动脉内钙剂刺激试验在功能性胰岛素瘤术前定位中的应用

目的:评价动脉内钙剂刺激试验在功能性胰岛素瘤术前定位诊断中的作用。方法:对10例胰岛素瘤患者行动脉内钙剂刺激肝静脉采血试验(ASVS)测定胰岛素的研究,ASVS前均行超声、CT、MRI及内镜超声检查。10例功能性胰岛素瘤均得到手术病理证实,病灶大小为0．8-2．0 cm。分别行胃十二指肠动脉(GDA)、肠系膜上动脉(SMA)、脾动脉近端(sAP)和脾动脉远端(SAD)造影,并通过导管注射钙剂5 m1(含Ca2 约27 mg),于每次动脉刺激后30、60、90、120、 150和180 s行右肝静脉取血测定胰岛素:不同动脉激发试验的间隔时间为15 min。阳性判断标准:若胰岛素峰值达到或超过基础值的4倍以上,即提示该动脉为肿瘤的供血动脉,肿瘤即被定位于相对应的胰腺区域。结果:10例中9例ASVS 结果与最终诊断完全一致,1例肿瘤位于胰尾,因未行SAD激发而漏诊。结论:ASVS是功能性胰岛素瘤安全、准确的术前定位方法,尤其适用于病灶较小、其他影像学检查结果为阴性的病例。     

动脉钙刺激静脉采血检查术前定位胰岛素瘤的临床价值

目的评价动脉钙刺激静脉采血(ASVS)检查术前定位胰岛素瘤的临床价值。方法对12例临床定性诊断为胰岛素瘤患者术前行ASVS检查,选择性插管至胃十二指肠动脉、肠系膜上动脉、脾动脉近段和远段,分别快速注入葡萄糖酸钙激发,于激发前和激发后30、60、90、120、150和180 s经肝静脉采血测胰岛素值,计算不同激发值与基础值之比值,将比值最高者的动脉所供应的胰腺区域认定为肿瘤所在区域。结果ASVS定位准确性为83.3%,优于经腹超声(33.3%)、内镜超声(42.9%)、CT(75%)、MR(80%)和选择性血管造影(16.7%)。结论ASVS在胰岛素瘤术前定位中准确率高而且安全,尤其适合于其他形态学检查阴性的隐匿型胰岛素瘤。     

优化CT扫描方案在胰岛素瘤术前定位诊断中的临床价值

目的：分析优化CT扫描方案对于胰岛素瘤术前定位诊断的临床价值。方法：90名低血糖症患者接受多层螺旋CT胰腺增强扫描,CT扫描后7天内81名患者接受手术治疗。术前随机选择45名患者接受常规组CT扫描方案检查,另45名患者接受改良组扫描方案检查。根据病理结果,将CT诊断结果包括影像学诊断为真阳性的肿瘤大小及肿瘤-胰腺CT值差进行组间比较,并评价两种不同扫描方案的定位诊断准确率、敏感度及特异度。结果：常规组（男/女为16/29,平均年龄40.2岁）中40例患者接受手术治疗,34例经病理诊断为胰岛素瘤。后者中共16例术前经CT增强检查准确定位。常规组图像的医师间一致性kappa值为0.57）,肿瘤直径（18.6±6.5）mm,动脉期肿瘤/胰腺CT值差（52.5±26.2）HU。常规CT术前定位诊断胰岛素瘤的准确率、敏感度、特异度、阳性预测率及阴性预测率分别为50%（20/40）、47.1%（16/34）、66.7%（4/6）、88.9%（16/18）、18.2%（4/22）。改良组（男/女为18/27,平均年龄47.3岁）中41例患者接受手术治疗,36例经病理诊断为胰岛素瘤。34例经术前CT增强检查正确诊断为胰岛素瘤。改良组图像的医师诊断一致性kappa值为0.77,肿瘤直径为（12.6±4.6）mm,两组间肿瘤大小差异有显著性意义（P〈0.01）;动脉期肿瘤/胰腺实质CT值差异为（74.5±28.2）HU,明显高于常规组（P〈0.05）。改良组定位诊断的准确率、敏感度、特异度、阳性预测率及阴性预测率分别为95.1%（39/41）、94.4%（34/36）、100%（5/5）、100%（34/34）、71.4%（5/7）。结论：改良后的多层螺旋扫描方案可以帮助更准确及敏感的进行胰岛素瘤定位诊断,对于胰岛素瘤的手术治疗起到了极为重要的作用。     

