Recognition and management of contrast media extravasation

Intravenous contrast agents are frequent adjuncts used in diagnostic imaging. Despite the well‐recognized complications of contrast media extravasation, its treatment remains an enigma to many. This article reviews the recognition, prevention and treatment options, with a summary of the contrast media extravasation policy implemented in our department.     

低对比剂用量条件下256层螺旋CT诊断肺动脉栓塞

目的:探讨低对比剂用量条件下256层螺旋CT(256-MSCT)对分支肺动脉栓塞的诊断价值及预后评估.方法:收集我院行256层MSCT肺动脉CTA检查诊断为肺动脉栓塞患者20例.对采集的数据进行多平面重建(MPR)、立体重建(VR)等后处理重建,分析各种肺动脉栓塞的影像学特征.结果:肺叶及分支肺动脉栓塞5例,肺段及分支肺动脉栓塞6例,亚段肺动脉栓塞9例.结论:低对比剂用量条件下256层螺旋CT能较准确显示肺内较小分支肺动脉内的肺栓塞.     

MSCT充气造影检查对食管疾病的诊断价值

目的：探讨多层螺旋CT（MSCT）充气造影检查对食管疾病的诊断价值。方法选择100例经胃镜及手术病理证实的食管疾病患者,均行MSCT充气造影检查,将扫描后的图像进行薄层重建及后处理,对MSCT充气造影结果与病理结果进行比较,并采用Kappa检验分析其一致性。结果100例食管疾病患者中,经消化胃镜及术后病理证实,食管平滑肌瘤62例,食管癌8例,食管憩室6例,食管囊肿8例,隆突下增大淋巴结结核2例,食管血管瘤4例,正常食管10例。所有患者均顺利完成MSCT充气造影检查,食管管腔扩张良好。经Kappa检验,MSCT充气造影结果与病理结果具有良好的一致性（Kappa值=0.898,P﹤0.001）。MSCT充气造影诊断食管平滑肌瘤的特异度、灵敏度和准确率分别为96.8%、78.9%、90.0%,诊断食管癌的特异度、灵敏度和准确率均为100%。结论 MSCT充气造影检查作为一种诊断食管疾病的新方法,有利于提高食管疾病的检出率,在临床中具有重要的应用价值。     

静脉注射造影剂对妇科肿瘤全盆腔放疗剂量分布的影响

目的探讨静脉注射造影剂对妇科肿瘤术后全盆腔放疗剂量分布的影响。方法选择10例接受术后全盆腔放疗的子宫内膜癌和子宫颈癌患者。对每例患者静脉注射造影剂前后相同体位下行CT模拟定位扫描,在平扫图像和增强图像上为每例患者设计相同的三维适形全盆腔放疗计划。比较两组计划靶区、危及器官和正常组织剂量分布。结果增强计划的靶区、危及器官和正常组织平均剂量均低于平扫计划,但两组计划间差异均〈1.0Gy,危及器官和正常组织最大剂量差异均〈2.0 Gy,差异均无统计学意义。结论静脉注射造影剂对妇科肿瘤术后全盆腔适形放疗剂量分布影响很小,临床上可以忽略。     

Diagnostic error due to vicarious excretion of rectal iodinated contrast

Introduction of iodinated contrast into the intact colon is not expected to result in imaging‐visible renal excretion of this contrast and is a phenomenon that has only rarely been described. We present a case in which such vicarious renal excretion was misinterpreted as a recto‐vesical fistula which resulted in unnecessary delay in the patient’s management.     

Renal colic: A prospective evaluation of non‐enhanced spiral CT versus intravenous pyelography

The aim of this study was to compare non‐enhanced spiral CT (NECT) and intravenous pyelography (IVP) in patients with suspected acute renal colic. Two‐hundred patients presenting to the Emergency Department with suspected acute renal colic were randomized into groups undergoing NECT or IVP. The main outcome measures were diagnostic utility, incidence of alternative diagnoses, requirement for further imaging, length of hospital stay, urological intervention rates, radiation dosage and costs. Non‐enhanced spiral CT was better than IVP in making a definitive diagnosis of ureteric calculus or of recent calculus passage (65/102 or 66% vs 42/98 or 41%; P = 0.003). Calculi were missed in two patients in the IVP group. Two patients in each group had alternative diagnoses by initial imaging. There was no difference in the length of hospital stay or intervention rate. More plain X‐rays during admission and more IVPs during follow up were performed in the NECT group. Effective radiation dosages were 2.97 mSv (IVP) and up to 5 mSv (NECT). Non‐enhanced spiral CT provided greater diagnostic utility in this randomized comparison but no difference in measured outcomes. The incidence of alternative diagnoses was low, probably due to patient selection. Financial costs for each modality are comparable in a public tertiary hospital. Radiation dosages are higher for NECT and, for this reason, it might be appropriate to consider limiting NECT use to patients who have do not have classical symptoms of renal colic, to older patients and those with a contraindication to the administration of intravenous contrast media.     

