Gd-DTPA: a bowel contrast agent for magnetic resonance imaging of the abdomen

Forty patients with suspected pathology in the abdomen and pelvis have been investigated with MRI before and after administration of Gd-DTPA as an oral or rectal resolution. The findings are analysed with respect to (a) filling of the GI tract; (b) contrast in the region of interest, surrounding fat and vessels; (c) diagnostic yield in comparison to non-enhanced MRI and contrast CT. At a concentration of 1 mmol/l Gd-DTPA provided consistent positive contrast in the stomach achieved complete filling of the GI tract. The opacification in the region of interest was good or satisfactory in 90% of cases. The diagnostic value of contrast MRI was better in 93% of cases than the non-enhanced MRI of the abdomen. In comparison with contrast CT, the contrast MRI was better or of the same value in 92% of cases. Despite the disadvantages of poor fat-to-bowel contrast (35% of cases were classified as poor), it is concluded that Gd-DTPA-enhanced MRI provides good delineation of organs adjacent to the bowels so this contrast agent has potential for a future role in abdominal MRI. Correspondence to: L. Vlahos     

Gadolinium-DTPA as a contrast agent in MRI: initial clinical experience in 20 patients

Magnetic resonance imaging (MRI) was performed in 20 patients before and after intravenous administration of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) in a dose of 0.1 mmol/kg. Twelve of the patients had clinical and histologic diagnoses of cerebral tumor, six had hepatic tumors, one had hepatic cysts, and one had transitional cell carcinoma of the bladder. Contrast enhancement was seen with all tumors, but not with the hepatic cysts. The degree of enhancement was greater than that seen with computed tomography (CT) in 13 cases, equal to it in six, and less in one. Contrast enhancement was detectable as long as 18 hr after injection of Gd-DTPA in one case of cerebral tumor. The margin between cerebral tumor and peritumoral edema could be delineated with contrast-enhanced MRI to the degree possible with contrast-enhanced CT. In the liver isointense enhancement was seen with saturation-recovery (SR), inversion-recovery (IR), and spin-echo (SE) sequences although not with all three sequences simultaneously. In general IR sequences were most sensitive for display of the contrast agent, but the enhancement often decreased the difference between abnormal and normal tissue. No short-term side effects were encountered and no significant change was seen in urea, creatinine, electrolytes, liver function tests, blood coagulation, or urine testing after injection of Gd-DTPA. Although much more work will be required to evaluate this contrast agent, these initial experiences are very promising.     

Gadolinium DTPA in a MR study of expansive lesions of the cranial base

Twenty-five patients were investigated by MR imaging in order to evaluate the diagnostic value of Gadolinium (Gd)-DTPA in skull-base tumors. The patients were studied with standard acquisition techniques (T1, mixed and T2-weighted images) without contrast medium. The images obtained were then compared with the T1-weighted images obtained after intravenous injection of Gd-DTPA. The contrastographic results in the different types of acquisition were evaluated. Thanks to the extraordinary increase in contrast resolution it provides, Gd-DTPA allowed the precise evaluation of the lesion and of its perfect spatial definition in all cases. Our experience demonstrated that Gd-DTPA considerably increases the sensitivity of the technique in this anatomical region. On the contrary, as regards the nature of the lesion, the signal did not significantly vary after the iv injection of Gd-DTPA in the various kinds of lesion. In addition to the important diagnostic advantages of Gd-DTPA, its excellent tolerability and the absence of side-effects must be stressed.     

Gadolinium-DTPA in magnetic resonance tomography. Clinical use--indications

Magnetic resonance tomography was performed on 158 patients with different indications before and after the administration of contrast medium. The MR examination included various plain T1 and T2 weighted spin echo sequences as well as T1 weighted examinations after intravenous application of Gadolinium-DTPA ("Magnevist", Schering AG) in a dosage of 0.1 mmol/kg body weight. The following conclusions were drawn: The sensitivity of MR in detecting brain tumors, acoustic neuromas and pituitary adenomas was improved considerably after the administration of "Magnevist". To diagnose the type of tumor, the criteria which apply to Gd-DTPA are similar to those used for iodine-containing contrast medium in CT. In about 2/3rds of the cases, delineation of pathological tissues from surrounding edema and normal structures was better than in plain films. Hence, accurate, pretherapeutic staging of bronchial carcinomas and an exact definition of the expansion of the malignancies in the muscle-skeleton system were possible. In respect of tumors in the region of the base of the skull, we could omit T2-weighted sequences without noticeable loss of diagnostically relevant information; the examination time could thus be shortened by about 12 minutes.     

