Current research status of Gd-EOB-DTPA-enhanced MRI in evaluating liver reserve function in residual liver tissue after liver tumor surgery / 临床肝胆病杂志

As a non-invasive， simple， and reproducible examination， Gd-EOB-DTPA-enhanced magnetic resonance imaging （MRI） has an important application value in evaluating liver reserve function. Currently in clinical practice， Gd-EOB-DTPA-enhanced MRI is mainly used to measure liver parenchymal signal intensity parameters， magnetic resonance relaxation time parameters， biliary tract enhancement parameters， and liver volume parameters to evaluate the liver reserve function of patients. In recent years， the use of Gd-EOB-DTPA-enhanced MRI in predicting liver reserve function in residual liver tissue after liver tumor surgery has become one of the hotspots in clinical research， and certain progress has been made in related studies in China and globally. This article reviews the research advances in recent years.

Two Cases of Secondary Hypertension with Rare Aetiology

Secondary Hypertension comprises approximately 5% of Systemic Hypertension1. Renal parenchymal, Renovascular and Endocrine Diseases are amongst the common causes of Secondary Hypertension. Takayasu,s Arteritis is a rare form of Primary Systemic Vasculitis that appears to be commoner in Asia than Europe or North America2 and in contrast to Japanese patients, who have a higher incidence of aortic arch involvement, the series from India reports higher incidences of thoracic and abdominal involvement. In general, patients from Indian subcontinent tend to have greater prevalence of Pan-aortic Disease (both above and below the diaphragm) when compared with the west. In India the women : men ratio is around 1.5:1. Takayasu, s Arteritis most frequently affects young women3. Therapeutic intervention like Percutaneous Transluminal Angioplasty (PTA) and Stenting, By-pass Surgeries or surgical reconstruction should be performed when disease is made inactive by the use of effective immunosuppressive Therapy4

Comparison of the diagnostic performance in the hepatocellular carcinoma with cirrhosis between the 2017 and 2018 versions of LI-RADS based on Gd-EOB-DTPA enhanced MRI / 中华放射学杂志

Objective:To compare the diagnostic performance in the hepatocellular carcinoma(HCC) with cirrhosis between the 2017 version of liver imaging reporting and data system (LI-RADS v2017) and 2018 version of LI-RADS (LI-RADS v2018) based on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced MRI.Methods:Clinical data of 213 patients with 246 hepatic lesions with cirrhosis who underwent Gd-EOB-DTPA enhanced MRI in the Third Affiliated Nantong Hospital of Nantong University from October 2015 to July 2020 were retrospectively collected. The MRI major features and LR categories of lesions were respectively reviewed by two radiologists according to LI-RADS v2017 and LI-RADS v2018, respectively. Taking postoperative histopathological results or follow-up imaging as references, with the LR-5 and LR-4+LR-5 as the diagnosis of HCC, the sensitivity, specificity and accuracy of the LI-RADS v2017 and LI-RADS v2018 were evaluated, respectively. The McNemar test or Fisher exact test was used to compare the diagnostic performance between the two LI-RADS versions.Results:In 246 hepatic lesions, 165 were HCCs, 31 were non-HCC malignancies and 50 were benign lesions. Due to the threshold growth and more simplified definition and changes in the LR-5 classification criteria in LI-RADS v2018, the categories of 38 (15.4%, 38/246) lesions were changed. The threshold growths of 84.6% (33/39) lesions in v2017 were reclassified to subthreshold growth in v2018. Using LI-RADS v2018, 10 lesions were down-categorized compared with LI-RADS v2017, including LR-5 to LR-4 in 7 lesions and LR-4 to LR-3 in 3 lesions, and 28 lesions were up-categorized LR-4 to LR-5, in which 25 were small HCC. With LR-5 as the diagnosis criteria of HCC, the sensitivity and accuracy of LI-RADS v2018 were 66.7% (110/165) and 73.6% (181/246); and the sensitivity and accuracy of LI-RADS v2017 were 55.8% (92/165) and 67.5% (166/246), both with statistical differences (χ2=4.13, P=0.001, χ2=6.20, P<0.001). No significant difference was found in the specificity values of LI-RADS v2018 and v2017 [87.7% (71/81) vs. 91.4% (74/81)], χ2=0.59, P=0.442). Compared with v2017, LI-RADS v2018 increased the sensitivity in the diagnosis of small HCC lesions (10-19 mm) [62.9% (56/89) vs. 40.4% (36/89), χ2=9.00, P<0.001]. With LR-4+LR-5 as the diagnostic criteria of HCC, there was no significant difference in the sensitivity, specificity and accuracy of LI-RADS v2017 and v2018 in the diagnosis of HCC (all P>0.05). Conclusions:Based on Gd-EOB-DTPA enhanced MRI, LI-RADS v2018 has higher sensitivity and similar specificity in the diagnosis of HCC compared to v2017, especially in the diagnosis of small HCC (10-19 mm).

