急性胰腺炎预后的CT研究进展

急性胰腺炎(AP)早期是诊断与治疗的关键时期,早期影像诊断可对预后进行推测并判断一些重要并发症出现的可能性。目前,CT检查为早期AP最重要的影像检查技术,已建立多种评分系统进行AP严重度的评估,其中应用最广泛的是CT严重度指数(CTSI)及修订的CTSI(MCTSI)。CT评分可较好地预测预后,甚至判断是否出现器官衰竭。CECT所见的低强化及CTP显示的灌注减低是预示胰腺梗死的较好指标,但CT难以预测AP是否出现血管并发症及合并感染。     

Contrast-enhanced sonography in pancreatic diseases

Contrast-enhanced sonography is a widely available imaging modality for the diagnosis of pancreatic diseases. With this procedure, pancreatic tumours can be differentiated better. Furthermore, contrast-enhanced sonography produces good results in the staging of acute pancreatitis severity, especially in the detection of pancreatic necrosis. In this review article the value of contrast-enhanced sonography in the diagnosis of pancreatic diseases will be described and discussed.     

Scintigraphic evaluation of acute pancreatitis patients with 99mTc-HMPAO-labelled leukocytes

OBJECTIVE: To demonstrate the localization of leukocytes in the pancreas during acute pancreatitis and to evaluate the potential use of 99mTc-HMPAO-labelled leukocytes in the diagnostic assessment of patients with acute pancreatitis. METHODS: The study was performed with 20 patients (11 females, nine males; ranging in age from 26 to 86 years, mean 55 years). Labelled leukocyte scintigraphy using planar imaging was performed on all patients, seven of whom were also examined by single photon emission computed tomography (SPECT). According to Ranson criteria, 10 patients had mild pancreatitis (group A), six had severe pancreatitis (group B) and four had necrotic pancreatitis (group C). Twelve patients had biliary pancreatitis and the other eight patients had no obvious cause. RESULTS: All patients of group C, four of group B, two of group A had a positive leukocyte scan. The positive leukocyte scintigraphy value for the detection of a lethal course of acute pancreatitis was 100%; of a severe course, 66.7%; and of a mild course, 20%. These findings are statistically significant (P=0.005 in chi-squared tests result). The results of leukocyte scintigraphy compared with those of CT were also statistically significant (P=0.001 in chi-squared tests). All the patients diagnosed with pancreatic necrosis by CT had a positive leukocyte scan, but only three of 13 patients without pancreatic necrosis that could be detected by computed tomography had a positive leukocyte scan. CONCLUSIONS: There was a significant correlation between the severity of the disease and leukocyte infiltration. Considering these results, we believe that leukocyte infiltration in acute pancreatitis can be demonstrated rapidly and accurately and by noninvasive 99mTc-HMPAO labelled leukocyte scintigraphy.     

Multidetector row computed tomography of acute pancreatitis: Utility of single portal phase CT scan in short-term follow up

Objective

The purpose of this study is to evaluate the question of whether nonenhanced CT or contrast enhanced portal phase CT can replace multiphasic pancreas protocol CT in short term monitoring in patients with acute pancreatitis.

Materials and methods

This retrospective study was approved by the Institutional Review Board. From April 2006 to May 2010, a total of 52 patients having acute pancreatitis who underwent initial dual phase multidetector row CT (unenhanced, arterial, and portal phase) at admission and a short term (within 30 days) follow up dual phase CT (mean interval 10.3 days, range 3–28 days) were included. Two abdominal radiologists performed an independent review of three sets of follow up CT images (nonenhanced scan, single portal phase scan, and dual phase scan). Interpretation of each image set was done with at least 2-week interval. Radiologists evaluated severity of acute pancreatitis with regard to pancreatic inflammation, pancreatic necrosis, and extrapancreatic complication, based on the modified CT severity index. Scores of each image set were compared using a paired t-test and interobserver agreement was evaluated using intraclass correlation coefficient statistics.