螺旋CT双低技术在肺结节检查中的应用

目的:研究双低技术在肺结节CT增强成像的临床意义.方法:胸部检查发现肺结节需行CT扫描增强的患者40例,按体质量指数BMI:18～26 kg/m2随机分两组:常规剂量组(采用滤波反投影重建)和低剂量组(等渗低浓度对比剂)迭代重建.结果:100 kV扫描条件下采用40％ASIR迭代重建与120 kV扫描条件下采用FBP滤...     

低剂量对比剂在64排螺旋CT主动脉成像中的探讨

目的探讨64排螺旋CT不同体重注射不同对比剂量在胸腹主动脉血管成像的中应用。方法临床可疑主动脉病变患者,知情同意后分A、B两组。A组20例:体重在60 kg以上注射60ml对比剂+40 ml生理盐水、B组20例:体重在60 kg以下按1 ml/kg对比注射+适量的生理盐水;两组均采用相同注射速率和浓度行对比剂浓度实时监控触发扫描,测量升主动脉、胸7(T7)及腰2(L2)水平降主动脉、主动脉分叉处CT值及血管横截面直径,并在扫描前测量患者的体重、身高、血压、心率。由两位影像诊断高级职称医师对重组主动脉及分支血管显示进行评价,并对血管强化程度、血管横截面直径、体重、身高、血压、心率数据进行统计学分析。结果两组在升主动脉、胸7(T7)及腰2(L2)水平降主动脉、主动脉分叉等处的平均CT值分别为:331.10 Hu、342.52 Hu、308.71 Hu、299.75 Hu和337.10 Hu、325.59 Hu、322.06 Hu、308.34 Hu,血管横截面平均直径为:37.40 mm、25.12mm、17.91 mm、15.50 mm和35.20mm、23.08 mm、12.37 mm、11.80 mm,体重为:72.50 kg、49.50 kg,身高为:175.70 cm、150.50 cm,血压为:130/78 mmHg、124/78 mmHg,心率76.5次/分、74.6次/分;两组间各点的平均CT值强化不具有统计学意义(P>0.05),重组血管清晰度及显示血管分支也无差异,各点的血管横截面平均直径具有统计学意义(P<0.05),体重、身高具有明显差异(P<0.01)、血压、心率各组不具有统计学意义(P>0.05)。结论 64层螺旋CT行主动脉MSCTA检查时,个性化因人而异不同体重注射不同对比剂量可获得良好的CTA图像,并满足诊断要求,为临床提供可靠的诊断依据,还降低了CIN潜在的风险。     

Randomized prospective comparison of non‐contrast enhanced helical computed tomography and intravenous urography in the diagnosis of acute ureteric colic

Non‐contrast enhanced helical CT has become an accepted technique for evaluating acute ureteric colic. The results of a randomized prospective comparison of the accuracy, cost and radiation dose of CT and intravenous urography (IVU) are presented. All patients presenting to the Emergency Department with symptoms and signs suggestive of ureteric colic over a 16‐month period (n = 242) were randomized to CT or IVU. Follow up was obtained for 228 patients (94%), with 14 patients (6%) lost to follow up. One hundred and twenty‐three patients (54%) underwent CT and 105 (46%) had an IVU. At follow up the sensitivity and specificity of CT were each 100%, while those of IVU were 99% and 100%, respectively. Computed tomography demonstrated seven of 26 (27%) potential alternative diagnoses, whereas IVU suggested one of 23 (4%). Estimates of the average effective dose were calculated for CT (4.95 mSv) and IVU (1.48 mSv, 95% confidence interval (CI) 0.7–2.27). Radiation dose and intravenous contrast material safety are discussed and the relative costs are considered. Computed tomography is as accurate as IVU in the diagnosis of acute ureteric colic. It confers certain major diagnostic benefits, and is a fast, well‐tolerated technique. Its accompanying higher effective radiation dose is recognized.     

