99mTc-EDDA/HYNIC-octreotate in detection of atypical bronchial carcinoid.

Pulmonary carcinoids cause serious difficulties in imaging diagnostics in all stages of the disease. SRS holds great promise for detecting occult primary tu and metastatic lesions. (99m)Tc-EDDA/HYNIC-octreotate, a new scintigraphic agent, should significantly improve sensitivity of the diagnostics of carcinoids due to better affinity to SSR2 than (111)In-Octreoscan and the higher count rate obtained from (99m)Tc over (111)In. We present a case of a 40-year-old women operated on because of lung carcinoid tumour in 2002. The symptoms did not resolve after the operation and 5-OHIAA was still elevated. The thorax spiral CT revealed the focal lesion beneath carina. (111)In-Octreoscan and (99m)Tc-EDDA/HYNIC-octreotate SRS revealed two focal lesions in the mediastinum. (99m)Tc-EDDA/HYNIC-octreotate detected two additional lesions in the lower part of the right lung. Target/non-target count ratios of the lesions were as follows: (99m)Tc-EDDA/HYNIC-octreotate scans - 2,9, (111)In-Octreoscan- 2,1. PET-FDG examination revealed no pathology. Owing to severe bone pains and carcinoid symptoms the patient was referred for the 90Y-DOTA-octreotate treatment. Conclusions: SRS with a new 99mTc marked somatostatin analogue - octreotate allows for a more sensitive detection of metastatic leasions in carcinoid tumours. The usefulness of 18F-FDG PET, widely used as a powerful imaging technique in clinical oncology, is limited in detection of carcinoid tumours due to the low proliferative activity.     

Whole-body (11)C-5-hydroxytryptophan positron emission tomography as a universal imaging technique for neuroendocrine tumors: comparison with somatostatin receptor scintigraphy and computed tomography

Neuroendocrine tumors (NETs) can be small and situated almost anywhere throughout the body. Our objective was to investigate whether whole-body (WB) positron emission tomography (PET) with (11)C-5-hydroxytryptophan (5-HTP) can be used as a universal imaging technique for NETs and to compare this technique with established imaging methods. Forty-two consecutive patients with evidence of NET and a detected lesion on any conventional imaging (six bronchial, two foregut, 16 midgut, and two thymic carcinoids; one ectopic Cushing's syndrome; four gastrinomas; one insulinoma; six nonfunctioning endocrine pancreatic tumors; one gastric carcinoid, one paraganglioma; and two endocrine-differentiated pancreatic carcinomas) were studied. The WB-(11)C-5-HTP-PET examinations were compared with WB-computed tomography (CT) and somatostatin receptor scintigraphy (SRS). Tumor lesions were imaged with PET in 95% of the patients. In 58% of the patients, PET could detect more lesions than SRS and CT and equal numbers in 34%, whereas in three cases, SRS or CT showed more lesions. In 84% (16 of 19 patients), PET could visualize the primary tumor compared with 47 and 42% for SRS and CT, respectively. The surgically removed PET-positive primary tumor sizes were 6-30 mm. To conclude, this study indicates that WB-(11)C-5-HTP-PET can be used as a universal imaging method for detection of NETs. This study also shows that WB-(11)C-HTP-PET is sensitive in imaging small NET lesions, such as primary tumors, and can in a majority of cases image significantly more tumor lesions than SRS and CT.     

Endoscopic ultrasonography and somatostatin receptor scintigraphy in the preoperative localisation of insulinomas and gastrinomas.

