Distinct Imaging Features Research Articles

Distinct magnetic resonance imaging features in a patient with novel RARS2 mutations: A case report and review of the literature

Pontocerebellar hypoplasia type 6 (PCH6) is a rare autosomal recessive disease that occurs due to mutations in the mitochondrial arginyl-tRNA synthetase 2 (RARS2) gene. To the best of our knowledge, 23 cases with relatively complete clinical data have been reported thus far. In the present study, a case with PCH6 caused by novel RARS2 mutations is described, in which distinct magnetic resonance imaging (MRI) features were identified. In addition, 23 PCH6 cases found in the literature were reviewed. Early onset hypotonia (43.48%), epileptic seizures (34.78%), encephalopathy (26.08%) and feeding difficulties (17.39%) were common initial symptoms of PCH6. During disease progression, the patients presented refractory epileptic seizures (94.12%), feeding problems (60.87%), severe developmental delay (100%), microcephaly (88.89%) and hyperlactacidemia (76.47%). The clinical features of the present patient were suggestive of PCH6, with early onset epilepsy, feeding difficulties, severe developmental delay, microcephaly, hearing loss and hyperlactacidemia. According to available MRI data from 20 reported cases with PCH6, the characteristic finding in MRI was pontocerebellar dysplasia or progressive cerebral/pontocerebellar atrophy in 16 cases, while 4 cases did not present pontocerebellar hypoplasia, and no basal ganglia involvement was observed in any of the cases. Distinctive MRI features were also identified in the present case, including pontocerebellar preservation after 1 year of age, as well as a high diffusion-weighted imaging signal suggesting intracellular edema in the cerebellar hemispheres, basal ganglia, thalamus and corpus callosum. Progressive loss of cerebral white matter and cortical volume were common features shared by all patients. In conclusion, in the present study, two novel heterozygous mutations were identified in RARS2, namely c.1718C>T(p.Thr573Ile) and c.991A>G (p.Ile331Val). Thus, the present case enriched the phenotypic and genotypic spectrum of the RARS2 mutations.

Distinct imaging features of different pathological subtypes of B cell non-Hodgkin′s lymphomas of the nose and pharynx ministry type NK/T cell

Objective To investigate the distinct imaging features of different pathological subtypes of non-Hodgkin′s lymphomas(NHL)of the nose and pharynx and to improve its diagnostic accuracy. Methods A retrospective study was performed on the imaging materials(including CT or MRI)of 32 patients who were confirmed as NHL of the nose and pharynx by pathology.The materials were divided into two groups: NK/T cell lymphoma(NKTCL)and B cell lymphoma(BCL). The characteristics of the site, size, morphology, growth pattern, regional structure invasion of these lymphomas were evaluated and compared.The results were analyzed by Chi-quare test. Results A total of 12 cases(37.5%)were NK/T cell type, 10 cases(83.3%)mainly had nasal cavity involvement, 2 cases(16.7%)showed Waldeyer′s ring involvement, which were characterized by nasal soft tissue with mold growth.Among these, 7 cases(58.3%)had superficial ulcerations, 6 cases(50.0%)with regional structure invasion, 2 cases(16.7%)lymph node involvements.Besides, 20 cases(62.5%)were B cell type NHL.Among these, 19 cases(95.0%)had Waldeyer′s ring involvement and 1 case(5.0%)occurred in nasal cavity with pharyngeal lymphatic loop soft tissue incrassation, and 2 cases(16.7%)had regional structure involvement of pharyngeal space and bone.All cases showed cervical lymphadenopathy.Results of the Chi-square test showed that NKTCL had a higher incidence of nasal cavity involvement than B cell type NHL(χ2=20.401, P=0.000)and regional structure invasion (χ2=6.400, P=0.011), as well as superficial ulcerations (χ2=11.378, P=0.001). BCL had a higher incidence of Waldeyer′s ring involvement and creeping growth pattern(χ2=20.519, P=0.000), as well as lymphadenopathy(χ2=23.058, P=0.000)compared to NKTCL. Conclusion Primary NHLs of the nose and pharynx of different pathological subtypes has some characteristics on imaging, which may have supplementary value in the lymphoma diagnosis. Key words: Lymphoma; Pathological subtypes; MR; CT

Hypoglossal Canal Lesions: Distinctive Imaging Features and Simple Diagnostic Algorithm.

