Pulmonary tumorlets: CT findings

OBJECTIVE: Pulmonary tumorlets are defined in pathologic terms as benign localized neuroendocrine cell proliferations a few millimeters in size that are usually associated with damaged and ectatic small airways. The purpose of this study was to determine the frequency with which pulmonary tumorlets can be seen on CT and to describe their CT appearance. CONCLUSION: In 33 patients with proven tumorlets, a nodule was visible on CT in the same region as that of the resected specimen. Despite its ominous-sounding name, a pulmonary tumorlet represents benign tissue that may manifest as a subcentimeter pulmonary nodule and should be considered in the differential diagnosis of small pulmonary nodules visible on CT.     

Pulmonary lymphangioleiomyomatosis: CT findings

Lymphangioleiomyomatosis, a rare disease occurring in women of childbearing age, is characterized by proliferation of smooth muscle in pulmonary lymphatic channels and mediastinal and abdominal lymph nodes. Chest radiographs typically reveal interstitial disease with normal lung volume. Pneumothorax and pleural effusions may be present. CT scans in eight patients with biopsy-proved pulmonary lymphangioleiomyomatosis were reviewed. The prominent feature of the disease was multiple thin-walled cysts throughout the lungs, best visualized on scans made with 1.5-mm collimation. Mediastinal and/or retrocrural lymphadenopathy, often not appreciated on the chest radiograph, was present in four of eight patients. CT can suggest a diagnosis of lymphangioleiomyomatosis when diagnosis by clinical presentation and chest radiographs is uncertain.     

Pulmonary hamartoma: CT findings

Forty-seven patients with a proved (n = 31) or presumed (n = 16) diagnosis of pulmonary hamartoma were studied prospectively by thin-section computed tomography (CT). CT criteria for hamartoma included a diameter of 2.5 cm or less, a smooth edge, and focal collections of fat or fat alternating with areas of calcification. No case of cancer (n = 283) or metastatic disease (n = 72) fulfilled these criteria. Seventeen hamartomas with no detectable calcium or fat were not diagnosed by means of CT. Two other lesions contained diffuse calcium deposits. In 28 lesions, a CT diagnosis of hamartoma was based on the detection of fat (n = 18) or calcium plus fat (n = 10). Twelve such cases were proved histologically by means of thoracotomy or needle biopsy; the remainder, including eight in asymptomatic patients aged 65 years or older, were managed with conservative follow-up.     

Intrahepatic arterioportal shunt: helical CT findings

The purpose of this study was to characterize the appearance of intrahepatic arterioportal shunts (APS) on two-phase helical CT, with emphasis on the importance of the hepatic arterial-dominant phase (HAP) to demonstrate perfusion disorders. We review eight cases of APS diagnosed by helical CT in our institution from January 1996 to March 1997 and describe the CT findings that established diagnosis. Five of them were confirmed by angiography. In seven (87.5 %) cases of APS we found early enhancement of the peripheral portal branches during the HAP of helical CT, whereas the superior mesenteric and splenic veins remained unenhanced. In five (62.5 %) cases of APS, transient, peripheral, triangular parenchymal enhancement was depicted during the HAP of helical CT; in four of these cases there was associated early enhancement of the portal branches. Helical CT can show perfusion alterations that might remain undiagnosed with conventional CT. An understanding of the hemodynamic changes that occur in APS can help in the interpretation of focal transient hepatic parenchymal enhancement and to differentiate APS from hypervascular tumors. We believe that the helical CT findings described herein are characteristic enough to suggest the diagnosis of APS. Received: 9 February 1998; Revision received: 25 May 1998; Accepted: 7 September 1998     