BACKGROUND: Endoscopic ultrasonography (EUS) and somatostatin receptor scintigraphy (SRS) can detect a high percentage of gastroenteropancreatic neuroendocrine tumours especially in the upper gastrointestinal tract. The ability of these procedures to localise primary tumour lesions and metastases of gastrinomas and insulinomas was evaluated in comparison with transabdominal ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI). PATIENTS AND METHODS: In a prospective trial, patients with gastrinomas (n = 10) and insulinomas (n = 10) diagnosed by clinical signs and laboratory tests were assessed by EUS, SRS, US, CT and MRI. RESULTS: In 10 patients with gastrinoma and 10 patients with insulinoma, a total of 14 separate primary tumour lesions were histologically confirmed for each of the tumour entities. The mean diameter was 2.1 cm for gastrinomas and 1.5 cm for insulinomas. All insulinomas and nine gastrinoma lesions were located in the pancreas. Three gastrinomas were found in the duodenal wall, one in a periduodenal lymph node, and one in the liver, For gastrinomas, sensitivities were 79% with EUS, 86% with SRS and 29% with CT, US, and MRI. For insulinomas, sensitivities were 93% with EUS, 14% with SRS, 21% with CT and 7% with US and MRI. CONCLUSIONS: EUS is of high value for localising primary lesions of both tumour entities. SRS is a very sensitive procedure for diagnosing of gastrinomas but not insulinomas. CT, US and MRI are primarily useful for visualising metastases.     

Usefulness of somatostatin receptor scintigraphy in patients with occult ectopic adrenocorticotropin syndrome

SRIF receptor scintigraphy (SRS) has been proposed for the localization of ectopic ACTH-secreting tumors responsible for Cushing's syndrome. However, in most cases reported, the tumors were also visible using conventional imaging. Therefore, the usefulness of SRS in localizing truly occult ectopic ACTH-secreting tumors remains unknown. We report the results of SRS in 12 patients with ectopic ACTH syndrome (EAS) and in whom the source of ACTH was occult at presentation despite carefully performed conventional imaging. The diagnosis of EAS was made by identification of an ACTH-secreting tumor during follow-up in 5 patients or given a pituitary-to-peripheral ACTH ratio of 1.9 or less during petrosal sinus sampling combined with CRH injection and a negative pituitary magnetic resonance imaging (MRI). Whole-body planar SRS, using (111)In-pentetreotide, was performed 19 times in the 12 patients during initial workup and/or follow-up. Axial tomography imaging (single-photon emission-computed tomography) was performed in 7 of these. Conventional imaging was performed within a month of SRS, allowing comparison of the two approaches for the localization of the ACTH-secreting tumors. In addition, the response of plasma cortisol, after a single injection of 200 microg octreotide, was studied in 6 patients. Five patients had negative SRS and conventional imaging studies. The source of ACTH secretion remains occult despite 10-55 months of follow-up in four of these, whereas a 2-cm ileal carcinoid tumor, with liver micrometastases, was found at laparotomy in one patient, 14 months after presentation. SRS was positive in 4 of 12 patients. It was false-positive in 1 patient with follicular thyroid adenoma. Nineteen months after presentation, SRS identified liver metastasis that was also visible using MRI in one patient, but the primary tumor remains occult. SRS identified a 10-mm pancreatic tumor that became detectable, using computed tomography (CT) scanning 9 months later, in 1 patient; and 2 mediastinal lymph nodes of 10 mm, previously ignored by MRI, in another patient, whereas no tumor was detectable within the parenchymal lung. SRS had little influence on therapeutic options in these 2 patients, in whom no final diagnosis could be made. Repetition of SRS during the follow-up of patients with previously negative scintiscans was useless. Conventional imaging was positive in 6 of 12 patients. In the 2 patients with pancreatic tumor and isolated mediastinal lymph nodes, conventional imaging studies were interpreted as positive only after the results of SRS. One patient had liver metastasis that was also visible using SRS. Thin-section CT scanning visualized ACTH-secreting bronchial tumors and metastatic mediastinal lymph nodes of 10-15 mm in diameter in 3 patients after 14-72 months of follow-up, whereas SRS was negative. There was no evident relationship between the endocrine status (hyper- or eucortisolism) and the results of SRS. The in vivo response of plasma cortisol to octreotide correlated to the results of SRS in 4 of 6 cases. In conclusion, both imaging procedures had a low diagnostic yield in this series. However, the sensitivity of SRS for the detection of bronchial carcinoids was lower than that of thin-section CT scanning. We therefore advocate the use of conventional imaging, including thin-section CT scanning of the chest, analyzed by experienced radiologists, as the first-line investigation in patients with occult EAS. SRS should not be repeated during the follow-up in patients with a previously negative scintigram.     

