细支气管肺泡癌的CT诊断与误诊

目的 回顾性分析细支气管泡癌（ＢＡＣ）的ＣＴ表现的误诊原因,提高影像诊断准确率。材料与方法 ４２例经寅理证实的ＢＡＣ,根据ＣＴ表现分为结节型、实变型和多结节型,为２３．１６和３例,其中误诊１２例（２８．６％）。结合文献资料分析各型肺泡癌的ＣＴ征象。结果 结节型ＢＡＣ主要表现为：结节位于肺外围（９５．７％）,有分叶（９１．３％）、毛刺（６９．６％）、空泡征或支气管气相（６５．２％）、密度不均（６５．     

Mucinous versus nonmucinous rectal carcinomas: differentiation with MR imaging.

PURPOSE: To determine if quantitative and qualitative magnetic resonance (MR) imaging measures can help differentiation of mucinous from nonmucinous rectal tumors. MATERIALS AND METHODS: In 26 patients with pathologically proved mucinous (n = 9) and nonmucinous (n = 17) rectal tumors, MR imaging was performed with T1-weighted spin-echo (SE) and T2-weighted fast SE sequences in all patients and with a gadolinium-enhanced T1-weighted sequence in 18. With use of the signal intensity (SI) measurements in the tumors and reference tissues, tumor-to-muscle, tumor-to-fat, and tumor-to-urine SI ratios were calculated. In addition, the SI and contrast-enhancement patterns in the tumors were assessed qualitatively by three blinded readers. RESULTS: Mucinous tumors had a much higher SI on the T2-weighted fast SE images. Tumor-to-muscle, tumor-to-fat, and tumor-to-urine SI ratios were significantly higher in the mucinous compared with the nonmucinous tumors (P = .0004, P = .0008, and P = .00002, respectively). Qualitative evaluation of the SI correlated well between readers 1 and 2 (r = 0.93), readers 1 and 3 (r = 0.94), and readers 2 and 3 (r = 0.91). Agreement for the contrast-enhancement patterns was 67%, 72%, and 67%, respectively, with most mucinous tumors having predominantly high SI and a peripheral contrast-enhancement pattern. CONCLUSION: Mucinous and nonmucinous rectal tumors can be differentiated with MR imaging because mucinous tumors show high SI on T2-weighted fast SE images.     

Pulmonary atelectasis: signal patterns with MR imaging

To assess the signal characteristics of different types of pulmonary atelectasis on magnetic resonance (MR) images, the authors studied obstructive atelectasis (OA) in 17 patients and nonobstructive atelectasis (NOA) in 25 patients. All patients underwent electrocardiographically gated MR imaging studies of the thorax with standard spin-echo sequences. No signal differences were observed between either type of atelectasis on T1-weighted images. Conversely, OA and NOA appeared significantly different on spin-density-weighted images (P less than .001) and on T2-weighted studies (P less than .0001). On T2-weighted images, all 17 cases of OA appeared hyperintense, whereas 22 of 25 cases of NOA demonstrated a very low signal intensity. Differences in the pathophysiology of OA and NOA presumably account for this observation. In OA, alveolar air is totally resorbed and secretions accumulate in the obstructed lung. The resulting increase in free fluid prolongs the T2 relaxation times and leads to high signal intensity on T2-weighted images. In NOA, the short T2 relaxation time of lung tissue in the absence of secretions and potential magnetic susceptibility effects due to residual air are likely to be responsible for the low T2 signal pattern.     

Computed tomography features of primary pulmonary non-Hodgkin's lymphoma.

AIM: To characterize computed tomography (CT) features of primary pulmonary lymphoma (PPL). METHODS: The CT films of six patients (five men, one woman; 63.2 +/- 14.5 years) with low grade non-Hodgkins PPL were evaluated for alveolar opacities (lobar consolidation, masses or nodules, and ill-defined consolidations), peribronchial disease or bronchial wall thickening, mediastinal nodes and pleural effusion. RESULTS: Multilobar bilateral, multilobar unilateral, and unilobar unilateral involvement were present in three, one and two cases respectively. CT features were: ill-defined mainly subpleural consolidations (n = 4), mass-like consolidation (n = 1), lobar consolidation (n = 1), and pleural effusion (n = 1). Minor peribronchial disease was seen in two patients, heterogeneous enhancement in four patients, and CT-angiogram sign in one patient. There were no lymphadenopathy or lung nodules. Although the pleura were inseparable from subpleural disease, pleural enhancement was noted on magnetic resonance imaging (MRI) of a patient with lobar lymphoma. CONCLUSION: PPL is characterized by ill-defined alveolar opacities that are usually multifocal. Peribronchial disease, proximal bronchiectasis and positive CT-angiogram sign are ancillary features. MRI may be useful in further evaluation with respect to pleural or chest wall involvement.     

