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.

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.

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.

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.

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.

A feasibility study evaluating the relationship between dose and focal liver reaction in stereotactic ablative radiotherapy for liver cancer based on intensity change of Gd-EOB-DTPA-enhanced magnetic resonance images

PURPOSE: In order to evaluate the relationship between the dose to the liver parenchyma and focal liver reaction (FLR) after stereotactic ablative body radiotherapy (SABR), we suggest a novel method using a three-dimensional dose distribution and change in signal intensity of gadoxetate disodium-gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) hepatobiliary phase images. MATERIALS AND METHODS: In our method, change of the signal intensity between the pretreatment and follow-up hepatobiliary phase images of Gd-EOB-DTPA-enhanced MRI was calculated and then threshold dose (TD) for developing FLR was obtained from correlation of dose with the change of the signal intensity. For validation of the method, TDs for six patients, who had been treated for liver cancer with SABR with 45-60 Gy in 3 fractions, were calculated using the method, and we evaluated concordance between volume enclosed by isodose of TD by the method and volume identified as FLR by a physician. RESULTS: The dose to normal liver was correlated with change in signal intensity between pretreatment and follow-up MRI with a median R2 of 0.935 (range, 0.748 to 0.985). The median TD by the method was 23.5 Gy (range, 18.3 to 39.4 Gy). The median value of concordance was 84.5% (range, 44.7% to 95.9%). CONCLUSION: Our method is capable of providing a quantitative evaluation of the relationship between dose and intensity changes on follow-up MRI, as well as determining individual TD for developing FLR. We expect our method to provide better information about the individual relationship between dose and FLR in radiotherapy for liver cancer.

Evaluation of diffusion weighted imaging after contrast in characterizing breast tumors / 实用放射学杂志

Objective To evaluate the effect of intravenous administration of gadolinium-DTPA on diffusion weighted imaging (DWI)of breast lesions and apparent diffusion coefficient(ADC)values,and to evaluate the diagnostic performance of post-contrast ADC for differentiating benign from malignant lesions in breast.Methods Thirty-eight histopathologically-confirmed breast lesions were analyzed.We examined the signal to noise ratio(SNR)of normal breast tissue and lesions and evaluated the contrast to noise ratio(CNR)of each lesion.We also assessed the relation between pre-and post-contrast ADC values.Results SNRs and CNRs of DWI before and after contrast were not significantly different.The mean post-contrast ADC values for malignant lesions significantly decreased after contrast injected (mean of -1 1.6%),while ADC values in the benign lesions were not significantly different before and after contrast.Conclusion Post-contrast ADC values may be a better indicator of potential breast tumors than pre-contrast ADC values.

MR score system on spatium perilymphaticum gadolinium opacification and its application for diagnosis of Meniere's disease / 中华放射学杂志

Objective To propose a MR scoring methods for spatium perilymphaticum gadolinium opacification and explore the value of their diagnosis of Meniere' s disease. Methods Fifty-one asymptomatic and 65 symptomatic patients with Meniere's disease were enrolled in this study.MR imaging ofspatium perilymphaticum after intratypanic gadolinium injection were analyzed with following scoring method.　( 1 ) Semicircular canal not visualized equal to score 0 ; some visualized equal score 1 ; full visualized equal　score 2.(2)There were high-signal and low-signal in the vestibule,low-signal areas above the lateral　semicircular canal plane equal score 6 ; low signal areas down to lateral semicircular canal plane equal score　3 ; no higher signal in the vestibule area equal score 0.( 3 ) Basal turn of cochlea:full visualized equal score　3; part visualized equal score 2; scala vestibule of basal turn smaller than scala tympani equal score　1 regardless of full or visualized in basal turn; no visualized equal score 0. Medial turn of cochlea:full　visualized equal score 2 ; part visualized equal score 1 ; no visualized equal score 0.Apical turn of cochlea:　visualized equal score 1 ; no visualized equal score 0. One radiologist scored all cases with double blind.　SPSS 17.0 software was used to conduct multiple independent-samples nonparametric tests,multivariate　Logistic regression, and ROC curve analysis. Evaluate the sensitivity and specificity for diagnosis of　Meniere's disease with the scoring system. Results ( 1 ) Meniere's disease summation score 0 to 12,median 9 (quarter spacing 4.5 ) ; no symptoms group summation score 15 to 18,median 17 (quarter spacing 3),two group differences has statistics significance (Wilcoxon rank and inspection U =-9.118,P =0.00).(2)Based on summation score for the diagnosis of Meniere's disease,tangent point was 14.5,Youden index 0.969,specificity 100.0％,sensitivity 96.9％.( 3 ) Let cochlear,vestibular,semicircular canal scoring for association variable,Logistic regression model:LogitP =61.216 - 7.381 × vestibular -3.056 × canal,based on the P value of ROC curves,diagnostic cut-off point 0.651 (vestibular ≤ 3 or semicircular canals ≤ 4 points ),Youden index 96.9％,specifisity 100.0％, sensitivity 96.9％.Conclusions Perilymphatic space of gadolinium contrast MR score in distinguishing Meniere's disease have practical value,any case meet one of following point could be diagnostic:( 1 ) Perilymphatic space of gadolinium contrast MRI total less than 14.5 ; (2) Vestibular low signal areas down more than lateral semicircular canal plane,namely vestibular score value ≤3;( 3 )Semicircular Canal scoring value ≤4.