Results

Mean scores of sum of CT severity index on nonenhanced scan, portal phase scan, and dual phase scan were 5.7, 6.6, and 6.5 for radiologist 1, and 5.0, 5.6, and 5.8 for radiologist 2, respectively. In both radiologists, contrast enhanced scan (portal phase scan and dual phase scan) showed significantly higher severity score compared with that of unenhanced scan (P < 0.05), while portal phase and dual phase scan showed no significant difference each other. The trend was similar regarding pancreatic inflammation and extrapancreatic complications, in which contrast enhanced scans showed significantly higher score compared with those of unenhanced scan, while no significant difference was observed between portal phase scan and dual phase scan. In pancreatic necrosis analysis, there was no significant difference between the three image sets for both radiologists. However, when only the patients having pancreatic necrosis (n = 13) was separately analyzed, significant differences were observed between the unenhanced and portal phase scan (P = 0.04, for radiologist 1), or unenhanced and dual phase scan (P = 0.013, for radiologist 2).

Conclusion

For short-term follow up imaging in assessment of patients with acute pancreatitis, single portal phase CT images without adding unenhanced or arterial phase images provide sufficient information, and thereby reduce radiation exposure.     

螺旋CT双期增强扫描对可疑胰头癌的鉴别诊断

目的：探讨螺旋CT双期增强扫描对可疑胰头癌的鉴别诊断价值。方法：对49例经超声和临床拟诊的胰头癌行胰腺的螺旋CT双期增强扫描,动脉期和门静脉期延迟扫描时间分别为25秒和60秒,所有病例经病理或临床追踪诊断。结果：49例中,胰头变异例,胰头周围淋巴结病6例,慢性胰腺炎7例,胰头癌31例。其中46例（94%）诊断正确,1例胰头周围淋巴结结核和 2例慢性胰朱炎误诊为胰头癌。结论：螺旋CT双期增强扫描对可疑胰头癌的鉴别诊断有很高的价值。     

急性胰腺炎的电子束CT三期连续容积扫描技术

目的：探讨急性胰腺炎的电子束CT三期连续容积扫描的应用价值。方法：67例患者进行的103次扫描均进行了电子束CT三期连续容积扫描，而后参照Baltllazar CT评分系统对三期CT扫描图像进行观察并评分。结果：第一期可见高程度增强的胰腺实质及强化不明显的实质内坏死区、水肿区，正常胰腺组织与病变组织增强后的明显差值；第二期可见胰腺周围血管明显强化，胰腺周围的动静脉的良好显示、受累及空间关系；第三期可见胰腺周围蜂窝织炎组织以及周围间隙渗出的强化。结论：电子束CT三期连续容积扫描能够对急性胰腺炎进行准确分期，有利于胰腺炎治疗方案的确定以及预后评价。     

Phase-inversion tissue harmonic imaging compared with conventional B-mode ultrasound in the evaluation of pancreatic lesions

The aim of this study was to compare the diagnostic sensitivity, specificity, and image quality of conventional B-mode US (BM) and phase-inversion tissue harmonic imaging (PTHI) regarding pancreatic pathology. In a prospective study, 107 patients, aged between 28 and 85 years, underwent US examinations of the pancreas with both BM and PTHI in a randomly chosen order. As diagnostic reference, either contrast-enhanced CT or MRI examinations of the upper abdomen were obtained in all patients. Sensitivity and specificity were evaluated using the Students t test. Differences in overall image quality, lesion conspicuity, fluid–solid differentiation, and delineation of the pancreatic tail were analyzed using Wilcoxons signed ranks test and Bowkers symmetry test. Sixteen of 107 examined patients (15%) were non-diagnostic and excluded due to technical limitations such as abdominal gas. A total of 60 pancreatic lesions (cysts, acute pancreatitis, dilatation of the pancreatic duct, calcifications, and solid tumors) were diagnosed by CT or MRI. Phase-inversion tissue harmonic imaging had a higher sensitivity of 70% (14 of 20) than BM (60%; 24 of 40) for the detection of pancreatic lesions; however, the difference was not statistically significant (p=0.46). In the assessment of lesions <1 cm of size, PTHI had a sensitivity of 70% and BM 46.7%, whereby the difference again was not statistically significant. Phase-inversion tissue harmonic imaging proved to be superior to BM regarding overall image quality (p<0.0001), lesion conspicuity (p=0.0045), and fluid–solid differentiation (p=0.0002), as well as the delineation of the pancreatic tail (p<0.0001). These differences were statistically significant. The statistically significant improvement of image quality with regards to lesion conspicuity, fluid–solid differentiation, and delineation of the pancreatic tail favors the use of PTHI when evaluating the pancreas with US. Sensitivity for pancreatic lesions is increased with PTHI in comparison with conventional sonography (BM), especially in lesions <1 cm in diameter, although the difference was not statistically significant.     