颅脑血管外皮细胞瘤的CT、MRI与病理对照研究

目的：探讨颅脑血管外皮细胞瘤的临床、病理和ＣＴ、ＭＲＩ特征。材料与方法：收集经ＣＴ和ＭＲＩ诊断为脑膜瘤,经手术病理证实为血管外皮细胞瘤１２例,年龄３４￣５８岁。ＣＴ检查７例,均采用增强前、后常规扫描。ＭＲＩ检查１２例,采用ＳＥ序列增强前、后扫描。结果：１２例肿瘤全部发生在颅内脑外,７例ＣＴ平扫呈低等混合密度２例,呈等高混合密度５例;增强后扫描呈不均匀强化６例,均匀强化１例。骨窗显示病灶局部侵蚀性骨质破坏４例。ＭＲＩ平扫,Ｔ１ＷＩ呈等高不均匀信号１０例,呈等信号２例;Ｔ２ＷＩ呈不均匀等高信号１０例,呈等信号２例。１２例中７例显示脑膜尾征;增强后扫描１ 均呈不均匀强化。结论：血管外皮细胞瘤具有一定的ＣＴ、ＭＲＩ特征性表现：分叶状、丰富的血管流空、肿瘤内密度或信号不均匀、无肿瘤内钙化和骨质增生、局部颅骨呈溶骨性破坏。     

Tumors of the nasopharynx and adjacent areas: MR imaging with Gd-DTPA

The purpose of this study was to describe our experience with Gd-DTPA-enhanced MR imaging in the evaluation of the most common nasopharyngeal tumors. Forty-two patients with tumors of the nasopharynx and adjacent spaces had MR imaging before and after IV injection of Gd-DTPA. Images were obtained with a 1.0-T superconducting magnet imaging system in transverse, coronal, and sagittal planes with T1- and T2-weighted sequences. MR images were compared with CT scans and tumor histology. The studies were categorized by using a grading system with grades ranging from unsatisfactory (grade 0) to optimal (grade 3). Contrast-enhanced MR enables better identification of small anatomic details such as both palatini muscles and the pharyngobasilar fascia. MR after Gd-DTPA was superior to CT in all cases except for tumors of the maxillary sinuses. MR with Gd-DTPA is recommended for tumors that are small and difficult to detect on the initial nonenhanced MR examination or that show subtle infiltrations. Because of the increased cost and longer examination time, MR with Gd-DTPA does not need to be done when large tumors are well delineated.     

肿瘤非手术治疗后FDG PET随访的临床价值

目的　探讨 FDG PET影像诊断在肿瘤非手术治疗后临床随访中的价值。　方法　选择实质性肿瘤高强度聚焦超声 (HIFU)治疗后 2 1例 ,鼻咽癌患者放射治疗后 14例 ,共 35例 ,随访中同期行 FDG PET和 CT、MRI检查 ,并将结果进行双盲比较。　结果　 2 1例实质性肿瘤 HIFU治疗后 2～ 3个月复查 ,19例 CT、MRI表现密度和信号有变化 ,但形态、大小未见明显改变 ,另 2例 CT、MRI密度和信号变化不明显 ;PET示 17例肿瘤中心大部分放射性分布缺损 ,但以肿瘤边缘部分为主仍有 FDG代谢活跃现像 ,提示部分肿瘤存活 ,其中 6例在 FDG代谢活跃局部经穿刺活检证实肿瘤存活 ;4例 PET表现为 FDG摄取缺损 ,其中 1例局部穿刺活检证实为坏死组织。 14例鼻咽癌放疗后 12～ 18个月复查 ,CT和 MRI提示 11例未见局部肿瘤复发 ,PET显示其中 3例有局灶性 FDG浓聚病变 ,其中 1例局部穿刺活检证实为局部肿瘤复发 ;2例 CT和 MRI提示肿瘤复发 ,FDG显像病变处有明显的放射性浓聚 ;余 1例放射治疗后脑损伤 FDG PET显示为放射性分布缺损区。　结论　 FDG显像在实质性肿瘤 HIFU治疗后疗效判断和鼻咽癌放射治疗后肿瘤复发诊断上较 CT和 MRI准确 ,两者结合分析在临床随访中更具有明显的优势     

