Jay Starkey

A pictorial review of benign hepatocellular nodular lesions: comprehensive radiological assessment incorporating the concept of anomalous portal tract syndrome

Background/purposeAlthough the pathological categorization system advocated by the International Working Party (IWP) on Terminology has been helpful in categorizing benign hepatocellular lesions, the diverse clinicopathological features of the lesions still cause confusion of diagnosis in clinical settings. Recently, an integrated disease concept termed “anomalous portal tract syndrome” (APTS) has been proposed as a congenital anomaly of the portal tract, being a single unifying etiological factor underlying the disorder. In this article, we discuss the radiological features of benign nodular hepatocellular lesions incorporated in the concept of APTS.MethodsWe systematically reviewed the literature on benign hepatocellular lesions based on the concept of APTS, as well as standard IWP terminology. For this pictorial review, we selected six representative cases and assessed the radiological features of the cases based on the concept of APTS.ResultsThe comprehensive assessment based on APTS enabled the systematic categorization of benign hepatocellular lesions, including nodular regenerative hyperplasia, large regenerative nodules, partial nodular transformation, focal nodular hyperplasia, and hepatocellular adenoma, and was helpful in understanding the overlapping features of these lesions.ConclusionsAlthough the disease concept of APTS is still evolving, it is nonetheless helpful in comprehensively understanding the clinicopathological and radiological features of various benign hepatocellular lesions.

Cytotoxic Lesions of the Corpus Callosum That Show Restricted Diffusion: Mechanisms, Causes, and Manifestations

Cytotoxic lesions of the corpus callosum (CLOCCs) are secondary lesions associated with various entities. CLOCCs have been found in association with drug therapy, malignancy, infection, subarachnoid hemorrhage, metabolic disorders, trauma, and other entities. In all of these conditions, cell-cytokine interactions lead to markedly increased levels of cytokines and extracellular glutamate. Ultimately, this cascade can lead to dysfunction of the callosal neurons and microglia. Cytotoxic edema develops as water becomes trapped in these cells. On diffusion-weighted magnetic resonance (MR) images, CLOCCs manifest as areas of low diffusion. CLOCCs lack enhancement on contrast material-enhanced images, tend to be midline, and are relatively symmetric. The involvement of the corpus callosum typically shows one of three patterns: (a) a small round or oval lesion located in the center of the splenium, (b) a lesion centered in the splenium but extending through the callosal fibers laterally into the adjacent white matter, or (c) a lesion centered posteriorly but extending into the anterior corpus callosum. CLOCCs are frequently but not invariably reversible. Their pathologic mechanisms are discussed, the typical MR imaging findings are described, and typical cases of CLOCCs are presented. Although CLOCCs are nonspecific with regard to the underlying cause, additional imaging findings and the clinical findings can aid in making a specific diagnosis. Radiologists should be familiar with the imaging appearance of CLOCCs to avoid a misdiagnosis of ischemia. When CLOCCs are found, the underlying cause of the lesion should be sought and addressed. ©RSNA, 2017 An earlier incorrect version of this article appeared online. This article was corrected on February 13, 2017.

Human papillomavirus-associated plantar epidermoid cysts: MR and US imaging appearance

Epidermoid cysts are epithelial cysts that present as slow-growing intradermal or subcutaneous lesions. While recent epidemiological studies have isolated human papillomavirus (HPV) from plantar epidermoid cysts, imaging findings in HPV-associated epidermoid cysts have not been previously reported. We describe imaging findings in two patients with HPV-associated plantar epidermoid cysts. Magnetic resonance (MR) imaging and ultrasonography (US) showed linear arrangement of several adjacent globular cysts. This appearance is hypothesized to result from HPV-associated eccrine duct metaplasia leading to cyst formation and later traumatic rupture leading to formation of multiple adjacent cystic components. It may be useful to suggest assessing the presence of HPV antigen in plantar lesions having these imaging findings.

Cervical ultrasound and computed tomography of Kawasaki disease: Comparison with lymphadenitis

Differentiating Kawasaki disease (KD) from cervical lymphadenitis (CL) is clinically difficult but essential given that treatment and outcome differ significantly. Research on differentiation between KD and CL using ultrasound (US) and computed tomography (CT) is limited. The purpose of this study was to identify cervical US and CT findings that may differentiate KD from CL.

MR imaging findings in some rare neurological complications of paediatric cancer

Neurological complications of paediatric cancers are a substantial problem. Complications can be primary from central nervous system (CNS) spread or secondary from indirect or remote effects of cancer, as well as cancer treatments such as chemotherapy and radiation therapy. In this review, we present the clinical and imaging findings of rare but important neurological complications in paediatric patients with cancer. Neurological complications are classified into three phases: pre-treatment, treatment and post-remission. Paraneoplastic neurological syndromes, hyperviscosity syndrome, haemophagocytic lymphohistiocytosis and infection are found in the pre-treatment phase, while Trousseau’s syndrome, posterior reversible encephalopathy syndrome and methotrexate neurotoxicity are found in the treatment phase; though some complications overlap between the pre-treatment and treatment phases. Hippocampal sclerosis, radiation induced tumour, radiation induced focal haemosiderin deposition and radiation-induced white matter injury are found in the post-remission phase. With increasingly long survival after treatment, CNS complications have become more common. It is critical for radiologists to recognise neurological complications related to paediatric cancer or treatment. Magnetic resonance imaging (MRI) plays a significant role in the recognition and proper management of the neurological complications of paediatric cancer.Teaching Points• Neurological complications of paediatric cancer include various entities.• Neurological complications are classified into three phases: pre-treatment, treatment and post-remission.• Radiologists should be familiar with clinical and imaging findings of neurological complications.• MRI features may be characteristic and lead to early diagnosis and proper treatments.

Radiology of Fractures in Intoxicated Emergency Department Patients: Locations, Mechanisms, Presentation, and Initial Interpretation Accuracy

AbstractThe purpose of this study was to investigate the relationship of alcohol intoxication to time-to-presentation following injury, fracture type, mechanism of injury leading to fracture, and initial diagnostic radiology interpretation performance of emergency physicians versus diagnostic radiologists in patients who present to the emergency department (ED) and are subsequently diagnosed with fracture.Medical records of 1286 patients who presented to the ED and were diagnosed with fracture who also underwent plain film or computed tomography (CT) imaging were retrospectively reviewed. The subjects were divided into intoxicated and sober groups. Patient characteristics, injury-to-presentation time, fracture location, and discrepancies between initial clinical and radiological evaluations were compared.Of 1286 subjects, 181 patients were included in the intoxicated group. Only intoxicated patients presented with head/neck fractures more than 24 hours after injury. The intoxicated group showed a higher rate of head/neck fractures (skull 23.2% vs 5.8%, face and orbit 30.4% vs 9.5%; P < 0.001) and a lower rate of extremity injuries. The rate of nondiagnosis of fractures by emergency physicians later identified by radiologists was the same in both groups (7.7% vs 7.7%, P = 0.984).While the same proportion of intoxicated patients presented more than 24 hours following injury, only intoxicated patients presented with craniofacial and cervical spinal fractures during this period. Alcohol-related injuries are more often associated with head/neck fractures but less extremity injuries. The rate of fractures missed by emergency physicians but later diagnosed by radiologists was the same in intoxicated and sober patients.