小儿胰母细胞瘤的影像学诊断(附九例报告及文献复习)

目的 旨在提高对小儿胰母细胞瘤影像学方面的认识和诊断水平。方法 ９例经手术病理证实的小儿胰母细胞瘤术前均经Ｂ超检查，另外行ＣＴ平扫加增强３例，其中２例并行胃肠造影（ＧＩ）检查；ＣＴ平扫加ＧＩ１例，单行静脉肾盂造影（ＩＶＰ）３例，ＧＩ １例。结果 Ｂ超显示４例失去正常胰腺回声，６例可见瘤内钙化声影。４例ＣＴ扫描，肿瘤分别位于胰头、头体，体尾及胰尾部，显示为巨大块状混杂低或等密度影。２例瘤内有钙化灶，     

螺旋CT多期扫描技术对胰腺癌的诊断价值

目的：探讨螺旋CT多期扫描对胰腺癌的诊断价值。方法：搜集行SCT动脉期、胰腺期、肝脏期三期扫描的胰腺肿块75例，均经手术病理证实，其中胰腺癌53例，局限性胰腺炎22例，比较肿瘤与炎症在SCT增强扫描各期中的表现。结果：本组胰腺癌53例，其中胰头癌33例，胰颈癌4例、胰体癌14例，胰尾癌2例。局限性胰腺炎22例，头、颈、体、尾分别为17例、2例、2例、1例。增强扫描，动脉期胰腺癌低密度43例，等密度10例，胰腺炎低密度2例，等密度20例；胰腺期胰腺癌低密度51例，等密度2例，胰腺炎低密度1例，等密度21例；肝脏期胰腺癌低密度42例，等密度11例；胰腺炎22例均为等密度。结论：胰腺螺旋CT动脉期、胰腺期、肝脏期三期增强扫描在胰腺癌诊断中具有非常重要的临床价值。     

CT of acute pancreatitis: correlation between lack of contrast enhancement and pancreatic necrosis

This study was performed to determine if a correlation exists between pancreatic parenchymal enhancement or lack thereof on contrast-enhanced CT and surgical evidence of pancreatic necrosis. Accurate CT assessment of pancreatic vascular perfusion would be helpful in preoperative planning before pancreatic debridement and necrosectomy. The CT scans and medical records were blindly and retrospectively reviewed in 13 patients with the operative diagnosis of pancreatic necrosis. In all cases, CT examinations preceded surgery within 72 hr. Surgical and pathologic findings served as the gold standards for the diagnosis of pancreatic necrosis. Seven (54%) of 13 patients had a region or regions of parenchymal necrosis within the head, body, and/or tail of the pancreas seen during surgery. All seven of these patients had no pancreatic enhancement on CT in at least one region of the pancreas (CT sensitivity = 100%). In four of the seven, two regions were found to be necrotic at surgery, but only one of the two segments did not enhance on CT scans. In three of the seven patients, lack of contrast enhancement on CT (no enhancement of the pancreatic head and body in two patients and throughout the gland in another) correlated with necrosis in the same regions at surgery. The remaining six (46%) patients, who had peripancreatic or small, focal, and/or superficial areas of pancreatic necrosis at surgery, had normal pancreatic enhancement on CT. Our results show that regions of pancreatic necrosis found surgically correlate with lack of enhancement of pancreatic parenchyma on CT. Peripancreatic necrosis and minor areas of focal or superficial parenchymal necrosis were not detected on CT.     

Focal chronic pancreatitis mimicking pancreatic head carcinoma: are there suggestive features on ultrasound?

