心脏黏液瘤多模态成像特点及诊断模式

目的 探究心脏黏液瘤(CM)多模态成像特点及其多模态诊断模式.方法 回顾性研究2016年7月至2019年8月在阜外医院行二维经胸超声心动图检查初诊为CM的178例患者,以病理结果为金标准,将研究对象分为CM组和非CM组,根据超声心动图特点将CM组划分为典型CM组和非典型CM组.分析归纳各组患者的临床特征,二维经胸超声心...     

多发性骨髓瘤的影像学评估

多发性骨髓瘤具有独特的骨病表现,由于破骨细胞激活和成骨细胞功能抑制导致溶骨性破坏和严重骨质疏松。骨病严重程度对患者生活质量和生存均有负面影响。普通X线检出骨病的灵敏度很低,CT的灵敏度虽明显提高,但难以检出骨外病变。功能性影像方法(主要包括磁共振弥散加权成像和正电子发射断层显像/计算机体层成像)不仅能发现早期溶骨病灶,且在评估全身肿瘤负荷和缓解后微小残留病变方面更有优势。本文将对这些方面的进展进行综述。     

Localization of angiosarcoma by peri-operative transesophageal echocardiography

Transthoracic echocardiography (TTE), computed tomography (CT) and magnetic resonance (MR) cannot always clearly identify angiosarcoma. A 22 year old woman presented with dyspnea. Preoperative TTE showed no tumor, and CT and MR both gave the impression that an extra-cardiac, mediastinal tumor was present. Transesophageal echocardiography (TEE), performed during surgery showed an intra-cardiac tumor, which was a well-delineated mass at the intra-ventricular groove of the right heart and surrounding the superior vena cava. The tumor was excised and found to be a malignant angiosarcoma. TEE provides diagnostic advantages over other cardiac imaging techniques and can serve as a useful adjunct during and before intrathoracic surgery.     

Liver metastases from colorectal cancer: imaging with superparamagnetic iron oxide (SPIO)-enhanced MR imaging,computed tomography and positron emission tomography

The literature about superparamagnetic iron oxide-enhanced MR imaging, computed tomography (CT) and PET (positron emission tomography using fluorine-18 labelled fluoro-deoxy-glucose) in detection of liver metastases (LM) from colorectal cancer is reviewed in this update. Special emphasis is given to studies with surgical standard of reference allowing for the lesion-by-lesion sensitivity to be determined. Based on the review, it is concluded that state-of-the-art anatomical imaging, e.g., SPIO-enhanced MR imaging and multidetector CT (MDCT), must be considered more sensitive than PET in detection of individual LM, due to technical developments in MR imaging, such as liver specific contrast agents, modern sequences and high performance gradients, and in modern MDCT have increased the performance of these modalities. MR imaging with a liver specific contrast agent is recommended for the preoperative evaluation before liver surgery for LM because of high sensitivity and better discrimination between small LM and cysts compared to MDCT. PET or PET/CT can be used for detection of extra-hepatic tumor before liver surgery.     

Hypopharyngeal cancer

Hypopharyngeal cancers are usually squamous cell carcinomas (SCCs) that has the worst prognosis among the head and neck cancers. Overall, 5-year survival rate remains poor despite recent improvements in diagnostic imaging, radiation and chemotherapy, and improved surgical techniques. Hypopharyngeal cancers tend to present with advanced primary disease, and nodal metastasis is highly likely. The most important features determining prognosis are the size and extent of local spread of the primary carcinoma and the extent of involvement of regional lymph nodes. Distant metastasis at presentation is more common in hypopharyngeal cancers than in other head and neck cancers. Poor survival rate is partly due to emergence of second primary cancers but also to development of distant metastasis. Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) remain the mainstay of initial radiological evaluation of hypopharyngeal cancer. Imaging usually results in upstaging of the tumor at presentation. Meticulous evaluation of the extent of the primary tumor with attention to spread to the subsites of the hypopharynx, larynx, and cartilage invasion are necessary for accurate staging. After surgery and radiation therapy, it is difficult with CT and MR to differentiate residual and recurrent tumor from edema and scarring. Fluorine 18-fluoro-deoxy-glucose -positron emission tomography (FDG-PET) has high sensitivity in detection of occult, residual, and recurrent tumors but has low specificity. Combined PET and CT increase specificity and are increasingly being used to image posttreatment cases. Other newer imaging modalities such as diffusion-weighted imaging (DWI), MR spectroscopy, and MRI with superparamagnetic iron oxide (SPIO) contrast agent are reported to be useful and should be used more widely in difficult cases.     

