Abdominal lymphadenopathy: spectrum of CT findings

Many malignant processes cause abdominal lymphadenopathy, and computed tomography (CT) has become the primary modality for its detection. Diagnosis of lymphadenopathy is facilitated by optimal imaging techniques and a knowledge of the various nodal chains, their complex interconnections, and preferential pathways of spread. Optimal techniques include imaging after oral administration of adequate amounts of barium suspension and dynamic scanning after intravenous administration of contrast material with an infusion pump. Although such techniques help prevent misdiagnoses due to normal and anomalous vascular structures, other benign diseases can mimic the CT appearance of malignant lymphadenopathy. The authors emphasize a regional approach for the diagnosis of lymphadenopathy, according to the groupings of retrocrural, retroperitoneal, gastrohepatic ligament, porta hepatis, celiac and superior mesenteric artery, pancreaticoduodenal, perisplenic, mesenteric, and pelvic lymph nodes. Lymphadenopathy is defined as retrocrural nodes greater than 6 mm in short axis, upper abdominal nodes greater than 10 mm, and pelvic nodes greater than 15 mm.     

艾滋病肺门纵隔淋巴结结核的影像学表现

目的探讨获得性免疫缺陷综合征(AIDS)合并肺门和纵隔淋巴结结核的影像学表现。方法回顾性分析9例AIDS合并肺门和纵隔淋巴结结核的影像学表现(包括胸部平片、CT和MR扫描)。全部病例均作了胸部平片、CT扫描，5例作了增强CT扫描，1例作了MR检查。结果AIDS合并肺门和纵隔淋巴结结核时，增大的淋巴结主要位于7区9／9例，4R区7／9例，2R区5／9例。结论AIDS合并肺门和纵隔淋巴结结核的影像学表现为多组淋巴结增大，可相互融合及出现淋巴结外侵犯表现，CT和MR扫描对本病的诊断有重要意义。     

艾滋病合并肺结核CT与病理对照分析

目的：探讨艾滋病合并肺结核的CT影像表现与病理改变及其临床意义。方法：回顾性分析经确诊的13例艾滋病合并肺结核患者的CT影像表现及穿刺活检病理相关资料。13例患者CD4T淋巴细胞计数均小于200/μl。结果：13例肺结核中,CT多表现为结节、肿块影及片状实变影,合并纵隔淋巴结肿大及胸膜炎。病理组织抗酸杆菌染色阳性9例。干酪样坏死及炎性细胞浸润5例,淋巴细胞、纤维组织增生或类上皮细胞浸润5例,肺组织坏死并炎性细胞浸润3例。所有患者的病理组织中均未见到典型结核结节及朗罕氏巨噬细胞。结论：艾滋病合并肺结核主要表现为结节、肿块或片状实变影,合并胸膜炎或纵膈淋巴结肿大。其病理改变主要为炎性肉芽肿和/或合并干酪坏死,缺乏典型结核结节及郎罕氏巨噬细胞,诊断还应结合抗酸杆菌染色。     

High-attenuation recent thrombus of the portal vein: CT demonstration and clinical significance

Attenuation characteristics of portal vein thrombi on nonenhanced computed tomographic (CT) scans were assessed in 122 patients with proved portal vein thrombosis. Portal vein thrombi of high attenuation were found in four patients with hepatocellular carcinoma. From pathologic and radiologic studies, it was concluded that the high attenuation was caused by blood clots of recent onset formed at the tip of tumor thrombus. Differentiation from choledocholithiasis, hematobilia, and calcification of thrombi could be easily made by means of ultrasonography (US). Although plain CT is usually considered noncontributory in the diagnosis of venous thrombosis, it enabled the differentiation of recent thrombus in these four patients. Tumor thrombus in the major branches or main trunk of the portal vein is indicative of poor prognosis. When hepatic mass and high-attenuation portal vein thrombi are demonstrated with plain CT and substantiated by US, enhanced CT and angiography may be unnecessary for treatment of patients with advanced hepatocellular carcinoma.     

