State-of-the-art ultrasonography is as accurate as helical computed tomography and computed tomographic angiography for detecting unresectable periampullary cancer.

OBJECTIVE: To compare the ability of state-of-the-art ultrasonography with that of helical computed tomography and computed tomographic angiography in detecting unresectable periampullary cancer. In most patients periampullary cancer is unresectable because of either distant metastasis or local vascular involvement. The advent of gray scale and color Doppler ultrasonography has improved the ability of ultrasonography to detect vascular involvement. METHODS: Twenty-three consecutive patients with periampullary cancer were enrolled for prospective staging of their disease by comparing helical computed tomography and computed tomographic angiography with gray scale and color Doppler ultrasonography of the abdomen. Portal vein, superior mesenteric vein, splenic vein, and superior mesenteric artery involvement was graded 0 to 4, grade 0 being no vascular involvement and grade 4 being total occlusion of the vessel. Agreement between ultrasonography and computed tomographic angiography for determining vascular involvement was measured by chi2 analysis. RESULTS: Two patients (9%) were excluded because excessive overlying bowel gas hampered the ability of ultrasonography to visualize the pancreas. For the remaining 21 patients, there was significant agreement between ultrasonography and computed tomographic angiography for detecting vascular involvement in all vessels (P < .001; portal vein, kappa = 0.67; superior mesenteric vein, kappa = 0.67; splenic vein, kappa = 0.85; and superior mesenteric artery, kappa = 0.59). Ultrasonography was in agreement with computed tomographic angiography in all cases of unresectability. Both modalities were equally poor in preoperatively showing lymphadenopathy and metastases. CONCLUSIONS: Provided that there is adequate visualization on ultrasonography of the head of the pancreas in the periampullary region, then state-of-the-art gray scale and color Doppler ultrasonography are as accurate as helical computed tomography and computed tomographic angiography for detecting the unresectability of periampullary cancer. If performed as the initial investigation and the region of the pancreatic head is clearly shown, and if vascular encasement or occlusion or distant metastasis is identified, further investigations are unnecessary.     

Prospective ECG-gated 320 row detector computed tomography: implications for CT angiography and perfusion imaging

Cardiac multidetector computed tomography has evolved from early four detector systems that first demonstrated the feasibility of non-invasive angiography to today’s wide-area detector computed tomography systems, such as 320-row detector computed tomography. As detector arrays have widened, there have been great improvements in image quality that have improved test accuracy. In addition, wider detector arrays have allowed for the application of prospective ECG-gating for CT angiography, although the current 64-row detector systems have some limitations. 320-row detector computed tomography with full cardiac coverage allows for cardiac imaging in a single heart beat. This technology has realized some of the great advantages provided by full cardiac coverage in regards to image quality (elimination of step artifacts and variation in contrast enhancement), patient safety (reductions in overall radiation and contrast dose), and the prospects for combined CT angiography and myocardial perfusion imaging are very promising. We will review the technical aspects of 320-row detector computed tomography and their implications for coronary angiography and perfusion imaging.     

Prospective ECG-gated 320 row detector computed tomography: implications for CT angiography and perfusion imaging

Cardiac multidetector computed tomography has evolved from early four detector systems that first demonstrated the feasibility of non-invasive angiography to today’s wide-area detector computed tomography systems, such as 320-row detector computed tomography. As detector arrays have widened, there have been great improvements in image quality that have improved test accuracy. In addition, wider detector arrays have allowed for the application of prospective ECG-gating for CT angiography, although the current 64-row detector systems have some limitations. 320-row detector computed tomography with full cardiac coverage allows for cardiac imaging in a single heart beat. This technology has realized some of the great advantages provided by full cardiac coverage in regards to image quality (elimination of step artifacts and variation in contrast enhancement), patient safety (reductions in overall radiation and contrast dose), and the prospects for combined CT angiography and myocardial perfusion imaging are very promising. We will review the technical aspects of 320-row detector computed tomography and their implications for coronary angiography and perfusion imaging.     

Coronary computed tomography angiography versus stress testing in suspected coronary disease

The position of functional testing as the cornerstone of the non-invasive evaluation of patients with suspected coronary artery disease is currently being challenged by the emergence of non-invasive coronary angiography using computed tomography. Stress testing and cardiac computed tomography assess related but different aspects of ischemic heart disease, and therefore provide complementary diagnostic, and sometimes conflicting prognostic, information. While assessment of inducible ischemia is important for clinical decision making, computed tomography allows more confident exclusion of obstructive coronary artery disease in low-intermediate-risk patients. For which patient, and which situation, either modality is most useful will need to be determined in prospective clinical trials.     

Emergency Diagnosis of Subarachnoid Hemorrhage: An Evidence-Based Debate

Background

The diagnosis of subarachnoid hemorrhage is of paramount concern in patients presenting to the Emergency Department (ED) with acute headache. Computed tomography followed by lumbar puncture is a time-honored practice, but recent technologic advances in magnetic resonance imaging with magnetic resonance angiography and computed tomography with computed tomography angiography can present alternatives for clinicians and patients.