Detection of pulmonary embolism with gadolinium-enhanced dual energy CT: an experimental study / 中华放射学杂志

ObjectiveTo evaluate the feasibility of gadolinium-enhanced dual energy CT pulmonary angiography (CTPA) in detecting pulmonary embolism (PE).MethodsIn vitro dual energy CT of phantoms of gadolinium and iodinated contrast agents with different diluted ratio was performed,and CT values were measured at different tube voltages.Ten rabbits which were grouped into 3 ml/kg and 5 ml/kg groups underwent dual energy CT scan.CT values of pulmonary artery trunk and the first branch of pulmonary artery were measured.Sponge gelatin were injected into the femoral vein of 6 rabbits to make PE model next day,then lungs were re-imaged with dual energy CT 2 h after embolization.Creatinine was repeatedly measured before and one day after injection of gadolinium via ear marginal vein or femoral vein sampling.One-way ANOVA test and independent student t test were used to analyze the difference of pulmonary artery enhancement between different groups.Results ( 1 ) Compared with iodinated contrast agent,CT value of gadolinium-based contrast agent at 80 kV was higher than those at 140 kV and averageweighted 120 kV.(2) At 140,80,and average weighted 120 kV,CT values of pulmonary artery trunk [CT values were (463.1 ± 118.0),(664.2 ± 188.0),(522.9 ± 137.7) HU] and of the first branch of pulmonary artery [ CT values were (445.1 ± 82.3 ),(606.7 ± 207.2),(493.4 ± 117.3 ) HU ] were higher than those at 3 ml/kg [ CT value of pulmonary artery trunk was ( 258.1 ± 55.1 ),( 384.0 ± 92.3 ),(295.4 ± 73.6) HU,CT value of the first branch of pulmonary artery (245.0 ± 73.2 ),( 309.1 ± 94.2),(263.8 ±78.5) HU;all P ＜0.05].CT values of pulmonary artery trunk and the first branch of pulmonary artery at 80 kV were higher than those at 140 kV and average-weighted 120 kV ( pulmonary artery trunk:F =6.004,P =0.005 ; the first branch of pulmonary artery: F =4.374,P =0.018).In 6 rabbits,CTPA showed the enhancement cut-off of bilateral pulmonary arteries,gadolinium mapping showed decreased perfusion in the corresponding lung lobes,manifested as blue on color-coded map,while normal lung was color coded as red or yellow.Creatinine was higher by 6.7％ and 20.6％ for group 3 ml/kg and 5 ml/kg.ConclusionsWith similar X-ray attenuation characteristics as iodine,gadolinium-based contrast agent can be used to pulmonary contrast-enhanced dual energy CT imaging,simultaneously providing both CTPA and gadolinium maps to detect PE.

Effect of intravenous Gd-DTPA on 3.0T MR spectroscopy prescan of different organs / 中国医学影像技术

Objective To evaluate the effect of intravenous Gd-DTPA on 3.0T proton MR spectroscopy (MRS) water suppression and shimming. Methods Prospective study of proton MRS was performed with GE Signa Excite HD 3.0T system and eight-channel phased-array coils with PRESS sequence (head, liver and kidney, respectively). Routine auto prescan program was operated to record full width half maximum (FWHM) and water suppression (WS%). Routine scan was performed after injection of Gd-DTPA, then prescan program was reoperated to record FWHM and WS%. The data of FWHM and WS% in head, liver and kidney were compared between before and after injection of Gd-DTPA with the Wilcoxon matched pairs signed test. Results WS% of spectroscopy of head and liver after administration of Gd-DTPA decreased significantly (T_+=12, T_-=66, P=0.02; T_+=0, T_-=45, P=0.007). The effect of shimming of kidney after administration of Gd-DTPA was poor (T_+=0, T_-=435, P<0.001) and WS% of spectroscopy of kidney after administration of Gd-DTPA decreased significantly (T_+=0, T_-=435, P<0.001). Conclusion WS% of spectroscopy in head, liver and kidney can be impacted negatively by Gd-DTPA. Gd-DTPA has great influence on shimming of spectroscopy of kidney, but has little influence on shimming of spectroscopy of head and liver. It is better to acquire MRS data before administration of contrast medium in kidney.

