Multiple focal nodular hyperplasia: MRI features.

PURPOSE: To describe MRI features of multiple Focal Nodular Hyperplasia (FNHs). METHODS: 40 consecutive subjects (37 females, mean age, 38.8years) were included. All studies were independently reviewed. This was an observational study to define the radiological features of multifocal FNH. RESULTS: 130 lesions were evaluated. The majority (88.5%), were peripheral in location. 92.3% lesions were lobulated. Marked enhancement was present in 94.6% lesions. In the portal venous and delayed phase, 46.2% and 47.7% lesions were mildly hyperintense. Central scar was present in 77% lesions. CONCLUSIONS: Distinctive features included predominant subcapsular location and mild hyperintensity in the delayed phase, seen in nearly 50% of FNHs.

Comparison of Cartesian and radial acquisition on short-tau inversion recovery (STIR) sequences in breast MRI.

OBJECTIVE: The purpose of this study was to compare two short-tau inversion recovery (STIR) sequences, Cartesian and radial (BLADE) acquisitions, for breast magnetic resonance imaging (MRI) examinations. MATERIALS AND METHODS: Ninety-six women underwent 1.5 T breast MRI exam (48 Cartesian and 48 BLADE). Qualitative analysis including image artifacts, image quality, fat-suppression, chest-wall depiction, lesion detection, lymph node depiction and overall impression were evaluated by three blinded readers. Signal to noise ratios (SNRs) were calculated. Cronbach's alpha test was used to assess inter-observer agreement. Subanalyses of image quality, chest-wall depiction and overall impression in 15 patients with implants and image quality in 31 patients with clips were correlated using Pearson test. Wilcoxon rank sum test and t-test were performed. RESULTS: Motion artifacts were present in 100% and in 0% of the Cartesian and the BLADE exams, respectively. Chemical-shift artifacts were present in 8% of the Cartesian exams. Flow artifacts were more frequent on BLADE. BLADE sequence was statistically superior to Cartesian for all qualitative features (p < 0.05) except for fat-suppression (p = 0.054). In the subanalysis, BLADE was superior for implants and clips (p < 0.05). SNR was statistically greater for BLADE (48.35 vs. 16.17). Cronbach ranged from 0.502 to 0.813. CONCLUSION: BLADE appears to be superior to Cartesian acquisition of STIR imaging as measured by improved image quality, fewer artifacts, and improved chest wall and lymph node depiction.

OBJETIVO: Comparar duas sequências de aquisição, cartesiana e radial (BLADE) ponderadas em short-tau inversion recovery (STIR), em exames de ressonância magnética de mama. MATERIAIS E MÉTODOS: Noventa e seis pacientes foram submetidas a exame de ressonância magnética de mama em 1,5 T (48 aquisições STIR cartesianas e 48 aquisições STIR BLADE). A análise qualitativa incluindo artefatos, qualidade de imagem, supressão de gordura, avaliação da parede torácica, detecção de lesões, linfonodos e impressão geral foi avaliada independentemente por três leitores. Os signal to noise ratios (SNRs) foram calculados. Foi utilizado o teste alfa de Cronbach para avaliar a concordância interobservador. Subanálises da qualidade de imagem, avaliação da parede torácica e impressão geral em 15 pacientes com implantes e qualidade de imagem em 31 pacientes com clipes cirúrgicos foram correlacionadas aplicando o teste de Pearson. Os testes de Wilcoxon rank sum test e Student t foram utilizados para comparação qualitativa e quantitativa entre as duas sequências. RESULTADOS: Os artefatos de movimento estavam presentes em 100% e 0% dos exames de aquisição cartesiana e de BLADE, respectivamente. Os artefatos de desvio químico estavam presentes em 8% dos exames cartesianos. Artefatos de fluxo foram mais frequentes nas sequências BLADE. A sequência BLADE foi estatisticamente superior para todos os atributos qualitativos (p < 0,05), exceto na supressão de gordura (p = 0,054). O BLADE foi superior na avaliação dos implantes e clipes cirúrgicos (p < 0,05). O SNR foi estatisticamente superior na sequência BLADE (48,35 versus 16,17). Cronbach variou entre 0,502 e 0,813. CONCLUSÃO: A sequência BLADE foi superior à sequência de aquisição cartesiana de imagens na ponderação STIR, comprovada por uma melhor qualidade de imagem, menos artefatos e melhor avaliação da parede torácica e de linfonodos.