胰岛素瘤的影像学评价(附28例报告)

目的：探讨多种影像学方法在胰岛素瘤术前定位诊断中的价值。资料与方法：28例经手术病理证实的胰岛素瘤患者于术前做B超和DSA检查，22例行胰腺CT扫描，10例行MRI检查。结果：4种影像学方法对胰岛素瘤术前定位诊断准确率分别为：DSA 82％（23／28），超声57％（16／28），CT 41％（9／22），MRI90％（9／10）。DSA与超声。MRI相结合使本组术前定位诊断准确率达93％（26／28）。结论：MRI和DSA是胰岛素瘤术前定位诊断准确率高而有效的方法。对临床有Whipple三联征患者，应首先选用超声和MRI或螺旋CT检查，特别是MRI或螺旋CT薄层快速动态增强扫描。当上述无创检查方法仍不能明确诊断时，可进一步行胰血管造影，多种影像技术联合应用可以提高本病的诊断准确率。     

功能性胰岛细胞瘤的螺旋CT诊断

目的 探讨功能性胰岛细胞瘤的螺旋CT诊断价值及 T扫描方案。资料与方法 回顾性分析6例经临床和手术病理证实的功能性胰岛细胞瘤的螺旋CT扫描资料。结果 4例为胰岛素瘤，2例为胰高血糖素瘤。5例术前肿瘤准确定位，1例回顾诊断。肿瘤在动脉期、胰腺实质期的强化程度均高于正常胰腺实质，门脉期4例为稍高密度，2例为等密度。结论 螺旋cT多期增强扫描，对比剂用量按1．5ml／kg体重计算，流率2．5～3．0ml／s，层厚2～5mm，能够对功能性胰岛细胞瘤进行较准确的定位诊断，为外科医师提供重要的信息。     

胰岛素瘤CT诊断2例报告

胰岛素瘤是胰岛细胞瘤中最常见的肿瘤类型,功能性胰岛素瘤病人症状严重,就诊早、病灶较小,ＣＴ是术前定位的主要手段。例１男,２６岁,反复意识障碍半年余,再发加重１月。空腹血糖１．６２ｍｍｏｌ／Ｌ,临床诊断胰岛素瘤,曾在外院行超声、ＣＴ及腹腔动脉造影,胰腺...     

双期薄层动态增强CT在胰岛素瘤术前诊断中的价值

目的：定量分析胰岛素瘤动态增强扫描各期相的强化特点,探讨胰岛素瘤术前CT诊断的价值。方法：回顾性分析38例经手术及病理证实的胰岛素瘤患者的影像学资料,对肿瘤的形态特点、各期相的强化方式和强化程度及CT定位诊断的敏感度及假阴性的潜在原因等进行分析。结果：胰岛素瘤术前薄层双期增强CT诊断的敏感度为81．6％,单纯动脉期CT诊断的敏感度为81．6％,门静脉期为60．5％,两者间的差异有统计学意义（P=0．043）。胰岛素瘤平扫时平均CT值（40．32±8．13）HU,周围正常胰腺组织平均CT值为（44．48±6．75）Hu,两者差异有极显著性意义（P〈0．001）。38例中有36例肿瘤至少在一个期相上强化明显。动脉期胰岛素瘤的平均CT值（113．66±27．26）HU,周围正常胰腺组织为（80．5±15．43）HU;门静脉期胰岛素瘤的平均CT值为（111．59±19．05）HU,周围正常胰腺组织为（90．5±13．91）HU,两者间差异均有统计学意义（P〈0．001）。胰岛素瘤动脉期强化值（73．44±29．23）HU,门静脉期为（71．22±21．64）HU,两者间差异没有统计学意义（P=0．627）;胰岛素瘤动脉期较周围正常胰腺组织的强化程度为（33．16±20．64）HU,门静脉期为（20．09±16．31）HU,两者间差异有统计学意义（P=0．006）。7例漏诊的病例中,5例呈等密度,2例为异位胰岛素瘤。结论：薄层双期CT增强扫描对检查胰岛素瘤有较高的敏感性,动脉期扫描的诊断价值大。     