The objective of this study is to compare the prevalence of hypoglossal canal lesions and identify differentiating imaging features. A 15-year retrospective review of lesions of the hypoglossal nerve and hypoglossal canal, excluding those in patients with metastasis or prior head and neck cancer and those treated with radiation or surgery, was performed. Clinical findings and lesion imaging features were documented. The contrast-enhanced T1-weighted nonenhancing cystic component of hypoglossal schwannomas was compared with size-matched pathologically proven vestibular schwannomas. Our review identified 40 lesions encroaching on the hypoglossal canal, located within the hypoglossal canal, or found in both locations: 16 hypoglossal schwannomas, 15 juxtaarticular cysts, and nine purely cystic hypoglossal canal lesions. Hypoglossal schwannomas, which were intradural when involving the premedullary cistern, most commonly enhanced heterogeneously, with a thick peripheral enhancing component, a central enhancing component, or both enhancing components. Juxtaarticular cysts encroaching on the hypoglossal canal were extradural, were contiguous with a craniocervical junction synovial joint, and showed thin rim enhancement. Hypoglossal canal nonenhancing cystic lesions were confined to the hypoglossal canal, had signal intensity equivalent to CSF, and lacked any contrast enhancement. Although hypoglossal schwannomas, juxtaarticular cysts, and hypoglossal canal nonenhancing cystic lesions may all encroach on or lie within the hypoglossal canal, purely cystic lesions are unlikely to be schwannomas. A diagnostic algorithm applying key imaging and clinical findings allows differentiation of these lesions, which have vastly different treatment regimens.

Myelopathy in Behçet's disease: The Bagel Sign.

To describe the clinical and distinctive imaging features of myelopathy associated with Behçet's disease (BD). We evaluated the records of patients meeting the following criteria: (1) fulfillment of the International Study Group criteria for BD; (2) clinically suggestive of myelopathy; (3) simultaneous spinal cord and brain magnetic resonance images (MRIs) within 1 month of acute worsening of myelopathy; and (4) follow-up duration ≥ 1 year after initial MRI evaluation. Patients not fulfilling all inclusion criteria and having MRIs with poor quality or missing sequences were excluded. In 11 patients (9 men, 2 women), we studied 14 MRIs during distinct myelopathy episodes and nine follow-up MRIs. Two distinct MRI patterns of spinal cord involvement were described according to T2-weighted (T2W) axial images: (1) "Bagel Sign" pattern: a central lesion with hypointense core and hyperintense rim with or without contrast enhancement; and (2) "Motor Neuron" pattern: a symmetric involvement of the anterior horn cells. Bagel Sign was present in 13 of 14 myelopathy episodes whereas Motor Neuron pattern was observed in 1 of 14 MRIs. Of the 13 MRIs with Bagel Sign long myelopathy (n = 9), both long and short myelopathy (n = 2) and short myelopathy (n = 2) was observed. All patterns cleared with some residual lesions after steroid use and immunomodulation with associated clinical recovery in patients. The signal characteristics of the Bagel Sign potentially represent venous engorgement and/or acute blood products within the spinal cord. To our knowledge, Bagel Sign has not been observed in other forms of longitudinal myelopathy outside of BD, including neuromyelitis optica. Ann Neurol 2017;82:288-298.

