头颅磁共振及单光子发射断层扫描在老年期痴呆早期诊断中的价值

目的评价头颅磁共振（MRI）及单光子发射断层扫描（SPECT）对阿尔茨海默病（AD）及血管性痴呆（VD）早期诊断的应用价值,探讨局部脑萎缩程度及局部脑缺血程度与老年期痴呆严重程度的相关性。方法对36例AD患者、32例VD患者及年龄、性别相匹配的30名非痴呆老年人(NC)进行MRI脑局部萎缩定量检测,并同时应用SPECT对脑局部血流灌注情况进行半定量分析。结果头颅MRI显示,AD组较VD组及NC组海马萎缩程度明显,AD患者左侧海马高度为(9.27±3.43)mm,VD组为(11.62±5.72)mm,NC组为(12.13±2.97)mm（均为P＜0.01）。SPECT显示,AD组及VD组均有认知相关部位的血流灌注减低,AD患者左侧颞叶每像素计数与小脑每像素平均计数的比值(RAR)值为0.60±0.07,VD组为0.67±0.11,NC组为0.89±0.09,AD与VD组局部脑缺血情况明显较NC组严重（均为P＜0.01）。早期轻度AD患者简易智能状态量表（MMSE)评分22～26分,MRI左侧海马高度为(12.05±2.14)mm,与NC组差异无显著性(P＞0.05）,而SPECT显示有明显脑局部缺血,左侧海马的RAR值为0.61±0.07,低于NC组(P＜0.01）。MRI测量的脑局部萎缩程度（左侧海马高度）及SPECT检测的脑局部缺血程度（左侧颞叶）均与痴呆的严重程度（MMSE评分)呈正相关（r=0.96及0.98,均为P＜0.01）。结论MRI对AD有辅助诊断作用。对轻度的AD患者,MRI不如SPECT敏感。局部脑萎缩、局部脑缺血程度与痴呆的严重程度及病程相关。AD患者SPECT上均有缺血改变,提示AD的发生可能与局部脑血流灌注减低相关。     

Preoperative evaluation of colorectal cancer using CT colonography,MRI, and PET/CT

Imaging studies are a major component in the evaluation of patients for the screening,staging and surveillance of colorectal cancer.This review presents commonly encountered findings in the diagnosis and staging of patients with colorectal cancer using computed tomography(CT)colonography,magnetic resonance imaging(MRI),and positron emission tomography(PET)/CT colonography.CT colonography provides important information for the preoperative assessment of T staging.Wall deformities are associated with muscular or subserosal invasion.Lymph node metastases from colorectal cancer often present with calcifications.CT is superior to detect calcified metastases.Three-dimensional CT to image the vascular anatomy facilitates laparoscopic surgery.T staging of rectal cancer by MRI is an established modality because MRI can diagnose rectal wall laminar structure.N staging in patients with colorectal cancer is still challenging using any imaging modality.MRI is more accurate than CT for the evaluation of liver metastases.PET/CT colonography isvaluable in the evaluation of extra-colonic and hepatic disease.PET/CT colonography is useful for obstructing colorectal cancers that cannot be traversed colonoscopically.PET/CT colonography is able to localize synchronous colon cancers proximal to the obstruction precisely.However,there is no definite evidence to support the routine clinical use of PET/CT colonography.     

MRI vs CT for diagnosing brain disorders in the elderly

Following a very brief, simplified explanation of magnetic resonance imaging principles, the general advantages inherent in such a system, as compared to CT, are explored. Clinical exploitation of MRI's attributes are then specifically discussed and illustrated in multiple types of intracranial pathology.     

头部MRI及PET检查对进行性核上性麻痹与帕金森病的诊断价值

目的探讨头部磁共振成像(MRI)及以18F-脱氧葡萄糖(18F-FDG)为示踪剂的正电子发射计算机断层扫描(PET)两种影像学检查对进行性核上性麻痹(PSP)及帕金森病(PD)的诊断价值。方法对2004年8月至2006年11月在首都医科大学附属北京天坛医院神经内科就诊的11例PSP和178例PD患者进行常规头部MRI检查,并对其中5例PSP和48例PD患者进行18F-FDGPET检查。结果(1)MRI检查:11例PSP患者均可见矢状位T1加权像有中脑上缘平坦或者凹陷表现,PD组未见上述表现;正中矢状位T1加权像上计算中脑截面面积,PSP组低于PD组,差异有显著性意义(P<0.01)。(2)18F-FDGPET检查:PSP组主要表现为对称性额叶低代谢,纹状体代谢基本对称。PD组主要表现为顶叶代谢略低于额叶前部,首发症状肢体对侧顶叶代谢降低明显;纹状体呈不对称表现,首发症状肢体同侧纹状体代谢降低,对侧纹状体后部代谢降低;纹状体代谢高于同侧丘脑。结论MRI及18F-FDGPET检查对诊断PSP在中脑形态学改变(中脑萎缩)及脑葡萄糖低代谢方面有特异性,与PD组比较差异有显著性意义。     

New techniques in nuclear cardiology: SPECT, PET and antimyosin]

Nuclear Cardiology offers non-invasive techniques of high reproducibility for cardiovascular assessment. These techniques have advanced enormously in the latest years. The advances in areas such as general technology and computer systems, medicine, immunology and research, allow us to obtain and interpret cardiac information with immediate or potential clinical applications unavailable few years ago. This paper describes 3 of these new techniques in nuclear cardiology: Single Photon Computed Tomography (SPECT); Positron Emission Tomography (PET) and; the use of an Antimyosin monoclonal antibody.     