MR imaging of pneumonia in immunocompromised patients: comparison with helical CT

OBJECTIVE: A T2-weighted turbo spin-echo sequence was compared with CT in immunocompromised patients with opportunistic pneumonia. SUBJECTS AND METHODS: Sixteen patients with pneumonia shown on helical CT were examined using MR imaging within 2 days. MR examinations were performed on a 1.5-T system with a transversal T2-weighted ultrashort turbo spin-echo sequence using expiratory gating and diastolic triggering. Two radiologists reviewed the MR and CT images independently. The number, localization, and morphology of lesions were noted. MR image quality was rated using a 4-point scale. RESULTS: The results of the CT and MR examinations concerning the number and morphology of pulmonary lesions caused by pneumonia were identical in 75% of the patients (n = 12). MR imaging was able to depict all typical features of pneumonia including different stages of parenchymal infiltration (ground-glass versus consolidation). MR imaging depicted early necrotizing pneumonia not shown on contrast-enhanced CT in 25% of the patients (n = 4); 82% of the MR examinations were rated as excellent (1 point) or good (2 points). CONCLUSION: T2-weighted turbo spin-echo imaging is able to depict characteristic features of pneumonia and shows excellent results compared with CT. This MR technique offers advantages in patients with pneumonia because of its higher sensitivity for necrotizing pneumonia.     

Colorectal mucinous carcinoma: findings on MRI

PURPOSE: The purpose of this work was to define the characteristic MR features of colorectal mucinous carcinomas and to correlate the mucin pool with the signal intensity of this tumor. METHOD: MRI of 12 cases of pathologically proven colorectal carcinoma containing mucin was evaluated. We analyzed the signal intensity of tumor on T1- and T2-weighted MR images and correlated the area of intratumoral high signal intensity on T2-weighted images with the mucinous pool on the pathologic specimens. Two radiologists independently estimated the area of high signal intensity in the tumor on T2-weighted images and one pathologist estimated the amount of mucinous pool in the pathologic specimen. RESULTS: In 9 (75%) of 12 cases, focal or diffuse high signal intensity areas were detected on T2-weighted fast spin echo images. In seven cases in which mucin pools were seen macroscopically, partial (n = 3) or diffuse high signal intensity areas were noted on the T2-weighted images. Among the five cases in which microscopic mucinous pools were detected on the pathologic slides, three cases showed no high signal foci on MR images, and in the remaining two cases, high signal intensity areas were noted as small foci. CONCLUSION: Intratumoral high signal intensity on T2-weighted fast spin echo MR images occurs in mucinous carcinomas and correlates with the mucin pools on pathologic specimens.     

Early biliary complications of laparoscopic cholecystectomy: evaluation on T2-weighted MR cholangiography in conjunction with mangafodipir trisodium-enhanced 3D T1-weighted MR cholangiography

OBJECTIVE: Our aim was to assess preliminary experience with combined conventional T2-weighted and mangafodipir trisodium (MnDPDP)-enhanced T1-weighted MR cholangiography in evaluating early biliary complications of laparoscopic cholecystectomy. SUBJECTS AND METHODS: Conventional heavily T2-weighted MR cholangiography with MnDPDP-enhanced T1-weighted MR cholangiography and ERCP were performed in seven patients with high clinical suspicion of biliary complications after laparoscopic cholecystectomy. The final diagnoses of complications were classified according to the presence and degree of bile duct injury, bile leakage, and retained stones. RESULTS: The diagnoses on MR cholangiography were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 3), partial strictures of the common bile duct with bile leakage (n = 1), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). The final diagnoses at surgery (n = 2) and ERCP (n = 5) were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 2), partial strictures of the common bile duct with bile leakage (n = 2), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). MR cholangiography accurately yielded the same findings as the final diagnoses, except in one case with partial stricture of the bile duct with bile leakage (overdiagnosed as complete occlusion on MR cholangiography). CONCLUSION: Combined conventional T2-weighted and MnDPDP-enhanced T1-weighted MR cholangiography may eliminate the use of other studies for the imaging of biliary complications after cholecystectomy if this preliminary data can be verified in a larger study.     