Food Image Recognition via Superpixel Based Low-Level and Mid-Level Distance Coding for Smart Home Applications

Food image recognition is a key enabler for many smart home applications such as smart kitchen and smart personal nutrition log. In order to improve living experience and life quality, smart home systems collect valuable insights of users’ preferences, nutrition intake and health conditions via accurate and robust food image recognition. In addition, efficiency is also a major concern since many smart home applications are deployed on mobile devices where high-end GPUs are not available. In this paper, we investigate compact and efficient food image recognition methods, namely low-level and mid-level approaches. Considering the real application scenario where only limited and noisy data are available, we first proposed a superpixel based Linear Distance Coding (LDC) framework where distinctive low-level food image features are extracted to improve performance. On a challenging small food image dataset where only 12 training images are available per category, our framework has shown superior performance in both accuracy and robustness. In addition, to better model deformable food part distribution, we extend LDC’s feature-to-class distance idea and propose a mid-level superpixel food parts-to-class distance mining framework. The proposed framework show superior performance on a benchmark food image datasets compared to other low-level and mid-level approaches in the literature.

Magnetic resonance imaging and clinical features of glenoid labral flap tears

Displaced flaps of glenoid labral tissue are an uncommonly encountered finding on MRI of the shoulder, and are of unclear clinical significance. The purpose of this study is to describe the imaging characteristics of displaced glenoid labral flaps, evaluate for any common concomitant injuries, and identify the typical clinical presentation and management of patients with this lesion. This retrospective, observational study was approved by the institutional review board. Nineteen patients with flap-type tears of the labrum on preoperative MRI were identified. Each examination was retrospectively reviewed by two radiologists for size, location, and signal intensity of the displaced flap of tissue, in addition to any co-existing labrum or cartilage pathological conditions and clinical information. All displaced flaps extended from the inferior margin of the glenoid into the axillary recess. The average size of the visualized flap was 10.9 by 6.0 by 2.6mm. Seventy percent of the flaps had signal intensity isointense to labrum and hypointense to hyaline cartilage on T2-weighted images. All 19 patients had concomitant labral pathological conditions and 63% had cartilage defects, visualized on MRI. Clinical evidence of shoulder instability was seen in 83% of patients, and 67% were managed surgically. Glenoid labral flap tears have distinct imaging characteristics that may aid in their identification. Their presence should prompt careful evaluation of the glenoid articular cartilage. Recognition of a labral flap tear may have clinical importance, as 83% of patients with this finding demonstrated clinical evidence ofshoulder instability, often requiring surgical intervention.

Distinct MDCT imaging features to differential diagnosis of hepatic paragonimiasis and small hepatocellular carcinoma.

We used multi-row detector computed tomography (MDCT) to identify the distinguishing characteristics of hepatic paragonimiasis and small hepatocellular carcinoma lesions. We analyzed a cohort of 60 patients, of which 26 had hepatic paragonimiasis and 34 with a small (≤ 3cm) hepatocellular carcinoma. MDCT detected 65 lesions that were retrospectively reviewed and analyzed based on their imaging features. Both groups showed distinct MDCT imaging features that could contribute to an accurate diagnosis. In the paragonimiasis group, 75% (21/28) lesions were located in the hepatic subcapsular region, whereas only 10.8% (4/37) of lesions in the hepatocellular carcinoma group were subcapsular. Most hepatic paragonimiasis lesions (57.1%; 16/28) also showed characteristic tubular or tunnel features that were not present in hepatocellular carcinomas. Further, 71.4% (20/28) paragonimiasis lesions were rim enhanced with irregular tract-like non-enhanced internal areas with a characteristic target loop, while 94.6% (35/37) of small hepatocellular carcinoma lesions showed homogenous enhancement in the arterial and venous phase. In addition, the period CT values for hepatic paragonimiasis were less than those of hepatic carcinomas (P<0.001). These clinically significant findings illustrate the diagnostic features that enable one to distinguish hepatic paragonimiasis from small hepatocellular carcinomas.