各种影像技术对胰岛素瘤的定位诊断价值

胰岛素瘤又称胰岛β细胞肿瘤，是胰岛β细胞形成的具有内分泌功能的腺瘤或癌。胰岛素瘤是很少见的疾病，国外报道发生率为0．8／100万～0．9／100万，但在胰腺内分泌肿瘤中最多见，其中恶性胰岛素瘤占5％～16％。胰岛素瘤的定位诊断相对容易，但通常体积较小(80％以上的胰     

功能性小胰岛细胞瘤的CT定位诊断

目的：评价功能性小胰岛细胞瘤的ＣＴ术前定位价值。材料和方法：６例手术证实的功能性小胰岛细胞瘤的病人，术前行电子束ＣＴ增强动静脉双期扫描，测量肿瘤与胰腺实质的ＣＴ值并进行配对ｔ检验。结果：增强动脉期肿瘤显示较静脉期清晰。结论：动脉期ＣＴ扫描对胰岛细胞瘤的定位价值较大。     

巨大肝癌的多支动脉供血及其在栓塞治疗中的意义

目的：探讨巨大肝癌的多支动脉供血规律以及多支动脉供血在肝癌动脉栓塞治疗中的意义。材料与方法：７２例巨大（直径≥１０ｃｍ）肝癌，动脉栓塞术前选择性肝动脉及肝外动脉造影，观察多支动脉供血情况，并同时进行多支动脉栓塞治疗。结果：７５．０％（５４／７２）巨大肝癌存在多支动脉供血，其多支动脉来源为规则的肝总动脉的肝动脉、变异性动脉及肝外动脉三种类型，且多支动脉供血与肿瘤部位密切相关；随访２７例化疗栓塞效果，     

Localization of insulinomas. Comparison of conventional arterial stimulation with venous sampling (ASVS) and superselective ASVS

Purpose: To examine the value of superselective arterial stimulation venous sampling (ASVS) to localize insulinomas.Material and Methods: Superselective ASVS (SS-ASVS) was performed in 9 patients with insulinoma. Injection of secretagogue (calcium gluconate: 0.01 mEq Ca⁺⁺/kg) was performed into the gastroduodenal, splenic (proximal and distal), and superior mesenteric arteries in 9 patients and additionally into the dorsal pancreatic artery in 6 patients. Sampling from the hepatic vein was performed to measure serum insulin concentrations at 30, 60 and 120 s after each injection of secretagogue into these arteries. SS-ASVS results were correlated with surgical findings, compared to those of conventional ASVS.Results: Insulinomas were correctly localized to the head, body or tail of the pancreas by SS-ASVS in 8 patients (89%). Conventional ASVS detected insulinomas in 7 patients (78%), although it could not distinguish whether the insulinoma was located in the pancreatic body or tail in 4 of the 7 patients. There were eight-fold or more increases in serum insulin levels in hepatic venous samples related to the artery supplying the tumor in 8 patients. Localization of the insulinomas was verified at surgery in all patients.Conclusion: SS-ASVS is a useful method for detailed evaluation of overproduction of insulin from pancreatic insulinomas and their localization. When the pancreatic insulinoma is situated in the pancreatic body or tail, the localization is more accurately made by SS-ASVS than by conventional ASVS.     

Insulinomas: localization with selective intraarterial injection of calcium

To facilitate the noninvasive preoperative localization of islet cell tumors less than 15 mm in diameter, the authors examined the use of calcium as an insulin secretagogue in an arterial stimulation venous sampling (ASVS) technique. In four patients with episodic hypoglycemia, calcium gluconate (0.01-0.025 mEq Ca2+/kg) was injected directly into branches of the celiac plexus (gastroduodenal, splenic, and hepatic arteries) and the superior mesenteric artery. In all patients, serum levels of insulin rose abruptly in blood samples taken from the right hepatic vein 30 and 60 seconds after the infusion of calcium into the artery supplying the tumor; injection into an artery not supplying the tumor did not result in a similar rise. Accurate localization of the insulinomas was verified at surgery in three patients. In the fourth patient, who did not undergo surgery, arteriographic results were positive for insulinoma at the predicted site. On the basis of these results, the authors believe noninvasive ASVS may replace invasive portal venous sampling as the most effective method for the localization of occult insulinomas.     

