Subpleural micronodules in diffuse infiltrative lung diseases: evaluation with thin-section CT scans

Thin-section computed tomography (CT) was performed in 244 patients with infiltrative lung diseases and 29 healthy control subjects to evaluate the frequency, profusion, and diagnostic value of subpleural parenchymal micronodules. These areas of increased attenuation (less than 7 mm in diameter) were analyzed in four groups: coal miners with chest radiographic findings of coal worker's pneumoconiosis (n = 61), coal miners with no radiographic evidence of pneumoconiosis (n = 73), patients with nonoccupational chronic infiltrative lung disease (n = 110), and healthy adults (n = 29). Subpleural parenchymal micronodules were observed with high frequency in pulmonary lymphangitic carcinomatosis, coal worker's pneumoconiosis, and sarcoidosis but were also seen in 14% of control subjects. Predominant sites of lesions were the posterior subpleural areas in the upper lobes. Subpleural parenchymal micronodules have no diagnostic value when observed as an isolated CT finding but may suggest that diagnosis of pneumoconiosis, sarcoidosis, or pulmonary lymphangitic carcinomatosis when observed in association with mild parenchymal lesions.     

Calcification of the ligamentum arteriosum in children: a normal finding on CT

Calcification of the ligamentum arteriosum is a rare finding on plain radiographs. We commonly have seen the calcification on unenhanced CT scans of the chest, a finding not previously reported. A retrospective review of unenhanced CT scans of the chest was undertaken to determine the frequency of the described finding. Seven (13%) of 53 patients had a well-demarcated focus of calcification in the region of the ligamentum arteriosum. None of these patients had evidence of a patent ductus arteriosum. Calcification within the ligamentum arteriosum was seen in 13% of routine CT examinations of the chest in children and should not be confused with a pathologic process producing mediastinal calcifications.     

Brain damage in hanging: a new CT finding

We report a 23-year-old man who attempted suicide by hanging. There have been few reports of involvement of the brain parenchyma shown on CT, all showing ischaemic lesions. This is the first report of multifocal intracerebral haematomas due to hanging seen on CT.     

Pulmonary contusion: CT vs plain radiograms

In experimentally induced pulmonary contusions, CT (n = 27) and chest X-ray (n = 24) findings were compared with the findings at autopsy. Twenty-seven of 27 (100%) pulmonary contusions were visible by CT immediately after trauma compared with 9 of 24 (37.5%) in the chest X-ray. After 30 min follow-up, 18 of 24 (75%) lesions were seen on the plain film. Five of 24 (21%) contusions escaped detection on conventional radiographs. Computed tomography underestimated lesion size in 5 of 60 (8%) measurements, conventional radiographs in 21 of 36 (58%) measurements. Pathological examination never revealed a pulmonary contusion that was not demonstrated by CT. Therefore, pulmonary contusion seems unlikely in a trauma patient with normal pulmonary CT.     

猪肺挫伤数码断层图像与CT诊断的比较

目的比较分析病理数码断层图像(pathologicaldigitizedsectionalimage,PDSI)与CT扫描在猪肺挫伤诊断中的差异。方法采用BIMⅡ型生物撞击机制作小香猪肺挫伤模型,并于伤后6小时行CT断层摄影(层厚5mm),吸气末结扎气管后,行肺动脉冲洗及灌注。截取猪胸部并冰冻后,在-25℃低温实验室中用TK26350型数控铣床(铣切精度为1mm)逐层铣切,并逐层摄取猪胸部的连续断层图像数据,运用3Ddoctor软件分割数码断层图像并与对应层面CT扫描结果进行对比分析。结果CT扫描25层,采集PDSI167幅,对应的PDSI层面与CT图像基本吻合。PDSI上出血呈褐色改变。CT第14～18层提示肺中叶局限性挫伤出血,大小约为2.5cm×1.8cm×2.0cm,PDSI上相应部位出血区大小约为2.0cm×0.7cm×1.9cm。CT提示右肺中叶及下叶后外侧基底段为可疑的损伤区域,而在PDSI上,该区域呈形状不规则的大片深褐色出血改变,范围从第52层至114层。结论首次获得猪肺挫伤的数码断层图像集,CT表现与实际肺损伤之间存在差异,实际伤情较CT提示的重。PDSI的采集和研究对促进CT诊断水平有意义。     

胸部创伤的CT诊断(附219例分析)

回顾分析了219例胸部创伤CI影像,探讨胸部创伤的CI诊断价值及其特征。     

Focal hyperdense areas in endometriomas: a characteristic finding on CT.