Dexrazoxane (Totect): FDA review and approval for the treatment of accidental extravasation following intravenous anthracycline chemotherapy

Management of anthracycline extravasation is problematic and most reports are anecdotal. On September 6, 2007, the U.S. Food and Drug Administration approved Totect 500 mg (dexrazoxane hydrochloride for injection) for the treatment of extravasation resulting from i.v. anthracycline chemotherapy. In two studies, a total of 57 evaluable patients experienced extravasation from peripheral vein or central venous access sites with local swelling, pain, or redness. The presence of anthracycline in skin biopsy tissue was confirmed by tissue fluorescence, and treatment with a 3-day schedule of dexrazoxane began within 6 hours of the event. The primary endpoint was a reduction in the need for surgical intervention. Only one patient required surgical repair of the injury site, and late sequelae in the remainder were absent or mild. Also, the sponsor, TopoTarget A/S, Copenhagen, Denmark, performed controlled nonclinical studies in support of dexrazoxane dose and timing for the reduction of tissue injury resulting from anthracycline extravasation. For this uncommon but serious complication of anthracycline therapy, the need for surgical intervention was 1.7% with this regimen.     

右丙亚胺治疗蒽环类药物外渗2例疗效观察

蒽环类药物（Anthracyclines）由于其抗肿瘤谱广,疗效好,是乳腺癌、白血病、淋巴瘤、子宫癌、卵巢癌等多种恶性肿瘤的一线或基本用药,而乳腺癌大多数方案均以蒽环类药物为基础。既往化疗均为外周静脉化疗,而经外周静脉置入中心静脉导管术（ peripherally inserted central venous catheters, PICC）的开展,将很多患者从外周静脉化疗的痛苦中解脱出来,但仍然有部分病人因为经济原因、PICC 穿刺禁忌或维护不便等原因,选择外周静脉化疗。而蒽环类药物外渗一直是令医护人员倍感棘手的问题,目前还没有有效的方法解救其可能造成的毁灭性后果。欧盟及美国 FDA 分别于2006年和2007年批准右丙亚胺用于治疗葸环类药物外渗的适应症［1,2］,而国内仅见1例报道［3］。我科使用右丙亚胺治疗2例蒽环类药物外渗患者,对其疗效及安全性进行观察,报道如下。     

18F-FDG PET/CT与增强CT对胰腺癌可切除性评估价值分析

目的:探讨18F-FDG PET/CT与增强CT对胰腺癌可切除性评估价值。方法:回顾性分析病理、术中所见或临床综合及随访资料证实的胰腺癌病人18F-FDG PET/CT和增强CT影像资料,对比二者及二者联合对胰腺癌可切除性评估价值。结果:74例病人中24例进行了手术,其中仅15例成功完整切除了肿瘤,另9例因术中发现不可切除因素而行姑息手术。余50例均经随访证实因多发转移而不可切除。以不可切除为阳性指标,18F-FDG PET/CT显像对不可切除评估的灵敏度、特异性及准确性分别为79.66%,86.67%和81.08%,增强CT的灵敏度、特异性及准确性分别为84.75%,93.33%和86.49%,二者差异无显著性。以其中一种方法阳性即认为不可切除,二者联合判断的灵敏度、特异性及准确性分别为91.53%,86.67%和90.54%,显著优于单独PET/CT或增强CT。结论:18F-FDG PET/CT与增强CT均为胰腺癌可切除性评估重要手段,二者价值相似,具有互补性,联合应用准确性更高。     

Corticosteroid prophylaxis for patients receiving intravascular contrast agents: A survey of current practice in Australia and New Zealand

A survey was made of the use of corticosteroid prophylaxis in patients receiving intravascular contrast media. The replies of 807 respondents were available for analysis and they indicate that such a strategy is common for‘high-risk’patients (62.4%), but very few respondents use corticosteroid prophylaxis for all patients (0.74%).     

^（18）F-FDG PET/CT与增强CT对胰腺癌可切除性评估价值分析

目的：探讨18F-FDG PET/CT与增强CT对胰腺癌可切除性评估价值。方法：回顾性分析病理、术中所见或临床综合及随访资料证实的胰腺癌病人18F-FDG PET/CT和增强CT影像资料,对比二者及二者联合对胰腺癌可切除性评估价值。结果：74例病人中24例进行了手术,其中仅15例成功完整切除了肿瘤,另9例因术中发现不可切除因素而行姑息手术。余50例均经随访证实因多发转移而不可切除。以不可切除为阳性指标,18F-FDG PET/CT显像对不可切除评估的灵敏度、特异性及准确性分别为79.66%,86.67%和81.08%,增强CT的灵敏度、特异性及准确性分别为84.75%,93.33%和86.49%,二者差异无显著性。以其中一种方法阳性即认为不可切除,二者联合判断的灵敏度、特异性及准确性分别为91.53%,86.67%和90.54%,显著优于单独PET/CT或增强CT。结论：18F-FDG PET/CT与增强CT均为胰腺癌可切除性评估重要手段,二者价值相似,具有互补性,联合应用准确性更高。     

