Ultrasound evaluation of acute abdominal emergencies in infants and children

Ultrasound is extremely beneficial in the evaluation of acute pediatric abdominal disease, such as HPS, intussusception, and acute appendicitis. As techniques and equipment improve, its role in the evaluation of infants and children continues to increase.     

CT of the pericardial recesses

Within the pericardial cavity there are several recesses where fluid can collect in close contiguity to the major bronchi and lymph nodes. These include the transverse sinus, behind the ascending aorta and pulmonary trunk; the oblique sinus, behind the left atrium; and the left pulmonic recess, between the left pulmonary artery and the left superior pulmonary vein. There are also smaller pericardial recesses between the superior and inferior pulmonary veins, posterolateral to the superior vena cava, and between the inferior vena cava and coronary sinus. An understanding of sectional anatomy is valuable for differentiation of fluid within these recesses from mediastinal masses or enlarged lymph nodes on computed tomographic scans.     

Helical CT for the evaluation of acute pulmonary embolism

OBJECTIVE: In this article, we review the current role of CT pulmonary angiography and indirect CT venography for the evaluation of pulmonary thromboembolic disease. CONCLUSION: With advances in MDCT technology, evaluation of pulmonary thromboembolic disease can now be performed with combined CT pulmonary angiography and CT venography as a "one-stop-shopping" test. CT pulmonary angiography is cost-effective, is accurate, has high interobserver agreement, and has an added advantage of detecting other life-threatening diseases in the chest that mimic pulmonary embolism.     

CT评价急性重症胰腺炎预后的价值

目的：探讨CT对急性重症胰腺炎病变范围的诊断价值及其与预后的关系。方法：回顾分析42例急性重症胰腺炎患者的病例资料,按胰腺增大、胰周及胰外间隙扩散范围进行CT分级,分析CT分级（Ⅱ～Ⅳ级）与临床Ranson评分标准[R1（0～2分）,R2（3～5分）,R3（〉6分）]及预后因素（死亡人数、手术例数、非手术例数）的相关性。结果：病变范围的CT分级Ⅱ级且临床Ranson评分与R1～R2级者16例,病程相对平稳;同属于Ⅲ～Ⅳ级和R2～R3级者共21例,病程迁延、反复、并发症多,病情危重;介于中间者,同属于CT分级Ⅲ级和R1级者共5例。病变范围的CT分级与临床Ranson评分标准呈正相关（r=0.429,P=0.005）。CT分级Ⅱ级16例均采用非手术治疗;Ⅲ级14例中10例采用非手术治疗,3例手术,1例死亡;Ⅳ级12例中1例采用非手术治疗,7例手术,4例死亡。病变范围CT分级与临床预后间呈正相关（r=0.711,P〈0.001）。结论：病变范围的CT分级对急性重症胰腺炎的临床严重程度和预后评估具有重要的作用,与临床Ranson标准结合更能提高早期预后判断的准确性和可靠性。     

CT evaluation of distended pericardial recess presenting as a mediastinal mass

A patient with a remarkably distended pericardial recess due to massive pericardial effusion mimicking a mediastinal mass is reported. The nature of the "mass lesion" was clearly demonstrated by CT and the lesion disappeared after removal of the pericardial effusions. The importance and usefulness of CT in evaluation of pericardial recesses is stressed.     

CT and MR evaluation of pericardial and retrosternal adhesions after cardiac surgery

The visibility of the pericardium as well as of the space between the dorsal aspect of the sternal surface and the pericardial surface after cardiac surgery was determined by CT and/or MR with electrocardiographic (ECG)-gated spin-echo (SE) and gradient-echo sequences. Seventeen patients who had undergone cardiac operations and who were admitted for cardiac reoperation were investigated with CT and/or MR prior to sternal reentry. Five patients were investigated with CT alone, ten with both CT and MR, and two with MR only. At reoperation, retrosternal adhesions were classified as present or absent, and intrapericardial adhesions were classified as absent, minimal, moderate, or severe. A similar classification was applied to the CT and MR findings. In 14 of 15 patients, the CT findings were in agreement with those found at operation regarding postoperative retrosternal extrapericardial adhesions in the cranial retrosternal space and in 12 of 15 in the caudal retrosternal space. Computed tomography could not detect intrapericardial adhesions. Magnetic resonance was sensitive to metal artifacts from sternal sutures in both sequences and could therefore not be used to detect postoperative retrosternal extrapericardial adhesions. On the other hand, MR with ECG-gated SE sequences confirmed intrapericardial adhesions in 44 of 57 locations.     