Tumors of the nasopharynx and adjacent areas: MR imaging with Gd-DTPA

The purpose of this study was to describe our experience with Gd-DTPA-enhanced MR imaging in the evaluation of the most common nasopharyngeal tumors. Forty-two patients with tumors of the nasopharynx and adjacent spaces had MR imaging before and after IV injection of Gd-DTPA. Images were obtained with a 1.0-T superconducting magnet imaging system in transverse, coronal, and sagittal planes with T1- and T2-weighted sequences. MR images were compared with CT scans and tumor histology. The studies were categorized by using a grading system with grades ranging from unsatisfactory (grade 0) to optimal (grade 3). Contrast-enhanced MR enables better identification of small anatomic details such as both palatini muscles and the pharyngobasilar fascia. MR after Gd-DTPA was superior to CT in all cases except for tumors of the maxillary sinuses. MR with Gd-DTPA is recommended for tumors that are small and difficult to detect on the initial nonenhanced MR examination or that show subtle infiltrations. Because of the increased cost and longer examination time, MR with Gd-DTPA does not need to be done when large tumors are well delineated.     

Gadolinium-DTPA enhanced MR imaging in tuberous sclerosis

Summary Ten patients with clinical tuberous sclerosis were examined with CT and MR imaging, before and after IV contrast in order to determine the role of Gd-DTPA. Gd-DTPA enhancement occured in eleven subependymal nodules which did not enhance on CT after IV contrast. As illustrated by previous CT and pathologic observations and related to the histologic similarity of the subependymal nodules and giant-cell astrocytomas, these hyperintense nodules could represent active lesions with the potential to evolve. Four giant-cell astrocytomas were detected both with CT and Gd-DTPA-enhanced MRI; tumor conspicuity and size assessment were improved by postcontrast MRI in two cases. No cortical tuber or heterotopic cluster enhanced; T2-weighted sequences therefore remain necessary for their detection. If pre and post-Gd-DTPA T1-and T2-weighted imaging is negative, CT is clearly the most sensitive modality in the detection of the small calcified subependymal nodules.     

Magnetic Resonance Imaging of Acute Reperfused Myocardial Infarction: Intraindividual Comparison of ECIII-60 and Gd-DTPA in a Swine Model

Purpose To compare a necrosis-avid contrast agent (NACA) bis-Gd-DTPA-pamoic acid derivative (ECIII-60) after intracoronary delivery with an extracellular agent Gd-DTPA after intravenous injection on magnetic resonance imaging (MRI) in a swine model of acute reperfused myocardial infarction (MI). Methods Eight pigs underwent 90 min of transcatheter coronary balloon occlusion and 60 min of reperfusion. After intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg, all pigs were scanned with T1-weighted MRI until the delayed enhancement of MI disappeared. Then they were intracoronarily infused with ECIII-60 at 0.0025 mmol/kg and imaged for 5 hr. Signal intensity, infarct-over-normal contrast ratio and relative infarct size were quantified, compared, and correlated with the results of postmortem MRI and triphenyltetrazolium chloride (TTC) histochemical staining. Results A contrast ratio over 3.0 was induced by both Gd-DTPA and ECIII-60. However, while the delayed enhancement with Gd-DTPA virtually vanished in 1 hr, ECIII-60 at an 80× smaller dose depicted the MI accurately over 5 hr as proven by ex vivo MRI and TTC staining. Conclusion Both Gd-DTPA and ECIII-60 strongly enhanced acute MI. Comparing with fading contrast in a narrow time window with intravenous Gd-DTPA, intracoronary ECIII-60 persistently demarcated the acute MI, indicating a potential method for postprocedural assessment of myocardial viability after coronary interventions.     

