肺炎克雷伯菌肝脓肿的MRI表现

目的：探讨肺炎克雷伯菌肝脓肿的MRI表现。方法：回顾性分析30例肺炎克雷伯菌肝脓肿患者的临床及MRI资料,所有患者均行腹部MRI平扫、增强扫描和DWI检查,分析其MRI特征。结果：30例（共65个病灶）中,高毒力型16例;单发19例,多发11例;规则圆型或类圆型病灶45个,不规则型20个;病灶最大径0.6～12.0 cm。单叶26例,双叶4例;单房脓肿5例,多房25例;实性脓肿18例,囊性伴液化坏死12例;薄壁24例,厚壁6例;一过性灌注异常18例,脓肿周围无强化22例;脓腔积气17例,分隔强化18例。全部脓肿呈明显T₁WI低信号,T₂WI高信号,24例DWI呈高信号、ADC图呈低信号,6例DWI呈低信号、ADC图呈高信号。结论：肺炎克雷伯菌肝脓肿的MRI特征表现包括单发、单叶、实性、多房、薄壁、脓肿周围无强化、脓腔积气及分隔强化等,以上特征具备越多,该病的可能性越大。MRI可准确显示早期肺炎克雷伯杆菌的影像特征,对临床准确诊断有重要意义。     

Abdominal abscess. II. Diagnostic efficacy of computed tomography and comparison with ultrasonography

In our experience, a combination of Ultrasonographic and computed tomographic examinations is attended by a probability of less than 10% in failing to detect an intraabdominal abscess. Viewed as individual procedures, CT had an overall diagnostic accuracy between 80% and 85%, whereas the accuracy of US was 61%. A positive CT diagnosis denotes a 94% probability that a mass lesion is pressnt in the abdomen while a positive US diagnosis denotes a probability between 81% and 84%. The present patient sample suggests that between 62% and 72% of patients with negative CT diagnoses do not have an abscess, with a corresponding level of confidence of negative US diagnoses being restricted to 46 to 53%. It is to be emphasized that the cata was derived from a rather high risk patient population in which about two-thirds of the cases were found to be localized abscesses or other mass lesions. Patient-related factors are much more likely to render an ultrasonographic examination totally useless than is the case with CT.     

Prostatic abscess evaluated by serial computed tomography

Prostatic abscess appears on computed tomography (CT) as multiple, well-demarcated fluid collections within the prostate gland and/or periprostatic tissues. Since prostatic abscess may not be differentiated from other prostatic disease on the basis of history and physical examination alone, CT can contribute significantly to establishing this diagnosis. Prostatic abscess can be an aggressive lesion within the pelvis and may rupture into the urethra, peritoneum, prevesical space, rectum, perineum, and ischiorectal fossa. By defining the extent of the disease, CT can guide selection of an optimal surgical drainage procedure. CT can be used effectively to monitor the treatment of prostatic abscess.     

Aortic root abscess: multimodality imaging with computed tomography and gallium-67 citrate single-photon emission computed tomography/computed tomography hybrid imaging

Culture negative endocarditis and aortic root abscess can prove difficult diagnostic challenges. Computed tomography can be extremely useful in this setting. We report a case of an aortic root abscess 3 months after elective aortic valve replacement in which cardiac CT and hybrid imaging with Gallium-67 SPECT complemented workup with transesophageal echocardiography in establishing the diagnosis of an abscess.     

Vascular complications in intestinal obstructions. The role of computed tomography

INTRODUCTION: We investigated CT capabilities in showing vascular complications (ischemia, infarction) secondary to intestinal obstruction. SUBJECTS AND METHODS: 32 patients with small bowel obstruction, subdivided in two groups, were examined with CT. The first group consisted of 12 patients with small bowel obstruction complicated by ischemic injury. It was due to loop strangulation in 10 cases and loop distension secondary to colon carcinoma in 2 cases. At surgery the loop strangulation was caused by adhesions in 9 cases and by jejunal hernia in 1 case. Vascular complications were segmentary small bowel infarction in 7 cases, colonic infarction in 2 cases and ischemia, which was resolved after loop debridement, in 3 cases. The second group consisted of 20 patients with intestinal occlusion due to adhesions complicated by a closed loop in 4 cases. All patients were examined with(out) i.v. contrast agent administration. Filling of the intestinal loops by oral contrast agent was never performed. RESULTS: CT identified the vascular injury secondary to intestinal obstruction in 11/12 patients (91%). In one case it was not possible to diagnose mild ischemia, which was found of surgery. CT findings were: loops distention in all the cases; wall thickening in 11 cases with intramural gas in 8 cases and slight contrast enhancement in 1 case; ascites in 2 cases; mesenteric edema in 9 cases; gas at the mesenteric root in 1 case. In the control group, small bowel obstruction was diagnosed with CT in all cases based on the presence of distended loops up to the occlusion site. Parietal alterations above the lesion were never found. CONCLUSION: CT is a sensitive tool for diagnosing small bowel obstruction and for assessing the site and cause of obstruction. CT plays a pivotal diagnostic role in vascular complications, giving very important indications for a correct treatment.     