OBJECTIVE: Painless jaundice is one of the most common presentations of pancreatic head cancer. Chronic pancreatitis can also occasionally present with a mass or mass-like process in the pancreatic head, with the subsequent development of jaundice. In this retrospective review, we evaluate the clinical and imaging features of 22 patients presenting with painless jaundice, initially thought to have pancreatic head cancer and ultimately proven to have chronic focal pancreatitis, to determine whether there are any features on cross-sectional imaging to suggest the correct diagnosis. METHODS: Patients (n = 22) were identified from the medical and imaging records of more than 400 patients with an original diagnosis of pancreatic cancer who were seen at our institution from 1995 to 2003. Of the patients, 17 were men and 5 were women (age range 25 to 82 years, mean age 54 years). RESULTS: Initial ultrasound showed a large, hypoechoic, well-defined mass in the pancreatic head, varying in size from 3 to 7.5 cm; 14 of 22 masses were > 5 cm in maximal diameter. Diagnosis of focal pancreatitis was proven by surgical pathology in 14 cases and suggested by percutaneous biopsy in 3 cases; for all patients, prolonged imaging follow-up (at least 1 year) showed no disease progression or evidence of malignancy. The mean follow-up in our study group was 31 months (range 12 to 72 months). CONCLUSION: Male sex, large size of the pancreatic head mass (mean diameter 5.5 cm), and lack of atrophy of the pancreatic body and tail were the only features associated with chronic inflammation rather than neoplasm as an explanation for a pancreatic head mass. Chronic pancreatitis should be considered in the differential diagnosis of focal pancreatic masses, even in the absence of supporting clinical evidence.     

The effect of gastrografin and glucagon on CT scanning of the pancreas: a blind clinical trial

The effect of Gastrografin and glucagon on pancreatic CT scanning was studied in a blind clinical trial. Twenty-five patients had a pancreatic CT scan performed on an 18-second scanner and a repeat pancreatic CT scan following administration of Gastrografin and glucagon. The results were statistically significant: decreased streak artifacts; improved pancreatic head, body and tail delineation; and improved overall pancreatic visualization. Gastrografin-glucagon administration is recommended prior to pancreatic CT scanning if the scanning cycle is 18 seconds or longer.     

Failure of ultrasound to detect extra-pancreatic abscesses in severe acute pancreatitis

The development of intra-abdominal abscesses in patients with severe acute pancreatitis can be associated with a mortality as high as 100%. The clinical findings in these patients may be non specific and therefore imaging is essential. Computed tomography (CT) is the imaging modality of choice. However, a satisfactory ultrasound examination may be regarded as sufficient, particularly when there is limited availability of CT. A case of extra-pancreatic abscess complicating severe acute pancreatitis, in whom sonography was "normal", but CT demonstrated the abscess is presented. The importance of CT in these patients in whom an abscess is suspected and our experience with similar cases is discussed.     

Role of multislice computed tomography in the diagnosis of gene-mutation-associated pancreatitis (GMAP)

Purpose

The aim of this study was to review the computed tomography (CT) features of the pancreatic parenchyma and ducts in patients with gene-mutation-associated pancreatitis (GMAP).

Materials and methods

Twenty-five patients with GMAP were included in this retrospective study. Patients were divided into two groups according to the time interval between the onset of symptoms and the first CT examination (group A ≤24 months and group B >25 months).

Results

On qualitative image assessment, in group A patients, pancreatic duct stones were detected in 2/13 with GMAP. All stones were calcified and homogenous. Enhancement of the pancreatic parenchyma was hypovascular in 7/13 patients. In group B patients, pancreatic duct stones were detected in 12/12 with GMAP. Stones were calcified in 10/12 cases and noncalcified (protein plugs) in 2/12; in 5/10 cases, the calcified stones were heterogeneous with noncalcified central core (bull’s-eye appearance). Enhancement of the pancreatic parenchyma was hypovascular in 12/12 patients. On quantitative image assessment, in group A patients, the mean diameter of duct stones was 0.6 mm (range 0–5 mm). Mean diameter of the main duct in the pancreatic head and body/tail was 4.8 mm and 4.9 mm, respectively. In group B patients, the mean diameter of duct stones was 21.9 mm (range 2–50 mm). Mean diameter of the main duct in the pancreatic head and body/tail was 18.8 mm and 13.9 mm, respectively.