Pulmonary cryptococcosis: CT and pathologic findings

PURPOSE: The purpose of this work was to describe the CT and pathologic findings of pulmonary cryptococcosis. METHOD: CT scans of 11 patients (7 immunocompromised, 4 immunocompetent) with proven pulmonary cryptococcosis were analyzed for number, morphologic characteristics, and distribution of parenchymal abnormalities as well for presence of lymphadenopathy and pleural effusion. Pathology of lung specimens obtained by open biopsy or resection (n = 5) and transbronchial biopsy (n = 1) was reviewed by one dedicated pulmonary pathologist. RESULTS: Pulmonary nodules, either solitary or multiple, were the most common CT finding, present in 10 of 11 patients (91%); associated findings included masses (n = 4), CT halo sign (n = 3), and consolidation (n = 2). On histologic examination, focal areas of ground-glass attenuation surrounding or adjacent to nodules were found to represent airspace collections of macrophages and proteinaceous fluid. CONCLUSION: Pulmonary cryptococcosis should be considered in the differential diagnosis of solitary or multiple pulmonary nodules (with or without associated CT halo sign), particularly in immunocompromised patients.     

Pulmonary alveolar proteinosis: CT findings

In pulmonary alveolar proteinosis (PAP), a proteinaceous material accumulates in the alveolar air spaces, causing hypoxemia, restrictive lung disease, and dramatic abnormalities on chest radiographs. Complications are unusual, but of the ones that do occur, infection, particularly with Nocardia asteroides, and fibrosis are the most common. Few computed tomographic (CT) studies of this condition have been reported. The CT scans of nine patients with PAP were reviewed. Varying combinations of air-space and interstitial patterns were seen. The CT appearance of air-space disease ranged from ill-defined nodules to patchy consolidation to large regions of confluence. Air-space consolidation was sometimes sharply demarcated from surrounding normal lung tissue, which created a geographic pattern. Despite the predominance of air-space patterns, air bronchograms were not a prominent feature. CT showed the interstitial component of disease and the extent of disease more clearly than did plain radiography. In two cases, CT demonstrated focal pneumonia that was not visible on the radiographs.     

Pulmonary embolism: prognostic CT findings

PURPOSE: To retrospectively determine whether three computed tomographic (CT) findings-ventricular septal bowing (VSB), ratio between the diameters of right ventricle (RV) and left ventricle (LV), and embolic burden-are associated with short-term death, defined as in-hospital death or death within 30 days of CT, whichever was longer, due to acute pulmonary embolism (PE). MATERIALS AND METHODS: Institutional Review Board approval was obtained, and patient information was reviewed in compliance with HIPAA regulations. A total of 1193 patients with CT scans positive for PE from January 1, 1997, to December 31, 2002, who had given authorization for retrospective research were included. Scans were independently reviewed by two observers. CT findings were compared with risk of death by using univariate analysis (chi(2) statistic) and multivariate logistic regression. Interobserver variability (kappa statistic or intraclass correlation coefficient), sensitivity, and specificity of CT findings for predicting death were calculated. A third observer reviewed discrepant cases post hoc. RESULTS: Fifty-four percent of patients were women and 46% were men (mean age, 63 years +/- 16). For observer 1, VSB was associated with death in univariate (odds ratio [OR], 1.98; P = .04) and multivariate modeling (OR, 1.97; P = .05). Interobserver variability was only fair (kappa = 0.54) for VSB, and observer 2 found no association with death (OR, 1.52; P = .22). For both observers, VSB had low sensitivity (21% and 18%) and high specificity (88% and 87%) for predicting death. Neither RV/LV diameter ratio nor embolic burden was associated with increased risk of death. For observer 3, VSB was associated with death in univariate (OR, 2.10; P = .05) and multivariate analyses (OR, 2.18; P = .05). CONCLUSION: CT-depicted VSB is predictive of death due to PE, but with low sensitivity and high interobserver variability. RV/LV diameter ratio and embolic burden are not associated with short-term death due to PE.     

