Pulmonary septic emboli: diagnosis with CT

The CT scans of 18 patients with documented pulmonary septic emboli were reviewed. CT features of septic emboli included multiple peripheral nodules ranging in size from 0.5 to 3.5 cm (15 of 18 patients [83%]), a feeding vessel sign (n = 12; [67%]), cavitation (n = 9; [50%]), wedge-shaped peripheral lesions abutting the pleura (n = 9 [50%]), air bronchograms within nodules (n = 5 [28%]), and extension into the pleural space (n = 7 [39%]). In six of the 18 patients, CT was the first modality (before radiography) to show lesions compatible with septic emboli. In five clinically unsuspected cases, CT first suggested the correct diagnosis of septic emboli. In eight patients, CT also enabled identification of more parenchymal lesions, presumed to be septic emboli, and more pleural involvement than chest radiographs, thus demonstrating a greater extent of disease. The authors conclude that CT is an important modality for confirming the presence of pulmonary septic emboli even when conventional chest radiographs remain negative. In the proper clinical setting, characteristic CT features of septic emboli can suggest the correct diagnosis.     

中央型小细胞肺癌的CT诊断及鉴别诊断

目的:探讨中央型小细胞肺癌(Small Cell Lung Cancer,SCLC)的CT表现特点,并找出与非小细胞肺癌(NSCLC)、肺结核、结节病、纵隔淋巴瘤的鉴别诊断要点。方法:回顾性分析经病理证实的57例中央型SCLC、60例NSCLC,5例肺结核,2例结节病,3例纵隔淋巴病的胸部平片及CT资料,全部病例均行胸部平片和CT平扫、增强检查。结果:57例中央型SCLC,CT主要表现为沿支气管长轴生长的肺内肿块,肺门与纵隔广泛淋巴结肿大,而肺不张相对少见。NSCLC60例主要表现为肺门肿块,支气管阻塞性改变相对多见。5例肺结核表现为肺内结节和肺门、纵隔淋巴结肿大,伴有同侧和/或对侧肺内结核病灶。2例结节病,表现为双侧肺门对称性淋巴结肿大。3例纵隔淋巴病表现为中前纵隔的弥漫性软组织肿块。结论:沿支气管长轴生长的肺内肿块、肺门及纵隔淋巴结肿大。支气管阻塞改变少见,随访1～2个月,肿块体积增大1倍以上,是中央型SCLC的CT诊断要点,据此特征诊断正确率达80％。结合临床与其他检查方法可与NSCLC、肺结核、结节病、纵隔淋巴瘤鉴别。     

Deep venous thrombosis: comparison of indirect multidetector CT venography and sonography of lower extremities in 26 patients

OBJECTIVE: To compare the accuracy of indirect mutidetector row computed tomographic (MDCT) venography with lower extremity venous sonography for the diagnosis of femoropopliteal deep venous thrombosis (DVT), and to determine the frequency and location of DVT at MDCT venography. MATERIALS AND METHODS: Twenty-six consecutive patients suspected of having pulmonary embolism (PE) underwent both combined MDCT venography and MDCT pulmonary angiography and lower extremity venous sonography. Indirect MDCT venography was acquired from the upper calves to the mid-abdomen following MDCT pulmonary angiography. The CT venographic findings were compared with those of sonography for the diagnosis of femoropopliteal DVT. All CT scans were also reviewed for the frequency and location of DVT. RESULTS: Indirect MDCT venography disclosed DVT in 19 patients, and 12 of whom also had PE. Seventeen patients with thrombosis in the femoropopliteal veins were identified in both indirect MDCT venography and sonography. The sensitivity and specificity of indirect MDCT venography for femoropopliteal DVT, as compared with sonography, were both 100%. In one patient DVT in the superficial femoral vein was detected using only indirect MDCT venography. MDCT venography also showed superior extension of femoropopliteal DVT to the inferior vena cava and iliac veins in four patients and thrombosis isolated to the inferior vena cava and common iliac vein thrombosis in one patient. CONCLUSIONS: Indirect MDCT venography is as accurate as sonography in the diagnosis of femoropopliteal DVT. MDCT venography can further reveal thrombus in large pelvis veins and the inferior vena cava, an important advantage over sonographic screening for DVT.     