Measurement of liver volume by emission computed tomography.

In 22 volunteers without clinical or laboratory evidence of liver disease, liver volume was determined using single-photon emission computed tomography (ECT). This technique provided excellent object contrast between the liver and its surroundings and permitted calculation of liver volume without geometric assumptions about the liver's configuration. Reproducibility of results was satisfactory, with a root-mean-square error of less than 6% between duplicate measurements in 15 individuals. The volume measurements were validated by the use of phantoms.     

The role of computed tomography in the management of testicular teratoma.

CT scans of the lungs, mediastinum and abdomen have been performed in 65 patients with malignant teratoma between August 1977 and June 1978. CT is superior to conventional radiology in detecting pulmonary metastases and mediastinal lymphadenopathy. It is a valuable technique for defining the full extent of para-aortic nodal disease and provides more information than lymphography alone. In this series sequential CT scans have been used to monitor treatment response to detect relapse and to assess operability of demonstrable residual disease.     

The role of computed tomography in the staging of bladder cancer.

Computed tomography of the pelvis has been performed in 60 patients with epithelial bladder tumours. The CT findings have been compared with the clinical staging (T-stage), lymphography (N-stage) and wherever possible the surgical staging (P-stage). Although the intraluminal tumour was visualised in a high proportion of examinations, the greatest value of CT is in the accurate delineation of the extravesical extension of the growth. This is likely to be the primary role of CT in the staging of bladder cancer. Difficulties in detecting invasion of contiguous organs, particularly the prostate, and the failure to demonstrate nodal involvement within the pelvis were noted. The technique has clear advantages over more invasive investigations and the additional information provided over and above clinical staging is seen as a major advance in the assessment of these tumours.     

The role of computed tomography in the evaluation of neck masses.

Application of computed tomography (CT) to neck masses has received little attention. The authors reviewed 10 cervical masses studied with CT as well as conventional imaging modalities. CT was extremely useful in defining both the osseous and soft-tissue extent of the lesion. In several instances, CT was able to show the relationship of the tumor to the spinal canal. When combined with angiography, CT demonstrated the relationship of the major cervical vascular channels to the lesion. Pathological conditions included neurofibroma, chordoma, branchial cleft cyst, neuroblastoma, lymphoma, neurilemmoma, and metastatic carcinoma.     

Prostatic abscess. Contribution of the x-ray computed tomography. Apropos of a case

We reported a case of prostatic abscess due to staphylococeus aureus developed in a chronic alcoholic patient. The clinical symptoms and signs were largely masked by prior antibiotic therapy. Computed axial tomographic scanning of the pelvis made the diagnosis and demonstrated the resolution of the prostatic abscess following antibiotic therapy and spontaneous rupture to the urethra.     

The role of single-photon emission computed tomography/computed tomography in benign and malignant bone disease