Conclusions|

In patients with GMAP and time interval between symptom onset and first CT scan ≤24 months (group A), CT identified normal or slightly increased parenchymal thickness and a main pancreatic duct of normal calibre and without duct stones. In contrast, in patients with GMAP and time interval between symptom onset and first CT scan >25 months (group B), it identified large-calibre duct stones with bull’s-eye appearance.     

The benefits of comparing conventional sonography, real-time spatial compound sonography, tissue harmonic sonography, and tissue harmonic compound sonography of hepatic lesions

This study aimed to compare conventional sonography, tissue harmonic imaging (THI), spatial compound sonography (SONOCT), and SONOCT+THI for overall image quality, lesion conspicuity, and elimination of artifacts of hepatic lesions. Forty-five patients were randomly selected, and 51 different hepatic lesions were scanned using each of the four techniques. The combined images of SONOCT+THI exhibited the best image quality for solid and cystic lesions, while conventional images were the worst for most hepatic lesions (P<.001). SONOCT was the best for fatty liver.     

Moderne Ultraschalldiagnostik der Beinvenenthrombose bei unklarer Genese der Lungenembolie

PURPOSE: We compared innovative ultrasound techniques such as tissue harmonic imaging (THI) and cross-beam technique with speckle reduction imaging (SRI) to conventional fundamental B scan in the diagnosis of deep vein thrombosis. MATERIAL AND METHODS: We investigated a total number of 185 patients with clinical symptoms of acute vein thrombosis. We documented the thrombosis in the patients using multifrequency ultrasound probes (5-7 MHz, 6-9 MHz, 9-14 MHz, Logig 9, GE) and recorded ultrasound sequences in fundamental B scan, THI, and cross-beam technique with SRI (grade 2). Three blinded ultrasound investigators ranked the marking of the thrombosis in each of these image modalities and graded them with the numbers 5 = weak, 4 = moderate, 3 = satisfactory, 2 = good, and 1 = excellent. We calculated the median and a t-test for each of these image modalities. RESULTS: We diagnosed 115 thromboses (62%) in 185 investigated patients. This group could be divided as follows: 11 patients (6%) with three-level thrombosis, 37 patients (20%) with two-level thrombosis, and 67 (36%) with one-level thrombosis. The one-level thrombosis group included five (3%) patients with muscle vein thromboses, seven (4%) cases of thrombophlebitis without involvement of the deep vein system, and three (2%) cases of thrombophlebitis with involvement of the deep vein system. The t-test for unconnected samples showed significant differences (p <0.05) in iliac veins and highly significant differences (p <0.001) in the veins of the lower extremity due to the superior capabilities for detection of thrombosis using the cross-beam technique with SRI compared to THI and the fundamental B scan. CONCLUSION: The use of high-resolution linear ultrasound probes with the concomitant application of THI and cross-beam technique with SRI facilitates the diagnosis of deep vein thrombosis. The employment of these new ultrasound modalities is an advantage in distinguishing the veins from the surrounding tissue structures and helps in evaluating the compressibility of venous vessels.     

超声与增强CT诊断细菌性肝脓肿对照研究

目的评价超声与增强CT在诊断细菌性肝脓肿中的价值。方法回顾性分析1998年1月-2007年8月在我院住院治疗的同时行超声及增强CT检查的肝脓肿患者共44例的影像资料。结果超声诊断细菌性肝脓肿的准确率为93．1％（41／44）,增强cT诊断细菌性肝脓肿的准确率为95．5％（42／44）,两者之间的差异没有统计学意义（P=0．133）。单纯应用超声和超声与增强CT联合应用诊断细菌性肝脓肿的差异也没有统计学意义（P=-0．068）。结论超声与增强CT诊断在细菌性肝脓肿方面有相似的价值,由于超声具有无创、价格低廉的优势,是诊断肝脓肿的首选方法。     

Suspected early or mild chronic pancreatitis: enhancement patterns on gadolinium chelate dynamic MRI. Magnetic resonance imaging