Distinct brain imaging characteristics of autoantibody-mediated CNS conditions and multiple sclerosis.

Brain imaging characteristics of MOG antibody disease are largely unknown and it is unclear whether they differ from those of multiple sclerosis and AQP4 antibody disease. The aim of this study was to identify brain imaging discriminators between those three inflammatory central nervous system diseases in adults and children to support diagnostic decisions, drive antibody testing and generate disease mechanism hypotheses. Clinical brain scans of 83 patients with brain lesions (67 in the training and 16 in the validation cohort, 65 adults and 18 children) with MOG antibody (n = 26), AQP4 antibody disease (n = 26) and multiple sclerosis (n = 31) recruited from Oxford neuromyelitis optica and multiple sclerosis clinical services were retrospectively and anonymously scored on a set of 29 predefined magnetic resonance imaging features by two independent raters. Principal component analysis was used to perform an overview of patients without a priori knowledge of the diagnosis. Orthogonal partial least squares discriminant analysis was used to build models separating diagnostic groups and identify best classifiers, which were then tested on an independent cohort set. Adults and children with MOG antibody disease frequently had fluffy brainstem lesions, often located in pons and/or adjacent to fourth ventricle. Children across all conditions showed more frequent bilateral, large, brainstem and deep grey matter lesions. MOG antibody disease spontaneously separated from multiple sclerosis but overlapped with AQP4 antibody disease. Multiple sclerosis was discriminated from MOG antibody disease and from AQP4 antibody disease with high predictive values, while MOG antibody disease could not be accurately discriminated from AQP4 antibody disease. Best classifiers between MOG antibody disease and multiple sclerosis were similar in adults and children, and included ovoid lesions adjacent to the body of lateral ventricles, Dawson's fingers, T1 hypointense lesions (multiple sclerosis), fluffy lesions and three lesions or less (MOG antibody). In the validation cohort patients with antibody-mediated conditions were differentiated from multiple sclerosis with high accuracy. Both antibody-mediated conditions can be clearly separated from multiple sclerosis on conventional brain imaging, both in adults and children. The overlap between MOG antibody oligodendrocytopathy and AQP4 antibody astrocytopathy suggests that the primary immune target is not the main substrate for brain lesion characteristics. This is also supported by the clear distinction between multiple sclerosis and MOG antibody disease both considered primary demyelinating conditions. We identify discriminatory features, which may be useful in classifying atypical multiple sclerosis, seronegative neuromyelitis optica spectrum disorders and relapsing acute disseminated encephalomyelitis, and characterizing cohorts for antibody discovery.

P2.03b-006 Distinct MR Imaging Features of Metastatic Lesions in Brain with Non-Small Cell Lung Cancer According to EGFR Mutation Status: Topic: Brain Meta

It is often difficult to evaluate the status of EGFR mutation in non-small cell lung cancer (NSCLC) patients with brain metastases either from primary or metastatic lesions. Is it possible to ascertain the EGFR status and to guide the usefulness of TKI according to the MR imaging features of metastatic lesions in brain? Patients diagnosed with NSCLC from June 2014 through May 2015 were identified synchronous brain metastases based on enhanced magnetic resonance imaging (MRI). The variables of metastatic brain tumor included the numbers and the size of the brain lesions, the size of the associated peritumoral brain edema (PTBE) measured with brain MRI. The information was obtained mainly by transbronchial lung biopsy, percutaneous needle lung biopsy or cervical lymph nodes biopsy about EGFR mutation status. Among 156 patients, 41 had the exon 19 deletion, 48 had the exon 21 L858R point mutation, and 67 had the wild-type EGFR. The exon 19 deletion group and exon 21 point mutation group had smaller peritumoral brain edema than did the wild-type group (P = 0.002 and P = 0.010, respectively). Different from the wild-type group, the exon 21 point mutation group showed more multiple brain tumors (P = 0.020). There was no significant difference about the size of the largest brain tumors in either exon 19 deletion group or exon 21 point mutation group when compared with the wild-type group (P = 0.077 and P = 0.051, respectively), but the metastatic brain lesions were inclined to smaller in EGFR mutation groups. Specific features of MRI in brain metastatic lesions were found in NSCLC with EGFR mutation，including smaller peritumoral brain edema and more lesions than did those with wild-type EGFR. Meanwhile, there was the trend that the size of the largest brain lesion was smaller in EGFR mutation groups. Accumulation of more knowledge was needed to depend on radiomics to make a quantifying analysis of EGFR mutation status.