肺淋巴管肌瘤病HRCT诊断价值

目的：回顾性分析肺淋巴管肌瘤病的HRCT特征。方法：总结5例经病理证实并行HRCT检查的肺淋巴管肌瘤病，2例行支气管镜肺活检，2例经胸腔镜，1例经皮肺活检确诊。4例行吸气末HRCT扫描，其中1例表现阴性者加扫呼气末HRCT。分析X线胸片、常规CT以及HRCT表现特征。结果：X线胸片3例呈弥漫性网状阴影，1例可见蜂窝状囊腔，1例表现正常；HRCT4例为均匀散在性分布的10—20mm大小的薄壁囊腔，其中2例囊腔之间可见正常肺组织，1例吸气末HRCT正常，而呼气末HRCT可见到“空气潴留征”，提示有小气道狭窄。肺功能检查均有不同程度的阻塞型通气障碍和弥散功能异常。结论：尽管本病的最后确诊要依靠肺活检病理证实，但其HRCT具有较特征性的表现，呼气末HRCT可发现早期小气道狭窄引起的空气潴留，从而指导临床有目的进行纤维支气管镜活检，有助于早期诊断。     

Pulmonary alveolar microlithiasis: CT findings

We present five cases with confirmed diagnosis of pulmonary alveolar microlithiasis that illustrate the appearance of this rare chronic lung disease on conventional and high-resolution CT. Pulmonary alveolar microlithiasis is characterized by widespread intraalveolar calcification of both lungs. Conventional CT confirmed the inferior and posterior predominance of the lesions in four of our cases and showed an exceptionally high concentration of microliths in the subpleural parenchyma and along the bronchovascular bundles. High-resolution CT revealed a perilobular and bronchovascular distribution of the disease process at the level of the secondary pulmonary lobule. This pattern correlated closely with pathologic findings.     

Pulmonary lymphangioleiomyomatosis: high-resolution CT findings

Lymphangioleiomyomatosis (LAM) of the lung is a very rare disease. There are obvious discrepancies in the literature concerning the appearance of LAM on CT scans of the lung. This study adds the imaging findings of 11 patients and demonstrates how the imaging findings changed over time in four patients. Twenty-two CT examinations, and radiographs that had been obtained close to the CT examinations, of 11 patients with LAM confirmed by open lung biopsy were retrospectively evaluated with particular attention to the size of cystic lesions and wall thickness. Furthermore the CT scans were analysed for the type of pulmonary infiltration process and its distribution, presence or absence of pleural effusion, pneumothorax and lymph node enlargement. Clinical and CT follow-up studies were available in four patients. The CT scans revealed an increase in the interstitial pattern in all patients. Architectural distortion was seen in two patients and cystic lesions were present in all. The size of the cysts varied from small lesions to bullous emphysema. The cystic lesions revealed a wall thickness up to 2 mm but a wall was not perceptible in all. Pneumothorax was seen in only two patients; pleural effusion was seen in two patients. CT examination of patients with LAM reveals neither a uniform nor a pathognomonic appearance. In the early stages of LAM or in cases with interstitial changes the differential diagnosis of centrilobular emphysema or idiopathic pulmonary fibrosis seems to be more difficult than most authors believe. Received: 28 July 1997; Revision received: 20 October 1997; Accepted: 25 March 1998     

Pulmonary lymphangitic carcinomatosis: CT and pathologic findings

The authors retrospectively reviewed the computed tomographic (CT) scans, biopsy specimens, autopsy results, and lobectomy specimens of 21 patients who had lymphangitic carcinomatosis. Ten-millimeter collimation CT scans were obtained from all patients, and selected 1.5-mm CT scans were obtained from ten patients. In five patients, the diagnosis was established with open lung biopsy, lobectomy, or autopsy; in nine, with bronchial biopsy or transbronchial biopsy; and in seven, with clinical and radiologic criteria. Certain characteristic findings on CT scans were evident: uneven thickening of bronchovascular bundles, thickening of isolated interstitial lines, and the presence of polygonal lines. These findings may be seen on CT scans even if the findings on chest radiographs are normal or nonspecific. The pathologic basis for these characteristic CT findings may relate to tumor thrombi in lymphatic vessels rather than edema and fibrosis, at least in the early stages of disease.     