小细胞肺癌的螺旋CT表现特征

目的 明确未治疗小细胞肺癌的螺旋CT表现特征，以利于提高CT诊断的准确性。资料与方法 搜集未经治疗且行胸部螺旋CT增强扫描并经病理证实的小细胞肺癌32例，观察其胸部螺旋CT表现特征，结合其他临床资料进行分期。结果 32例小细胞肺癌中，局限性病变6例(18．8％)，广泛播散性病变26例(81．2％)；中心型27例(84．4％)，周围型5例(15．6％)。3l例(96．9％)表现为肺内肿块或结节，其中肿块密度均匀29例(90．6％)，钙化及空洞各1例。19例(59．4％)发现支气管狭窄，16例(50％)伴阻塞性肺炎，10例(31．3％)伴阻塞性肺不张。14例(43．8％)纵隔大血管被包埋或侵犯。31例(96．9％)肺门淋巴结增大，25例(78．1％)纵隔淋巴结增大。转移至对侧肺5例(15．6％)、神经系统5例(15．6％)、腹部脏器(肝、肾上腺)4例(12．5％)、骨骼3例(9．4％)。结论 小细胞肺癌以中心型为主，呈实体性生长，CT上肿块密度较均匀，易侵犯支气管及纵隔大血管，伴肺门、纵隔淋巴结转移。     

Threshold-dependent variability of coronary artery calcification measurements -- implications for contrast-enhanced multi-detector row-computed tomography

INTRODUCTION: The present study investigated the threshold-dependent variability of coronary artery calcification (CAC) measurements and the potential to quantify CAC in contrast-enhanced multi-detector row-computed tomography (MDCT). METHODS: We compared the mean CT attenuation of CAC to luminal contrast enhancement of the coronary arteries in 30 patients (n = 30) undergoing standard coronary contrast-enhanced spiral MDCT. The modified Agatston score [AS], calcified plaque volume [CV], and mineral mass [MM]) at four different thresholds (130, 200, 300, and 400 HU) were measured in 50 patients who underwent non-contrast-enhanced MDCT. RESULTS: Mean CT attenuation of CAC was similar to the attenuation of the contrast-enhanced coronary lumen (CAC 297.1 +/- 68.7 HU versus 295 +/- 65 HU (p < 0.0001), respectively). Above a threshold of 300 HU CAC measurements significantly varied to standard measurements obtained at a threshold of 130 HU (p < 0.0001). The threshold-dependent variation of MM measurements was significantly smaller than for AS and CV (130 HU versus 400 HU: 63, 75, and 81, respectively; p < 0.001). These differences resulted in a change of age and gender based percentile category for AS in 78% of subjects. DISCUSSION: We demonstrated that CAC measurements are threshold dependent with MM measurements having significantly less variation than AS or CV. Due to the similarity of mean CT attenuation of CAC and the contrast-enhanced coronary lumen accurate quantification of CAC may be difficult in standard coronary contrast-enhanced spiral MDCT.     

右上纵隔增宽的CT诊断价值(附56例分析)

目的探讨X线平片右上纵隔增宽的CT诊断价值。方法分析56例经手术、病理或CT增强扫描、心脏超声证实的右上纵隔增宽X线和CT表现。所有病例均行X线平片和CT平扫,其中51例行CT增强扫描。结果非侵袭性胸腺瘤6例;侵袭性胸腺瘤致上腔静脉综合征2例;胸内甲状腺肿瘤2例;升主动脉或无名动脉迂曲14例;胸主动脉瘤3例;肺动脉狭窄致主肺动脉扩张1例;右位主动脉弓2例;淋巴瘤4例;右肺纵隔型肺癌16例;隐匿型肺癌2例;食管下段癌致胸上段食管明显扩张2例;食管异物继发上纵隔脓肿2例。经CT平扫 增强扫描、手术、病理、心脏超声证实病例数分别为33、10、12、1例。结论CT扫描是诊断右上纵隔增宽的可靠检查方法。     

Clinical relevance of retrograde inferior vena cava or hepatic vein opacification during contrast-enhanced CT