Frontotemporal dementia as the presenting phenotype of p.A53T mutation carriers in the alpha-synuclein gene

IntroductionThe p.A53T point mutation in SNCA, the alpha-synuclein gene, has been linked to a rare dominant form of Parkinson's disease (PD). MethodsHere, we describe two apparently unrelated cases of p.A53T (G209A) SNCA mutation carriers with an atypical initial manifestation and disease course. Moreover, cerebrospinal fluid (CSF) levels of tau, p-tau and amyloid Aβ42 were measured in these patients and in an additional cohort of 5 symptomatic and 2 asymptomatic p.A53T carriers without an initial manifestation of dementia. ResultsBoth patients exhibited an early onset frontal-dysexecutive dysfunction with apathy and emotional blunting resembling frontotemporal dementia (FTD). Motor symptoms typical of Parkinson's disease appeared only later in the disease course and were less prominent than cognitive ones, which included language impairment. Autonomic dysfunction and myoclonus also emerged in a more advanced disease stage. In both patients, Brain Magnetic Resonance Imaging showed fronto-temporo-parietal atrophy, and CSF analysis showed elevated tau protein levels. In contrast, tau protein levels were normal in a cohort of 7 other p.A53T mutation carriers (5 symptomatic/2 asymptomatic). A screen of Greek patients presenting with frontotemporal dementia failed to identify any additional subjects with the p.A53T SNCA mutation. ConclusionAlthough cognitive decline has been recognized as a feature of the full-blown clinical picture of p.A53T related parkinsonism, a predominant frontotemporal dementia-like phenotype at presentation has not been previously described. This may represent a subtype of this disorder, with distinctive clinical, imaging and CSF biochemical characteristics, in which additional genetic or epigenetic factors may play a role.

Acquired portosystemic collaterals: anatomy and imaging.

Portosystemic shunts are enlarged vessels that form collateral pathological pathways between the splanchnic circulation and the systemic circulation. Although their causes are multifactorial, portosystemic shunts all have one mechanism in common-increased portal venous pressure, which diverts the blood flow from the gastrointestinal tract to the systemic circulation. Congenital and acquired collateral pathways have both been described in the literature. The aim of this pictorial essay was to discuss the distinct anatomic and imaging features of portosystemic shunts, as well as to provide a robust method of differentiating between acquired portosystemic shunts and similar pathologies, through the use of illustrations and schematic drawings. Imaging of portosystemic shunts provides subclinical markers of increased portal venous pressure. Therefore, radiologists play a crucial role in the identification of portosystemic shunts. Early detection of portosystemic shunts can allow ample time to perform endovascular shunt operations, which can relieve portal hypertension and prevent acute or chronic complications in at-risk patient populations.

Vascular Disorders of the Cerebellum in Children.

Key differences exist in the epidemiology, pathophysiology, and clinical presentation of vascular lesions of the cerebellum in children versus adults. An understanding of these differences and an appreciation of the distinct imaging features of these lesions aid in distinguishing normal vascular variations from pathology, in predicting lesion etiology, and in directing effective treatment strategies. This paper reviews the embryogenesis of the normal vascular system of the cerebellum and brainstem and then discusses the clinical and imaging features of the common vascular lesions affecting these structures in the pediatric population.