Physicians with self-diagnosed gadolinium deposition disease: a case series / Médicos com doença de deposição de gadolínio autodiagnosticada: relato de série

Abstract Objective: The objective of this study was to allow physicians with self-diagnosed gadolinium deposition disease symptoms to report their own experience. Materials and Methods: Nine physicians (seven females), with a mean age of 50.5 ± 8.3 years, participated in this case series. Nationalities were American (n = 6), British, Portuguese, and Romanian. Medical practices included internal medicine (n = 2), trauma surgery, ophthalmology, gastroenterology, psychiatry, family medicine, obstetrics/gynecology, and general practice. Results: Genetically, eight of the physicians were of central European origin. Underlying autoimmune conditions were present in four. Symptoms developed after a single injection in one physician and after multiple injections in eight. The precipitating agent was gadobenate dimeglumine in four physicians, gadobutrol in three, gadoterate meglumine in one, and gadopentetate dimeglumine in one. The most consistent symptoms were a burning sensation, brain fog, fatigue, distal paresthesia, fasciculations, headache, and insomnia. Eight of the physicians were compelled to change their practice of medicine. Conclusion: In the various physicians, gadolinium deposition disease showed common features and had a substantial impact on daily activity. Physicians are educated reporters on disease, so their personal descriptions should spark interest in further research.

Resumo Objetivo: O objetivo deste estudo foi possibilitar que médicos com sintomas de doença de deposição de gadolínio autodiagnosticada relatassem sua própria experiência. Materiais e Métodos: Nove médicos (sete mulheres), com média de idade de 50,5 ± 8,3 anos, participaram desta série de casos. As nacionalidades foram americana (n = 6), britânica, portuguesa e romena. As práticas médicas incluíram medicina interna (n = 2), traumatologia, oftalmologia, gastroenterologia, psiquiatria, medicina de família, ginecologia/obstetrícia e clínica geral. Resultados: Geneticamente, oito dos médicos tinham origem europeia central. Condições autoimunes subjacentes estavam presentes em quatro médicos. Os sintomas se desenvolveram após uma única injeção em um médico e após várias injeções em oito. O agente precipitante foi gadobenato dimeglumina em quatro médicos, gadobutrol em três, gadoterato meglumina em um e gadopentetato dimeglumina em um. Os sintomas mais consistentes foram sensação de queimação, confusão mental, fadiga, parestesia distal, fasciculações, cefaleia e insônia. Oito dos médicos foram forçados a alterar a sua prática médica. Conclusão: Em vários médicos, a doença de deposição de gadolínio mostrou características comuns e teve um impacto substancial na atividade diária. Os médicos são repórteres treinados sobre doenças, assim, suas descrições pessoais devem despertar interesse em pesquisas futuras.

Renal functional compensation after unilateral radical nephrectomy of renal cell carcinoma / 北京大学学报(医学版)

OBJECTIVE@#To investigate factors influencing renal functional compensation(RFC) of the preserved kidney after radical nephrectomy (RN).@*METHODS@#A total of 286 patients treated with RN in Peking University People's Hospital were retrospectively analyzed. Preoperative body mass index (BMI), systolic blood pressure (SBP), history of smoking, history of chronic diseases and other basic information, as well as preoperative blood biochemistry, urine routine, imaging examination results were recorded. All the patients underwent 99mtechnetium-diethylenetriamine pentaacetic acid (99mTc-DTPA) renal scans before operation. The surgical method, pathology and blood creatinine values from 1 month to 60 months after RN were recorded. Preoperative and postoperative estimated glomerular filtration rate (eGFR) was calculated by the chronic kidney disease epidemiology collaboration (CKD-EPI) formula. Renal functional compensation was defined as percent change in eGFR of the preserved kidney after RN compared with the preoperative eGFR. Univariate and multivariate regression analyses were used to identify predictive factors of RFC.@*RESULTS@#Median age was 61 years and 65.4% of the patients were male. Early stage (T1 or T2) tumors were found in 83.6% of the cases. 18.5% of the patients had preoperative diabetes mellitus, 39.5% had hypertension, 19.2% had a history of smoking, and 27.6% were found to have renal cyst on the contralateral side. In the study, 226 cases underwent laparoscopic radical nephrectomy and 60 cases underwent open radical nephrectomy. Renal clear cell carcinoma was the most common pathological type, accounting for 88.5%. The median tumor maximum diameter was 4.5 cm (0.7-13.5 cm). Median renal function compensation was 27% one month after radical nephrectomy. Functional stability was then observed to 5 years. The results of univariate analysis showed that age, gender, preoperative blood uric acid, preoperative urine protein, contralateral renal cyst, and percentage of split renal function of contralateral kidney were correlated with RFC (P < 0.05). Among them, UA level and split renal function of contralateral kidney were strongly negatively correlated with RFC. The results of multivariate linear regression analysis showed age (P < 0.001), blood uric acid (P < 0.001), urine protein (P=0.002), preoperative eGFR (P < 0.001) and the split renal function of contralateral kidney (P < 0.001) were independent predictors of RFC.@*CONCLUSION@#The basic examinations, such as blood biochemistry, urine routine and renal scan before RN are of great significance in predicting the compen-satory ability of the preserved kidney after RN, which is supposed to be taken into consideration when making clinical decision.