Radiological (plain radiographs, computed tomography [CT], magnetic resonance imaging [MRI]) and nuclear medicine methods (bone scan, leukocyte scan) both provide unique information about the status of the skeleton. Both have typical strengths and weaknesses, which often lead to the sequential use of different procedures in daily routine. This use causes the unnecessary loss of time and sometimes money, if redundant information is obtained without establishing a final diagnosis. Recently, new devices for hybrid imaging (single-photon emission computed tomography/computed tomography [SPECT/CT], positron emission tomography/computed tomography [PET/CT]) were introduced, which allow for direct fusion of morphological (CT) and functional (SPECT, PET) data sets. With regard to skeletal abnormalities, this approach appears to be extremely useful because it combines the advantages of both techniques (high-resolution imaging of bone morphology and high sensitivity imaging of bone metabolism). By the accurate correlation of both, a new quality of bone imaging has now become accessible. Although researchers undertaking the initial studies exclusively used low-dose CT equipment, a new generation of SPECT/CT devices has emerged recently. By integrating high-resolution spiral CT, quality of bone imaging may improve once more. Ongoing prospective studies will have to show whether completely new diagnostic algorithms will come up for classification of bone disease as a consequence of this development. Besides, the role of ultrasonography and MRI for bone and soft-tissue imaging also will have to be re-evaluated. Looking at the final aim of all imaging techniques--to achieve correct diagnosis in a fast, noninvasive, comprehensive, and inexpensive way--we are now on the edge of a new era of multimodality imaging that will probably change the paths and structure of medicine in many ways. Presently, hybrid imaging using SPECT/CT has been proven to increase sensitivity and specificity of bone scintigraphy. This was mainly achieved by identifying benign bone conditions with increased bone turnover. Therefore, SPECT/CT should be applied whenever equivocal findings of planar bone imaging occur. It also helps to improve accuracy of leukocyte scanning to detect/exclude osteomyelitis and to define sites of inflammation. We therefore regard SPECT/CT as a valuable tool to optimize bone imaging, which might become even more important if new radiopharmaceuticals become available to image specific cell functions.     

The role of computed tomography in screening for cancer

Recent technical developments have revolutionized computed tomographic (CT) capabilities, and therefore its clinical applications. Multidetector CT (MDCT) allows scanning of the entire body within a few minutes. Over 60 million CT examinations were performed last year in the United States and Western Europe. Many emergency room physicians use it as a virtual physical examination. Its applications to early cancer detection have been controversial. Targeted CT screening for widely prevalent cancers, namely lung and colon, has been advocated in the literature. Combining the two, a whole-body screening CT scan might be offered to appropriately selected, high-risk populations.     

The role of computed tomography in modern paediatric uroradiology

Computed tomography (CT) has developed a well-recognised role within paediatric uroradiology, especially in imaging of trauma, malignancy (in particular Wilms' tumour), atypical infection, and congenital urogenital abnormalities. CT can also be used for problem solving in nephrolithiasis and renal transplant assessment. These applications are illustrated and discussed, with an emphasis on particular information that can be gained from the CT study.     

The role of computed tomography in terminal ballistic analysis

Terminal ballistics concerns the science of projectile behaviour within a target and includes wound ballistics that considers what happens when a projectile strikes a living being. A number of soft tissue ballistic simulants have been used to assess the damage to tissue caused by projectiles. Standard assessment of these materials, such as ballistic soap or ordnance gelatine, requires the block to be opened or that a mould to be made to visualize the wound track. This is time consuming and may affect the accuracy of the findings especially if the block dries and alters shape during the process. Therefore, accurate numerical analysis of the permanent or temporary cavity is limited. Computed tomography (CT) potentially offers a quicker non-invasive analysis tool for this task. Four commercially purchased ballistic glycerine soap blocks were used. Each had a single firearm discharged into it from a distance of approximately 15 cm using both gunshot and shotgun projectiles. After discharge, each block was imaged by a modern 16 slice multi-detector CT scanner and analysed using 3-D reconstruction software. Using the anterior–posterior and lateral scout views and the multi-plane reconstructed images, it was possible to visualize the temporary cavity, as well as the fragmentation and dispersal pattern of the projectiles, the distance travelled and angle of dispersal within the block of each projectile or fragment. A virtual cast of the temporary cavity can be also be made. Multi-detector CT with 3-D analysis software is shown to create a reliable permanent record of the projectile path allowing rapid analysis of different firearms and projectiles.     

The role of computed tomography in screening for cancer

Recent technical developments have revolutionized computed tomographic (CT) capabilities, and therefore its clinical applications. Multidetector CT (MDCT) allows scanning of the entire body within a few minutes. Over 60 million CT examinations were performed last year in the United States and Western Europe. Many emergency room physicians use it as a virtual physical examination. Its applications to early cancer detection have been controversial. Targeted CT screening for widely prevalent cancers, namely lung and colon, has been advocated in the literature. Combining the two, a whole-body screening CT scan might be offered to appropriately selected, high-risk populations.