THE STRUCTURE OF SPECIFIC FEATURES OF BIOCHEMICAL IMAGES / BIOCHEMINIŲ VAIZDŲ CHARAKTERINGŲJŲ POŽYMIŲ SANDARA

Nowadays three-dimensional imaging technology is used in biochemistry very intensively. It helps to distinguish image features faster with less resources, which are necessary to describe cell characteristics and to explain the origin of the biochemical processes. The article on the strength of Fuzzy logic classification solves fluorescent microscopy of HeLa cells image three-dimensional visualisation characteristic features problem. It is shown that object “luminance“ and “size“ characteristic features are useful to apply for three-dimensional biochemical images analysis. Biochemijoje itin intensyviai pradedamos naudoti trimačio vaizdinimo technologijos. Jos leidžia greičiau ir naudojant mažiau resursų, išskirti vaizduose esančius požymius, reikalingus ląstelių savybėms bei biocheminių procesų kilmei išaiškinti. Straipsnyje sprendžiama fluorescencinės mikroskopijos HeLa ląstelių vaizdų charakteringųjų požymių atrankos trimačio vaizdavimo, naudojant neraiškios logikos klasifikatorių, uždaviniui problema. Parodyta, kad tikslinga biocheminių vaizdų trimatei analizei taikyti objektų skaisčio ir dydžio charakteringuosius požymius.

Myxoid hepatocellular neoplasms: imaging appearance of a unique mucinous tumor variant.

To describe the imaging appearance of myxoid hepatocellular neoplasms (MHNs), including adenomas and carcinomas, a recently described pathologically unique tumor variant. Single-institution review of pathologically proven MHNs revealed 4 patients with imaging prior to resection. All available cross-sectional imaging was then retrospectively reviewed in consensus using specified descriptive characteristics previously published for hepatocellular adenoma subtypes. Imaging characteristics on magnetic resonance imaging (MRI), ultrasound (US), and computed tomography (CT) were reviewed. MHNs were predominantly markedly T2 hyperintense with thin internal septations, circumscribed with lobulated margins, and demonstrated heterogeneous enhancement on arterial phase that became more homogenous on delayed phases. The lesions were hypodense on CT with similar enhancement characteristics as on MRI. On US, they were mildly hyperechoic and heterogeneous with posterior acoustic enhancement. MHNs show distinct imaging features that may allow accurate noninvasive diagnosis and differentiation from other hepatic lesions, including cavernous hemangioma, focal nodular hyperplasia, and other variants of hepatocellular adenoma or carcinoma. Differentiation between benign and malignant MHN may not be possible by imaging, possibly necessitating earlier definitive therapy or surgical management.

Beyond Prostate Adenocarcinoma: Expanding the Differential Diagnosis in Prostate Pathologic Conditions.

Recent advances in magnetic resonance (MR) imaging of the prostate gland have dramatically improved the ability to detect and stage adenocarcinoma of the prostate, one of the most frequently diagnosed cancers in men and one of the most frequently diagnosed pathologic conditions of the prostate gland. A wide variety of nonadenocarcinoma diseases can also be seen with MR imaging, ranging from benign to malignant diseases, as well as infectious and inflammatory manifestations. Many of these diseases have distinctive imaging features that allow differentiation from prostate acinar adenocarcinoma. Early recognition of these entities produces a more accurate differential diagnosis and may enable more expeditious clinical workup. Benign neoplasms of the prostate include plexiform neurofibroma and cystadenoma, both of which demonstrate distinctive imaging features. Stromal neoplasms of uncertain malignant potential are rare tumors of uncertain malignant potential that are often difficult to distinguish at imaging from more-malignant prostate sarcomas. Other malignant neoplasms of the prostate include urothelial carcinoma, primary prostatic carcinoid, carcinosarcoma, endometrioid or ductal adenocarcinoma, and mucinous adenocarcinoma. Prostatic infections can lead to abscesses of pyogenic, tuberculous, or fungal origins. Finally, miscellaneous idiopathic disorders of the prostate include amyloidosis, exophytic benign prostatic hyperplasia, and various congenital cysts. Considerable overlap can exist in the clinical history and imaging findings associated with these prostate pathologic conditions, and biopsy is often required for ultimate confirmation of the diagnosis. However, many diagnoses, including cystadenoma, mucinous adenocarcinoma, sarcoma, and abscesses, have distinct imaging features, which can enable the informed radiologist to identify the diagnosis and recommend appropriate clinical workup and management. (©)RSNA, 2016.