Vacunación de la embarazada / Maternal immunization

Las vacunas han sido una de las herramientas más útiles para lograr disminuir la mortalidad infantil. Sin embargo, los beneficios de las vacunas para menores de un año son dispares, debido a que son muy pequeños para ser vacunados. Otro grupo vulnerable son las embarazadas, quienes presentan mayor morbimortalidad por enfermedades como la influenza. La inmunización materna puede proteger a la madre contra las infecciones prevenibles por vacuna y al recién nacido mediante el traspaso de anticuerpos específicos al feto. No hay evidencia de resultados adversos en el embarazo o el feto/recién nacido por la vacunación de mujeres gestantes con vacuna inactivada contra virus, bacterias o toxoides. Por lo tanto, el embarazo no debe impedir que las mujeres reciban las vacunas que están médicamente indicadas. En Chile, se recomienda la vacunación de las mujeres gestantes, antes o durante la temporada de influenza. A fines de 2017 se implementó la vacunación con dTpa de las embarazadas con más de 28 semanas de gestación, con el objetivo de proteger al recién nacido contra el coqueluche y sus complicaciones. En el presente artículo, se hace una revisión de la literatura disponible sobre la vacunación de las embarazadas, principalmente enfocado en inmunización contra la influenza, el coqueluche y los beneficios en sus hijos.

Vaccines have been one of the most useful tools to reduce infant mortality. However, the benefits of vaccines for children under one year are disparate, because they are too small to be vaccinated. Another vulnerable group are pregnant women, who have a higher morbidity and mortality due to diseases such as influenza. Maternal immunization can protect the mother against vaccine-preventable infections and the newborn by transferring specific antibodies to the fetus. There is no evidence of adverse outcomes in pregnancy or the fetus / newborn by vaccination of pregnant women with inactivated vaccine against viruses, bacteria or toxoids. Therefore, pregnancy should not prevent women from receiving vaccines that are medically indicated. In Chile, vaccination is recommended for pregnant women, before or during the influenza season. In addition to the end of 2017, vaccination with Tdap of pregnant women with more than 28 weeks of gestation was implemented, with the aim of protecting the newly born against pertussis and its complications. In this article, we review the available literature on the vaccination of pregnant women, mainly focused on immunization against influenza, pertussis and benefits in their children.

A comparative study of different methods of estimating glomerular filtration rate in a subset of Filipinos with normal renal function

@#Kidney function is commonly quantified using the glomerular filtration rate (GFR). However, the gold standard of measuring GFR, inulin clearance, is not practical for daily clinical use. This study compares different methods of GFR estimation based on serum creatinine, plasma levels of 99mTc-diethylenetriaminepentaacetic acid (DTPA), and camera acquisition of 99mTc-DTPA uptake. Seventy-five Filipino adults between ages 20 and 35 presumed to have normal kidneys were recruited. Each subject underwent gamma camera scintigraphy using the Gates and Inoue protocols after receiving a dose of 99mTc-DTPA. Blood samples were subsequently extracted at 1 hour and 3 hours after tracer injection, and GFRs were calculated based on single- and double-plasma sampling methods (SPSM and DPSM, respectively). Serum creatinine was also measured to derive GFR using the CKD-EPI, MDRD, and CockroftGault equations. Each method was correlated with a reference standard (DPSM) based on accuracy, linear regression, bias, and precision. SPSM tends to overestimate GFR unlike the other methods evaluated, but otherwise shows the most favorable diagnostic performance among the six methods when correlated with DPSM. The Inoue method appears modestly better than the routinely utilized Gates protocol, though both methods exhibit lack of precision. The CKD-EPI formula shows similar, if not slightly superior, diagnostic properties to the MDRD and Cockroft-Gault equations, thus confirming its validity for use in this Filipino population subset. Further studies are needed, particularly involving SPSM and CKD-EPI, to determine the applicability of our findings in Filipinos with varying degrees of kidney function. It is hoped that modifications to these methods can be made that are tailor-fit to derive more accurate and population-specific GFR values.

Impact of percutaneous nephrolithotomy operation on non-operated kidney: a single center based study

Background: Effects of percutaneous nephrolithotomy (PCNL) operation on ipsilateral renal function are widely known but functional changes in opposite kidney are limited. Authors have conducted this study to evaluate the impact of PCNL operation on the contralateral side during early post-operative period.Methods: From 1st November 2016 to 30th September 2018, those patients presented with unilateral renal stone disease were enrolled. After exclusion they were subjected to PCNL operation under general anaesthesia. Along with preoperative period, 99 m Tc DTPA renal scan is repeated at 3rd and 14th post-operative period.Results: Out of 121 patients enrolled we included 96 patients after exclusion. They are divided into 3 age groups, 19-32, 33-47 and 48-60 years. The mean GFR at pre-operative, post-operative day-3 and 14 of normal kidney in these 3 age groups are 47.32, 47.63 and 42.32 ml/min, 44.29, 45.78 and 40.63 ml/min and 47.10, 48.47 and 41.01 ml/min respectively. At post op day-3 there are reduction of mean GFR in all age groups but statistically not significant (p >0.05). At post-operative day-14 GFR improved towards the pre-op value but the change is also not significant (p >0.05).Conclusions: There are reduction of GFR of contralateral normal kidney following PCNL operation in early post-operative period. So, along with operated kidney normal kidney also showed decrease GFR. It is better to avoid further trauma in post PCNL patient like avoidance of using nephrotoxic medication, contrast agents, ESWL, etc. This study can guide us to avoid further trauma of any kidney.