纵隔型肺癌的CT及MR表现分析

目的 探讨纵隔型肺癌CT及MRI诊断能力.方法 回顾分析15例经纤支镜、穿刺活检及手术病理证实为纵隔型肺癌的CT及MRI影像资料,15例全部行CT平扫,其中11例增强扫描,3例行MR平扫与增强扫描.分析CT及MRI图像上肿块的位置、大小、形态、边缘及其与纵隔和肺的关系.结果 15例纵隔型肺癌为单发肿块,5例小细胞型肺癌,8例鳞癌、腺癌及腺鳞癌各1例.肿块均位于纵隔胸膜下,与纵隔呈宽基底相贴,大多呈类圆形或椭圆形.边缘分叶12例,毛刺9例.肿块位于上纵隔8例,中纵隔5例,下纵隔2例.其中前中纵隔区12例,后纵隔3例.肿块与肿大淋巴结融合7例.癌肿邻近相应支气管变窄或闭塞9例.4例有胸廓骨转移性骨质破坏.结论 纵隔型肺癌易误诊,仔细分析CT及MRI表现,结合临床可作出较准确的诊断.     

巨噬细胞活性MRI对多发性硬化大鼠模型中枢神经系统病灶诊断价值的初步研究

目的 探讨巨噬细胞活性成像(MAI)对多发性硬化(MS)模型大鼠脑和脊髓病灶的诊断价值.方法 20只正常Lewis大鼠用数字表法随机分成实验组15只,对照组5只.应用髓鞘少突胶质细胞糖蛋白多肽35-55(MOG35-55)致敏实验组大鼠制备MS动物模型实验性自身免疫性脑脊髓炎(EAE),大鼠首次急性发病后第3天行MR检查.分别对大鼠脑和脊髓行T2WI、T1WI和Gd-DTPA增强T1WI的三维容积扫描.经大鼠尾静脉注入超微超顺磁性氧化铁(USPIO)24 h后行USPIO增强T2WI(即MAI).利用工作站专业软件获得大鼠脑和脊髓冠状面、横断面和矢状面的重组图像,并与常规图像进行比较.结果 成功建立MOG35-55-EAE模型大鼠15只.MOG35-55-EAE大鼠急性发病期相关的中枢神经系统病灶多数分布在脑内(58/63),少数位于脊髓(5/63).常规MRI上病灶表现为T2WI高信号、T1WI低信号,部分出现Gd-DTPA强化.在MAI图像上病灶呈低信号,部分USPIO强化病灶在T2WI上呈等信号,病灶的USPIO强化与Gd-DTPA强化表现不完全一致.T2WI(14/15)和MAI(13/15)对MOG35-55-EAE大鼠急性期病灶的敏感度高,两者联合对病灶的检出率高达100%(15/15),增强T1WI的敏感度相对较低(7/15).对照组大鼠MAI未见异常.结论 MAI弥补传统MR检查技术的不足,能监测EAE的炎症反应,与常规T2WI联合能提高MOG35-55-EAE大鼠病灶的检出率;Gd-DTPA增强能显示EAE血脑屏障破坏的早期活动性病灶,MAI与之联合成像对EAE病灶的诊断和监测有互补作用.     

Intradural spinal metastases in pediatric patients with primary intracranial neoplasms: Gd-DTPA enhanced MR vs CT myelography

Recently, the application of intravenous gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) has been shown to improve the detection of intradural extramedullary spinal disease in adults. The ability of Gd-DTPA enhanced magnetic resonance (MR) to detect intradural extramedullary spinal metastases was studied in pediatric brain tumor patients. Spinal MR images before and after intravenous injection of Gd-DTPA were analyzed retrospectively in eight pediatric patients with known intracranial neoplasms and clinically suspected subarachnoid tumor seedings. Contrast enhanced spinal MR was compared with CT myelography in four of these patients. In our pediatric population Gd-DTPA enhanced images revealed tumor seeding not appreciable on noncontrast images. Although CT myelography has been the accepted standard investigation in the evaluation of suspected spinal metastases in children, we found that contrast enhanced MR is equal or superior in sensitivity to CT myelography. Spinal MR also provided information not obtainable via CT myelography. In the future, Gd-DTPA enhanced spinal MR should be considered in the initial evaluation of suspected subarachnoid spinal metastases in pediatric patients with known primary brain tumors.     