OBJECTIVE. To assess the value of a hyperdense focus seen on CT scans of endometrial cysts in the differential diagnosis of a lesion. MATERIALS AND METHODS. The preoperative CT scans of 328 patients with 410 ovarian masses (54 patients with 62 pathologically proved endometriomas and 274 patients with 348 pathologically proved other ovarian masses) were retrospectively reviewed in a random fashion without knowledge of the pathologic findings to determine whether a hyperdense focus was visible inside a cyst. RESULTS. In nine of 62 endometrial cysts (sensitivity, 15%), CT scans showed a hyperdense round or crescent-shaped focus, measuring 2 to 15 mm. This focus was located close to the inner border of the cyst in eight cases and in the central part of the cyst in one case. A hyperdense focus was not seen on CT scans of 348 other ovarian masses (specificity, 100%). An in vitro CT study of two specimens showed that this hyperdense area corresponded to a blood clot next to the inner wall of the cyst. This hyperdense area appeared as a nonspecific hyperechogenic focus on sonograms in five of nine cases and as a hypointense signal on T1- and/or T2-weighted MR images in four of five cases. CONCLUSION. The finding on CT scans of a hyperdense focus inside an ovarian cyst is suggestive of endometrioma and should help distinguish endometrioma from other pelvic masses.     

肺挫伤合并肺撕裂伤的CT诊断

我院自2003年～2007年诊治的肺挫伤合并肺撕裂伤共20例,现报告分析如下.     

Cystic fibrosis: CT assessment of lung involvement in children and adults.

PURPOSE: To compare a computed tomographic (CT)-based scoring system with nonimaging indexes of pulmonary status in patients with cystic fibrosis. MATERIALS AND METHODS: Pulmonary CT findings were assessed in 117 patients with cystic fibrosis, with cases classified according to three groups by age; 0-5 years, 6-16 years, and 17 years and older. Images were examined for specific abnormalities, and the severity and anatomic extent of each sign were used to generate a score. Scores in each category and the global score for each patient were correlated with pulmonary function test results, clinical status, serum immunoglobulin levels, and genotype, all obtained within 2 weeks of CT. RESULTS: The most frequent individual CT abnormalities were bronchiectasis in 94 (80.3%), peribronchial wall thickening in 89 (76.1%), mosaic perfusion in 71 (63.9%), and mucous plugging in 56 (51.3%) patients. The percentage of patients with specific CT findings and the overall CT scores increased significantly (P < .05) with progressively increasing age groups. All CT findings and the overall CT scores correlated significantly (P < .05) with the pulmonary function test results, serum immunoglobulin levels, and clinical scores. No relationship was observed between genotype and CT scores. CONCLUSION: Scoring of CT studies in patients with cystic fibrosis seems to offer a reliable way to monitor disease status and progression and may provide a reasonable tool to assess treatment interventions.     

Teflon granuloma in the nasopharynx: a potentially false-positive PET/CT finding

Positron emission tomography (PET) has become a critical diagnostic tool in the discovery and staging of malignancies in the head and neck. Although PET is accurate for detecting cancer, increased 18 F-fluorodeoxyglucose (FDG) uptake can be seen in healthy tissues such as muscle, fat, and glands and uptake can be seen in tissues affected by inflammation or granulomatous disease. Combined PET and CT (PET/CT) can often overcome these difficulties by fusing anatomic and physiological data, but radiographic findings of some disease processes can be confusing even with fused imaging techniques. We present two cases of FDG uptake in the posterior pharynx, localized by combined PET/CT, which was initially interpreted as squamous cell carcinoma. The increased activity was ultimately attributed to Teflon-induced granulomas. It is important for radiologists to recognize potential causes of false-positive PET/CT findings to improve our diagnostic accuracy and to avoid unnecessary biopsies and surgeries.     