Doppler images of intra-pulmonary shunt within atelectasis in anesthetized children

Background

Doppler images of pulmonary vessels in pulmonary diseases associated with subpleural consolidations have been described. Color Doppler easily identifies such vessels within consolidations while spectral Doppler analysis allows the differentiation between pulmonary and bronchial arteries. Thus, Doppler helps in diagnosing the nature of consolidations. To our knowledge, Doppler analysis of pulmonary vessels within anesthesia-induced atelectasis has never been described before. The aim of this case series is to demonstrate the ability of lung ultrasound to detect the shunting of blood within atelectatic lung areas in anesthetized children.

Findings

Three anesthetized and mechanically ventilated children were scanned in the supine position using a high-resolution linear probe of 6–12 MHz. Once subpleural consolidations were detected in the most dependent posterior lung regions, the probe was rotated such that its long axis followed the intercostal space. In this oblique position, color Doppler mapping was performed to detect blood flow within the consolidation. Thereafter, pulsed waved spectral Doppler was applied in the previously identified vessels during a short expiratory pause, which prevented interferences from respiratory motion. Different flow patterns were identified which corresponded to both, pulmonary and bronchial vessels. Finally, a lung recruitment maneuver was performed which leads to the complete resolution of the aforementioned consolidation thereby confirming the pathophysiological entity of anesthesia-induced atelectasis.

Conclusions

Lung ultrasound is a non-invasive imaging tool that not only enables the diagnosis of anesthesia-induced atelectasis in pediatric patients but also analysis of shunting blood within this consolidation.

     

实变型细支气管肺泡癌的CT表现及病理基础

目的:探讨实变型细支气管肺泡癌(BAC)的CT表现特点。方法:对13例经病理证实的实变型BAC的CT征像及其病理特征进行回顾性分析。结果:13例中,单发肺叶实变8例,多发肺叶或肺段实变3例,单发肺段实变2例;实变肺密度低于心肌8例,伴见血管造影征或血管高密度征7例、支气管气像征9例伴枯树枝征6例;实变肺周见蜂窝肺征9例,磨玻璃征7例,多发小结节2例;少量胸水1例,肺门淋巴结肿大及肺气囊腔各1例。13例中9例CT首诊误诊为肺炎,4例正确诊断。结论:实变肺密度低、蜂窝肺征、血管造影征尤其是血管高密度征、枯树枝征及多发腺泡结节是实变型BAC的主要CT表现特点;磨玻璃影是早期表现,但特异性不大;CT引导肺穿刺活检是较理想的确诊手段。     

细支气管肺泡癌的CT分型及其临床意义

目的 评价细支气管肺泡癌（BAC）的CT分型及其临床意义。资料与方法 搜集经病理证实的BAC43例。按CT和HRCT的表现形式将其分为局限型和弥漫型,并分析局限型和弥漫型BAC的临床表现、CT特征、治疗方案和预后等特点。结果 （1）局限型26例。呈胸膜下区分布,含磨玻璃密度结节和实性密度结节,有分叶、毛刺、胸膜凹陷征、空泡征和细支气管充气征等。临床无症状者17例,咳嗽、痰中带血和胸痛9例。26例进行根治性肺叶切除,术后随访18例,其中死亡7例,生存期16～38个月,平均27．7个月。（2）弥漫型17例。肺实变16例,2个孤立病灶位于2个肺叶1例。实变内见“枯树枝征”11例,“峰窝征”4例,叶间裂膨隆7例;磨玻璃密度影12例,腺泡结节14例,分布于实变影的边缘和／或非实变的肺叶。4例X线胸片仅显示实变病灶而没有显示远离实变区的结节。咳嗽11例,咯大量泡沫痰8例,伴痰中带血3例;憋气7例。肺叶根治性切除3例。随访17例,死亡12例,生存期2～13个月,平均6．1个月。结论 根据CT和HRCT表现,BAC可分为局限型和弥漫型。两型BAC的临床表现、治疗方案和预后皆不同。     

Focal nodular hyperplasia of the liver: MR imaging and pathologic correlation in 37 patients.