MRI对脊髓型多发性硬化临床分期的价值

目的:探讨脊髓型多发性硬化(MS)的MRI表现及其病理基础,评价MRI对MS临床分期价值。方法:脊髓型MS患者43例,按临床特点分为急性期、静止期和缓解复发期。对所有患者行头部和脊柱磁共振检查,分析各期的MRI表现。结果:脊髓型MS的主要MRI表现为髓内长或等T1、长T2信号改变。脊髓型MS各期的MRI特点:①急性期11例,均表现为脊髓轻度~中度肿胀,增强扫描时10例(90.9%)髓内病灶有明显强化,其中9例呈斑片状或边缘环状强化,1例呈结节状强化,范围明显小于T2WI上所见;1例无强化。4例伴脊髓中央管扩张。有8例经治疗后病灶缩小,脊髓肿胀消失。②静止期17例,14例(82.4%)脊髓形态、大小未见异常,髓内病灶均无强化。③缓解复发期15例中,11例(73.3%)伴有脊髓萎缩,增强扫描时5例出现轻度点状或条状强化,病变范围与T2WI所见相似。各期脊髓型MS的病变范围及分布差异无显著性意义(P>0.05)。结论:MRI能反映脊髓型MS各期的病理变化,对脊髓型MS的分期具有重要价值。     

松果体区生殖细胞瘤的CT、MRI诊断

目的　探讨CT、MRI对松果体区生殖细胞瘤的诊断价值。方法　 11例经手术和病理证实的松果体区生殖细胞瘤患者 ,对其CT、MRI表现进行分析。结果　 11例CT平扫多呈高密度肿块 ,增强扫描呈明显均一强化 ;其MRI表现为 :(1)T1 WI等或稍低信号 ,T2 WI等或稍高信号 ,肿瘤无水肿 ;(2 )Gd -DTPA增强扫描肿瘤呈不均匀或均匀明显强化。结论　CT和MRI的多轴位成像及Gd-DTPA应用有助于松果体区生殖细胞瘤的诊断与鉴别诊断 ;病人性别和肿瘤部位具有一定特点     

Gadolinium DTPA in magnetic resonance. Clinical experience in intracranial pathology

Sixty-seven patients with various intracranial pathologies were studied using Gd-DTPA as a contrast medium applied to MRI. This paramagnetic substance was well tolerated by all patients, and proved particularly useful in improving the diagnosis of extra-axial tumors, in which a rich enhancement was always present. Gd-DTPA allowed a better definition of the tumor outlines, as well as its differentiation from edema, and the demonstration of its relationship to brain parenchyma and cerebral vessels. This was particularly true for meningiomas, which often display poor contrast enhancement at MRI. Even though acoustic neuromas had, as a rule, high signal intensity, Gd-DTPA was useful to precisely recognize the intracanalar part of the tumor. The value of Gd-DTPA was less evident in intra-axial lesions. It proved nonetheless useful in demonstrating the portions of the tumor where, due to alterations in BBB, enhancement was present. This allowed both to characterize the lesion and to perform accurate biopsies.     

卵巢肿瘤的MR诊断

目的：探讨卵巢肿瘤的MRI诊断价值。材料与方法：回顾性分析17例经手术／病理证实的卵巢肿瘤的MRI表现（包括T1、T2及静脉注射Gd－DTPA后T1三相）。结果：3例卵巢囊肿表现为单个或多个园形、椭园形等或稍长T1及长T2像；1例巧克力囊肿呈短T1长T2像；1例畸胎瘤呈实性，有脂肪及钙化信号。12例恶性肿瘤中2例转移瘤均表现等T1长T2肿块，Cˉ后增强，并均有腹水征。10例原发性卵巢癌中9例信号不均匀，呈囊实性肿块或肿块内不规则坏死液化。3例侵及周围脂肪层或盆隔，Cˉ更清楚。另1例卵巢癌术后MR复查，腹腔内广泛种植。结论：MRI诊断卵巢囊肿或良性肿瘤与B超、CT的价值相似；对恶性卵巢肿瘤的诊断与TNM分期明显优于CT或B超，值得推广。     