Prospective comparative study of ability of MR imaging and other imaging modalities to localize tumors in patients with Zollinger-Ellison syndrome

The role of magnetic resonance (MR) imaging in patients with pancreatic endocrine tumors such as Zollinger-Ellison syndrome (ZES) is controversial. In the present study we have examined the ability of current MR imaging compared with other imaging modalities, to localize gastrinomas in 43 patients with ZES. All results were subsequently assessed at exploratory laparotomy (N=34) or by liver biopsy (N=9). For the 18 patients with metastatic gastrinoma in the liver, MR imaging had a sensitivity of 83%, ultrasound 50%, CT 56%, and angiography 61%. The combination of MR imaging, ultrasound, and CT were the same as MR imaging alone. For MR imaging, both T1 and STIR sequences had equal sensitivity, although tumors were more easily seen with STIR sequences. Specificity of MR imaging was slightly lower (88%) than the other modalities (96–100%) because MR imaging incorrectly identified small hemangiomas as possible tumors in four patients. MR imaging was better than CT in identifying metastatic lesions in the liver. For the localization of primary gastrinoma, assessed in 32 patients, MR imaging had a sensitivity of 25%, ultrasound 19%, CT 28%, all three together 38%, and angiography 59%. Localization of metastatic gastrinoma in the liver or primary gastrinomas in 16 patients was assessed before and after gadolinium-DTPA (0.1 mmol/kg). The sensitivity and specificity of MR imaging was unchanged but bolus injection and rapid MR acquisition techniques were not used. These results indicate that recent advances in MR imaging have greatly improved its sensitivity for the detection and assessment of the extent of metastatic gastrinoma. MR imaging is now the imaging study of choice to assess metastatic pancreatic endocrine tumors in the liver. In contrast, the detection of primary tumors by MR imaging has not improved; therefore, angiography remains the study of choice.     

18F-FDG PET/CT显像判断乳腺癌复发及转移的价值

目的探讨^18F-FDG PET/CT显像判断乳腺癌复发和转移的临床价值.方法28例手术治疗后临床疑有肿瘤复发或转移的乳腺癌患者均进行^18F-FDG PET/CT全身显像,应用目测法和半定量分析法判断结果（标准摄取值,SUV）.结果病理、活检、细胞学检查等证实17例有局部复发和（或）转移,^18F-FDG PET/CT显像正确诊断16例,检测灵敏度、特异性（94.12%,90.91%）明显高于传统影像学方法;在62个肿瘤复发和（或）转移灶中,PET/CT及常规影像学检查检出率分别为91.94%（57/62）、72.58%（45/62）,P＜0.05.结论^18F-FDG PET/CT显像是早期诊断乳腺癌复发和（或）转移良好的、无创性方法.     

Prospective study of thymic carcinoids in patients with multiple endocrine neoplasia type 1

Little is known of the natural history of thymic carcinoids in multiple endocrine neoplasia type 1 (MEN1). This is important because in 1993 they were identified as a frequent cause of death, yet only small retrospective studies and case reports exist. We report results of a prospective study of 85 patients with MEN1 evaluated for pancreatic endocrine tumors and followed over a mean of 8 yr with serial chest computed tomography, magnetic resonance imaging (MRI), chest x-ray, and, since 1994, octreoscans [somatostatin receptor scintigraphy (SRS)]. Seven patients (8%) developed thymic carcinoids. Patients with and without carcinoids did not differ in clinical, laboratory, or MEN1 tumor features, except for male gender and the presence of a gastric carcinoid. All thymic tumors were hormonally inactive. Four thymic carcinoids lacked 11q loss of heterozygosity, although it was found in three pancreatic endocrine tumors. Computed tomography and/or MRI were more sensitive than SRS or chest x-ray in detecting tumors initially or with recurrence. All patients underwent resection of the thymic carcinoid, and in all patients followed more than 1 yr, the tumor recurred. Bone metastases developed in two patients and were detected early only on MRI, not SRS. This study provides information on early thymic carcinoids and allows modifications of existing guidelines to be recommended for their diagnosis, surveillance, and treatment.     