Pulmonary paracoccidioidomycosis and AIDS: high-resolution CT findings in five patients

OBJECTIVE: To study the high-resolution computed tomographic (HRCT) findings in patients with AIDS and pulmonary paracoccidioidomycosis (PCM). MATERIALS AND METHODS: The study included 5 consecutive patients (4 men and 1 woman, with ages ranging between 35 and 57 years; mean, 48 years) with diagnosis of AIDS and pulmonary PCM. All patients underwent HRCT, and the images were reviewed by 2 radiologists who reached decisions by consensus. RESULTS: The predominant HRCT findings in the present series were large nodules (80%), cavited air-space consolidations (80%), ground-glass attenuation (80%), and cicatricial emphysema in the bases (80%). These lesions predominated bilaterally in the middle regions (80%) of the lungs. CONCLUSIONS: The most common HRCT features in patients with AIDS and pulmonary PCM are large nodules associated with cavitated air-space consolidations and ground-glass attenuation, as well as cicatricial emphysema in the pulmonary bases. These findings are usually distributed bilaterally in the middle lung zones of the lungs.     

Paratracheal lymphadenopathy: radiographic findings and correlation with CT

Possible signs of paratracheal lymphadenopathy on the posteroanterior (PA) chest radiograph were assessed in 98 patients and correlated with computed tomography (CT). The nodes were normal in size in 62 patients and enlarged (greater than 15 mm) in 36. Among the latter group, widening of the right paratracheal stripe was seen in 11 (31%) and enlargement of the azygos node in 15 (42%). While the lateral contour of the superior vena cava (SVC) was convex in 46 patients (47%), 81 (83%) had an increased density in the region of the SVC. When all four parameters were combined, lymphadenopathy could be detected on the PA view in 87 patients (89%). CT demonstrated that the enlarged nodes were anterolateral rather than directly lateral to the trachea and also immediately posterior to the SVC, explaining the findings on the PA radiograph.     

Rhodococcus equi pneumonia in AIDS: high-resolution CT findings in five patients

The aim of this study was to describe the high-resolution CT scan findings in five patients with AIDS and pulmonary infection due to Rhodococcus equi. The study included five patients with AIDS and proven R. equi infection. The CT scans were reviewed by two observers. The patients included four men and one woman ranging from 39 years to 49 years in age (mean 42 years). The findings included areas of consolidation (n=5) with single (n=1) or multiple cavitation (n=4), ground-glass opacities (n=5), centrilobular nodules (n=3), small centrilobular nodular opacities (n=3) and "tree in bud" opacities (n=3). None of the patients had pleural effusion or lymph node enlargement. The most common high-resolution CT manifestations of R. equi infection consist of areas of consolidation with cavitation, ground-glass opacities, nodules and a tree-in-bud pattern.     

艾滋病合并肺部卡波西肉瘤的CT表现

【摘要】目的：探讨艾滋病合并肺部卡波西肉瘤的CT表现及特征。方法：回顾性分析19例艾滋病合并肺部卡波西肉瘤患者的临床及胸部CT表现。结果：19例艾滋病合并肺部卡波西肉瘤患者中,发现双肺内多发结节影16例,多发斑片状实变影8例;其中肺内结节影均沿支气管血管束分布。双肺支气管血管束增厚9例,同时合并小叶间隔增厚。纵隔淋巴结肿大10例,9例发现少量胸水,均累及双侧胸腔。19例患者均未发现病变累及段以上支气管内壁。17例患者发现卡波西肉瘤时,体内CD4+ T淋巴细胞计数低于100个/UL。结论：艾滋病合并肺部卡波西肉瘤患者胸部CT表现以双肺各叶多发结节影和斑片状实变影多见,肺内结节影多沿支气管血管束分布;斑片状实变影形态多不规则,类似火焰状为其特征性改变。     

Intracranial tuberculosis in AIDS: CT and MRI findings

Summary CT and MRI findings in 35 patients with the acquired immune deficiency syndrome (AIDS) and proven intracranial tuberculosis (TB) are presented. Over 90% of the patients were intravenous drug abusers and in two-thrids TB was the first manifestation of AIDS. CT was normal in one quarter, the most frequent findings being hydrocephalus (51%) and meningeal enhancement (41%), commonly seen together (31.5%). Meningeal enhancement was seen in 48% of the CT studies with intravenous contrast medium and in 3 cases studied with MRI and iv gadolinium DPTA, in 2 of which CT was negative. Parenchymal involvement was found in 37% of cases; MRI was more sensitive than CT for its detection. One quarter of the patients had ischaemic lesions, mainly in the basal ganglia. We confirm the usefulness of CT and the superiority of MRI in the diagnosis of intracranial TB and in differential diagnosis from other conditions likely to be found in these patients.     