MO-DE-207B-01: JACK FOWLER JUNIOR INVESTIGATOR COMPETITION WINNER: Between Somatic Mutations and PET-Based Radiomic Features in Non-Small Cell Lung Cancer

Purpose: Although PET-based radiomic features have been proposed to quantify tumor heterogeneity and shown promise in outcome prediction, little is known about their relationship with tumor genetics. This study assessed the association of [18F]fluorodeoxyglucose (FDG)-PET-based radiomic features with non-small cell lung cancer (NSCLC) mutations. Methods: 348 NSCLC patients underwent FDG-PET/CT scans before treatment and were tested for genetic mutations. 13% (44/348) and 28% (96/348) patients were found to harbor EGFR (EGFR+) and KRAS (KRAS+) mutations, respectively. We evaluated nineteen PET-based radiomic features quantifying phenotypic traits, and compared them with conventional PET features (metabolic tumor volume (MTV) and maximum-SUV). The association between the feature values and mutation status was evaluated using the Wilcoxcon-rank-sum-test. The ability of each measure to predict mutations was assessed by the area under the receiver operating curve (AUC). Noether’s test was used to determine if the AUCs were significantly from random (AUC=0.50). All p-values were corrected for multiple testing by controlling the false discovery rate (FDRWilcoxon and FDRNoether) of 10%. Results: Eight radiomic features, MTV, and maximum-SUV, were significantly associated with the EGFR mutation (FDRWilcoxon=0.01–0.10). However, KRAS+ demonstrated no significantly distinctive imaging features compared to KRAS− (FDRWilcoxon≥0.92). EGFR+ and EGFR− were significantly discriminated by conventional PET features (AUC=0.61, FDRNoether=0.04 for MTV and AUC=0.64, FDRNoether=0.01 for maximum-SUV). Eight radiomic features were significantly predictive for EGFR+ compared to EGFR− (AUC=0.59–0.67, FDRNoether=0.0032–0.09). Normalized-inverse-difference-moment outperformed all features in predicting EGFR mutation (AUC=0.67, FDRNoether=0.0032). Moreover, only the radiomic feature normalized-inverse-difference-moment could significantly predict KRAS+ from EGFR+ (AUC=0.65, FDRNoether=0.05). All measures failed to predict KRAS+ from KRAS− (AUC=0.50–0.54, FDRNoether≥0.92). Conclusion: PET imaging features were strongly associated with EGFR mutations in NSCLC. Radiomic features have great potential in predicting EGFR mutations. Our study may help develop a non-invasive imaging biomarker for EGFR mutation. R.M. has consulting interests with Amgen

What MRI can tell us about neurogenic tumors and rhabdomyosarcoma.

This review focuses on the MRI features of neurogenic tumors and rhabdomyosarcoma in children. Neurogenic tumors include those arising from a nerve sheath and neuroblastic tumors that arise from the sympathetic nervous system. Nerve sheath tumors can be benign or malignant and occur sporadically or in association with neurofibromatosis type 1. Neuroblastic tumors comprise a spectrum of tumors ranging from highly malignant neuroblastoma to the benign ganglioneuroma. These neurogenic tumors arise in typical locations within the chest, abdomen and pelvis and have distinctive and characteristic imaging features that should suggest their diagnosis. Rhabdomyosarcoma encompasses a variety of histological subtypes that exhibit varying degrees of aggressiveness and biological behavior. While some abdominal and pelvic locations are well known to give rise to rhabdomyosarcoma, this tumor can arise in any tissue in the body except bone. The paper reviews the MRI and clinical features of neurogenic tumors and rhabdomyosarcoma and the imaging findings that can aid in clinical management.