Multidetector CT angiography in the evaluation of acute mesenteric ischemia

The aim of this study was to determine the accuracy of multidetector row CT angiography in the diagnosis of acute mesenteric ischemia. Ninety-three consecutive studies on 91 patients with clinically suspected acute mesenteric ischemia underwent abdominal CT angiography as the first, and usually the sole, diagnostic procedure. CT was performed with a multidetector 16-row CT system from the level of the diaphragm to the pelvis in two phases: early arterial and late portal phase. CT examinations were reviewed by the duty radiologist. Final diagnosis was established by a senior radiologist. CTA was diagnostic in 92 studies. Mesenteric ischemia was diagnosed in 18 patients, 14 of them were of the thromboembolic type and four from the nonocclusive type. Positive CTA findings were confirmed by surgery in 13 patients and by clinical follow-up in three cases. Other reasons for abdominal pain were diagnosed by CT in 38 patients out of the remaining 74. There were two false positive and two false negative CT results, resulting in an overall accuracy of 95.6%. Multidetector CT angiography is a fast and accurate investigation for the diagnosis of acute mesenteric ischemia and in most cases can be used as the sole diagnostic procedure.     

ECG门控双源CT胸痛检查模式的辐射剂量估测

目的是评估应用ECG门控双源CT检查胸痛的模式的辐射剂量。采用装有热释光剂量仪的Alderson Rando模型测定剂量。在不同模拟心率（HR）下应用双源CT系统以评估胸痛的标准模式（120kV，320mAs／r）曝光，并测量标准胸部CT检查（120kV，160mAs）的剂量。胸痛模式的有效剂量男、女分别为19．3、21．9mSv（HR60），17．9、20．4mSv（HR80）和14．7、16．7mSv（HR100）。     

Non-traumatic thoracic emergencies: CT diagnosis of acute pulmonary embolism: the first 10 years

Over the past 10 years, spiral CT angiography of the pulmonary arteries has reached a high accuracy in the evaluation of pulmonary embolism. Major advantages of CT compared with ventilation/perfusion lung scintigraphy and pulmonary angiography is direct visualization of clots in the pulmonary arteries, and to provide alternative findings or diagnosis. The recent introduction of multislice CT has improved the evaluation of peripheral pulmonary arteries, enabling high-resolution CT examinations over the entire thorax in a short breathhold. The examination techniques, imaging findings, pitfalls, and results of CT in the diagnosis of pulmonary embolism are reviewed in comparison with other diagnostic tests.     

CT features of a pericardial gossypiboma

We report a case of surgically retained pericardial sponge as a cause of paracardiac mass in a woman who had thoracotomy 3 weeks prior for replacement of mitral valve prosthesis. Computed tomography examination showed a thin-walled mass containing relatively high-density material in the central part with low-density rim at the periphery suggesting a haematoma with clot formation at first. Surgically removed mass was a retained sponge between right atrium and pericardium. Gossypiboma should be included in the differential diagnosis of an intrathoracic mass besides haematoma and abscess formation in any patient who has had previous thoracotomy. Received: 17 February 1998; Revision received: 1 July 1998; Accepted: 1 September 1998     

Diagnostic performance of multidetector CT for acute cholangitis: evaluation of a CT scoring method

Objective

The aim of this study was to retrospectively assess the diagnostic performance of multidetector CT (MDCT) for the diagnosis of acute cholangitis using a new scoring method.

Methods

Of 80 patients with suspected biliary disease who underwent biphasic CT and endoscopic retrograde cholangiography, 39 were diagnosed as having acute cholangitis (Group 1) and 41 patients were classified as suspected biliary disease (Group 2). 100 age-matched patients without evidence of biliary disease were selected randomly as a control group (Group 3). Each patient''s axial scan was scored by two independent radiologists for the extent of transient hepatic attenuation difference, the presence of biliary dilatation and identification of a biliary obstructive lesion. The difference in the scores among the three groups was evaluated and the optimal cut-off score for the diagnosis of acute cholangitis was determined. Interobserver agreement was also evaluated.

Results

The total scores (mean±standard deviation) for Groups 1, 2 and 3 were 7.0±2.0, 4.4±2.4 and 0.9±1.2, respectively, for Reviewer 1 and 7.2±1.8, 4.3 ±2.7 and 0.7±1.1, respectively, for Reviewer 2. Significant differences were found for the subscores and the total scores among the three groups (p<0.001). Using a cut-off score of ≥5, the sensitivity and specificity for diagnosing acute cholangitis were 84.6% and 83.7%, respectively, for Reviewer 1 and 89.7% and 83.7%, respectively, for Reviewer 2. Agreement for the subscores between readers was good to excellent (κ=0.74–0.86).