Colonography by CT, MRI and PET/CT combined with conventional colonoscopy in colorectal cancer screening and staging

Colorectal cancer （CRC） remains a leading cancer killer worldwide. But the disease is both curable and preventable at an early stage. Regular CRC cancer screening has been shown to reduce the risk of dying from CRC. However, the importance of large-scale screening is only now starting to be appreciated. This article reviews a variety of imaging procedures available for detecting ulcerative colitis （UC） and Crohn＇s disease （CD）, polyps and CRC in their early stage and also presents details on various screening options. Detecting, staging and re-staging of patients with CRC also require multimodality, multistep imaging approaches. Staging and re-staging with conventional colonoscopy （CC）, computer tomography colonography （CTC）, magnetic resonance colonography （MRC） and positron emission tomography/computer tomography colonography （PET/CTC） are of paramount importance in determining the most appropriate therapeutic method and in predicting the risk of tumor recurrence and overall prognosis. The advantages and limitations of these modalities are also discussed.     

Muscle imaging in myositis: MRI,US, and PET

Imaging is an important tool in the evaluation of idiopathic inflammatory myopathies. It plays a role in diagnosis, assessment of disease activity and follow-up, and as a non-invasive biomarker. Among the different modalities, nuclear magnetic resonance imaging (MRI), ultrasound (US), and positron emission tomography (PET) may have the most clinical utility in myositis. MRI is currently the best modality to evaluate skeletal muscle and provides excellent characterization of muscle edema and fat replacement through the use of T1-weighted and T2-weighted fat suppressed/STIR sequences. Although MRI can be read qualitatively for the presence of abnormalities, a more quantitative approach using Dixon sequences and the generation of water T2 parametric maps would be preferable for follow-up. Newer protocols such as diffusion-weighted imaging, functional imaging measures, and spectroscopy may be of interest to provide further insights into myositis. Despite the advantages of MRI, image acquisition is relatively time-consuming, expensive, and not accessible to all patients. The use of US to evaluate skeletal muscle in myositis is gaining interest, especially in chronic disease, where fat replacement and fibrosis are detected readily by this modality. Although easily deployed at the bedside, it is heavily dependent on operator experience to recognize disease states. Further, systematic characterization of muscle edema by US is still needed. PET provides valuable information on muscle function at a cellular level. Fluorodeoxyglucose (FDG-PET) has been the most common application in myositis to detect pathologic uptake indicative of inflammation. The use of neurodegenerative markers is now also being utilized for inclusion body myositis. These different modalities may prove to be complementary methods for myositis evaluation.     

Combined imaging of molecular function and morphology with PET/CT and SPECT/CT: Image fusion and motion correction

Imaging of the cardiovascular system with a combination of positron emission tomography (PET) and computer tomography (CT) or with a combination of single-photon emission computerized tomography (SPECT) and CT holds great promise for the future. Owing to the movement of the heart and the great vessels due to heart contraction and respiration this is, however, not straightforward. This article provides an overview over the principles of combined PET/CT or SPECT/CT imaging. It points out technical challenges inherent in imaging of cardiovascular system and presents possible solutions that allow for optimal fusion and motion correction of the combined molecular, functional and morphological image data.     

Biliary cystadenoma: ultrasound, CT, and MRI

Two cases of intrahepatic biliary cystadenoma, a rare tumor with malignant potential, are discussed. The sonographic, computed tomographic (CT), and magnetic resonance imaging (MRI) findings are presented together with clinical features of this entity and a brief review of the pertinent literature.     

Role of radiography, MRI and FDG-PET/CT in diagnosing, staging and therapeutical evaluation of patients with multiple myeloma

Multiple myeloma is a malignant B-cell neoplasm that involves the skeleton in approximately 80% of the patients. With an average age of 60 years and a 5-years survival of nearly 45% Brenner et al. (Blood 111:2516–2520, 35) the onset is to be classified as occurring still early in life while the disease can be very aggressive and debilitating. In the last decades, several new imaging techniques were introduced. The aim of this review is to compare the different techniques such as radiographic survey, multidetector computed tomography (MDCT), whole-body magnetic resonance imaging (WB-MRI), fluorodeoxyglucose positron emission tomography- (FDG-PET) with or without computed tomography (CT), and ^99mTc-methoxyisobutylisonitrile (^99mTc-MIBI) scintigraphy. We conclude that both FDG-PET in combination with low-dose CT and whole-body MRI are more sensitive than skeleton X-ray in screening and diagnosing multiple myeloma. WB-MRI allows assessment of bone marrow involvement but cannot detect bone destruction, which might result in overstaging. Moreover, WB-MRI is less suitable in assessing response to therapy than FDG-PET. The combination of PET with low-dose CT can replace the golden standard, conventional skeletal survey. In the clinical practise, this will result in upstaging, due to the higher sensitivity.     