Usefulness of Gd-EOB-DTPA-enhanced MRI for evaluating the potential for early development of hepatocellular carcinoma after HCV eradication by direct-acting antiviral treatment / Journal of Rural Medicine

Objective: The development of hepatocellular carcinoma (HCC) is not uncommon in patients who achieve eradication of the hepatitis C virus through direct-acting antiviral (DAA) treatment. The aim of this study was to identify the patients at high risk for novel HCC development after a sustained virologic response (SVR) by DAA treatment.Patients and Methods: A total of 518 patients with no history of HCC treatment and who achieved SVR by DAA treatment were evaluated retrospectively. The correlations between HCC development and the patients’ characteristics were evaluated. For patients who underwent gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) or dynamic contrast-enhanced computed tomography, the relationship between the imaging findings and subsequent HCC development was also assessed.Results: HCC developed newly in 22 patients, and the 1-year and 3-year cumulative HCC rates were 2.0% and 8.5%, respectively. In multivariate analysis, a FIB-4 index >4.0 and a post-treatment α-fetoprotein >4.0 ng/ml were significant risk factors for HCC. In 26 of 118 patients who underwent an MRI before DAA treatment, a non-hypervascular hypo-intense nodule was seen in the hepatobiliary phase, and in 6 of 182 patients who underwent a CT, a non-hypervascular hypo-enhanced nodule was seen in the delayed phase. The sensitivity and specificity of the MRI-positive findings for the subsequent development of HCC were 0.92 and 0.87, respectively, and those of the CT were 0.40 and 0.99, respectively. In multivariate analysis of patients who underwent an MRI, a non-hypervascular hypo-intense nodule was the only factor that was significantly related to HCC development (HR 32.4, p = 0.001).Conclusion: Gd-EOB-DTPA-enhanced MRI was found to be reliable for risk evaluation of subsequent HCC development in patients after SVR by DAA treatment. Patients with a non-hypervascular hypo-intense nodule need more careful observation for incident HCC.

Intraindividual Comparison between Gadoxetate-Enhanced Magnetic Resonance Imaging and Dynamic Computed Tomography for Characterizing Focal Hepatic Lesions: A Multicenter, Multireader Study

OBJECTIVE: To compare the diagnostic accuracy of dynamic computed tomography (CT) and gadoxetate-enhanced magnetic resonance imaging (MRI) for characterization of hepatic lesions by using the Liver Imaging Reporting and Data System (LI-RADS) in a multicenter, off-site evaluation.MATERIALS AND METHODS: In this retrospective multicenter study, we evaluated 231 hepatic lesions (114 hepatocellular carcinomas [HCCs], 58 non-HCC malignancies, and 59 benign lesions) confirmed histologically in 217 patients with chronic liver disease who underwent both gadoxetate-enhanced MRI and dynamic CT at one of five tertiary hospitals. Four radiologists at different institutes independently reviewed all MR images first and the CT images 4 weeks later. They evaluated the major and ancillary imaging features and categorized each hepatic lesion according to the LI-RADS v2014. Diagnostic performance was calculated and compared using generalized estimating equations.RESULTS: MRI showed higher sensitivity and accuracy than CT for diagnosing hepatic malignancies; the pooled sensitivities, specificities, and accuracies for categorizing LR-5/5V/M were 59.0% vs. 72.4% (CT vs. MRI; p < 0.001), 83.5% vs. 83.9% (p = 0.906), and 65.3% vs. 75.3% (p < 0.001), respectively. CT and MRI showed comparable capabilities for differentiating between HCC and other malignancies, with pooled accuracies of 79.9% and 82.4% for categorizing LR-M, respectively (p = 0.139).CONCLUSION: Gadoxetate-enhanced MRI showed superior accuracy for categorizing LR-5/5V/M in hepatic malignancies in comparison with dynamic CT. Both modalities had comparable accuracies for distinguishing other malignancies from HCC.

ThevalueofGd-EOB-DTPA-enhanced MRIindiagnosisofhepatocellularcarcinoma / 实用放射学杂志

Objective ToexplorethediagnosticvalueofenhancedCTandGd-EOB-DTPA-enhanced MRIinthedetectionofhepatocellular carcinoma (HCC).Methods 41patientswith52HCCsunderwentenhancedCTandGd-EOB-DTPA-enhancedMRIrespectively.The imagingmanifestationswereanalyzed,andthelesionsweregrouped.Theimagingdiagnositicresultswerecomparedwiththepathologicalresults, andtheefficacyofthetwomodalitieswasevaluatedusingtheaccuracyindex.Results Ofthetotal52HCCs,42lesionswereidentifiedexactlyby enhancedCT,and51byGd-EOB-DTPA-enhancedMRI.Foralllesions,includingsmalllesions(≤2cm),theaccuracyratioofGd-EOB-DTPA-enhancedMRIwashigherthanthatofenhancedCT withastatisticallysignificantdifference(P<0.05),however,therewasnosignificant differenceforthelesionsbiggerthan2cm (P>0.05).Conclusion EnhancedCTislimitedindiagnosisoftheHCCssmallerthanor equalto2cm.ThediagnosticefficacyofGd-EOB-DTPA-enhanced MRIishigherthanthatofenhancedCT,anditcansignificantly improvethediagnosisofsmallHCC.