Cortical bone invasion in non-transfusion-dependent thalassemia: tumefactive extramedullary hematopoiesis reviewed.

To assess the prevalence of cortical bone invasion (CBI) with secondary extramedullary hematopoiesis (EMH) in patients with non-transfusion-dependent thalassemia (NTDT), to determine its predilection sites on thoracic and abdominal imaging, to determine whether there is an association between various clinical and hematological parameters, and to evaluate its various findings mainly on magnetic resonance imaging (MRI), in addition to computed tomography (CT) scans. This is a retrospective cohort study of 57 patients with NTDT imaged by CT or MRI. Both clinical and laboratory data were gathered. An imaging scoring system was used to describe the appearance of CBI by MRI. Twenty-seven patients (47.4%) were found to have CBI and EMH with the most common location being the thoracic spine. Splenectomy and lower hemoglobin level were found to be independent risk factors for its development. Most lesions were homogenous (70%), had predominant red marrow signal (67%), and well-defined margins (89%). CBI and secondary tumefactive EMH are common findings in patients with NTDT, with distinct imaging and clinical characteristics. An increased risk was seen in patients with splenectomy and lower hemoglobin. The imaging scoring system described is helpful in diagnosing and describing this entity, hence precluding unnecessary biopsies.

Clinicopathologic and neuroradiologic studies of papillary glioneuronal tumors

Papillary glioneuronal tumor (PGNT) is a rare, recently described distinct low-grade brain neoplasm. This study was performed to characterize the clinicopathologic and neuroradiologic features of PGNTs. We reviewed the medical records of 16 patients with PGNT who underwent surgery, including 11 males and five females (median age 27years). The clinical, neuroradiologic, histopathologic, and immunohistochemical findings were documented. Headache was the principal presentation. Neuroimaging showed contrast-enhancing, cystic-solid or cystic masses with a mural nodule, mostly involved the frontal or parietal lobes. Histologically, the tumors were characterized by glial fibrillary acidic protein (GFAP)-positive small cuboidal cells lining hyalinized vascular pseudopapillae and synaptophysin and/or NeuN-positive interpapillary neuronal elements. Other findings included small angiomatous areas in ten, small islands of neuropil and rosettes in seven, and microvascular proliferation and/or nuclear atypia in six. Mitoses or necrosis were absent. All lacked isocitrate dehydrogenase 1 (IDH1) R132H protein expression. Low expression of p53 was observed in three cases. Ki67 labeling index ranged from less than 1to 3%. All but one was totally resected. Median follow-up was 65months, and one patient had tumor recurrence. PGNTs display distinct clinicopathologic and imaging characteristics and indicate a favorable prognosis. However, recurrences sometimes occur. Immunohistochemistry facilitates the appropriate diagnosis of these tumors. Complete resection of the tumor is important for a favorable outcome.

Radiologic Differentiation of Adrenal Lesions and Its Impact on Patient Management

Adrenal lesions are a relatively common incidental finding and are estimated to be present in 4.4% of all abdominal CT scans.1 The detection of an adrenal lesion often necessitates a thorough clinical evaluation that frequently requires a comprehensive patient history, biochemical studies, and radiologic studies such as dedicated adrenal protocol CT or MRI. The primary goal of additional radiologic studies is to differentiate benign from malignant adrenal lesions. It is, therefore, important for the radiologist to be familiar with a variety of benign and malignant adrenal lesions and to recognize distinctive imaging characteristics that can help make this distinction. This article reviews typical and useful imaging features of more commonly encountered benign and malignant adrenal lesions.