PURPOSE: To assess whether measuring the pattern of pancreatic enhancement on gadolinium chelate dynamic magnetic resonance imaging (MRI) is helpful for diagnosis of suspected early or mild chronic pancreatitis. MATERIALS AND METHODS: In this retrospective study, 24 patients with suspected early or mild chronic pancreatitis, classified by imaging criteria of equivocal chronic pancreatitis (ultrasound, computed tomography [CT] or ERCP) grading, had dynamic MRI that included unenhanced, arterial dominant, early venous, and late venous phases of contrast enhancement. Twenty patients without pancreatic diseases also had the dynamic sequence as a control group. The signal intensity was measured at the pancreatic head, body, and tail on all phases, and for each, the signal intensity ratio (SIR, the signal intensity in postcontrast divided by that in precontrast) was calculated. Two radiologists independently reviewed the images of the patients with suspected early or mild chronic pancreatitis for pancreatic morphologic abnormalities without knowing the results of signal intensity measurements. RESULTS: On unenhanced images, there was no significant difference of signal intensity between control and pancreatitis groups (P < 0.05). In the pancreatitis group, but not in the control group, the unenhanced signal intensity of the pancreatic head and body were significantly higher than that of the tail (P < 0.05). In the control group, the greatest enhancement (highest SIR) after injection was in the arterial phase (1.89 +/- 0.31), significantly higher than that in the early venous phase (1.68 +/- 0.17, P < 0.01) and in the late venous phase (1.61 +/- 0.15, P < 0.001). The pancreatitis group, however, had an arterial phase SIR (1.65 +/- 0.23) that was significantly lower than its early venous phase SIR (1.75 +/- 0.22, P < 0.05) and lower than the arterial phase SIR of the control group (P < 0.01). The presence of an SIR less than 1.73 in the arterial phase and/or a delayed peak enhancement after contrast agent administration had a sensitivity and specificity of diagnosing early or mild chronic pancreatitis of 92% and 75%, respectively. This sensitivity was significantly higher than the sensitivity of 50% for diagnosis based on morphologic abnormalities (P < 0.05). CONCLUSION: Measuring pancreatic signal intensity on gadolinium chelate dynamic MRI is helpful for diagnosing early or mild chronic pancreatitis, especially before apparent pancreatic morphologic or signal intensity changes are present.     

Magnetic resonance imaging for acute pancreatitis

Acute pancreatitis is characterized by acute chemical injury of the pancreatic parenchyma and peripancreatic tissue. The increased frequency of death in acute pancreatitis is directly correlated with the degree and progress of pancreatic necrosis. Moreover, the occurrence of some local complications in acute pancreatitis, such as pancreatic hemorrhage, peripancreatic abscess or large pseudocyst, and pseudoaneurysm, could influence the choice of treatment for these patients. Magnetic resonance imaging (MRI) can be used to help evaluate the presence and degree of pancreatic necrosis, and is crucial for identifying complications of acute pancreatitis and predicting prognosis. The purpose of this article is to describe MRI techniques for acute pancreatitis, to review the spectrum of pancreatic and peripancreatic patterns, as well as to survey various complications secondary to acute pancreatitis on MRI. The role of MRI in the initial evaluation and staging of acute pancreatitis is emphasized.     

Tissue harmonic imaging sonography of breast lesions: Improved margin analysis, conspicuity, and image quality compared to conventional ultrasound

The purpose of this preference study is to determine if tissue harmonic imaging (THI) is preferred over conventional sonography for imaging breast masses. A prospective evaluation of 73 identical image pairs (one obtained with conventional sonography, one with THI sonography) was performed, examining 25 cysts, 36 solid masses, and 12 indeterminate lesions. Each image was evaluated for lesion contrast, margins, and overall image quality using a graduated score. Statistical analysis was performed using a modified t test. For cystic and solid lesions, THI was preferred for lesion conspicuity, margin, and overall quality (P<.001). For indeterminate lesions, THI was significantly preferred for lesion conspicuity and overall quality (P<.05), but the preference for margins was not significant. Overall, THI of breast lesions was significantly preferred for lesion contrast and margin evaluation compared to conventional sonography. This modality deserves further evaluation and may improve detection and evaluation of breast lesions.