes (ALL), consisting of a supernumerary lobe of normal hepatic parenchyma in continuity with the liver. This paper reviews the embryology, frequency, anatomy, and types of ALL. Furthermore, we describe computed tomography and magnetic resonance imaging findings in a range of such cases, including those simulating disease or presenting with complications. Knowledge about ALL may facilitate imaging interpretation of such alterations, avoiding inappropriate additional work-up and unnecessary interventions.

Vaginal cancer: Why should we care? Anatomy, staging and in-depth imaging-based review of vaginal malignancies focusing on MRI and PET/CT.

Vaginal cancer often poses a challenge for clinical and radiological diagnosis, and its risk factors, progression, and treatment are still poorly established. Although vaginal malignancies are rare, even globally, their rates have increased due to the increased access to healthcare and the evolution of screening measures and diagnostic methods. Because the vaginal cavity is a virtual space, it can harbor lesions that often go unnoticed and, not infrequently, diagnosed belatedly. MRI and, more recently, PET/CT are part of the imaging armamentarium that have already been incorporated into the clinical staging and management of gynecological tumors, allowing excellent morphological characterization of the lesion, its topography and relationship with adjacent structures for the investigation of disease dissemination, overcoming limitations of clinical methods, such as speculum examination, usually restricted to observation only of the superficial characteristics of these lesions. Some vaginal neoplasms have characteristic MRI patterns, which, combined with expert knowledge of anatomy, allow identification of local macroscopic details (such as the mucosal, submucosal, and muscle layers). Furthermore, the application of PET/CT, already well established for identifying systemic disease, has a large impact on patient prognosis. The objective of this work is to review the epidemiological aspects of primary vaginal cancers and the imaging patterns of their main histological subtypes based on MRI and PET/CT, with a brief discussion of the local anatomy, oncological staging, and treatment.

The "streamline phenomenon" of the portal vein flow and its influence on liver involvement by gastrointestinal diseases: current concepts and imaging-based review.

The streamline flow in the portal system is a phenomenon by which blood from superior mesenteric vein goes preferentially to the right hepatic lobe, while splenic and inferior mesenteric veins divert preferentially to the left lobe. Such a phenomenon results in different patterns of distribution of several liver diseases. The purpose of this article is to discuss the concepts behind the theory of streamline flow and to perform an imaging-based review of representative cases, demonstrating how it may influence the patterns of liver involvement in different gastrointestinal diseases.

Is liver perfusion CT reproducible? A study on intra- and interobserver agreement of normal hepatic haemodynamic parameters obtained with two different software packages.

OBJECTIVE: To evaluate the agreement between the measurements of perfusion CT parameters in normal livers by using two different software packages. METHODS: This retrospective study was based on 78 liver perfusion CT examinations acquired for detecting suspected liver metastasis. Patients with any morphological or functional hepatic abnormalities were excluded. The final analysis included 37 patients (59.7 ± 14.9 y). Two readers (1 and 2) independently measured perfusion parameters using different software packages from two major manufacturers (A and B). Arterial perfusion (AP) and portal perfusion (PP) were determined using the dual-input vascular one-compartmental model. Inter-reader agreement for each package and intrareader agreement between both packages were assessed with intraclass correlation coefficients (ICC) and Bland-Altman statistics. RESULTS: Inter-reader agreement was substantial for AP using software A (ICC = 0.82) and B (ICC = 0.85-0.86), fair for PP using software A (ICC = 0.44) and fair to moderate for PP using software B (ICC = 0.56-0.77). Intrareader agreement between software A and B ranged from slight to moderate (ICC = 0.32-0.62) for readers 1 and 2 considering the AP parameters, and from fair to moderate (ICC = 0.40-0.69) for readers 1 and 2 considering the PP parameters. CONCLUSION: At best there was only moderate agreement between both software packages, resulting in some uncertainty and suboptimal reproducibility. Advances in knowledge: Software-dependent factors may contribute to variance in perfusion measurements, demanding further technical improvements. AP measurements seem to be the most reproducible parameter to be adopted when evaluating liver perfusion CT.

Tomografia por emissão de pósitron no câncer colorretal: [revisão] / Positron emission tomography in colorectal cancer: [review]

Após introdução sobre as bases físicas e biológicas da tomografia por emissão de pósitron, este artigo revisa a situação atual da geração de imagens por tomografia por emissão de pósitron/tomografiacomputadorizada (PET/CT), utilizando o análogo da glicose FDG, no câncer colorretal. Analisa-se a utilização da PET-FDG quanto à detecção, ao estadiamento inicial ao monitoramento da terapêutica e ao estadiamento de recidivas da neoplasia.

After an introduction on the physical and biological basics of positron emission tomography, this paper reviews the current status of PET imaging using the glucose analogue FDG in colorectal cancer. The use of PET-FDG is reviewed for detection, initial staging, therapy monitoring and staging of disease relapse.

Intussuscepção intestinal secundária a tumor do estroma gatrointestinal (GIST) / Intussusception due to a gastrointestinal stromal tumor (GIST)

O presente artigo relata o caso de um paciente idoso com sinais e sintomas de obstrução intestinal. Após realização de exames de imagem e intervenção cirúrgica, o diagnóstico final foi compatível com intussuscepção intestinal decorrente de tumor estromal gastrintestinal. O presente artigo relata o caso de um paciente idoso com sinais e sintomas de obstrução intestinal. Após realização de exames de imagem e intervenção cirúrgica, o diagnóstico final foi compatível com intussuscepção intestinal decorrente de tumor estromal gastrintestinal.

We report a case of an elderly patient with signs and symptoms of intestinal obstruction. The final diagnosis was intestinal intussusception secondary to a gastrointestinal stromal tumor.We report a case of an elderly patient with signs and symptoms of intestinal obstruction. The final diagnosis was intestinal intussusception secondary to a gastrointestinal stromal tumor.