Comparison of Cartesian and radial acquisition on short-tau inversion recovery (STIR) sequences in breast MRI / Comparação de aquisições cartesiana e radial nas sequências short tau inversion recovery (STIR) na RM de mama

Abstract Objective: The purpose of this study was to compare two short-tau inversion recovery (STIR) sequences, Cartesian and radial (BLADE) acquisitions, for breast magnetic resonance imaging (MRI) examinations. Materials and Methods: Ninety-six women underwent 1.5 T breast MRI exam (48 Cartesian and 48 BLADE). Qualitative analysis including image artifacts, image quality, fat-suppression, chest-wall depiction, lesion detection, lymph node depiction and overall impression were evaluated by three blinded readers. Signal to noise ratios (SNRs) were calculated. Cronbach's alpha test was used to assess inter-observer agreement. Subanalyses of image quality, chest-wall depiction and overall impression in 15 patients with implants and image quality in 31 patients with clips were correlated using Pearson test. Wilcoxon rank sum test and t-test were performed. Results: Motion artifacts were present in 100% and in 0% of the Cartesian and the BLADE exams, respectively. Chemical-shift artifacts were present in 8% of the Cartesian exams. Flow artifacts were more frequent on BLADE. BLADE sequence was statistically superior to Cartesian for all qualitative features (p < 0.05) except for fat-suppression (p = 0.054). In the subanalysis, BLADE was superior for implants and clips (p < 0.05). SNR was statistically greater for BLADE (48.35 vs. 16.17). Cronbach ranged from 0.502 to 0.813. Conclusion: BLADE appears to be superior to Cartesian acquisition of STIR imaging as measured by improved image quality, fewer artifacts, and improved chest wall and lymph node depiction.

Resumo Objetivo: Comparar duas sequências de aquisição, cartesiana e radial (BLADE) ponderadas em short-tau inversion recovery (STIR), em exames de ressonância magnética de mama. Materiais e Métodos: Noventa e seis pacientes foram submetidas a exame de ressonância magnética de mama em 1,5 T (48 aquisições STIR cartesianas e 48 aquisições STIR BLADE). A análise qualitativa incluindo artefatos, qualidade de imagem, supressão de gordura, avaliação da parede torácica, detecção de lesões, linfonodos e impressão geral foi avaliada independentemente por três leitores. Os signal to noise ratios (SNRs) foram calculados. Foi utilizado o teste alfa de Cronbach para avaliar a concordância interobservador. Subanálises da qualidade de imagem, avaliação da parede torácica e impressão geral em 15 pacientes com implantes e qualidade de imagem em 31 pacientes com clipes cirúrgicos foram correlacionadas aplicando o teste de Pearson. Os testes de Wilcoxon rank sum test e Student t foram utilizados para comparação qualitativa e quantitativa entre as duas sequências. Resultados: Os artefatos de movimento estavam presentes em 100% e 0% dos exames de aquisição cartesiana e de BLADE, respectivamente. Os artefatos de desvio químico estavam presentes em 8% dos exames cartesianos. Artefatos de fluxo foram mais frequentes nas sequências BLADE. A sequência BLADE foi estatisticamente superior para todos os atributos qualitativos (p < 0,05), exceto na supressão de gordura (p = 0,054). O BLADE foi superior na avaliação dos implantes e clipes cirúrgicos (p < 0,05). O SNR foi estatisticamente superior na sequência BLADE (48,35 versus 16,17). Cronbach variou entre 0,502 e 0,813. Conclusão: A sequência BLADE foi superior à sequência de aquisição cartesiana de imagens na ponderação STIR, comprovada por uma melhor qualidade de imagem, menos artefatos e melhor avaliação da parede torácica e de linfonodos.