Thirty-seven patients with 48 lesions of focal nodular hyperplasia (FNH) underwent preoperative magnetic resonance (MR) examination and surgical resection. Sixteen lesions were imaged at 0.5 T with T1- and T2-weighted spin-echo sequences; 32 lesions were imaged at 2 T with T1-and T2-weighted spin-echo and gradient-recalled-echo sequences. Contrast material-enhanced MR imaging was performed in 20 lesions. MR imaging failed to depict six tumors that were less than 3 cm in diameter. Typical appearance was present in 18 of the 42 (43%) lesions seen at MR. Atypical lesion features included no scar (n = 15), hypointense scar on T2-weighted images (n = 7), pseudocapsule (n = 6), strong hyperintense lesion on T2-weighted images (n = 3), diffuse hyperintensity on T1-weighted images (n = 3), and heterogeneous lesion (n = 1). Comparison between findings at MR imaging and at histopathologic examination was performed in 38 lesions: There was good correlation between presence and size of the scar on both examinations. In 13 of 20 (65%) of the hyperintense scars on T2-weighted images, edema was prominent, whereas in five of the seven (71%) hypointense scars on T2-weighted images, edema was absent or low.     

Abnormalities of the pulmonary veins: evaluation with MR imaging and comparison with cardiac angiography and echocardiography

Seventy-seven patients underwent T1-weighted spin-echo magnetic resonance (MR) imaging. Group 1 (n = 56) consisted of patients with various types of congenital heart disease but normal pulmonary veins. Group 2 (n = 22) consisted of patients with the following conditions: partial anomalous pulmonary venous connection (n = 11), total anomalous pulmonary venous connection (n = 5), cor triatriatum (n = 4), or pulmonary vein stenosis (n = 2). In group 1, the sites of connections of all four pulmonary veins were identified with MR imaging in 88% of cases; the connections of at least three pulmonary veins were seen in all patients. In group 2, the prospective detection rate of pulmonary venous abnormalities with MR imaging was 95%. The prospective detection rates of pulmonary venous abnormalities with cardiac angiography (n = 13) and echo-cardiography (n = 13) were 69% and 38%, respectively. This study indicates that MR imaging can accurately demonstrate the normal pulmonary veins and abnormalities of the pulmonary veins.     

MR imaging of the brachial plexus: current imaging sequences,normal findings,and findings in a spectrum of focal lesions with MR-pathologic correlation

Currently in many centers, magnetic resonance (MR) imaging is the technique of choice for the assessment of brachial plexopathies. The anatomy of the brachial plexus is complex, and is surrounded by other anatomic structures, making artifact-free imaging quite challenging. With the faster breathing-independent and breath-hold MR imaging sequences, brachial plexopathies can be assessed with more confidence. Over a 2-year period, 20 patients underwent MR imaging of the brachial plexus at our department. MR imaging was based on a comprehensive protocol, including T(1)-weighted gradient echo, T(2)-weighted single-shot fast spin-echo, and gadolinium-enhanced T(1)-weighted gradient echo with fat suppression. Nine of the 20 patients had proved diagnoses at pathology, and included schwannoma (n = 2), ganglioneuroblastoma (n = 1), hemangioma (n = 1), metastatic breast cancer (n = 2), Pancoast tumor (n = 1), and metastatic lung cancer (n = 2). Most of the lesions had presenting symptoms, such as pain, swelling, paresthesia, and arm weakness. At MR imaging, the location and characteristics of the lesions on different types of T(1)-weighted and T(2)-weighted sequences were described with pathologic correlation.     