Objective

The aim of this article was to compare diagnostic strategies for ED patients in whom subarachnoid hemorrhage is suspected.

Methods

We analyze and discuss current protocols, in addition to summarizing the advantages and disadvantages of each method.

Results

Through our residency's journal club, we organized an evidence-based debate that pitted proponents of the three subarachnoid hemorrhage diagnostic strategies against one another. Proponents of each strategy described its advantages and disadvantages. Briefly, computed tomography/lumbar puncture is time honored and effective, but is limited by complications and indeterminate lumbar puncture results. Magnetic resonance imaging with magnetic resonance angiography might be more effective in late presentations and can visualize aneurysms, yet has limited availability. Computed tomography with computed tomography angiography offers rapid diagnosis and is considered the most sensitive for diagnosing aneurysms, but has the highest radiation exposure.

Conclusions

Each of the three strategies used to diagnose subarachnoid hemorrhage has advantages and disadvantages with which clinicians should be familiar. Patient factors (e.g., age, body habitus, and risk factors), presentation factors (e.g., time from headache onset and severity of presentation), and institutional factors (availability of magnetic resonance imaging with magnetic resonance angiography) can influence the choice of protocol.     

冠状动脉斑块性质的CT表现研究

目的:探讨冠状动脉粥样硬化斑块在64排螺旋CT血管造影中的表现。材料与方法:对130例行64排螺旋CT冠状动脉成像检查显示有粥样硬化斑块的CT图像进行回顾性分析。结果:软斑块46处,纤维斑块50处,钙化斑块122处,混合斑块62处。结论:64排螺旋CT作为一种新的诊断冠心病的无创检查方法,其测量结果准确、可信,有一定的临床实用意义。     

Alternative imaging techniques in vascular surgery

Progress in vascular surgery has led to the need for more sophisticated methods of imaging the vascular system. Although conventional contrast angiography is still the primary method of visualizing the vascular system, it has problems and limitations that occasionally render it unsafe or inadequate. When conventional angiography cannot provide the needed information, 3 newer imaging methods--3-dimensional (3-D) spiral computed tomographic scanning, computed tomographic angiography, and magnetic resonance angiography--are being used more widely to supplement or replace contrast angiography. The advantages, disadvantages, and clinical application of each method will be described. These methods have fundamentally changed the practice of vascular surgery and a thorough knowledge of them is essential.     

Ultrasonics and computerized tomography in the diagnosis of large cavernous hemangiomas of the liver

Cavernous haemangiomas of the liver often pose problems in the differential diagnosis on ultrasound because of the complex echo pattern. Some typical features of their sonomorphology are exemplified by the data obtained in 4 patients. In combination with the almost pathognomonic delayed contrast enhancement on computed tomography, additional angiography seems to be no longer necessary for an accurate diagnosis in most cases.     

Giant cell tumor of bone

Giant cell tumor is the second most common benign tumor of bone. Plain radiographs may demonstrate distinctive features but can also be misleading. The diagnosis may be aided by the use of other imaging modalities, such as bone scan, computed tomography and angiography. The recurrence rate is high, but some of the newer treatments seem to be associated with better outcomes.     

Thebesian valve imaging with electron beam CT angiography: implications for resynchronization therapy

We report visualization of a prominent coronary sinus os valve (Thebesian valve), by electron beam computed tomographic angiography, which impeded an endocardial approach to left ventricular pacing. Resynchronization therapy was therefore performed with an epicardial approach to left ventricular lead placement. Electron beam computed tomographic angiography can provide detailed information for coronary sinus instrumentation, including anomalies potentially affecting the approach to resynchronization therapy.     

CT angiography of intrahepatic portal aneurysm

We report a case of an asymptomatic portal vein aneurysm diagnosed at ultrasonography and documented with multidetector computed tomography. We describe the features found at quadriphasic multidetector computed tomography with three-dimensional computed tomographic angiography.     

Technical and Clinical Aspects of Coronary Computed Tomography Angiography

Coronary computed tomography angiography is an emerging imaging technique that has attracted much scientific attention over the past years. Improved scanner technology and dedicated protocols have made noninvasive coronary a reliable diagnostic test in patients with suspected coronary artery disease (CAD). Several technical steps such as the introduction of 64-slice scanners, multisegment reconstruction, and dual-source computed tomography have substantially improved temporal and spatial resolution. With these sophistications, coronary computed tomography angiography enables reliable exclusion of CAD in patients with low to intermediate pretest probability of having CAD or with inconsistent ischemia test results.     

The strategy of new imaging procedures in the diagnosis of malignant bone processes

From the comparison of conventional radiography, computed tomography and angiography the diagnostic value of each of these methods is evaluated. Conventional radiography will remain the most significant method for detecting primary skeletal tumours even if magnetic resonance imaging is considered. CT is an important additional method for the evaluation of tumour size, but is disappointing for tumour classification. Bone scintigraphy is the most sensitive method for the differentiation of solitary and multiple tumours. Angiography is not necessary, except for the planning of surgery in certain cases.     