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.

Magnetic resonance imaging of the cirrhotic liver: diagnosis of hepatocellular carcinoma and evaluation of response to treatment – Part 2 / Ressonância magnética do fígado cirrótico: diagnóstico de carcinoma hepatocelular e avaliação da resposta ao tratamento – Parte 2

Abstract 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.

Resumo 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.

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 1 / Ressonância magnética do fígado cirrótico: diagnóstico de carcinoma hepatocelular e avaliação da resposta ao tratamento - Parte 1

Abstract 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.

Resumo 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.

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.

Technical aspects of MRI signal change quantification after gadolinium-based contrast agents' administration.

Over the last 2years several studies have been published regarding gadolinium deposition in brain structures in patients with normal renal function after repeated administrations of gadolinium-based contrast agents (GBCAs). Most of the publications are magnetic resonance imaging (MRI) based retrospective studies, where gadolinium deposition may be indirectly measured by evaluating changes in T1 signal intensity (SI) in brain tissue, particularly in the dentate nucleus (DN) and/or globus pallidi (GP). The direct correlation between T1 signal changes and gadolinium deposition was validated by human pathology studies. However, the variability of the MR equipment and parameters used across different publications, along with the inherent limitations of MRI to assess gadolinium in human tissues should be acknowledged when interpreting those studies. Nevertheless, MRI studies remain essential regarding gadolinium bio-distribution knowledge. The aim of this paper is to overview current knowledge of technical aspects of T1 signal intensity evaluation by MRI and describe confounding factors, with the intention to achieve higher accuracy and maximize reproducibility.

Gadolinium deposition disease: Initial description of a disease that has been around for a while.

PURPOSE: To describe the clinical manifestations of presumed gadolinium toxicity in patients with normal renal function. MATERIALS AND METHODS: Participants were recruited from two online gadolinium toxicity support groups. The survey was anonymous and individuals were instructed to respond to the survey only if they had evidence of normal renal function, evidence of gadolinium in their system beyond 30days of this MRI, and no pre-existent clinical symptoms and/or signs of this type. RESULTS: 42 subjects responded to the survey (age: 28-69, mean 49.1±22.4years). The most common findings were: central pain (n=15), peripheral pain (n=26), headache (n=28), and bone pain (n=26). Only subjects with distal leg and arm distribution described skin thickening (n=22). Clouded mentation and headache were the symptoms described as persistent beyond 3months in 29 subjects. Residual disease was present in all patients. Twenty-eight patients described symptoms following administration of one brand of Gadolinium-Based Contrast Agent (GBCA), 21 after a single GBCA administration and 7 after multiple GBCA administrations, including: gadopentetate dimeglumine, n=9; gadodiamide, n=4; gadoversetamide, n=4; gadobenate dimeglumine, n=4; gadobutrol, n=1; gadoteridol, n=2; and unknown, n=4. CONCLUSIONS: Gadolinium toxicity appears to arise following GBCA administration, which appears to contain clinical features seen in Nephrogenic Systemic Fibrosis, but also features not observed in that condition.

MRI Evaluation of cooperative and non-cooperative patients with non-traumatic acute abdominal pain - preliminary observations.

PURPOSE: To compare diagnostic performance of two MRI protocols, motion resistant and conventional breath-hold, in patients with acute abdominal pain. MATERIALS AND METHODS: Thirty-five patients unable to breath-hold underwent a motion-resistant protocol (Radial group). Twenty-seven patients able to breath-hold underwent conventional protocol. The diagnostic performance of MRI was calculated. Cartesian and radial 3D-GRE sequences were compared. RESULTS: In Radial group, diagnosis was correct in 31/35 patients (88.5%), with sensitivity and specificity of 85.7% and 87.5%. In Cartesian group, diagnosis was correct in 24/27 patients (88.9%), with sensitivity and specificity of 93.7% and 81.8%. CONCLUSION: MRI appeared moderately successful for non-cooperative patients presenting with acute abdominal pain, with comparable accuracy to the standard breath-hold protocol.