PreoperativePredictionoftheExpressionofCK19inHepatocellularCarcinomaby Gd-EOB-DTPAEnhancedMRI / 中山大学学报(医学科学版)

@#【Objective】 To investigate the predictive value of preoperative Gd- EOB- DTPA enhanced MRI in the expression of cytokeratin 19（CK19）in hepatocellular carcinoma（HCC）.【Methods】A total of 102 patients，including 94 male and 8 female，with single HCC confirmed by pathology after operation who underwent preoperative enhanced MRI were retrospectively analyzed. A total of 25 were CK19-positive HCC and 77 were CK19-negative HCC. Two radiologists evaluated MR features including tumor size，tumor margin，intratumoral vessels，signal intensity（SI）on arterial phase （AP） ，enhancement pattern ，arterial rim enhancement ，peritumoral enhancement ，internal cystic or necrotic portion，hemorrhage，intratumoral fat，tumor capsule，vascular invasion，lymph node metastasis，intratumoral septum， target sign on diffusion weighted imaging（DWI）or hepatobiliary phase（HBP），peritumor hypointensity，SI on ADC，SI on HBP ，T1 relaxation times and T1 reduction rate between pre- and post- contrast enhancement. The associations between these imaging features and CK19 expression were investigated. 【Results】SI on AP（P = 0.013），arterial rim enhancement（P = 0.018），target sign on DWI（P = 0.001）and target sign on HBP（P = 0.005）were significantly associated with CK19 expression. Delayed enhanced intratumoral septum（P = 0.042）was associated with CK19 expression between HCCs less than 5 cm. Target sign on DWI（P = 0.001，OR = 4.875，95%CI：1.838~12.927）were independent significant factors of CK19- positive HCC.【Conclusion】Preoperative enhanced MRI with Gd- EOB- DTPA is helpful to predict CK19 expression of HCC.

Nuclear Imaging in Pediatric Kidney Diseases

Renal scintigraphy is a useful tool in diagnosis and management of various nephro-urological conditions. Tc-99m dimercaptosuccinicacid renal scintigraphy (Tc-99m-DMSA), Tc-99m mercaptoacetyltriglycine (Tc-99m-MAG3) or Tc-99m diethylenetriaminepentaaceticacid (Tc-99m-DTPA) dynamic renal scintigraphy, and Radionuclide micturating cystography are the common scans used in children withkidney diseases. These studies are minimally invasive, easily available, and offer both anatomic details and functional informationrequired for thorough evaluation. At the same time, it is essential to have appropriate knowledge to interpret these studies and be awareof their limitations and pitfalls. The advent of Positron emission tomography-computed tomography/magnetic resonance imaging (PET-CT/MRI) has broadened the scope of nuclear medicine. This article focuses on the technique, interpretation, indication and recentpractice guidelines of renal scintigraphy in children with kidney diseases.

Myocardial T1 mapping and determination of partition coefficients at 3 tesla: comparison between gadobenate dimeglumine and gadofosveset trisodium / Mapa T1 e coeficiente de partição do miocárdio em aparelho 3 tesla: comparação entre gadobenato de dimeglumina e gadofosveset trissódico

Abstract Objective: To compare an albumin-bound gadolinium chelate (gadofosveset trisodium) and an extracellular contrast agent (gadobenate dimeglumine), in terms of their effects on myocardial longitudinal (T1) relaxation time and partition coefficient. Materials and Methods: Study subjects underwent two imaging sessions for T1 mapping at 3 tesla with a modified look-locker inversion recovery (MOLLI) pulse sequence to obtain one pre-contrast T1 map and two post-contrast T1 maps (mean 15 and 21 min, respectively). The partition coefficient was calculated as ΔR1myocardium /ΔR1blood , where R1 is 1/T1. Results: A total of 252 myocardial and blood pool T1 values were obtained in 21 healthy subjects. After gadolinium administration, the myocardial T1 was longer for gadofosveset than for gadobenate, the mean difference between the two contrast agents being −7.6 ± 60 ms (p = 0.41). The inverse was true for the blood pool T1, which was longer for gadobenate than for gadofosveset, the mean difference being 56.5 ± 67 ms (p < 0.001). The partition coefficient (λ) was higher for gadobenate than gadofosveset (0.41 vs. 0.33), indicating slower blood pool washout for gadofosveset than for gadobenate. Conclusion: Myocardial T1 times did not differ significantly between gadobenate and gadofosveset. At typical clinical doses of the contrast agents, partition coefficients were significantly lower for the intravascular contrast agent than for the extravascular agent.