Role of the intra-arterial calcium stimulation test in the preoperative localization of insulinomas

The aim of this study was determination of the significance of the arterial stimulation test with venous sampling (ASVS) in the preoperative localization of insulinoma. Eleven patients with endogenous hyperinsulinism underwent preoperative transabdominal US, spiral computer tomography (spiral CT), MRI, endoscopic ultrasound (EUS) as well as angiography (DSA) combined with ASVS. The results were compared with intraoperative findings, intraoperative ultrasound (IOUS) and histopathology. There were no complications related to the ASVS test. In 11 patients the tumor could be localized with the various modalities as follows: US 1 of 11 (9 %), MRI 3 of 10 (30 %), spiral CT 4 of 11 (36 %), EUS 5 of 10 (50 %), DSA 8 of 11 (73 %), and ASVS 10 of 11 (91 %). In 2 patients the tumors were intraoperatively neither palpable nor detectable by IOUS, and consequently the intraoperative management was governed by information provided by DSA combined with the ASVS test. Ten patients had solitary benign insulinomas and 1 patient with multiple endocrine neoplasia I had two tumors adjacent to each other in the pancreatic tail. Arterial stimulation test with venous sampling was the most sensitive preoperative test for regionalizing the insulinoma in our set of patients. It can be performed safely in the course of a regular DSA examination and may affect intra-operative management in patients in whom the tumors are not detectable by palpation or IOUS. Received: 23 June 1999; Revised: 13 January 2000; Accepted: 29 February 2000     

The role of arterial stimulation and simultaneous venous sampling in addition to cross-sectional imaging for localisation of biochemically proven insulinoma

Insulinomas, although rare, cause considerable morbidity but are frequently amenable to surgical cure. Laparoscopic surgery can now be considered if the tumour is localised pre-operatively, but the optimal imaging approach has not been determined. The objective of this study was to evaluate the ability of different imaging investigations, including CT, MRI, endoscopic ultrasound, octreotide scintigraphy and arterial stimulation with simultaneous venous sampling (ASVS), to localise insulinomas. All patients with biochemically proven insulinoma at our institution underwent ASVS along with other imaging investigations as part of their routine investigation. The results of these investigations were compared with histological findings. Twenty-eight patients with biochemically proven insulinoma confirmed by histology were identified. Ultimately ASVS localised a lesion in all patients. Seventeen patients (61%) had laparoscopic surgery. Tumor-detection rates for other imaging investigations included 43.5% of cases using CT, 71% using MRI, 86% using endoscopic ultrasound and 33% using octreotide scintigraphy. In four patients, the ASVS was the only test to correctly localise the lesion. ASVS should be considered routinely before surgery to ensure accurate localisation of insulinomas.     

Intraarterial calcium stimulation (ASVS) for pancreatic insulinoma: comparison of preoperative localization procedures

PURPOSE: Evaluation of clinical relevance of the arterial stimulation procedure with venous sampling (ASVS) in the preoperative localization of insulinoma. METHODS: Thirteen patients with endogenous hyperinsulinism underwent preoperative transabdominal ultrasound (US), helical CT (CT), MRI, endoscopic ultrasound (EUS), and angiography (DSA) in conjunction with the ASVS-test for the detection of insulinoma. The results were compared with intraoperative findings, intraoperative ultrasound (IOUS) and histology. RESULTS: Sensitivity was as follows: US 8%, MRI 27%, CT 46%, EUS 50%,DSA 69%,and ASVS 92%. Intraoperative palpation and IOUS yielded a sensitivity of 77%. In 3 patients the tumors were neither palpable nor detectable by IOUS, the mode of resection was based on preoperative diagnostics. The ASVS procedure as a functional test was superior to all other modalities for the preoperative tumor detection. CONCLUSION: The ASVS was the most sensitive diagnostic modality. It should especially be considered in terms of health economical aspects when CT or MRI do not yield conclusive results.     

Selective Intra-Arterial Calcium Stimulation with Hepatic Venous Sampling for Preoperative Localization of Insulinomas

Objective

To determine the value of selective intra-arterial calcium stimulation with hepatic venous sampling using serum insulin and C-peptide gradients for the preoperative localization of insulinomas.