Combined imaging with multi-detector row computed tomography and diffusion-weighted imaging in the detection of pancreatic cancer

Pancreatic cancer is one of the most aggressive malignant tumor types. Its prognosis is extremely poor without early detection, and an accurate diagnosis with imaging techniques is vital for any chance of long-term survival after treatment. Despite the great technical advances that have been made with various kinds of imaging equipment, detection of pancreatic cancer is unsatisfactory, and new modalities are required. Diffusion-weighted imaging (DWI) on magnetic resonance imaging (MRI) has high sensitivity and specificity for the detection of pancreatic cancer; however, it does not provide anatomic information. Quite often, the necessary spatial correlation of a high-intensity area with anatomic structures is constrained. If it becomes possible to combine the imaging technique of DWI with multi-detector row computed tomography (MDCT), such as is done with positron emission tomography (PET) and computed tomography (CT), it is expected that the early diagnostic capability will improve. The objective of this study was to introduce combined imaging with DWI and CT into clinical practice to improve the diagnosis of pancreatic cancer. In the current report, we demonstrate a clinical attempt to combine DWI on MRI with the anatomical accuracy of MDCT for two patients of pancreatic adenocarcinoma. Analysis of these two patients revealed that the combined images corresponded precisely to the operative findings. Thus, the combined imaging with DWI and MDCT is useful for the detection of the pancreatic cancer.     

Main applications of hybrid PET‐MRI contrast agents: a review

In medical imaging, the continuous quest to improve diagnostic performance and optimize treatment strategies has led to the use of combined imaging modalities. Positron emission tomography (PET) and computed tomography (CT) is a hybrid imaging existing already for many years. The high spatial and contrast resolution of magnetic resonance imaging (MRI) and the high sensitivity and molecular information from PET imaging are leading to the development of this new hybrid imaging along with hybrid contrast agents. To create a hybrid contrast agent for PET‐MRI device, a PET radiotracer needs to be combined with an MRI contrast agent. The most common approach is to add a radioactive isotope to the surface of a small superparamagnetic iron oxide (SPIO) particle. The resulting agents offer a wide range of applications, such as pH variation monitoring, non‐invasive angiography and early imaging diagnosis of atherosclerosis. Oncology is the most promising field with the detection of sentinel lymph nodes and the targeting of tumor neoangiogenesis. Oncology and cardiovascular imaging are thus major areas of development for hybrid PET‐MRI imaging systems and hybrid contrast agents. The aim is to combine high spatial resolution, high sensitivity, morphological and functional information. Future prospects include the use of specific antibodies and hybrid multimodal PET‐MRI‐ultrasound‐fluorescence imaging with the potential to provide overall pre‐, intra‐ and postoperative patient care. Copyright © 2015 John Wiley & Sons, Ltd.     

Early gastric cancer: virtual gastroscopy

Gastric cancer is one of the most common cancers and one of the most frequent causes of cancer-related deaths worldwide. Early detection and accurate preoperative staging of early gastric cancer (ECG) offers the best prognosis and is essential for planning optimal therapy such as endoscopic mucosal resection or gastric resection. Recent advances in computed tomographic technology and three-dimensional imaging software have enabled more accurate gastric imaging. Virtual gastroscopy (VG) is helpful in the detection and evaluation of EGC in the same way as gastroscopy. VG has a wider field of view than conventional gastroscopy, the angle of the virtual cancer can be adjusted omnidirectionally, and it has no blind point because retrospective reconstruction is available. Thus, VG is a promising method for evaluating gastric lesions despite its limitations. This report describes the clinical usefulness of VG with multidetector row computed tomography for EGC and axial computed tomography.     