Diagnostic management of suspected metastatic thyroid carcinoma: clinical value of octreotide scintigraphy in patients with negative high-dose radioiodine scans

OBJECTIVES: Somatostatin receptor scintigraphy (SRS) with (111)In-octreotide has been suggested as a potential tool for the detection of recurrent or metastatic differentiated thyroid cancer when no radioiodine uptake can be demonstrated in tumour sites. However, there is no consensus concerning the performance and clinical impact of this examination in such instances. DESIGN AND METHODS: A prospective study was undertaken to evaluate SRS in 43 patients (18 men, 25 women) with papillary (n=20), follicular (n=9), insular (n=6) and oncocytic (n=8) thyroid carcinomas with elevated serum thyroglobulin (Tg) levels and no detected radioiodine uptake. RESULTS: Evaluation criteria were interpreted in terms of an assumed presence of tumoural tissue. Sensitivity of SRS was 51%, clearly lower than that of conventional imaging procedures, and of positron emission tomography using [(18)F]-2-fluoro-2-deoxy-d-glucose, performed in a subset of 27 patients. In addition, we observed two false-positive foci of uptake of octreotide that corresponded to inflammatory pulmonary sites. The sensitivity was higher in patients with Tg levels greater than 50 microg/l (76%) for detecting mediastinal lesions (93%), and in patients with oncocytic cancer (88%). Finally, SRS changed treatment strategy in four patients. CONCLUSION: In differentiated thyroid cancer, SRS is a moderately sensitive method for the detection of lesions unable to concentrate iodine and appears useful only in patients with very high Tg levels or in oncocytic cancer.     

EUS, PET, and CT scanning for evaluation of pancreatic adenocarcinoma

BACKGROUND: Preoperative diagnosis of pancreatic adenocarcinoma can be difficult. Computed tomography (CT) is the standard, noninvasive imaging method for evaluation of suspected pancreatic adenocarcinoma, but it has limited sensitivity for diagnosis, local staging, and metastases. Endoscopic ultrasound (EUS) and fluoro-deoxyglucose/positron emission tomography (FDG-PET) are imaging methods that may improve diagnostic accuracy. METHODS: Thirty-five patients with presumed resectable pancreatic adenocarcinoma were prospectively evaluated with helical CT, EUS, and FDG-PET. RESULTS: Sensitivity for the detection of pancreatic cancer was higher for EUS (93%) and FDG-PET (87%) than for CT (53%). EUS was more sensitive than CT for local vascular invasion of the portal and superior mesenteric veins. EUS diagnosis of vascular invasion was associated with poor outcome after surgery. EUS-guided, fine-needle aspiration allowed tissue diagnosis in 14 of 21 attempts (67%). FDG-PET diagnosed 7 of 9 cases of proven metastatic disease, 4 of which were missed by CT. Two of three metastatic liver lesions suspected by CT were indeterminate for metastases. FDG-PET confirmed metastases. CONCLUSIONS: EUS and PET improve diagnostic capability in pancreatic adenocarcinoma. EUS is useful in determining local vascular invasion and obtaining tissue diagnosis. FDG-PET is useful in identifying metastatic disease. Both techniques are more sensitive than helical CT for identification of the primary tumor. (Gastrointest Endosc 2000;52:367-71).     