OBJECTIVE: The purpose of this investigation was to explore the clinical relevance of retrograde inferior vena cava or hepatic vein opacification during contrast-enhanced CT. MATERIALS AND METHODS: We retrospectively identified 127 patients who underwent contemporaneous contrast-enhanced CT of the chest or abdomen and echocardiography. On CT, the presence of retrograde inferior vena cava or hepatic vein opacification and the rate of IV contrast injection (> 3 mL/sec, high; < or = 3 mL/sec, low) were recorded. On echocardiography, the presence of tricuspid regurgitation, pulmonary hypertension, or right ventricular systolic dysfunction was recorded. RESULTS: Retrograde inferior vena cava or hepatic vein opacification was more common in studies performed with a high rather than a low contrast injection rate (28/56 vs 6/71 patients, respectively; p < 0.01). This finding was 31% sensitive (5/16) and 98% specific (54/55) for right-sided heart disease at low contrast injection rates, and 81% sensitive (17/21) and 69% specific (24/35) at high injection rates. Multivariate logistic regression models showed that high injection rate, tricuspid regurgitation, pulmonary hypertension, and right ventricular systolic dysfunction were independent predictors of retrograde inferior vena cava or hepatic vein opacification (p < 0.05 for each). CONCLUSION: Retrograde opacification of the inferior vena cava or hepatic veins on CT is a specific but insensitive sign of right-sided heart disease at low contrast injection rates, but the usefulness of this classic sign decreases with high injection rates. This realization is important because many centers increasingly use high-injection-rate CT.     

Hemopericardium After Superior Vena Cava Stenting for Malignant SVC Obstruction: The Importance of Contrast-Enhanced CT in the Assessment of Postprocedural Collapse

We report the complication of hemopericardium following superior vena cava (SVC) stenting with an uncovered Wallstent in a patient with malignant SVC obstruction. The patient collapsed acutely 15 min following stent placement with hypoxemia and hypotension. A CT scan demonstrated a hemopericardium which was successfully treated with a pericardial drain. The possible complications of SVC stenting, including hemopericardium, pulmonary embolism, mediastinal hematoma, and pulmonary edema from increased venous return resulting from improved hemodynamics, ensure a wide differential diagnosis in the postprocedural collapsed patient and this case emphasizes the important role of contrast-enhanced CT in the peri-resuscitation assessment of these patients.     

周围型小细胞肺癌的CT征象分析

目的 探讨周围型小细胞肺癌(SCLC)的CT征象.方法 回顾分析78例经病理证实的周围型SCLC的CT影像特点.根据有无纵隔淋巴结转移及其大小,将78例周围型SCLC分为2型:Ⅰ型孤立病灶型、Ⅱ型肺内病灶+淋巴结型;又将Ⅱ型分为2个亚型:Ⅱa型,肺门、纵隔淋巴结短径<10 mm;Ⅱb型,肺门、纵隔淋巴结短径≥10 mm.结果 Ⅰ型7例,Ⅱ型71例,其中Ⅱa型8例,Ⅱb型63例.78例SCLC均为实性病变;圆形、类圆形52例,纺锤形、蠕虫状9例,其他形状17例.71例行CT增强扫描,9例呈均匀强化,58例呈不均匀强化,4例病灶内见大面积不强化坏死区.边缘光整65例,毛糙12例,模糊1例.支气管充气征3例,空泡征4例,钙化4例.分叶征46例,毛刺征5例;支气管血管束增粗、结节41例,胸膜凹陷6例,边缘磨玻璃影5例,血管集束征1例;肺气肿42例,阻塞性肺炎4例;支气管与结节边缘截断18例.纵隔淋巴结转移63例,纵隔淋巴结大于肺原发灶42例.少量胸腔积液9例.     

Reduction of contrast material dose and artifacts by a saline flush using a double power injector in helical CT of the thorax

OBJECTIVE: Our objective was to evaluate a combined method of contrast material bolus followed by saline solution flush for thoracic helical CT and statistical comparison with a uniphasic injection protocol. MATERIALS AND METHODS: Fifty patients underwent helical CT of the thorax using 60 ml of contrast material (370 mg I/ml) followed by flushing with 30 ml of physiologic saline solution. These 50 patients had been examined before using our previous protocol, 75 ml of the same contrast material without a subsequent saline solution. Mean attenuation values for both protocols were measured in the superior vena cava, the pulmonary trunk, and the ascending aorta. Image artifacts and mediastinal and hilar depiction were graded and compared. RESULTS: Mean attenuation values in the superior vena cava were considerably higher in the regimen without saline solution flush (459 H versus 352 H) and in the pulmonary trunk and the ascending aorta were almost identical for both protocols. Injection of saline solution diminished surrounding artifacts (p = 0.001). Grading results for the evaluation of mediastinal and hilar structures were not significantly different in the two protocols (p = 0.564). CONCLUSION: Injection of contrast material followed by a saline solution bolus using a double power injector when performing thoracic helical CT allows a 20% reduction of contrast material volume to 60 ml with a similar degree of enhancement. In addition, perivenous artifacts in the superior vena cava are significantly reduced.     