Resumo Objetivo: Avaliar o efeito da utilização de um agente de contraste intravascular baseado em gadolínio quelado a albumina (gadofosveset) no tempo T1 e no coeficiente de partição do miocárdio, quando comparado com um agente de contraste extravascular baseado no gadolínio não quelado a albumina (gadobenato). Materiais e Métodos: Os participantes do estudo foram submetidos a dois exames para aquisições do mapeamento T1 em aparelho de 3 tesla. Utilizando uma sequência de pulso modificada - modified look-locker inversion recovery (MOLLI) -, realizou-se uma etapa pré-contraste e duas etapas pós-contraste do mapa T1 (média de 15 e 21 minutos). O coeficiente de partição foi calculado como: ΔR1miocárdio /ΔR1sangue. Resultados: Um total de 252 valores de mapa T1 no miocárdio e no sangue foi obtido em 21 indivíduos saudáveis. Após a administração do meio de contraste, a diferença média do tempo T1 do miocárdio entre os agentes de contraste foi -7,6 ± 60 ms (p = 0,41) (isto é, gadobenato T1 < gadofosveset T1). Já no sangue, a diferença média de tempo T1 foi 56,5 ± 67 ms (p < 0,001) (isto é, gadobenato T1 > gadofosveset T1). O coeficiente de partição foi maior para o gadobenato (λ = 0,41) do que para o gadofosveset (λ = 0,33), refletindo uma eliminação mais lenta do gadofosveset em comparação com o gadobenato. Conclusão: Os tempos T1 do miocárdio não foram significativamente diferentes entre gadobenato e gadofosveset. Os coeficientes de partição foram significativamente mais baixos para o agente de contraste intravascular em comparação com o agente extravascular em doses clínicas típicas de cada contraste.

A comparative study of fluoroscopic triggering method and empirical delay method for Gd-EOB-DTPA dynamic enhanced MRI in the liver / 实用放射学杂志

Objective To compare the effect of fluoroscopic triggering method and empirical delay method on image quality in the liver Gd-EOB-DTPA dynamic enhanced MRI,and to investigate the value of fluoroscopic triggering method in Gd-EOB-DTPA dynamic enhanced MRI.Methods The patients underwent Gd-EOB-DTPA dynamic enhanced MRI were randomly divided into two groups according to the starting modes in the artery phase.Group A used fluoroscopic triggering method and group B used empirical delay method.Eliminating the images with severe respiratory motion artifacts,the quality of the remaining images in 78 cases of group A and 85 cases of group B were assessed in scores (excellent=5 scores;good=4 scores).Data was statistically analyzed with Mann-whitney tests,and P<0.05 was considered statistically significant.Results The excellent rate of the images in group A was 96.15% (75/78).The excellent rate of the images in group B was 67.06% (57/85).There were significant differences between the two groups in the excellent rate (χ2=27.889, P<0.001)and the image quality scores (Z=-4.747,P<0.001).Conclusion For the liver Gd-EOB-DTPA dynamic enhanced MRI, fluoroscopic triggering method is more likely to get better image quality and higher success rate in artery phase than empirical delay method,which indicates that fluoroscopic triggering method have obviously advantages in clinical applications.

Optimization of delivering minimum Gd-DTPA at the posterior upper point on tympanic medial wall and hT2W-3D-FLAIR sequence for detecting endolymphatic hydrops / 中华耳鼻咽喉头颈外科杂志