Imaging modalities for the staging of patients with colorectal cancer

Dutch guidelines made the following recommendations for staging colorectal cancer (CRC). For liver metastases, computed tomography (CT) or magnetic resonance imaging (MRI) could be used. For lung metastases, imaging could be limited to chest X-ray. The primary aim of this survey was to summarise the use of imaging modalities and the variation in techniques. Three surveys were created and sent to three groups of medical specialists, namely surgeons, radiologists and nuclear medicine physicians. The management survey included questions on the role of different modalities for evaluation of synchronous liver, lung and extrahepatic metastases. The radiological survey included questions concerning the technical aspects of ultrasound (US), CT and MRI. The nuclear medicine survey included questions concerning the technical aspects of FDG-PET and FDG-PET/CT. The management and radiological surveys were sent to abdominal surgeons and abdominal radiologists within 88 hospitals and the nuclear medicine survey to specialists within 34 hospitals. Response rates were 75.0% (n=66/88), 77.3% (n=68/88) and 64.7% (n=22/34) for the management, radiological and nuclear medicine surveys, respectively. For liver metastases, the first modality of choice was CT in 52 (78.8%) and US in 12 hospitals (18.2%). Lung metastases were evaluated by either chest X-ray or chest CT and extrahepatic metastases mainly by CT (n=55). In the radiological and nuclear medicine surveys, some variations in techniques of US, CT, MRI , FDG-PET and FDG-PET/CT were seen. CT is primarily used for liver and extrahepatic metastases and both chest CT and chest X-ray for lung metastases. There are discrepancies between the survey of daily practice and the present guidelines. Comparative studies on different staging strategies for colon and rectal cancer, including comparing a strategy of CT liver/abdomen versus MRI liver/abdomen for the evaluation of liver and extrahepatic disease and chest X-ray or chest CT for lung metastases would be important for well-founded adjustments of the present guidelines.     

An analysis of imaging studies and liver function tests to detect hepatic neoplasia

A retrospective study was conducted to determine the sensitivity, specificity, and accuracy of scintigraphy, ultrasound, and CT scanning in conjunction with biochemical tests in the detection of liver neoplasia. Sixty-three patients with metastatic liver disease and 45 patients with nonmalignant liver disease received a total of 46 liver/spleen scan, 61 ultrasounds, and 49 CT scans. The sensitivities of liver/spleen scan, ultrasound, and CT scan were 72, 73, and 81%, respectively; the specificities were 86, 94, and 83%, respectively; and, the accuracies were 78, 84, and 82%, respectively. No statistically significant difference in specificity, sensitivity, or accuracy was seen between the three imaging studies. The serum alkaline phosphatase was significantly more accurate than total bilirubin and SGOT in detecting liver metastasis. However, 19 and 13% of the malignant and nonmalignant groups, respectively, had normal biochemical tests. The sensitivity, specificity, and accuracy of the imaging studies in the presence of an abnormal alkaline phosphatase, SGOT, or total bilirubin were not significantly different than in the presence of normal biochemical tests. These results suggest that other factors such as cost, reproducibility, and availability of skilled interpreters should be considered in the selection of imaging studies for the detection of neoplastic liver disease.     

The Value of Restaging With Chest and Abdominal CT/MRI Scan After Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

Little was known with regard to the value of preoperative systemic restaging for patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (CRT). This study was designed to evaluate the role of chest and abdominal computed tomography (CT) scan or magnetic resonance imaging (MRI) on preoperative restaging in LARC after neoadjuvant CRT and to assess the impact on treatment strategy.Between January 2007 and April 2013, 386 newly diagnosed consecutive patients with LARC who underwent neoadjuvant CRT and received restaging with chest and abdominal CT/MRI scan were included. Imaging results before and after CRT were analyzed.Twelve patients (3.1%) (6 liver lesions, 2 peritoneal lesions, 2 distant lymph node lesions, 1 lung lesions, 1 liver and lung lesions) were diagnosed as suspicious metastases on the restaging scan after radiotherapy. Seven patients (1.8%) were confirmed as metastases by pathology or long-term follow-up. The treatment strategy was changed in 5 of the 12 patients as a result of restaging CT/MRI findings. Another 10 patients (2.6%) who present with normal restaging imaging findings were diagnosed as metastases intra-operatively. The sensitivity, specificity accuracy, negative predictive value, and positive predictive values of restaging CT/MRI was 41.4%, 98.6%, 58.3%, and 97.3%, respectively.The low incidence of metastases and minimal consequences for the treatment plan question the clinical value of routine restaging of chest and abdomen after neoadjuvant CRT. Based on this study, a routine restaging CT/MRI of chest and abdomen in patients with rectal cancer after neoadjuvant CRT is not advocated, carcino-embryonic antigen (CEA) -guided CT/MRI restaging might be an alternative.     