Correlation between computed tomographic and magnetic resonance imaging findings of parenchymal lung diseases

Computed tomography (CT) is considered to be the gold standard method for the assessment of morphological changes in the pulmonary parenchyma. Although its spatial resolution is lower than that of CT, MRI offers the advantage of characterizing different aspects of tissue based on the degree of contrast on T1-weighted image (WI) and T2-WI. In this article, we describe and correlate the MRI and CT features of several common patterns of parenchymal lung disease (air trapping, atelectasis, bronchiectasis, cavitation, consolidation, emphysema, ground-glass opacities, halo sign, interlobular septal thickening, masses, mycetoma, nodules, progressive massive fibrosis, reverse halo sign and tree-in-bud pattern). MRI may be an alternative modality for the collection of morphological and functional information useful for the management of parenchymal lung disease, which would help reduce the number of chest CT scans and radiation exposure required in patients with a variety of conditions.     

艾滋病合并马红球菌肺炎的胸部影像表现

目的 探讨艾滋病合并马红球菌肺炎的胸部影像表现.方法 回顾性分析3例艾滋病合并马红球菌肺炎的胸部影像表现.结果 3例X线胸片均可见斑片状渗出实变和小结节,见大面积实变及空洞2例.CT显示大面积(叶、段分布)实变及多发空洞、斑片状渗出实变、小叶中心结节和树芽征各2例,支气管扩张1例.结论 肺浸润实变伴空洞及散发结节是艾滋病合并马红球菌肺炎的常见胸部影像表现.

Abstract：

Objective To study the imaging appearances of Rhodococcus equi pneumonia in three patients with acquired immunodeficiency syndrome ( AIDS). Methods Thoracic imaging appearances of Rhodococcus equi pneumonia in three patients with AIDS were retrospectively analyzed. Results The chest radiograph showed patchy consolidations and small nodules ( n = 3 ), large consolidations with multiple cavitations ( n = 2). CT showed large lobar or segmental consolidations with multiple cavitations (n=2),patchy consolidations (n=2), bronchiectasis (n=1), multiple small centrilobular nodules ( n = 2) and tree-in-bud patterns (n = 2). Conclusion The most common radiological findings in AIDS patients with Rhodococcus equi pulmonary infection are large consolidations with multiple cavitations and multiple centrilobular nodules.     

Intraocular tumors: evaluation with MR imaging

Sixty-seven ocular tumors were studied with magnetic resonance (MR) imaging and computed tomography (CT). These tumors included primary uveal melanoma (n = 55), circumscribed choroidal hemangioma (n = 3), diffuse choroidal hemangioma (n = 1), retinal capillary hemangioma (n = 1), medulloepithelioma (n = 1), choroidal nevus (n = 1), retinoblastoma (n = 1), and choroidal metastases (n = 4). MR imaging demonstrated all these lesions, while CT demonstrated 88%. Associated retinal detachment was more easily distinguished from the neoplasms with MR imaging. Extrascleral extension of melanoma and hemorrhagic cystic necrosis within the melanoma were clearly demonstrated with MR imaging, but not with CT. Ninety-three percent of melanomas were markedly hyperintense, compared with the intensity of the vitreous body, on T1-weighted images and hypointense on T2-weighted images. All metastatic lesions were isointense on T1-weighted images and hypointense on T2-weighted images. The circumscribed choroidal hemangiomas were hyperintense on T1-weighted images and isointense on T2-weighted images. MR imaging is superior to CT in detection of intraocular tumors and may be more specific in diagnosis.     

Goodpasture综合征的HRCT诊断

目的 探讨Goodpasture综合征的高分辨率CT(HRCT)影像学表现及随访变化特点.方法 回顾性分析本院15例经临床确诊的Goodpasture综合征患者的HRCT表现及随访复查情况.分别记录病变范围、形态及动态变化情况.结果 病变累及2叶1例,累及3叶2例,累及4叶5例,累及5个肺叶7例.右肺上叶最易受累.双侧以肺门为中心分布实变伴边缘磨玻璃密度影(GGO)7例,5例呈双肺弥漫分布GGO.病变实变区短期复查呈GGO改变,GGO能短期吸收.结论 咯血并贫血患者,双肺多叶的肺内实变混杂GGO,不累及肺尖及肺外带胸膜下是Goodpasture综合征的特征性表现.HRCT是Goodpasture综合征诊断和疗效观察的有效手段.     