Objective@#To optimize delivery of gadolinium-diethylenetriamine pentaacetic acid(Gd-DTPA) at the posterior upper point on tympanic medial wall and heavily T2-weighted 3-dimensional fluid-attenuated inversion recovery (hT2W-3D-FLAIR) sequence, and to implement the technique of detecting endolymphatic hydrops using gadolinium-enhancement MRI.@*Methods@#Thirteen patients with periphery vertigo, who visited Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Changhai Hospital during June and December of 2017, were enrolled in the study.0.10-0.20 ml of Gd-DTPA in various dilutions (10, 20, and 40-fold) were delivered at the posterior upper point on tympanic medial wall using a soft-tipped tympanic suction and drug-spraying needle through an artificially perforated tympanic membrane. Inner ear MRI was performed at 8, 24 h after Gd-DTPA administration using a 3T MR machine in combination with a 20-channel Tim 4G head/neck coil and the sequence of hT2W-3D-FLAIR to detect the gadolinium-enhancement signal within the inner ear and possible endolymphatic hydrops. The scanning time was either 8 min 35 s or 15 min 11 s.@*Results@#Efficient inner ear uptake of Gd-DTPA was detected and induced high signal to noise ratio of MRI in patients receiving targeted delivery of 0.15-0.20 ml of 10-fold diluted contrast agent at the posterior upper point on tympanic medial wall. At 8 h after delivery, significant uptake was detected in the scala tympani and vestibuli of hook region and basal turn of the cochlea, and perilymhatic compartment of the vestibule. At 24 h after delivery, the distribution of Gd-DTPA became homogenous in each turn of the cochlea and perilymphatic compartment of the vestibule. However, obvious individual variance existed in the inner ear uptake when 0.10 ml of 40-fold diluted Gd-DTPA was delivered. Efficient inner ear uptake and high quality images that generated in patients receiving 0.10, 0.15, and 0.20 ml of 20-fold Gd-DTPA demonstrated endolymphatic hydrops with minor individual variance. There was insignificant difference in the enhancement signal of inner ear between 0.15 and 0.10 ml groups when Gd-DTPA was diluted at 20-fold except for the signal of semicircular canal of 0.15 ml group (190.00±53.95 vs 165.50±42.13, t=2.61, P<0.05). There was insignificant difference in the image quality between 8 min 35 s and 15 min 11 s canning time. Various degrees of endolymphatic hydrops were detected in 7 cochleae and 11 vestibule, and both simultaneous cochlear and vestibular endolymphatic hydrops were detected in 4 ears. Cochlear endolymphatic hydrops was detected in all the 3 patients with definite Meniere′s disease, and 2 of them had combined cochlear and vestibular endolymphatic hydrops. Endolymphatic hydrops was not detected in patients with possible Meniere′s disease nor with symptoms of superior semicircular canal dehiscence.@*Conclusion@#Targeted delivery of 0.10 ml with 20-fold diluted Gd-DTPA (total dosage of 5 μmol) at the posterior upper point on tympanic medial wall in combination with 8 min 35 s scanning time hT2W-3D-FLAIR sequence for inner ear MRI in a 3T MR machine is a clinically practical method to detect endolymphatic hydrops, and reduce the requirement for MRI hardware.

Optimization of the Flip Angle and Scan Timing in Hepatobiliary Phase Imaging Using T1-Weighted, CAIPIRINHA GRE Imaging

PURPOSE: This study was designed to optimize the flip angle (FA) and scan timing of the hepatobiliary phase (HBP) using the 3D T1-weighted, gradient-echo (GRE) imaging with controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique on gadoxetic acid-enhanced 3T liver MR imaging. MATERIALS AND METHODS: Sixty-two patients who underwent gadoxetic acid-enhanced 3T liver MR imaging were included in this study. Four 3D T1-weighted GRE imaging studies using the CAIPIRINHA technique and FAs of 9° and 13° were acquired during HBP at 15 and 20 min after intravenous injection of gadoxetic acid. Two abdominal radiologists, who were blinded to the FA and the timing of image acquisition, assessed the sharpness of liver edge, hepatic vessel clarity, lesion conspicuity, artifact severity, and overall image quality using a five-point scale. Quantitative analysis was performed by another radiologist to estimate the relative liver enhancement (RLE) and the signal-to-noise ratio (SNR). Statistical analyses were performed using the Wilcoxon signed rank test and one-way analysis of variance. RESULTS: The scores of the HBP with an FA of 13° during the same delayed time were significantly higher than those of the HBP with an FA of 9° in all the assessment items (P < 0.01). In terms of the delay time, images at the same FA obtained with a 20-min-HBP showed better quality than those obtained with a 15-min-HBP. There was no significant difference in qualitative scores between the 20-min-HBP and the 15-min-HBP images in the non-liver cirrhosis (LC) group except for the hepatic vessel clarity score with 9° FA. In the quantitative analysis, a statistically significant difference was found in the degree of RLE in the four HBP images (P = 0.012). However, in the subgroup analysis, no significant difference in RLE was found in the four HBP images in either the LC or the non-LC groups. The SNR did not differ significantly in the four HBP images. In the subgroup analysis, 20-min-HBP imaging with a 13° FA showed the highest SNR value in the LC-group, whereas 15-min-HBP imaging with a 13° FA showed the best value of SNR in the non-LC group. CONCLUSION: The use of a moderately high FA improves the image quality and lesion conspicuity on 3D, T1-weighted GRE imaging using the CAIPIRINHA technique on gadoxetic acid, 3T liver MR imaging. In patients with normal liver function, the 15-min-HBP with a 13° FA represents a feasible option without a significant decrease in image quality.

Lexiscan can open the blood-brain barrier temporarily and reversibly / 中华核医学与分子影像杂志

Objective To evaluate the opening level and optimal time window of the blood-brain barrier induced by adenosine A2 receptor agonist ( Lexiscan) via dynamic enhanced MRI. Methods Twen-ty New Zealand white rabbits were divided into experiment group ( group A, n=10) and control group ( group B, n=10) . Rabbits in group A were injected with Lexiscan and rabbits in group B were injected with physiological salt via ear vein, then the coronary scanning was performed. Contrast enhanced MRI was performed at different time points ( 5, 10, 15, 20 min, and then every 10 min, until 2 h) following the in-fusion of Gd-diethylene triamine pentaacetic acid (DTPA). The signal intensity (SI) of region of interest ( ROI) was measured and the percent enhancement of SI was calculated. Evens blue staining results in brain tissues were observed. Pair t test was used to analyze the data. Results The percent enhancement of SI in group A significantly increased to (40. 93±3.70)％ at 5 min, reached the maximum of (43.03±3.62)％ at 30 min, slowly decreased until 50 min, and got to a stable level at almost 80 min. At each time point, the per-cent enhancement of SI in group A was significantly higher than that in group B ( t values:6.88-20.28, all P<0. 05) . The staining was evident in group A. Conclusions Lexiscan can open blood-brain barrier tem-porarily and reversibly, and the optimal opening time window is 10-50 min post-injection.