Thebesian valve imaging with electron beam CT angiography: implications for resynchronization therapy

We report visualization of a prominent coronary sinus os valve (Thebesian valve), by electron beam computed tomographic angiography, which impeded an endocardial approach to left ventricular pacing. Resynchronization therapy was therefore performed with an epicardial approach to left ventricular lead placement. Electron beam computed tomographic angiography can provide detailed information for coronary sinus instrumentation, including anomalies potentially affecting the approach to resynchronization therapy.     

64排螺旋CT血管成像评估内瘘血管的价值

目的 探讨64排螺旋CT血管成像(computed tomographic angiograhpy,CTA)评估血液透析患者动静脉内瘘血管的临床价值.方法 应用64排CTA对14例功能不全的内瘘血管及临床评估自体血管无条件造瘘的患者进行扫描、采象,应用最大密度投影、容积成象和曲面重建技术对图象数据进行处理和3维重建.结...     

Non-small cell lung cancer - diagnostics and stage-adapted therapy]

Non-small cell lung cancer is a common disease. Adeno- and squamous-cell type are the most frequent subtypes, the former with rising incidence. The clinical picture is nonspecific until late in the course of the disease. The most important diagnostic tools are chest X-ray, computed tomogram of the chest, and bronchoscopy. Additional tests often used for staging are abdominal ultrasound, computed tomography of the abdomen, bone scintigraphy, and magnetic resonance imaging of the head. Positron emission tomography is of rising importance. Therapy is guided by stage. Stage I disease is a domain of surgery, in stage II combined with adjuvant chemotherapy. In stage III, multimodality treatment, mostly chemoradiotherapy, is indicated. Stage IV disease is treated with palliative chemotherapy. Newer, so-called targeted therapies are more and more implemented into therapy. There are three substances approved for second-line therapy with response rates of just under 10%.     

ECG电流调控模式在256层螺旋CT冠脉成像中的应用

目的比较256层螺旋CT冠脉成像中ECG电流调控模式及回顾性心电门控扫描的图像质量和病人的辐射剂量。方法对62例怀疑冠心病患者进行256层螺旋CT冠状动脉造影,患者随机分成两组,A组采用回顾性心电门控扫描成像,B组采用ECG电流调控模式成像,对两组患者的图像质量进行主观及客观评价,客观评价包括信号噪声比及对比度噪声比,同时对患者的辐射剂量进行比较。结果 A组及B组的图像信号噪声比分为（14.41±1.05）和（15.07±3.29）,差异无统计学意义（t=-1.07,P=0.29）。两组图像对比度噪声比分别为（12.03±0.98）和（12.64±3.02）,差异无统计学意义（t=-1.08,P=0.28）。A组及B组的有效剂量分别为（10.77±0.96）mSv和（8.59±2.50）mSv,差异有统计学意义（t=4.59,P〈0.001）。结论 256层螺旋CT冠状动脉造影中,与回顾性心电门控扫描比较,ECG电流调控模式在没有降低图像质量的情况下,射线剂量降低约20.2%,病变检出的准确率达95.7%。     

Small intestinal tumors as a cause of chronic iron deficiency anemia

A brief update literature review on different methods of diagnosis of small intestinal tumors indicates angiography, videointestinoscopy and positron-emission tomography as most sensitive methods in diagnosis of intestinal tumors. A case of a small intestinal tumor is reported (a male of 46 years of age with chronic iron deficiency anemia) which was diagnosed with videointestinal camera and was confirmed histologically as adenocarcinoma). The patient was successfully operated and is now on chemotherapy.     

冠状动脉旁路移植术后移植血管64排螺旋CT血管成像与选择性血管造影对比研究

目的:探讨64排螺旋CT血管成像对冠状动脉旁路移植血管诊断的准确性和应用价值。方法:对20例实施冠状动脉旁路移植5 a以上冠心病患者进行随访。冠状动脉及移植血管同时行64排螺旋CT血管成像和选择性血管造影,比较分析2种检查结果。结果:共移植血管58支。以选择性移植血管造影结果为标准,64排螺旋CT血管成像对移植血管闭塞诊断的敏感性为77.27%,特异性为97.22%,阳性预测值为94.44%,阴性预测值为87.50%,准确性为89.66%;对于闭塞加狭窄诊断的敏感性为81.48%,特异性为93.55%,阳性预测值为91.67%,阴性预测值为85.29%,准确性为87.93%。结论:64排螺旋CT血管成像对移植血管病变具有较高敏感性和特异性,可作为冠状动脉旁路移植手术后检查方法,尤其适用于选择性血管造影检查困难的移植血管。     

CT angiography: principles, techniques and study optimization using 16-slice multidetector CT with isotropic datasets and 3D volume visualization

Significant advances in computed tomography (CT) scanner technology as well as 3D imaging software and hardware have resulted in amazing improvements in CT imaging of blood vessels. CT angiography has now been incorporated into daily practice and in may cases has replaced conventional angiography. CT angiography has also resulted in new applications for CT such as coronary angiography. This article discusses the current state of the art of 3D CT angiography and reviews the literature. Extensive case examples are included.