The target sign: a CT finding in tumors of the corpus callosum.

An unusual computed tomography finding, the "target sign," is demonstrated in a patient with a corpus callosum tumor mass extending to the right lateral ventricle. The central low attenuation of the "target" is produced by the isolated part of the dilated lateral ventricle surrounded by tumor tissue, the dense area of the "target." The diagnosis of the tumor of the corpus callosum and the explanation of the "target sign" was made by polytome pneumoencephalography.     

CT doses in children: a multicentre study

We evaluated examination protocols used for common CT procedures of paediatric patients at different hospitals in Belgium in order to determine whether adjustments related to patient size are made in scanning parameters, and to compare patient doses with proposed reference levels. Three paediatric hospitals and one non-paediatric hospital participated in the study. Weighted CT dose-index (CTDI(w)), dose-length product (DLP) and effective dose (E) were evaluated for three patient ages (1 year, 5 years and 10 years) and three common procedures (brain, thorax and abdomen). CTDI(w) and DLP values higher than the reference levels were found for all types of evaluated examination. E ranged from 0.4 mSv to 2.3 mSv, 1.1 mSv to 6.6 mSv, and 2.3 mSv to 19.9 mSv for brain, thorax and abdomen examinations, respectively. All centres but one adapted their protocols as a function of patient size. However, no common trend in the selection of protocols was observed. Some centres divided the whole range of patient size into only two/three groups by age, while others classified the patients into six groups by weight. It was also observed that some centres used the same mAs for the total range of patient sizes and decreased the pitch factor for small children, which resulted in higher doses. This indicates the importance of careful selection of technical scan parameters. If CT parameters used for paediatric patients are not adjusted on the basis of examination type, age and/or size of the child, then some patients will be exposed to an unnecessarily high radiation dose during CT examinations.     

Interruption of gallbladder wall with pericholecystic fluid: a CT finding of perforation

In this report, we present an unusual case of gallbladder perforation due to acalculous cholecystitis, masked clinically by acute pancreatitis. Severe abdominal pain referred to the patient's back, nausea, vomiting, and high serum and urinary amylase values were compatible with acute pancreatitis. However, on contrast-enhanced CT, the size and appearance of the pancreas were normal while the gallbladder was abnormally enlarged with a wall defect indicating perforation, soon afterward confirmed by surgery.     

Infected aneurysm of abdominal aorta: early CT finding

Infected abdominal aortic aneurysm is an uncommon but life-threatening disease, especially in case of salmonella infection. Early CT findings should be well known in order to allow immediate diagnosis and accurate management. The authors present an early CT finding of a salmonella infected aneurysm of abdominal aorta in an HIV-infected patient. This pattern consists in a slight-enhancing focal densification of periaortic soft-tissue, while aorta remains of normal size. Within two weeks, infection progressed to the constitution of an infected aneurysm. This CT finding seems to be initial to previously described signs.     

III-defined focal low attenuation in the posterior internal capsule: a normal CT finding

Although many pathological changes in the internal capsule may lead to neurological deficits, we often encounter ill-defined focal low attenuation in the posterior limb of the internal capsule (PIC) on CT in patients with no neurological disturbance. Brain CT studies of 141 patients without neurological deficites were reviewed to investigate the position of the focal low attenuation by analysis of a profile density curve. Nine patients with lacunar infarcts only within the posterior internal capsule were also studied. The focal low attenuation areas were ill-defined and bilaterally symmetrical, without mass effect. They were seen consistently within the posterior limb of the posterior internal capsule. Correlation between the distribution of these foci and the position of lacunar infarcts in the posterior internal capsule in nine patients with neurological deficits suggests that they may be related to the corticospinal tract.