Fibrosing mediastinitis.

Fibrosing mediastinitis is a rare benign disorder caused by proliferation of acellular collagen and fibrous tissue within the mediastinum. Although many cases are idiopathic, many (and perhaps most) cases in the United States are thought to be caused by an abnormal immunologic response to Histoplasma capsulatum infection. Affected patients are typically young and present with signs and symptoms of obstruction or compression of the superior vena cava, pulmonary veins or arteries, central airways, or esophagus. There may be two types of fibrosing mediastinitis: focal and diffuse. The focal type usually manifests on computed tomographic (CT) or magnetic resonance (MR) images as a localized, calcified mass in the paratracheal or subcarinal regions of the mediastinum or in the pulmonary hila. The diffuse type manifests on CT or MR images as a diffusely infiltrating, often noncalcified mass that affects multiple mediastinal compartments. CT and MR imaging play a vital role in the diagnosis and management of fibrosing mediastinitis.     

肺癌致上腔静脉综合征的CT诊断

目的:探讨肺癌致上腔静脉综合征(SVCS)的CT表现。材料和方法:病理确诊肺癌致SVCS51例,回顾性分析肺癌、上腔静脉梗阻及SVCS继发病变的CT特征,并作统计分析。结果:(1)原发疾病特征:致SVCS肺癌位于右上肺叶32例、右中肺叶3例、右下肺叶5例、左上肺叶2例、左下肺叶5例、右全肺4例;大体类型:中央型35例、右上纵隔型12例、周围型4例。(2)上腔静脉梗阻征:环状包埋11例、半环状包埋5例、夹心状包埋5例、推移10例、向左推压15例、完全闭塞5例。梗阻程度不同,前五者发生率有差异(P<0.05)。(3)继发病变征:单纯侧枝循环建立与开放14例、单纯胸壁肿胀12例、二者均有16例、二者均无9例,上腔静脉梗阻程度不同,侧枝循环和/或胸壁水肿CT显示率不同(P<0.05)。结论:CT增强扫描能全面诊断肺癌致SVCS。     

102例肺小细胞未分化癌的X线表现(附30例X线误诊分析)

本文分析了102例肺小细胞未分化癌(SCLC)的临床X线表现和30例X线误诊病例,将本组SCLC X线表现分为肺门型(57例),周围型(17例),纵隔型(15例)和特殊型(13例),讨论了有关的鉴别诊断,认为纵隔型肺癌与纵隔肿瘤的主要区别在于前者有支气管异常和肺野阻塞性变化。要提高SCLC诊断正确率必须了解其X线影像的复杂性,要充分运用支气管体层摄影(包括CT扫描)来发现并认识异常的支气管。     

Acute pancreatic transplant rejection: evaluation with dynamic contrast-enhanced MR imaging compared with histopathologic analysis

PURPOSE: To evaluate the use of dynamic contrast material-enhanced gradient-recalled-echo MR imaging for the diagnosis of acute pancreatic transplant rejection, as confirmed at histopathologic analysis. MATERIALS AND METHODS: Thirty MR imaging studies were performed in 25 patients within 3 days of percutaneous biopsy or pancreatectomy. The mean percentage of parenchymal enhancement (MPPE) at dynamic contrast-enhanced MR imaging was calculated. RESULTS: Biopsy findings were no evidence of rejection (n = 7 [23%]), mild rejection (n = 10 [33%]), moderate (n = 6 [20%]) and severe (n = 2 [7%]) acute rejection, and infarction (n = 5 [17%]). The corresponding MPPEs at 1 minute were 106%, 66%, 62%, 57%, and 3%, respectively. Overlap of cases in the normal and rejection groups occurred; however, using an MPPE cutoff of 100% resulted in a sensitivity of 96%. An MPPE over 120% was seen in the normal group only. The MPPE was significantly greater in the normal group than in the rejection or infarction group (P < .05). CONCLUSION: Dynamic contrast-enhanced MR imaging is highly sensitive for the detection of acute pancreatic transplant rejection. Because of overlap of cases in the normal and rejection groups, percutaneous biopsy may be needed in some cases. Pancreatic allografts with infarction can be clearly identified.     