Conclusion

Based on dynamic MDCT and the described CT scoring method, the diagnosis of acute choangitis can be made with high sensitivity and specificity.Acute cholangitis is a potentially life-threatening condition that occurs as a result of acute inflammation and infection in an obstructed bile duct [1,2]. Because both biliary obstruction and bile infection are required for the development of acute cholangitis, these factors are essential to the pathophysiology and diagnosis of this entity [3,4].Traditionally, the clinical manifestations, including Charcot''s triad (the presence of fever and/or chills, abdominal pain and jaundice), have been regarded as important factors for making the diagnosis of acute cholangitis [1-4]. However, the frequency of Charcot''s triad varies and has been reported to be present in 15.4–72.0% of patients [4]. Diagnostic criteria were established by. the International Consensus Meeting, held in Tokyo in 2006 [4]. The diagnostic criteria for a definite diagnosis of acute cholangitis include the presence of Charcot''s triad. In addition, laboratory data and imaging findings are needed to support the clinical diagnosis in patients without all of the components of Charcot''s triad. In this situation, laboratory data provide information about infection/inflammation and imaging is used to determine the degree and level of the biliary obstruction and to identify the obstructing lesion in the bile duct. In previous studies, multidetector CT (MDCT) has been shown to be an accurate imaging tool for the detection of biliary obstruction [5,6].Transient hepatic attenuation differences (THADs), which appear as focal or diffuse hyperdense areas during the hepatic arterial phase on the CT, have been reported to be common in patients with acute cholangitis [7-9]. The incidence of THADs in patients with acute cholangitis has ranged from 71% to 98%. In addition, one study reported that the THADs observed in patients with suspected biliary disease correlated with the clinical parameters of inflammation [9]. Therefore, we developed a new scoring method for the diagnosis of acute cholangitis using dynamic contrast-enhanced MDCT. This method considers two important diagnostic factors: biliary obstruction and biliary inflammation. The purpose of this study was to retrospectively assess the diagnostic performance of MDCT for the diagnosis of acute cholangitis using a new scoring system.     

CT angiography for evaluation of cerebral vasospasm following acute subarachnoid haemorrhage

Introduction  

Cerebral vasospasm (CV) is one of the most dreaded complications in patients who survive acute subarachnoid haemorrhage (SAH), and conventional cerebral angiography (DSA) is the gold standard for its diagnosis. We evaluated CT angiography (CTA) as a non-invasive alternative for diagnosis of CV and assessed if CTA could have a role in choosing appropriate treatment.     

Helical CT for the evaluation of suspected acute pulmonary embolism: diagnostic pitfalls

Helical CT is being increasingly utilized for the evaluation of suspected pulmonary embolism (PE). Proper scan interpretation depends on the awareness of several diagnostic pitfalls that may simulate PE, including normal bronchovascular structures such as pulmonary veins, bronchi, and lymph nodes, technical considerations such as improper bolus timing and streak artifacts, and patient-related factors such as motion artifacts, pulmonary arterial catheters, and vascular shunts. An understanding of these pitfalls facilitates accurate diagnosis.     

Sequelae of acute renal infections: CT evaluation

Seventeen patients with upper urinary tract infection who underwent 51 computed tomographic studies (two to five per patient; mean, three) were retrospectively evaluated. Five to 10 days after the initial examination, there was little change in parenchymal abnormalities, but perirenal inflammation worsened and then subsided over 2-8 weeks. Enlargement of the affected kidney, present initially in 12 patients, persisted up to 6 weeks and resolved by 10-16 weeks. Abnormalities of parenchymal contrast material enhancement persisted for 1-2 months. New cortical scars appeared in six of 12 patients with an initially normal renal contour and in one of five patients who had scars initially. Three patients with a renal abscess developed a new calyceal diverticulum, presumably by rupture of the abscess into the collecting system. The present study shows that abnormalities of renal size and enhancement persist for weeks to months after clinical signs of infection resolve and that scarring in adults with urinary tract infection occurs more frequently than was previously realized.     

Complications of acute pancreatitis: helical CT evaluation

Acute pancreatitis represents one of the more commonly encountered etiologies of acute abdominal pain. Many complications can present emergently, including pancreatic abscess, necrosis, and hemorrhage. The purpose of this pictorial essay is to educate the reader about the spectrum of CT findings in patients with complications from pancreatitis. Emphasis is placed on evaluation with helical CT, stressing optimal technique and the imaging parameters essential for accurate diagnosis.     

急性颈椎外伤的CT诊断与评价

目的分析急性颈椎外伤（ａｃｕｔｅｃｅｒｖｉｃａｌｔｒａｕｍａ，ＡＣＴ）的ＣＴ表现，评价ＣＴ在ＡＣＴ诊断中的价值及限度。方法对临床拟诊的ＡＣＴ３７例行平片及薄层ＣＴ或高分辨率ＣＴ（ＨＲＣＴ）检查，并做多平面及三维（３Ｄ）重建。４例同时行ＭＲＩ检查。结果经影像学诊断３１例ＡＣＴ，其中ＣＴ诊断２９例，２例ＣＴ阴性而由平片及ＭＲＩ各确诊１例。平片与ＣＴ的骨折检出率分别为３２．８％及９８．５％，两者有极显著性差异。结论ＣＴ能对ＡＣＴ做出较全面而准确的诊断，与平片比较ＣＴ明显提高了骨折的检出率。在ＡＣＴ的诊断中，ＣＴ尚有某些限度。