CT in hepatic cirrhosis and chronic hepatitis.

Cirrhosis is a diffuse liver disease with premalignant potential in which hepatocellular carcinoma (HCC) frequently develops. The hemodynamics of contrast material are the key to diagnosis of focal liver lesions with computed tomography (CT). Lesions with arterial-dominant vascularity, such as HCC, show brisk enhancement during the arterial phase, whereas lesions with portal blood supply can appear as hyperenhancing lesions in the portal phase. The advent of helical CT has significantly improved the CT examination of the liver because the arterial phase can be displayed independently of the portal phase. The addition of arterial phase imaging to conventional portal phase imaging seems to improve tumor detection and characterization. Although HCC is the single most frequent tumor seen in chronic liver disease, other lesions such as peripheral cholangiocarcinoma and hemangioma should be considered in the differential diagnosis. Optimization of helical CT techniques may allow better detection and characterization of these lesions. In addition to tumor detection, CT plays an important role in preoperative staging of HCC as well as in preoperative assessment of patient candidates to hepatic transplantation. The use of CT angiography with maximum intensity projection techniques may allow for better preoperative work-up and vascular mapping in HCC patients. This article shows the spectrum of helical CT findings in chronic liver disease and specifically in the imaging of HCC and other focal lesions.     

Automatic detection and classification of nasopharyngeal carcinoma on PET/CT with support vector machine

Purpose  

Positron emission tomography/computed tomography (PET/CT) has established values for imaging of head and neck cancers, including the nasopharyngeal carcinoma (NPC), utilizing both morphologic and functional information. In this paper, we introduce a computerized system for automatic detection of NPC, targeting both the primary tumor and regional nodal metastasis, on PET/CT.     

Cardiac Masses on Cardiac CT: A Review

Cardiac masses are rare entities that can be broadly categorized as either neoplastic or non-neoplastic. Neoplastic masses include benign and malignant tumors. In the heart, metastatic tumors are more common than primary malignant tumors. Whether incidentally found or diagnosed as a result of patients’ symptoms, cardiac masses can be identified and further characterized by a range of cardiovascular imaging options. While echocardiography remains the first-line imaging modality, cardiac computed tomography (cardiac CT) has become an increasingly utilized modality for the assessment of cardiac masses, especially when other imaging modalities are non-diagnostic or contraindicated. With high isotropic spatial and temporal resolution, fast acquisition times, and multiplanar image reconstruction capabilities, cardiac CT offers an alternative to cardiovascular magnetic resonance imaging in many patients. Additionally, cardiac masses may be incidentally discovered during cardiac CT for other reasons, requiring imagers to understand the unique features of a diverse range of cardiac masses. Herein, we define the characteristic imaging features of commonly encountered and selected cardiac masses and define the role of cardiac CT among noninvasive imaging options.     

State-of-the-art magnetic resonance imaging of pancreatic cancer

Technical advances of magnetic resonance imaging (MRI), including ultrahigh-field magnetic resonance at 3.0 T, parallel imaging techniques, and multichannel receive coils of the abdomen, have promoted MRI of the pancreas. For adenocarcinoma, which is the most common malignant pancreatic tumor, helical CT has been most often used for detection and staging, but it has limitations in the detection of small cancers 2 cm in diameter or less (sensitivity, 63%). Moreover, it is not very accurate in determining nonresectability, because small liver metastases, peritoneal carcinomatosis, and subtle signs of vascular infiltration may be missed. At ultrahigh field at 3.0 T, gadolinium-enhanced MRI using volume-interpolated 3-dimensional gradient-recalled echo pulse sequences with near-isotropic voxels are very useful for detection of subtle abnormalities. Mangafodipir-enhanced MRI reveals a very high tumor-pancreas contrast, which helps to diagnose small cancers. Contrast-enhanced MRI is a problem-solving tool in case of equivocal CT: it helps to differentiate between cancer and focal pancreatitis. Neuroendocrine carcinoma may present with a spectrum of appearances at MRI, but the primary tumor and liver metastases are hypervascular in approximately 70%. In this article, pancreas imaging protocols for 1.5 and 3.0 T are explained. We present the imaging features of pancreatic cancer and the important questions in staging, which should be addressed by the radiologist.     