Neurotoxic Manifestations of an Overdose Intrathecal Injection of Gadopentetate Dimeglumine

The intravenous administration of gadopentetate dimeglumine (GD) is relatively safe and rarely causes systemic toxicity in the course of routine imaging studies. However, the general safety of intrathecal GD has not been established. We report a very rare case of an overdose intrathecal GD injection presenting with neurotoxic manifestations, including a decreased level of consciousness, global aphasia, rigidity, and visual disturbance.

In vivo imaging of colon mucosa targeted gadolinium-loaded chitosan particles in mice with MRI / 中华放射学杂志

Objective To synthesize a novel vector of chitosan-particles loaded with gadolinium (Gd-CPs) and observe the adhesion and absorption of the particles in the colon wall of mice with MR imaging in-vivo.Methods Chitosan particles (CPs) with and without gadolinium loaded were synthesized with the emulsion-droplet coalescence method.Sixteen mice were randomly classified into two groups.The suspension with Gd-CPs or with CPs was infused into the rectum of the 8 mice of each group,respectively.MR scans were performed before,during and 40 minutes after infusion for each mouse.Samples of the colon correlated to the enhanced area were obtained for electron microscopy examination.Signal intensity (SI) of ROIs in the wall of rectum or colon,muscles of the pelvis near the rectum and background were measured and corresponding relative SIs were calculated.Relative SI values between the two groups and pre- and post- infusion were compared with pared t test.Results Dimension of the Gd-CPs was about 500 nm,and content rate was about 30%. Values of relative SI of the rectum for pre- and post- infusion in the Gd-CPs group were 0.84±0.06 and 0.98±0.09(t=4.327,P＜0.01),respectively,while those in CPs group were 0.83±0.04 and 0.84±0.05(t=0.658.P＞0.05). The medial value of signal increase rate for CPs group was 19.0%.Gd-CPs particles were found inside the mucosal cells under the electron microscopy.Conclusion MR imaging in-vivo can reveal the phenomenon of adhesion and absorption of mucosa targeted chitosan particle carriers. Clinical MR imaging based on small animal coil is a good method to monitor colon mucosa targeted particle vectors in-vivo.

Usefulness of Intrathecal Gadolinium Enhanced Magnetic Resonance Cisternography in Cerebrospinal Fluid Fistula: Case Report

Accurate localization of cerebrospinal fluid(CSF) fistulae makes the planning of surgery easier, increases the chances of successful dural repair and eliminates negative exploration. The authors report our early experience with intrathecal use of gadolinium DTPA(Gd-DTPA) magnetic resonance(MR) cisternography for evaluation of CSF leakage and localization. By means of lumbar puncture, a single dose of 1ml of gadolinium DTPA mixed with 4ml NaCl 5% was injected. The images were interpreted by comparing those before and after injection. Three patients showed leakage of contrast material through the cribriform plate into the ethmoid or sphenoid air cells. No leakage was observed in one patient. The study results show the relatively safety and feasibility of low-dose Gd-DTPA MR cisternography in confirming the presence and determining the focus of active CSF leaks.

Effect of Gd-DTPA on Diffusion in Canine Brain with Hyperacute Stroke

PURPOSE: To evaluate the effect of Gd-DTPA on signal intensity of diffusion-weighted magnetic resonance (MR) image and apparent diffuse coefficient (ADC) in dog brain with hyperacute stroke. MATERIALS AND METHODS: Experimental canine model of hyperacute cerebral infarction was made by selective intraarterial embolization with particulate embolic material. Diffusion-weighted MR imaging was performed in five dogs at 1 hour after the embolization of internal carotid artery. After intravenous bolus injection of Gd-DTPA, additional 11 diffusion-weighted MR images were serially obtained from 2 minutes to 90 minutes after injection in each dog. The author evaluated findings of hyperacute cerebral infarction on diffusion-weighted MR imaging, and calculated mean signal intensity and mean ADC in infarcted region and contralateral normal region. Statistical analysis of mean signal intensity, mean ADC and contrast-noise ratio before and after Gd-DTPA injection was performed. RESULTS: Hyperacute cerebral infarction developed in all five dogs on diffusion-weighted MR images obtained 1 hour after embolization. The area of hyperacute infarction had steady increase in signal intensity on diffusion-weighted MR image and decrease in ADC. In normal perfusion area, decrease in signal intensity was observed at 2 minutes the Gd-DTPA injection, whereas ADC did not changed. CONCLUSION: Intravenous injection of Gd-DTPA had no influence on ADC in both hyperacute infarction and normally perfused area, but caused initial transient signal reduction in normally perfused area on diffusion-weighted MR image due to susceptibility effect of Gd-DTPA. It is important to calculate ADC in evaluating the effect of diffusion after injection of Gd-DTPA.