Characterization of focal liver lesions with SonoVue(R)-enhanced sonography: International multicenter-study in comparison to CT and MRI

AIM: To evaluate in a multicenter study whether the sonographic characterization of focal liver lesions can be improved using SonoVue(R)-enhancement; and to compare this method with computed tomography (CT) and magnetic resonance imaging (MRI). METHODS: One hundred and thirty four patients with one focal liver lesion detected in baseline ultrasound (US) were examined with conventional US, contrastenhanced US ( n = 134), contrast-enhanced CT ( n = 115) and/or dynamic contrast-enhanced MRI ( n = 70). The lesions were classified as malignant, benign or indeterminate and the type of lesion was determined.The final diagnosis based on the combined information of all imaging examinations, clinical information and histology ( n = 32) was used. Comparisons were made to see whether the addition of contrast-enhanced US led to the improvement of the characterization of doubtful focal liver lesions. RESULTS: In comparison with unenhanced US, SonoVue(r) markedly improves sensitivity and specificity for the characterization (malignant/benign) of focal liver lesions. In comparison with CT and/or dynamic MRI, SonoVue(r) -enhanced sonography applied for characterization of focal liver lesions was 30.2% more sensitive in the recognition of malignancy and 16.1% more specific in the exclusion of malignancy and overall 22.9% more accurate. In the subgroup with confirmative histology available ( n = 30), sensitivity was 95.5% (CEUS), 72.2% (CT) and 81.8% (MRI), and specificity was 75.0% (CEUS), 37.5% (CT) and 42.9% (MRI). The sensitivity and specificity of CEUS for the identification of focal nodular hyperplasia (FNH) and hemangiomas was 100% and 87%, resulting in an accuracy of 94.5%. CONCLUSION: SonoVue(r)-enhanced sonography emerges as the most sensitive, most specific and thus most accurate imaging modality for the characterization of focal liver lesions.     

Characterization of focal liver lesions with SonoVue- enhanced sonography： International multicenter-study in comparison to CT and MRI

AIM： To evaluate in a multicenter study whether the sonographic characterization of focal liver lesions can be improved using SonoVue-enhancement; and to compare this method with computed tomography （CT） and magnetic resonance imaging （MRI）.
METHODS： One hundred and thirty four patients withone focal liver lesion detected in baseline ultrasound （US） were examined with conventional US, contrastenhanced US （n = 134）, contrast-enhanced CT （n = 115） and/or dynamic contrast-enhanced MRI （n = 70）. The lesions were classified as malignant, benign or indeterminate and the type of lesion was determined. The final diagnosis based on the combined information of all imaging examinations, clinical information and histology （n = 32） was used. Comparisons were made to see whether the addition of contrast-enhanced US led to the improvement of the characterization of doubtful focal liver lesions.
RESULTS： In comparison with unenhanced US, SonoVue markedly improves sensitivity and specificity for the characterization （malignant/benign） of focal liver lesions. In comparison with CT and/or dynamic MRI, SonoVue -enhanced sonography applied for characterization of focal liver lesions was 30.2% more sensitive in the recognition of malignancy and 16.1% more specific in the exclusion of malignancy and overall 22.9% more accurate. In the subgroup with confirmative histology available （n = 30）, sensitivity was 95.5% （CEUS）, 72.2% （CT） and 81.8% （MRI）, and specificity was 75.0% （CEUS）, 37.5% （CT） and 42.9% （MRI）. The sensitivity and specificity of CEUS for the identification of focal nodular hyperplasia （FNH） and hemangiomas was 100% and 87%, resulting in an accuracy of 94.5%.
CONCLUSION： SonoVue-enhanced sonography emerges as the most sensitive, ost specific and thus most accurate imaging modality for the characterization of focal liver lesions.     