Maximizing dose reductions with cardiac CT

Multidetector computed tomography has come a long way in a short time, quickly becoming a standard tool in the cardiac imaging armamentarium. The promise of plaque imaging, combined with both anatomical visualization and stenosis detection, has made this a preferred first line test of many cardiologists and radiologists. This test is well suited to rule out coronary artery disease (obstruction) and still diagnosing subclinical plaque, with may be a good target for anti-atherosclerotic therapies. There has been recent criticism against CT imaging, and cardiac CT specifically, due to the high radiation doses that being employed. New advances have allowed for dramatic dose reductions. These include more routinely performed methods such as dose modulation, and newer methods such as prospective gating or minimizing the field of view. This paper will review the different applications to reduce cardiac CT radiation doses to nominal levels, potentially expanding the applications of cardiac CT by removing one of the biggest barriers.     

Maximizing dose reductions with cardiac CT

Multidetector computed tomography has come a long way in a short time, quickly becoming a standard tool in the cardiac imaging armamentarium. The promise of plaque imaging, combined with both anatomical visualization and stenosis detection, has made this a preferred first line test of many cardiologists and radiologists. This test is well suited to rule out coronary artery disease (obstruction) and still diagnosing subclinical plaque, with may be a good target for anti-atherosclerotic therapies. There has been recent criticism against CT imaging, and cardiac CT specifically, due to the high radiation doses that being employed. New advances have allowed for dramatic dose reductions. These include more routinely performed methods such as dose modulation, and newer methods such as prospective gating or minimizing the field of view. This paper will review the different applications to reduce cardiac CT radiation doses to nominal levels, potentially expanding the applications of cardiac CT by removing one of the biggest barriers.     

Hepatic hemangioma supplied by abnormal portal vein: A case report

Hepatic hemangioma is the most common hepatic tumor with a prevalence of approximately 3%. It is typically supplied by the hepatic artery as evident from findings of abdominal angiography, contrast-enhanced ultrasonography (CEUS), contrast-enhanced computed tomography (CT), and contrast-enhanced magnetic resonance imaging. However, few cases of hepatic hemangioma supplied by the portal vein have been reported. In this paper, we report a rare case of hepatic hemangioma supplied by the portal vein as shown on CEUS and CT arterioportography.     

Diagnosing pulmonary embolism: time to rewrite the textbooks

Computed tomography (CT) is rapidly becoming the first line modality for imaging pulmonary embolism (PE). However, limitations for the accurate diagnosis of small peripheral emboli have prevented the unanimous acceptance of CT as the new standard of reference for imaging PE although the actual significance of the detection and treatment of isolated peripheral emboli is uncertain. At the same time the high negative predictive value of CT pulmonary angiography for excluding clinically significant PE has been established in retrospective and prospective studies. The introduction of multidetector-row spiral CT has greatly improved visualization of peripheral pulmonary arteries and detection of small emboli. Previous concerns regarding the accuracy of spiral CT for the accurate diagnosis of peripheral pulmonary emboli should thus be overcome. Multidetector-row spiral CT has become a widely available and cost-effective modality, which has surpassed other imaging modalities for PE diagnosis to a point where over-utilization may become of concern. Our most immediate goal must be to educate our referring colleagues about these important transitions so that the diagnostic algorithm in patients with suspected acute PE is updated to accurately reflect our current diagnostic prowess in medical imaging.     