串珠征在周围型小细胞肺癌中的诊断价值

目的：探讨串珠征的形成机制,评价其在周围型小细胞肺癌(SCLC)、周围型肺腺癌及周围型肺鳞癌中的鉴别诊断意义。方法收集病理证实的周围型 SCLC 78例、周围型肺腺癌69例、周围型肺鳞癌33例,分别统计串珠征的阳性率、纵隔淋巴结的转移率及纵隔淋巴结大于肺原发灶的比例,对相关数据进行统计分析。结果78例周围型 SCLC中10例串珠征阳性(12.8%),且纵隔淋巴结均大于肺原发灶;78例中63例纵隔淋巴结转移(80.8%),42例纵隔淋巴结大于肺原发灶(53.8%)。69例周围型实性肺腺癌中,无1例出现串珠征,25例纵隔淋巴结转移(36.2%),2例纵隔淋巴结大于原发灶(2.9%)。33例周围型肺鳞癌中1例串珠征阳性(2.8%),该例肺门淋巴结明显小于肺原发灶,33例中13例纵隔淋巴结转移(39.4%),6例纵隔淋巴结大于原发灶(16.7%)。经统计分析,串珠征在周围型 SCLC与周围型肺鳞癌中差异无统计学意义,周围型 SCLC与周围型肺腺癌、肺鳞癌在纵隔淋巴结转移率及纵隔淋巴结大于肺原发灶的阳性率差异均有统计学意义。结论串珠征在一定程度上反映 SCLC 的生物学特性,在周围型SCLC与周围型肺腺癌、肺鳞癌的鉴别诊断中有重要价值,应结合纵隔淋巴结大小。     

不典型肺结核CT诊断

分析不典型肺结核CT表现,并探讨其CT诊断价值.材料和方法:回顾性分析不典型肺结核63例,所有病例均得到证实,CT扫描包括常规层厚和薄层扫描或HRCT扫描,52例行增强扫描.结果:不典型CT表现有6种,粟粒性病变缺乏临床症状8例,肺炎实变型16例,磨玻璃密度阴影4例,气管支气管结核20例,结节或肿块9例,纵隔淋巴结结核6例.结核诊断率39.7%(25例),误为肿瘤19.0%(12例).结论:不典型肺结核CT表现多样,类似肺炎和肺癌,多数诊断困难.     

小细胞肺癌的CT表现与诊断途径

目的探讨小细胞肺癌（SCLC）的CT表现、分型及诊断途径。方法对220例SCLC进行X线CT回顾性分析,并与54例病理观察相对照,讨论SCLC的CT表现与病理基础。结果肺内肿块、肺门与纵隔广泛性淋巴结肿大,而肺不张少见,是SCLC的CT表现特点,CT诊断的可能性达80.5%,结合经皮针刺活检阳性率可达91.1%。结论CT平扫结合CT导向经皮针刺活检是SCLC确诊的主要途径。     

The superior vena cava syndrome caused by malignant disease. Imaging with multi-detector row CT