Pulmonary vein varix: diagnosis with multi-slice helical CT

The diagnosis of a pulmonary vein varix with a recently introduced new CT technology, multi-slice helical CT, is discussed. The advantage of multi-slice helical CT lies in increased thin-slice coverage during a single breath hold, which is the predominant factor limiting scan time. This CT technique facilitates the diagnosis of vascular pulmonary pathology. Received: 6 September 1999; Revised: 16 December 1999; Accepted: 15 February 2000     

Intestinal metastases from gastric adenocarcinoma: helical CT findings

PURPOSE: The purpose of this work was to describe the helical CT findings of intestinal metastasis from gastric adenocarcinoma. METHOD: Twenty-three patients with intestinal metastasis from gastric adenocarcinoma found at helical CT were included. CT findings and clinical and pathologic data were reviewed. RESULTS: The most common characteristic finding was target-like concentric bowel wall thickening (thick inner high-outer low, n = 18) involving multiple long segments with progressive thickening of the enhancing inner layer. Fifteen cases (65%) involved multiple sites, and the ascending colon (n = 12) and rectum (n = 11) were the two most common sites. Peritoneal carcinomatosis (n = 15, 65%) and bowel obstruction (n = 14, 61%) were common associated findings. Regarding the primary lesion, the majority was linitis plastica (n = 16) and poorly differentiated adenocarcinoma with or without signet-ring cell differentiation (n = 14). CONCLUSION: Intestinal metastasis from gastric adenocarcinoma, especially of the linitis plastica type, most commonly showed target-like long segmental wall thickening with a characteristically thick inner enhancing layer on helical CT.     

肺淋巴管肌瘤病多层螺旋CT诊断价值

目的:通过分析肺淋巴管肌瘤病(PLAM)多层螺旋CT(MSCT)的影像特点,旨在探讨其对肺淋巴管肌瘤病(PLAM)的影像诊断价值。方法:回顾性分析12例经病理证实的PLAM的胸部影像表现,包括常规扫描、横轴面薄层重组和冠状面、矢状面多平面重组(MPR)图像。结果:12例成年女性患者胸部MSCT典型征象为:双肺弥漫分布大小不等的类圆形囊腔影,常规层厚图像显示囊腔影的径线5～30mm,较小的囊腔影不能显示明确的薄壁。薄层重组和MPR图像可明确显示囊腔壁,壁厚<2mm,囊壁可见散在的血管断面影和血管穿插其中。气胸5例,乳糜胸3例,1例合并前纵隔淋巴结肿大。结论:MSCT薄层重组和冠状面、矢状面MPR对该病的早期诊断、鉴别诊断具有重要价值,同时也是判断病变进展及预后的有效指标。必要时需行肺活检,以明确病理诊断。     

肠系膜脂膜炎的多层螺旋CT诊断

目的 探讨多层螺旋CT（MSCT）对肠系膜脂膜炎的诊断价值。方法 回顾性分析9例肠系膜脂膜炎的CT表现与诊断，其中3例经组织病理学证实，其余按照CT标准做出诊断。应用MSCT进行腹部平扫和双期增强扫描，并采用1．25mm层厚和1mm重组间隔获得最大密度投影（MIP）和多平面重组（MPR）图像，评价肠系膜、邻近肠管及血管改变。结果 所有肠系膜脂膜炎均起自系膜根部，围绕系膜血管，2例见血管远端明显变细。6例病变可见假包膜征。肠系膜脂膜炎CT值平扫为-47-36HU，增强后动脉期为-41-39HU，门脉期为-41-45HU，差异无统计学意义（P值均〉0．05），平扫时肠系膜脂膜炎密度明显高于腹膜后正常脂肪密度（-91--115HU），差异有统计学意义（P〈0．01）。5例肠系膜脂膜炎病变内可见界限清楚的小结节，增强明显。结论 多层螺旋CT是诊断肠系膜脂膜炎非常有用的影像手段。     

Pulmonary tuberculosis in infants: radiographic and CT findings

OBJECTIVE: As complications of tuberculosis are frequent in infancy, correct diagnosis of tuberculosis in infants is important. The purposes of this study are to summarize radiographic and CT findings of pulmonary tuberculosis in infants and to determine the radiologic features frequently seen in infants with this disease. CONCLUSION: Frequent radiologic findings of pulmonary tuberculosis in infants are mediastinal or hilar lymphadenopathy with central necrosis and air-space consolidations, especially masslike consolidations with low-attenuation areas or cavities within the consolidation. Disseminated pulmonary nodules and airway complications are also frequently detected in this age group. CT is a useful diagnostic technique in infants with tuberculosis because it can show parenchymal lesions and tuberculous lymphadenopathy better than chest radiography. CT scans can also be helpful when chest radiographs are inconclusive or complications of tuberculosis are suspected.     