Evaluation of the aortic and mitral valves with cardiac computed tomography and cardiac magnetic resonance imaging

Cardiac computed tomography (CT) produces high-quality anatomical images of the cardiac valves and associated structures. Cardiac magnetic resonance imaging (MRI) provides images of valve morphology, and allows quantitative evaluation of valvular dysfunction and determination of the impact of valvular lesions on cardiovascular structures. Recent studies have demonstrated that cardiac CT and MRI are important adjuncts to echocardiography for the evaluation of aortic and mitral valvular heart diseases (VHDs). Radiologists should be aware of the technical aspects of cardiac CT and MRI that allow comprehensive assessment of aortic and mitral VHDs, as well as the typical imaging features of common and important aortic and mitral VHDs on cardiac CT and MRI.     

Radionuclide Imaging of Cardiac Device Infection

Purpose of Review

Accurate diagnosis of cardiac device infection is critical for clinical decision-making and represents a challenge for current diagnostic methods. A non-invasive test with sufficient sensitivity and specificity to confirm or exclude infection would be desirable. ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) has been emerging as a promising diagnostic tool for cardiac implantable electrophysiological devices (CIED) infection and its complications. The aim of this review is to describe the role of radionuclide imaging in cardiac device infection according to the different clinical presentations.

Recent Findings

¹⁸F-FDG PET/CT plays an important role in the diagnosis of CIED infection. It has been demonstrated that PET/CT imaging can accurately diagnose and distinguish deep pocket infection from superficial soft tissue infection. In lead infection, this technique has high specificity and is helpful when transthoracic echocardiography (TTE) does not detect vegetation. In addition, PET/CT may be useful in patients with suspected prosthesis valve endocarditis, in whom the initial TEE is negative or indeterminate.

Summary

The use of ¹⁸F-FDG PET/CT in the diagnosis of CIED infection has been implemented to respond to specific clinical needs. Different studies provided important data on the optimal conditions of PET/CT acquisition to better discriminate the infection. However, multicenter trials performed under standardized protocols for both acquisition and quantification of FDG uptake are needed. These efforts could help to achieve the level of evidence allowing FDG PET/CT to be included in clinical guidelines.

     

原发性气管肿瘤延误诊断与影像检查的关系研究

目的:分析原发性气管肿瘤延误诊断的原因与影像检查的关系,并提出解决的可行办法。材料与方法:研究34例经纤支镜或/和手术病理证实的气管肿瘤的临床与各种影像检查的表现。结果:发现普通正位胸片漏诊率达90％(26/29),侧位片仅为7％(1/13)。高KV胸片、气管体层片、胸片CT与MRI均能发现气管肿瘤。结论:为及早提高气管肿瘤的发现率,除加强对本病的认识及警惕外,强调首次胸片一定要加照侧位片的重要性。而气管正侧位体层笔者认为是发现和鉴别良、恶性肿瘤较为可靠而又廉价的方法,若能加作CT与MRI进行综合诊断,效果更佳。     

CT and MR imaging in Hodgkin's disease--present and future

Initial staging of Hodgkin's disease is crucial to determine the location and extent of disease, and is the hallmark for the choice of treatment. At present, the established radiological technique for staging Hodgkin's disease is computed tomography (CT). Modern multidetector row CT scanners allow fast imaging from the scull base to the groins during a single breath hold with a spatial resolution of approximately 1 mm. Both, nodal and extranodal involvement of Hodgkin's disease can be diagnosed with CT. Magnetic resonance (MR) imaging is another useful cross-sectional imaging modality for staging Hodgkin's disease. The development of fast MR imaging techniques has considerably reduced imaging time without compromising the quality of MR images. As a consequence, MR imaging is now considered to be as diagnostic as CT for staging Hodgkin's disease. The excellent soft-tissue contrast and the lack of exposure to ionizing radiation are the main advantages of MR imaging. For the detection of extranodal Hodgkin's disease, MR imaging is superior to assess involvement of the brain, the spinal cord and bone marrow; while CT allows excellent evaluation of lung disease. Common major problems in staging Hodgkin's disease are still the detection of nodal involvement in normal sized lymph nodes and residual tumor masses after therapy. In the future, newly developed lymphotropic contrast agents for MR imaging might be helpful to answer these questions.