内镜超声在非胰岛素瘤胃肠胰腺神经内分泌肿瘤定位诊断中的作用

背景：准确的定位诊断是胃肠胰腺神经内分泌肿瘤（GEP-NETs）患者手术成败的关键。内镜超声（EUS）可在近距离内对胃肠壁、胰腺及其毗邻结构行超声检查。目的：评价EUS在非胰岛素瘤GEP-NETs定位诊断中的作用。方法：对1996年6月～2007年6月北京协和医院诊断的非胰岛素瘤GEP-NETs患者进行回顾性分析，总结其EUS表现．并与其他影像学检查方法的敏感性进行比较。结果：共纳入11例非胰岛素瘤GEP-NETs患者，检出原发病灶16个，EUS的敏感性为75．0％（12／16）。如剔除一例因有胃大部切除史而干扰检查者，EUS的敏感性可达90．9％（10/11）。腹部CT平扫＋增强、腹部B超、生长抑素受体显像和血管造影的敏感性分别为56．2％（9／16）、37．5％（6，16）、66．7％（8／12）和57．1％（4／7）。EUS显示的12个病灶中，低回声者8个（66．7％），回声不均匀者7个（58．3％），边界清晰者11个（91．7％）。EUS显示的最小病灶直径为0．5cm。结论：EUS对非胰岛素瘤GEP-NETs的定位诊断具有较高敏感性．优于腹部CT、腹部B超、生长抑素受体显像等传统定位方法。     

CT for the diagnosis of venous thromboembolic disease

Spiral CT, venous ultrasound, ventilation-perfusion scanning, and D-dimer tests are routinely used in the diagnosis of venous thromboembolic disease. Advances in multidetector spiral CT and the combination of CT pulmonary angiography and venography as a one-step evaluation of venous thromboembolic disease have markedly improved detection of subsegmental emboli and deep pelvic venous thrombi and decreased the role of conventional pulmonary angiography. As CT has improved, many have questioned what "gold standard" CT should be compared with. Recent clinical outcome studies suggest that CT results are as good as pulmonary angiography and conventional imaging algorithms. Because the sensitivity of CT pulmonary angiography now exceeds 85%, it also appears that it is also more cost effective than other diagnostic approaches.     

Lung ultrasound in the diagnosis of stroke-associated pneumonia

Pneumonia is a common complication in stroke patients; it is associated with an adverse outcome, prolonged hospital stay and increased health costs. The aim of this study was to assess the ability of lung ultrasound to rule in or rule out pneumonia in patients with stroke. Patients with ischemic or hemorrhagic stroke were included in the study if they had a clinical suspicion of pneumonia. Lung ultrasound imaging and chest X-ray studies were performed within 24 h from the onset of symptoms of pneumonia; the sonographer and radiologists were unaware of the chest X-ray study and ultrasound imaging results, respectively. In case of discordant results, lung computed tomography (CT) was performed if a definitive diagnosis was required to optimize clinical management. Seventy patients were included in the study. Among 24 patients with unilaterally positive chest X-ray studies, the ultrasound imaging was unilaterally positive in 19 cases (79.2 %), bilaterally positive in 3 cases (12.5 %) and negative in 2 cases (8.3 %). Among 44 patients with negative chest X-ray studies, ultrasound imaging was unilaterally positive in 17 cases (38.6 %), bilaterally positive in 2 cases (4.6 %), negative in 19 cases (43.2 %) and non-conclusive in 6 cases (13.6 %). A lung CT scan was performed in 9 of the 21 discordant cases, and it always confirmed the ultrasound imaging results. Ultrasound imaging and chest X-ray studies were concordant in 42 out of 63 cases, 66.7 % (Pearson χ² = 11.97, p = 0.001). In conclusions, this study shows the utility of LUS imaging to rule in or rule out pneumonia in patients with stroke. We believe that lung ultrasound imaging can help clinicians in the diagnosis of stroke-associated pneumonia.     

SPECT/CT hybrid imaging with 111In-pentetreotide in assessment of neuroendocrine tumours