OBJECTIVE: The superior vena cava (SVC) obstruction by malignant diseases is either by direct invasion and compression or by tumour thrombus of the SVC. Whatever is its cause, obstruction of the SVC causes elevated pressure in the veins draining into the SVC and increased or reversed blood flow through collateral vessels. Severity of the syndrome depends on the collateral vascular system development. Therefore, imaging of the collateral veins with variable location and connection is important in determining the extension and management of the disease. Our aims are to describe collateral vessels of the superior vena cava syndrome (SVCS) related with the malignant diseases and to assess the ability of multi-detector row CT with multiplanar and 3D volume rendering techniques in determining and describing collateral circulations. MATERIALS AND METHODS: We present CT angiography findings of seven patients with small cell carcinoma of the lung (n = 2), squamous cell carcinoma of the lung (n = 3), Hodgkin disease of the thorax (n = 1), and squamous cell carcinoma of the oesophagus (n = 1). The patients received contrast-enhanced CT scans of the chest and abdomen on a multi-detector row CT during breath holding at suspended inspiration. RESULTS: CT images revealed the cause and level of the SVC obstruction in all patients with axial and multiplanar reconstructed images. The SVC showed total obstruction in five patients and partial obstruction in two patients. The most common experienced collateral vessels were azygos vein (6), intercostal veins (6), mediastinal veins (6), paravertebral veins (5), hemiazygos vein (5), thoracoepigastric vein (5), internal mammary vein (5), thoracoacromioclavicular venous plexus (5), and anterior chest wall veins (5). While one case showed the portal-systemic shunt, V. cordis media and sinus coronarius with phrenic veins were enlarged in two cases, and the left adrenal vein was enlarged in a patient. In one case, the azygos vein with reversed blood flow was drained into both inferior vena cava and hemiazygos vein with the left renal vein. CONCLUSION: Multi-detector row CT with multiplanar and 3D imaging is an effective tool in evaluation of the SVCS and has a greater advantage than the other imaging techniques. 3D volume rendering is a useful technique in determining and describing collateral circulations in addition to the primary disease process.     

肺低分化腺癌的影像学表现

目的 了解肺低分化腺癌的影像学表现特征及发病率的变化趋势。材料与方法 搜集1989-1999年间肺低分化腺癌患者186例,其中有影像学表现：（1）中央型病变36例（22.9%),其中腔内外生长的气管肿物2例,腔内型病变1例,肺门肿物及阻塞性改变33例;伴广泛纵隔、肺门淋巴结肿大5例,（2）周围型病变121例（77.1%),最大径为1-10cm,中位值4cm。病灶≥4cm者76例（62.8%),浸润性病变5例（4.1%),空洞4例（3.3%)。（3）跨叶33例。（4）纵隔淋巴结肿大45例（29.0%)。大团融合纵隔肿大淋巴结7例（4.5%)。（2）1989-1999年间,腺癌占同期肺癌的20.4%,肺低分化腺癌占同期肺腺癌的14.5%（1979-1986年为7.7%,1989-1994年为13.1%,1995-1999年为17.0%）。结论 （1）肺低分化腺癌中,仅少数（29.0%)为典型腺癌影像学表现（小结节、分叶、毛刺）,非典型表现者占71.0%,包括中央型病变、周围型大肿物、浸润病变、空洞、跨叶。（2）CT示纵隔引流区成簇小淋巴结,应警惕有转移之可能。（3）本组肺腺癌在肺癌中所占比例和过去相仿,而肺低分化腺癌在肺腺癌中所占比例却有增高趋势。     

Computed tomography findings in fibrosing mediastinitis

AIM: To describe the CT features of fibrosing mediastinitis. MATERIALS AND METHODS: The clinical notes, histology, and CT images from 12 patients with fibrosing mediastinitis were reviewed. Clinical data regarding the presentation and suspected aetiology were correlated with location of mediastinal disease, calcification, effect on mediastinal structures, and additional pulmonary findings on computed tomography (CT). RESULTS: The mean age was 40.5 years, with seven female and five male patients. The most common presenting symptom was shortness of breath. Fibrosing mediastinitis diffusely infiltrated the mediastinum in five patients and was localized in seven. Calcification was present in two cases. Eleven of 12 cases had narrowing of mediastinal structures, including five with pulmonary artery narrowing, five with superior vena cava obstruction, four with bronchial narrowing, three with tracheal narrowing, and one with narrowing of the pulmonary vein. The disease was considered idiopathic in seven cases with a demonstrable aetiology in five cases. Eight out of 12 patients had additional pulmonary findings, including all patients with a known aetiology. CONCLUSIONS: In the present series of patients, fibrosing mediastinitis more commonly presented as a localized mediastinal mass than as diffuse mediastinal disease, with the anterior mediastinal compartment most frequently involved. Most cases were idiopathic compared with the majority of previous cases at this institution being ascribed to tuberculosis. There is a high incidence of concomitant pulmonary findings, in particular when an identifiable aetiology is present. Obstruction of vital structures frequently gives rise to complications.