Assessment of liver function of patients with HBV-related cirrhosis using T1 mapping on Gd-EOB-DTPA-enhanced MRI / 中华肝胆外科杂志

Objective To evaluate the value of T1 mapping in Gd-EOB-DTPA-enhanced MRI for the assessment of liver function with HBV-related cirrhosis according to the model for end-stage liver disease (MELD) score.Methods 158 patients with HBV-related cirrhosis were included in this prospective study,and divided into MELD score ≤10 (n =103) group and MELD score ＞ 10 (n =55) group.All patients un derwent non-enhanced and Gd-EOB-DTPA enhanced MRI of liver,and T1 mapping was performed using Look-Locker sequences with the same scan parameters and geometry position (the level of porta hepatis) preand post-contrast at 5,10,15 and 20 minutes after Gd-EOB-DTPA administration.T1 relaxation times of the liver were measured and reduction rates of T1 relaxation times (△T1) were calculated.Independent samples t test was performed to compare T1 relaxation times and △T1 between MELD score≤ 10 and MELD score ＞ 10 groups.Receiver operating characteristic curve (ROC) analysis were done to differentiate the diagnostic performance of T1 relaxation times and △T1 between MELD score ≤ 10 and MELD score ＞ 10 groups.Pearson correlation analysis was used to analyse the correction between T1 relaxation times,△T1 and MELD scores.Results T1 relaxation times pre-and post-contrast at 5,10,15 and 20 minutes and △T1 post-contrast at 5,10,15 and 20 minutes of MELD score≤10 group were (889.3 ±91.2) ms,(377.5 ± 55.0) ms,(350.8±61.2)ms,(328.0±69.4)ms,(302.7±73.7)ms,(57.4±5.6)％,(60.4± 6.5) ％,(63.0 ± 7.3) ％ and (65.9 ± 7.8) ％,respectively,and those of MELD score ＞ 10 group were (936.6 ±95.4) ms,(460.2 ±68.5) ms,(457.5 ±94.5) ms,(453.4 ± 116.4) ms,(444.6 ± 134.6) ms,(50.8 ± 5.7) ％,(51.3 ± 7.9) ％,(51.8 ± 10.3) ％ and (52.8 ± 12.2) ％,respectively,and T1 relaxation times and △T1 at all time points were significantly different (P ＜ 0.05) between the two groups.The areas under ROC curve of T1 relaxation time pre-and post-contrast at 5,10,15,20 minutes and △T1 post-contrast at 5,10,15,20 minutes for differentiating MELD score ≤ 10 and MELD score ＞ 10 groups were 0.638,0.824,0.832,0.832,0.830 and 0.795,0.814,0.820,0.825,respectively.The correlation coefficients between T1 relaxation time pre-and post-contrast at 5,10,15,20 minutes,△T1 post-contrast at 5,10,15,20 minutes and MELD scores were 0.256,0.499,0.540,0.538,0.548,-0.412,-0.495,-0.507 and-0.527,respectively.Conclusions T1 mapping on Gd-EOB-DTPA-enhanced MRI is helpful for evaluating liver function with HBV-related cirrhosis.T1 relaxation times post-contrast on different time points were equally accurate as △T1.T1 relaxation times post-contrast and △T1 were superior to T1 relaxation times pre-contrast.

Diagnostic value of Gd-EOB-DTPA enhanced MRI compared with contrast-enhanced ultrasound for small hepatocellular carcinoma / 实用放射学杂志

Objective To compare the diagnostic value of Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced MRI and contrast-enhanced ultrasound (CEUS) in detection of small hepatocellular carcinoma (sHCC).Methods A total of 22 patients with 29 lesions who underwent Gd-EOB-DTPA enhanced MRI and CEUS scan,and confirmed as sHCCs by pathology were included in this study.Gd EOB DTPA enhanced MRI pattern for the conclusive diagnosis of sHCC were lesions showed iso or low signal on T1 WI,showed slightly high signal or high signal on T2 WI,showed high signal on DWI and obviously enhanced in the arterial phase and/or clearance in the hepatobiliary phase;CEUS pattern for the conclusive diagnosis of sHCC were rapidly increasing in the arterial phase and showing low echo in the delay phase.Results The diagnostic sensitivity of detecting sHCC by Gd EOB-DTPA enhanced MRI and CEUS were 82.76％ and 65.52％ respectively,and there was no statistical difference (x2 =2.248,P=0.134),the diagnosis specificity were both 100 ％.Conclusion Both of the diagnostic sensitivity and specificity for detecting sHCC by Gd EOB DTPA enhanced MRI and CEUS showed no difference,the value of diagnostic sensitivity of the former is higher.