Comparison of two imaging protocols for acute stroke: Unenhanced cranial CT versus a multimodality cranial CT protocol with perfusion imaging

The aim of the study was to validate a multimodality cranial computed tomography (CCT) protocol for patients with acute stroke in the United Arab Emirates as a basic imaging procedure for a stroke unit. Therefore, a comparative study was conducted between two groups: retrospective, historical group 1 with early unenhanced CCT and prospective group 2 undergoing a multimodality CCT protocol. Follow‐up unenhanced CCT >48 h served as gold standard in both groups. Group 1: Early unenhanced CCT of 50 patients were evaluated retrospectively, using Alberta Stroke Program Early CT Score, and compared with the definite infarction on follow‐up CCT. Group 2: 50 patients underwent multimodality CCT (unenhanced CCT, perfusion studies: cerebral blood flow, cerebral blood volume, mean transit time and CT angiography) <8 h after clinical onset and follow‐up studies. Modified National Institute of Health Stroke Scale was used clinically in both groups. Group 1 showed 38 men, 12 women, clinical onset 2–8 h before CCT and modified National Institute of Health Stroke Scale 0–28. Group 2 included 38 men, 12 women, onset 3–8 h before CCT, modified National Institute of Health Stroke Scale 0–28. Sensitivity was 58.3% in group 1 and 84.2% in group 2. Computed tomography angiography detected nine intracranial occlusions/stenoses. The higher sensitivity of the multimodality CCT protocol justifies its use as a basic diagnostic tool for the set‐up of a first‐stroke unit in the United Arab Emirates.     

Relationship between specific organ doses and volumetric CT dose indices in multidetector CT studies

Organ doses are useful for estimating radiation doses to patients. However, it is impossible to determine specific organ doses for each patient. The aim of this study was to examine the relationship between specific organ doses and volumetric CT dose indices (CTDIvols) in multidetector CT studies to estimate specific organ doses in each patient. Radiophotoluminescent glass dosimeters were placed at locations corresponding to specific organs of an anthropomorphic phantom. Thereafter, the phantoms were examined with respect to various imaging ranges and protocols, including cranial, thoracic and abdominal acquisitions using a 64-section multidetector CT. Concurrently, we recorded the mean CTDIvol for each acquisition range. In the cranial acquisition, the displayed mean CTDIvol was 69.0mGy, and the absorbed doses for brain and intra-ocular lenses were 57.2±2.6 and 57.1±3.0mGy, respectively. In the thoracic acquisition, the displayed mean CTDIvol was 16.3mGy, and the absorbed doses for breast and lung were 19.1±6.4 and 31.7±2.2mGy, respectively. In the abdominal acquisition, the displayed mean CTDIvol was 21.6mGy, and the absorbed doses for stomach and colon were 28.2±6.1 and 28.0±8.6mGy, respectively. The displayed mean CTDIvols overestimated the specific organ doses in the cranial acquisition and underestimated them in the thoracic and abdominal acquisitions. However, the approximate specific organ doses may be estimated by multiplying the displayed mean CTDIvols with a conversion factor for each organ.     

Oesophageal dissection: Contrast studies and CT in diagnosis and monitoring

Oesophageal dissection with intramural haematoma formation can be difficult to diagnose. Endoscopy can be diagnostic, but imaging techniques including computed tomography and contrast swallows can both accurately demonstrate a dissection and exclude many other pathologies. A case utilizing both imaging modalities to diagnose and monitor the condition in a patient with a bleeding disorder is presented.     

The prognostic significance of postoperative residual contrast enhancement on CT scan in pediatric patients with medulloblastoma

The clinical and therapeutic features of 20 patients with medulloblastoma treated at Childrens' Hospital and Medical Center, Seattle, from 1980 to 1987, were retrospectively analyzed with regard to prognosis. The overall actuarial 5-year survival rate was 63%, with 57% of patients free from recurrence at 5 years. Residual contrast enhancement on CT scans taken immediately postoperatively was associated with a significantly decreased 5-year recurrence-free survival rate; the 5-year recurrence-free survival rate was 100% for those patients without post-operative residual enhancement compared to 41% for those patients with residual enhancement. A high risk group of patients with residual contrast enhancement persisting one year following diagnosis was identified. No patient in this group survived without disease progression. Other factors, including sex, age at diagnosis, evidence of tumor dissemination, or extent of surgical resection as reported by the neurosurgeon, did not significantly influence prognosis.