Abdominal Kaposiform Hemangioendothelioma Associated With Lymphangiomatosis Involving Mesentery and Ileum: A Case Report of MRI,CT, and 18F-FDG PET/CT Findings

Kaposiform hemangioendothelioma (KH) is a rare vascular tumor of intermediate malignancy that occurs mainly in the childhood. Adult patients with KH are rare. Imaging findings of KH have rarely been reported before. We present magnetic resonance imaging (MRI), computed tomography (CT), and fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/CT findings in an adult patient with KH associated with lymphangiomatosis involving mesentery and ileum.A 22-year-old female complained of a 9-month history of intermittent melena, weakness, and palpitation. Laboratory tests revealed anemia and hypoproteinemia. Fecal occult blood test was positive. Abdominal enhanced MRI and CT showed a large abdominal mass involving mesentery and ileum. On enhanced MRI, there were many hypervascular nodules in the mass. On FDG PET/CT, the mass and the nodules showed slight FDG uptake. Small bowel capsule endoscopy showed numerous grape-shaped red nodules in the luminal wall of the involved ileum. The patient underwent resection of the abdominal mass and a segment of the ileum invaded by the abdominal mass. KH arising within lymphangiomatosis involving mesentery and ileum was confirmed by pathology. After surgery, the patient''s symptoms improved.This is the first case of KH associated with lymphangiomatosis involving mesentery and ileum. In this case, the lymphangiomatosis overshadowed the small tumor nodules resulting in unusual imaging findings. Familiarity with these imaging findings is helpful for diagnosis and differential diagnosis of KH.     

Desmoid-Type Fibromatosis of the Thorax: CT,MRI, and FDG PET Characteristics in a Large Series From a Tertiary Referral Center

The purpose of this study was to describe the radiologic findings of computed tomography (CT), magnetic resonance (MR) imaging, and ¹⁸F-fluorodeoxy glucose positron emission tomography (FDG PET) in desmoid-type fibromatosis of the thorax.We retrospectively evaluated 47 consecutive patients with pathologically proven desmoid-type fibromatosis from January 2005 to March 2015. Patients underwent CT (n = 36) and/or MR (n = 32), and 13 patients also underwent FDG PET. Based on CT and MR, the sizes, locations, margins, contours, presence of surrounding fat, extra-compartment extension, bone involvement, and neurovascular involvement of the tumors were recorded. The attenuation, signal intensity, enhancement pattern, and presence of internal low signal band or signal void of the tumors were evaluated. Initial image findings were then compared between 2 groups of tumors: group 1 with recurrence or progression, and group 2 with no recurrence or stable without treatment.Median age at diagnosis of the tumors was 45 years, range 4 to 96, female-to-male ratio 1.8. Median tumor long diameter was 65 mm (range, 22–126 mm). The most common locations were chest wall (42.6%), followed by supraclavicular area, shoulder or axillary area, and mediastinum. The tumors had well-defined margins (83.0%), lobulated in contours (66.0%) surrounding fat (63.8%), extra-compartment extensions (42.6%), bone involvements (42.6%), and neurovascular involvements (27.7%). On CT, tumors had low attenuation (60.0%) with mild enhancement (median 24 HU, range 0–52). On MR, they showed iso-signal intensity (SI) (96.9%) on T1-weighted images (WI), and high SI (90.6%) on T2WI images, with strong (87.5%) and heterogeneous (96.9%) enhancement. Internal low signal bands (84.4%) and signal voids (68.8%) were noted. The median value of maxSUV was 3.1 (range, 2.0–7.3). In group 1 (n = 19, 40.4%), 13 patients suffered recurrence and 6 experienced progression. Group 2 (n = 28, 59.6%) consisted of 21 patients with no recurrence and 7 stable patients receiving no treatment. Partially ill-defined margins (OR, 0.167; 95% CI 0.029–0.943; P = 0.043) was the independent predictor for recurrence or progression of tumor.Knowledge of the radiological findings in desmoid-type fibromatosis on CT, MR, and FDG PET may help to improve diagnosis. Tumors with partially ill-defined margins have a tendency to recur or progress.     

Osteomyelitis of the foot: non-surgical management,SPECT/CT scanning and minimising the duration of antibiotic use

In a paper in this issue of Diabetologia (DOI:  https://doi.org/10.1007/s00125-017-4417-x), Vouillarmet and colleagues have explored the use of single-photon emission computed tomography (SPECT)/computed tomography (CT) to define remission during non-surgical management of osteomyelitis of the foot. Their experience in a non-controlled observational study of 45 individuals was that a negative white blood cell-SPECT/CT scan is a reliable marker of remission, while a positive scan at the end of antibiotic treatment may be relatively useful in the prediction of future short- to medium-term relapse. These findings and conclusions are discussed in the light of current uncertainties relating to the diagnosis of bone infection and the lack of any tested measure that can be used to indicate either its presence or its persistence. In this respect, it is concluded that the value of this approach, and in which population, remains to be clearly established.