Budd-Chiari综合征多层CT动态增强扫描及CT血管成像分析

目的探讨Budd-Chiari综合征(BCS)肝脏多层CT动态强化规律及形成机制，分析CT血管成像(CTA)在BCS诊断中的应用价值。方法经DSA证实的28例BCS患者，在DSA检查前1周内行多层CT动态增强扫描，并对其相关血管分别以最大密度投影法(MIP)、容积成像法(VR)和多平面重建法(MPR)进行血管重建。分析BCS患者的肝脏多层CT动态强化规律，并以DSA结果为对照，评价多层CT动态增强扫描及CTA技术在判断血管梗阻平面及显示肝内、外侧支循环中的价值。结果与DSA对照，28例BCS中多层CT扫描准确判断梗阻平面者26例，未能诊断者2例，为膈肌水平以上的下腔静脉膜性阻塞。22例肝静脉梗阻的患者中，CT动态增强扫描表现为肝脏典型斑片状强化者19例，不典型强化者3例，8例出现肝内良性结节，同时还显示门脉分支狭窄、僵直20例，肝动脉增粗14例，肝内侧支静脉开放20例。6例单纯性下腔静脉梗阻患者未出现肝脏异常表现。结论肝内、外侧支静脉的出现与梗阻部位有关。多层CT动态增强扫描能够准确地反映BCS患者肝脏血流动力学变化，结合CTA技术，能够更直观、准确地显示血管梗阻平面及肝内、外侧支循环。     

HIV-related cardiac complications: CT and MRI findings

OBJECTIVE: Cardiovascular complications in patients with HIV infection include myocardial, endocardial, pericardial, and vascular diseases. The complications are caused by the HIV infection itself, opportunistic infections, HIV-related tumors, and the side effects of highly active antiretroviral therapy. The article reviews the CT and MRI findings suggestive of HIV-related cardiovascular diseases. CONCLUSION: The cardiovascular complications of HIV infection frequently overlap, making the diagnosis difficult. CT and MRI are useful for the noninvasive evaluation of these complications.     

Diverticulitis versus colon cancer: differentiation with helical CT findings

PURPOSE: To retrospectively determine the computed tomographic (CT) signs associated with diverticulitis or colon cancer, and to prospectively apply these signs in the differentiation of these diseases. MATERIALS AND METHODS: Fifty-eight CT scans in cases of proved diverticulitis (n = 27) or colon cancer (n = 31) were evaluated retrospectively by radiologists (blinded to the proved diagnosis) for the presence or absence of previously reported CT findings. These findings were correlated with the pathologic or final clinical diagnosis. The retrospective findings were applied in a prospective evaluation with a new set of 72 CT scans. The same five radiologists rendered a diagnosis according to a five-point confidence scale from definitely benign to definitely malignant. Individual and consensus readings were correlated with the final diagnosis. RESULTS: Retrospectively, pericolonic inflammation (P < .01) and segment involvement greater than 10 cm (P < .012) were the most significant findings for diverticulitis; pericolonic lymph nodes (P < .0001) and luminal mass (P < .003) were the most significant findings for colon cancer. Prospectively, an unequivocal diagnosis was made correctly in 16 (40%) of 40 cases of diverticulitis and 21 (66%) of 32 cases of colon cancer. CONCLUSION: When there are no pericolonic lymph nodes adjacent to a segment of colonic wall thickening, with pericolonic inflammatory changes, the most likely diagnosis is diverticulitis. When pericolonic lymph nodes are present, with or without pericolonic edema, the most likely diagnosis is colon cancer.