Materials and Methods

Seven consecutive patients [three men and four women aged 15-77 (mean, 42.7) years] with hypoglycemia underwent selective intra-arterial calcium stimulation in conjunction with hepatic venous sampling. Insulin gradients were calculated by an individual blinded to all other preoperative imaging studies and operative findings. In all patients except one, C-peptide gradients were also analyzed. The results were compared with the preoperative findings of ultrasonography, computed tomography, arteriography and endoscopic ultrasonography, as well as with the intraoperative findings of ultrasonography and palpation at surgery.

Results

Eight insulinomas (mean diameter, 12.5 mm) were diagnosed after surgery. In six patients, the calcium stimulation test with insulin gradients allowed accurate localization of the pathologic source of insulin secretion. Both C-peptide and insulin gradients substantially increased diagnostic accuracy. In one patient, C-peptide gradients were more helpful than insulin gradients for tumor localization.

Conclusion

Selective intra-arterial calcium stimulation with hepatic venous sampling is a highly accurate and safe method for the preoperative localization of insulinomas. Additional C-peptide gradients seem to be helpful in assessing tumor location, but further study is needed.     

Selective arterial calcium stimulation and hepatic venous sampling in the evaluation of hyperinsulinemic hypoglycemia: potential and limitations

PURPOSE: To describe the potential and limitations of selective arterial calcium stimulation and hepatic venous sampling (ASVS) in the evaluation of patients with hyperinsulinemic hypoglycemia. MATERIALS AND METHODS: Twenty-seven consecutive adult patients with documented hyperinsulinemic hypoglycemia undergoing an ASVS test and histologically confirmed diagnosis were included. RESULTS: By histology, 24 patients were found to have an insulinoma, two had islet cell hyperplasia, and one had insulin-secreting neuroendocrine carcinoma of the liver. ASVS correctly predicted the source of excessive insulin secretion in 26 of 27 (sensitivity, 96%) patients. In two patients with an insulinoma, ASVS had to be repeated for correct diagnosis; in one patient with a glucose-sensitive insulinoma, ASVS was falsely negative. In one patient, a falsely negative ASVS test was caused by diazoxide treatment; in another patient a falsely negative ASVS test occurred because of extraordinarily high baseline insulin levels when the calcium stimulation was performed. CT and/or MR imaging correctly predicted the source of excessive insulin secretion in 59% of patients, the sensitivity of the intraoperative exploration was 88%. CONCLUSIONS: In the authors' experience, the ASVS test is superior to CT/MR imaging and even the intraoperative exploration in identifying the source of excessive insulin secretion in patients with hyperinsulinemic hypoglycemia. To prevent false negative ASVS tests, medications with an influence on insulin secretion have to be discontinued prior to ASVS and two baseline blood samples should be obtained before the calcium stimulation is performed.     

Assessment of contrast-enhanced ultrasonography in diagnosis and preoperative localization of insulinoma

ObjectiveThis study was to evaluate the value of contrast-enhanced ultrasonography (CEUS) in the diagnosis and preoperative localization of insulinoma and explore the enhancement patterns of the tumors.MethodsUnenhanced and contrast-enhanced ultrasonographic examinations of 31 patients who underwent resection of insulinomas were retrospectively reviewed. The diagnosis sensitivity and localization specificity of CEUS for insulinomas were determined. Results of unenhanced ultrasonography and CEUS were compared by Chi-square test.ResultsUnenhanced ultrasonography could display 9 of 37 (24.3%) surgically verified insulinomas in 31 patients, while the diagnosis sensitivity and localization specificity of preoperative CEUS was 33 (89.2%) and 32 (86.5%) of the 37 tumors, respectively. In contrast to the unenhanced ultrasonography, the improvement of CEUS in the diagnosis and preoperative localization of insulinomas was significant (p < 0.0001). The enhancement pattern of insulinoma on CEUS was fast wash-in and slow wash-out. All the tumors were homogeneous hypervascularity in the earlier arterial phase, while the tumors still displayed hyperenhancing pattern in the late phase.ConclusionOur study demonstrates the great potential of CEUS in the diagnosis and preoperative localization of insulinomas. Since CEUS is a convenient, inexpensive, effective and non-invasive modality, the study supports the use of CEUS as a primary tool in the evaluation of patients with insulinomas.