Lobulated margination of liver hemangiomas: Is this a definitive feature?

PURPOSE: To evaluate the occurrence rate of lobulated margination of hepatic hemangiomas. METHODS: The study population included 585 hemangiomas in 261 patients (161 females; mean age: 51.9years). Two readers independently reviewed all cases. RESULTS: Hemangiomas with lobulated margins accounted for 74.7% of all lesions. The incidence of lobulated margins was significantly higher (P<.001) in medium- and large-sized hemangiomas (77.6% and 99.5%, respectively). The majority of hemangiomas with type-3 enhancement showed lobulated margins (83.5%) (P<.001). CONCLUSION: Virtually, all hemangiomas>18mm show lobulated margins. The majority of hemangiomas with type-3 enhancement show lobulated margins. Lack of lobulated margins in larger lesions lowers the likelihood ratio for being hemangiomas.

Self-reported gadolinium toxicity: A survey of patients with chronic symptoms.

PURPOSE: This study aims to describe the self-reporting symptoms experienced by individuals with self-reported normal renal function after gadolinium based contrast agent (GBCA) administration. MATERIALS AND METHODS: This HIPAA-compliant, IRB-approved study consisted of an anonymous online survey of patients who believe that they suffer from gadolinium toxicity. 50 respondents completed the nine-question survey. RESULTS: Fifty (100%) of the subjects ascribed their complaints to gadolinium exposure. Thirty-three (66%) described the onset immediately following GBCA administration and 16 (32%) within 6weeks. The most common symptoms included bone/joint pain and head/neck symptoms including headache, vision change, and hearing change (77.6% each). Other symptoms occurred with lesser incidence. CONCLUSIONS: This survey represents an initial description of patients with normal renal function who self-described toxicity related to GBCA administration. Bone and joint complaints and skin changes are two of the most common complaints.

Gadolinium in Humans: A Family of Disorders.

OBJECTIVE: The literature informs us that gadolinium can cause health issues. At least four major gadolinium disorders, including the two well-recognized nephrogenic systemic fibrosis and severe acute adverse event, have been identified. CONCLUSION: We propose naming the histopathologically proven presence of gadolinium in brain tissue "gadolinium storage condition," and we describe a new entity that represents symptomatic deposition of gadolinium in individuals with normal renal function, for which we propose the designation "gadolinium deposition disease."

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.

Radiologist income, receipts, and academic performance: an analysis of many nations.

Background Considerable interest exists in comparison between healthcare systems across multiple countries, especially where cost enters the discussion. Purpose To evaluate the relationship between radiologists' income, receipts for studies, and academic performance across multiple countries. Material and Methods The annual income of radiologists and receipts for computed tomography (CT) and magnetic resonance imaging (MRI) were obtained based on a survey sent to expert radiologists practicing in 23 countries of varying developmental status. Articles published in generalist radiology journals determined the academic performance of each country. Results Among the developed countries, Canada has the highest estimated annual income for both private ($700,000/year) and university radiologists ($600,000/year) while Spain has the lowest income for private practice ($68,000/year) and Portugal has the lowest income for university practice ($57,300/year). Among the developing countries, Saudi Arabia has the highest incomes for both private ($210,000/year) and university ($140,000/year) radiologists and Vietnam has the lowest incomes for both private ($30,000/year) and university ($6,000/year) radiologists. Total receipts for CT and MRI studies ranged from $80/study (Portugal) to $1000/study (USA) in developed countries, and ranged from $30/study (Egypt) to $700/study (Saudi Arabia) in developing countries. A moderate correlation ( r = 0.482) was seen between radiologist's income and the receipts for combined practice in all countries. The radiology journal academic quotient was highest in The Netherlands among developed countries, and Turkey among developing countries. Conclusion A relatively broad range of radiologists' income is observed among developed and developing countries, which shows correlation with the receipts for advanced imaging studies. Countries with an acceptable compromise between income, receipts, and academic performance, may be the best models for other countries to emulate.