OBJECTIVE: Somatostatin receptor scintigraphy (SRS) of neuroendocrine (NE) tumours is often challenging because of minute lesion size and poor anatomic delineation. This study evaluates the impact of sequentially performed single-photon emission computed tomography (SPECT)/CT fusion on SRS study interpretation and clinical management of these tumours. PATIENTS AND DESIGN: Seventy-two patients were studied with routine SRS and SPECT/CT at 4, 24 and optionally 48 h after injection of 222 MBq 111In-pentetreotide. Forty-five patients were evaluated for carcinoid, 15 for islet cell tumour, seven for metastatic NE tumour, four for medullary thyroid carcinoma, and one patient had ophthalmopathy. SPECT/CT induced improvement in the interpretation of SPECT and conventional CT and resultant clinical management changes were recorded. RESULTS: SRS was negative in 28 patients and positive in 44 patients. SPECT/CT provided no additional information in 48 patients, including all 28 negative studies. SPECT/CT improved localization of the SPECT-detected lesions in 23 of the 44 positive studies. It defined the extent of disease in 17, showed unsuspected bone involvement in three, and differentiated physiological from tumour uptake in three studies. SPECT/CT affected the clinical management in 10 patients, altered the surgical approach in six, spared unnecessary surgery in two, and modified the therapeutic modality in two patients. CONCLUSIONS: SPECT/CT affected the diagnostic interpretation of SRS in 32% of the patients and induced changes in management in 14% of the patients.     

A Prospective Comparison of Laparoscopy and Imaging in the Staging of Esophagogastric Cancer Before Surgery

Objective: To carry out a prospective comparison of laparoscopy and combined imaging (CT and ultrasound) in the preoperative staging of distal esophageal and gastric cancer in patients who were selected for surgery.
Methods: Patients with clinically overt metastases or a contraindication to major surgery were excluded. One hundred and forty-five patients underwent chest radiography, CT of mediastinum and abdomen, and ultra-sonography of abdomen and laparoscopy. The primary diagnoses were adenocarcinoma of the esophagogastric region in 110 cases, squamous cell carcinoma of the distal esophagus in 30 patients, and five miscellaneous.
Results: Thirty nine (27%) patients had metastatic disease outside the potential field of resection. Metastases were detected preoperatively by laparoscopy in 30 patients (sensitivity 77%) and by combined imaging in 15 (sensitivity 38%) ( p < 0.01). Twenty four patients with adenocarcinoma had metastases to the peritoneal cavity, which were detected preoperatively by laparoscopy in 23 (sensitivity 96%) and by combined imaging in five (sensitivity 21%) ( p < 0.01). Peritoneal metastases were not seen in patients with squamous cell carcinoma. Fifteen patients had hepatic metastases, which were detected preoperatively by laparoscopy in nine (sensitivity 60%) and by combined imaging in seven (sensitivity 47%). Laparoscopy was more sensitive than combined imaging in detecting metastases in patients with adenocarcinoma [laparoscopy 28, combined imaging 10 ( p < 0.01)].
Conclusion: Addition of laparoscopy to the staging protocol prevented unbeneficial thoraco-abdominal exploration in 20 patients with adenocarcinoma. Thus, laparoscopy should be used in the assessment of patients with adenocarcinoma of the esophagogastric region before performing excisional surgery.     

Endoscopic ultrasonography of neuroendocrine tumours

Neuroendocrine tumours (NETs) of the upper gastrointestinal tract are mainly located in the pancreas, stomach or duodenum. The aims of preoperative work-up are the localization of primary tumour(s), determination of local tumour invasion, of lymph node metastases and of the hormones secreted by the tumour. Endoscopic ultrasonography (EUS) offers ideal conditions to localize and stage NETs of the foregut. We report our results in localizing and staging NETs of the foregut in 40 patients examined between 1990 and 1997 by EUS, somatostatin receptor scintigraphy (SRS), computed tomography (CT), magnetic resonance imaging (MRI) and transabdominal ultrasound (US). EUS shows the highest sensitivity in localizing insulinomas compared with SRS, US, CT and MRI. US and EUS should be the first-line diagnostics if insulinoma has been proven by a fasting test. Further diagnostic procedures are unnecessary in most cases. Further diagnostics such as CT or MRI to search for distant metastases are necessary in large tumours or local invasive tumours. EUS shows the highest accuracy to detect or exclude pancreatic gastrinomas, but fails to detect extrapancreatic gastrinomas in about 50%. The combination of EUS and SRS gives additional information. First-line diagnostics in gastrinoma patients should be SRS and CT or MRI. If no metastases are detected, EUS should be the next preoperative imaging procedure. In nonfunctional NETs, EUS provides the best information on local tumor invasion and regional lymph node involvement.