MR imaging of the oropharynx and tongue: comparison of plain and Gd-DTPA studies

The effect of intravenously administered gadolinium-diethylene-triamine pentaacetic acid (Gd-DTPA) on signal intensity in comparison to plain noncontrast imaging was analyzed. Sixty-one patients with diseases of the oropharynx and tongue base were examined using multiplanar magnetic resonance (MR) imaging. The contrast medium Gd-DTPA was administered in 26 cases. Thirty-eight patients also underwent CT. Forty-one patients had surgery and pathological verification. Plain MR imaging was equal or superior to CT in all except one patient. Marked contrast enhancement produced by Gd-DTPA was observed in carcinomas, sarcomas, inflamed salivary glands, and in normal pharyngeal mucosa. The usefulness of Gd-DTPA may be increased by measuring the enhancement in signal intensity versus time to allow a better differentiation of histological features.     

Intracranial meningiomas

Summary Fifty patients with intracranial meningiomas underwent plain and contrast-enhanced examinations with CT and MRI. Each of the MR studies consisted of three plain (T1, proton density and T2-weighted) and a post-contrast series (0.1 mmol Gd-DTPA/kg body weight). All techniques (plain CT, plain MRI, contrastenhanced CT, contrast-enhanced MRI) proved to be highly efficient as regards tumour detection: depending on the technique, an intracranial lesion was demonstrated in 47–50 cases. The image contrast was assessed as good or excellent in 21 cases having plain CT and in 33 cases having plain MRI, but in 46 and 50 of the contrast-enhanced CT and MRI studies respectively. Adequate tumour delineation was achieved in 18 cases with plain CT, in 35 cases with plain MRI and in 46 and 50 cases of the contrast-enhanced CT and MRI examinations. The contrast-enhanced studies proved to be superior to the plain CT and MRI studies as regards image contrast and tumor delineation. Because of the methodological advantages of the MRI technique, contrast-enhanced MRI was judged to be slightly superior to contrast-enhanced CT.     

Sudden deaths due to accidental intravenous injection of perfluorocarbon during MRI cranial examinations

Unexpected deaths of three patients happened at a magnetic resonance imaging (MRI) clinic during cranial examinations with gadolinium-based contrast media. A toxicological screening using liquid chromatography–tandem mass spectrometry (LC–MS–MS) and gas chromatography–mass spectrometry (GC–MS) for blood and urine samples collected during autopsy of the cases resulted negative. During the police investigation, it was learned that a special brand of perfluorocarbon (FC-770) had been in use at the radiological clinic for prostatic, genitals, and external soft tissue examinations, and could supposedly be available in the room where the cranial MRI examinations were performed. Histologically the lungs of the three victims showed alveolar edema associated with pulmonary venous air embolism. Using a target LC–MS–MS method, gadolinium-based contrast agents Gd-DTPA and Gd-DOTA were detected in blood samples and results showed lower levels of Gd-DTPA and Gd-DOTA when compared with literature data for that kind of MRI examinations. Free gadolinium (Gd³⁺) was also determined by inductively coupled plasma–mass spectrometry in blood samples showing also low levels. Perfluorocarbon FC-770 was determined in blood by headspace–GC–MS. Results showed the presence of 19.3, 20.9, and 20.0 μg/ml of FC-770 in blood of the three victims, estimating an injected dose of at least 230, 180, and 180 mg/kg, respectively. The smallest fatal dose established in an early experimental study was estimated to be 6.8 mg/kg. The investigations concluded that mistakenly intravenous injection of FC-770 led to the deaths of the three victims by a mechanism of pulmonary venous gas embolism secondary to the presence of non absorbable and high vapor pressure FC-770 in the pulmonary capillaries.