Signal intensity change on unenhanced T1-weighted images in dentate nucleus following gadobenate dimeglumine in patients with and without previous multiple administrations of gadodiamide.

OBJECTIVES: To evaluate the impact of previous administration of gadodiamide and neural tissue gadolinium deposition in patients who received gadobenate dimeglumine. METHODS: Our population included 62 patients who underwent at least three administrations of gadobenate dimeglumine, plus an additional contrast-enhanced last MRI for reference, divided into two groups: group 1, patients who in addition to gadobenate dimeglumine administrations had prior exposure to multiple doses of gadodiamide; group 2, patients without previous exposure to other gadolinium-based contrast agent (GBCAs). Quantitative analysis was performed on the first and last gadobenate dimeglumine MRIs in both groups. Dentate nucleus-to-middle cerebellar peduncle signal intensity ratios (DN/MCP) and relative change (RC) in signal over time were calculated and compared between groups using generalized additive model. RESULTS: Group 1 showed significant increase in baseline and follow-up DN/MCP compared to group 2 (p < 0.0001). The RC DN/MCP showed a non-statistically significant trend towards an increase in patients who underwent previous gadodiamide (p = 0.0735). CONCLUSION: There is increased T1 signal change over time in patients who underwent gadobenate dimeglumine and had received prior gadodiamide compared to those without known exposure to previous gadodiamide. A potentiating effect from prior gadodiamide on subsequent administered gadobenate dimeglumine may occur. KEY POINTS: • Neural gadolinium deposition is associated with multiple administrations of less stable GBCAs. • Less stable GBCA effect on subsequent more stable GBCA administrations is undetermined. • Significant increase of DN/MCP was seen in patients with previous gadodiamide exposure. • RC DN/MCP showed a non-significant increase in patients who received previous gadodiamide. • Potentiating effects from prior gadodiamide on subsequent administered gadobenate dimeglumine may occur.

Surrogate arterial phase imaging using a long duration (≈1.5 min) radial acquisition T1-weighted sequence: an alternative in patients unable to breath-hold.

BACKGROUND: Pediatric and adult patients unable to suspend respiration generally undergo magnetic resonance (MR) examinations that lack arterial phase imaging, which is a phase that provides substantial information on disease processes. An MR strategy that provides this type of information may be of considerable value. PURPOSE: To describe and assess the feasibility and enhancement quality of early-phase imaging utilizing long-duration radial 3D-GRE imaging by initiating the sequence prior to starting contrast injection. MATERIAL AND METHODS: Thirty-three consecutive patients (10 men, 23 women; 50.7 ± 25.5 years) underwent free-breathing gadolinium-enhanced radial 3D-GRE, with sequence initiation 30 s prior to contrast injection. Late hepatic arterial (LHA) phase was chosen for comparison. Images were evaluated for enhancement and overall image quality. Organ enhancement was calculated. Sub-group analysis was performed. RESULTS: Twenty-two examinations of radial 3D-GRE sequences were acquired during the LHA phase. Organ enhancement scores were of satisfactory to good quality (range, 3.32-3.82). There was a significant trend of superior overall enhancement quality scores in pediatrics and examinations performed at 3 T (P = 0.0225 and 0.0001, respectively). CONCLUSION: Arterial phase abdominal MR imaging is feasible using conventional radial 3D-GRE by adopting this simplistic proposed approach, which may allow arterial-phase imaging in patients unable to breath-hold.

An overview of imaging techniques for liver metastases management.

Evaluation of liver metastases is one of the most common indications for liver imaging. Imaging plays a key role in the of assessment liver metastases. A variety of imaging techniques, including ultrasonography, computed tomography, MRI and PET combined with CT scan are available for diagnosis, planning treatment, and follow-up treatment response. In this paper, the authors present the role of imaging for the assessment of liver metastases and the contribution of each of the different imaging techniques for their evaluation and management. Following recent developments in the field of oncology, the authors also present the importance of imaging for the assessment of liver metastases response to therapy. Finally, future perspectives on imaging of liver metastases are presented.