Biliary dilatation: differentiation of benign from malignant causes--value of adding conventional MR imaging to MR cholangiopancreatography

PURPOSE: To determine the value of conventional T1 - and T2-weighted images and gadolinium-enhanced dynamic magnetic resonance (MR) images as a supplement to MR cholangiopancreatographic (MRCP) images in differentiation of benign from malignant causes of biliary dilatation. MATERIALS AND METHODS: MR studies in 62 patients with biliary dilatation with proved causes included conventional T1- and less heavily T2-weighted images, as well as gadolinium-enhanced dynamic images and heavily T2-weighted MRCP images. Two radiologists reviewed MRCP images alone, MRCP images with nonenhanced T1 - and T2-weighted MR images, and MRCP images with nonenhanced and gadolinium-enhanced dynamic images. RESULTS: For differentiation of benign from malignant causes of biliary dilatation, the area under the receiver operating characteristic curve (A(z)) was significantly (P < .05) larger for MRCP images interpreted with T1 - and T2-weighted images (0.9547 for reader 1, 0.8404 for reader 2) than for MRCP images alone (0.8144 for reader 1, 0.8122 for reader 2). The addition of gadolinium-enhanced dynamic MR images to MRCP images with nonenhanced T1- and T2-weighted images did not significantly increase accuracy (A(z) = 0.9554 for reader 1 and 0.8650 for reader 2), but the level of confidence was increased in 17%-24% of cases. CONCLUSION: Use of nonenhanced T1- and less heavily T2-weighted images with MRCP images significantly improved the diagnostic accuracy of MR examinations of pancreaticobiliary disease.     

MR imaging of solitary pulmonary lesion: emphasis on tuberculomas and comparison with tumors

The aim of this study was to determine whether solitary pulmonary tuberculoma and malignant tumor can be differentiated on the basis of magnetic resonance (MR) signal intensity. Twenty-eight patients with solitary pulmonary lesions were prospectively studied with MR imaging: T1-weighted, enhanced T1-weighted, proton density-weighted, and T2-weighted spin echo images were obtained. The confirmation methods used were computed tomography (CT)-guided biopsy in seven patients with lung cancer and four patients with tuberculosis; surgery in ten patients with lung cancer and five patients with tuberculosis; and laboratory data in two patients with tuberculosis. Morphologic features and MR signal intensity were examined in detail. As the test for detection of tuberculoma, signal difference on T2-weighted images was carefully analyzed. The signal intensity ratio of the nodule to thoracic muscle signal intensity was measured. The signal intensities obtained from the lung cancers and tuberculomas were variable on pre-and post-enhanced T1-weighted images and proton density-weighted images. Masses were hypointense in 2 of 17 patients with lung cancer and in 9 of 11 patients with tuberculoma on T2-weighted images (sensitivity 82%, specificity 89%, accuracy 87%). The mean signal intensity ratios of the tuberculomas to muscle were significantly lower than those of malignant tumors on T1-weighted, enhanced T1-weighted, proton density-weighted, and T2-weighted images (P < 0.0001). After gadolinium-DTPA enhancement, 2 malignant tumors and 7 tuberculomas showed a marginal rim enhancement pattern, whereas 15 malignant tumors and 2 tuberculomas revealed a diffuse enhancement. The results of MR imaging were consistent with those of CT in 84% of the patients. MR imaging is a helpful adjunctive method in terms of differentiating a tuberculoma from a malignant tumor.     

Radiation fibrosis: differentiation from recurrent tumor by MR imaging

Magnetic resonance (MR) images of 21 patients who had undergone radiation therapy were analyzed and compared with those of 15 patients who had untreated tumors. T2-weighted images (TR = 1,500 msec, TE = 90 msec) were most helpful in distinguishing recurrent tumor from radiation fibrosis. Radiation fibrosis, like muscle, usually remained low in signal intensity on T2-weighted images, while tumor demonstrated higher signal intensity. In no patient was the signal intensity of tumor the same or less than muscle on the T2-weighted images. However, relatively high signal intensity on T2-weighted images is not specific for tumor recurrence and may be seen in acute radiation pneumonitis, infection, hemorrhage, and even pulmonary radiation fibrosis.