Extrapulmonary Pneumocystis carinii infection in AIDS: CT findings

Clinical and computed tomographic (CT) findings in three cases of extrapulmonary Pneumocystis carinii infection in patients with acquired immunodeficiency syndrome (AIDS) were reviewed. Proved sites of involvement included the spleen (n = 2), bone marrow (n = 1), liver (n = 1), and peritoneal and pleural fluid (n = 1). CT findings included focal low-attenuation splenic lesions that became progressively calcified in rimlike or punctate fashion; punctate calcifications in the liver, renal cortices, and adrenal glands; calcification of lymph nodes; and pleural and peritoneal effusions with subsequent calcifications of the pleural and peritoneal surfaces. Although rare both before and since the onset of the AIDS epidemic, extrapulmonary P carinii infection in AIDS patients has been reported with increasing frequency in recent years, and more cases with radiologic manifestations should be expected.     

Renal diseases in patients with AIDS: sonographic findings.

This essay illustrates the spectrum of sonographic findings of various renal manifestations of AIDS. The most common renal abnormality in patients with AIDS is nephropathy, which is manifested by deterioration of renal function and proteinuria. Acute tubular necrosis, intrarenal infections, focal nephrocalcinosis, hydronephrosis, and neoplasms also may occur.     

Swyer-James syndrome: CT findings in eight patients.

To determine the importance of chest CT findings in patients with Swyer-James syndrome (unilateral small lung with air trapping) and to compare these findings with those on chest radiographs and scintigrams, we reviewed the CT scans, chest radiographs, and scintigrams of eight patients with the syndrome. Radiographs showed unilateral hyperlucency in seven patients and bilateral asymmetric hyperlucency in one. CT showed that the hyperlucency was unilateral in only three and that hyperlucency in one. CT showed that the hyperlucency was unilateral in only three and that hyperlucent regions on radiographs contained patches of normal lung attenuation in five patients. Conversely, in four patients, CT also showed small hyperlucencies in regions considered normal on radiographs. These lucencies usually had poorly defined margins and irregular shapes (five patients), but sometimes were peripheral, wedge shaped, and sharply demarcated (two patients). CT also showed subtle abnormalities not visible on radionuclide scans in two patients. Air trapping in hyperlucent regions was confirmed by a lack of change in volume on expiratory CT scans in five cases. Bronchiectasis was found in only three patients. CT helps to exclude central bronchial obstruction, cysts, and vascular disease as causes of hyperlucency. By excluding central obstruction, CT may make bronchoscopy unnecessary in some patients. CT is more sensitive than radiographs and radionuclide scans in detecting hyperlucent regions and in showing their distribution. Our experience suggests that bronchiectasis is not a necessary component of the Swyer-James syndrome.     

Abdominal desmoids: CT findings in 25 patients.

Desmoids are histologically benign but locally aggressive fibrous tumors. Although overall they are rare lesions, they are a common manifestation of Gardner syndrome. We retrospectively reviewed clinical records and CT scans of 25 patients with abdominal desmoids. The number, location, and CT characteristics of the lesions were recorded for each patient. Tumors were solitary in 72% of patients and multiple in 28%. Fifty percent were located in the abdominal wall, 41% in the mesentery, and 9% in the retroperitoneum. More than two thirds of the lesions had well-defined borders, with the remainder displaying an infiltrative outer margin. The majority of tumors had attenuation values equal to (47%) or greater than (41%) the attenuation of muscle on contrast-enhanced CT scans. Complications attributable to the desmoid were commonly detectable on CT (hydronephrosis occurred in 36% and small-bowel obstruction in 20%). Our results detail the spectrum of CT findings and complications caused by abdominal desmoids.     

Thoracic actinomycosis: CT findings in eight patients.

The chest radiographs and computed tomographic (CT) scans obtained in eight patients with pathologically proved cases of thoracic actinomycosis were independently reviewed by two observers. All patients were alcoholic men aged 42-62 years. Air-space consolidation, seen on the radiograph and CT scan in each case, was present in the lower lobes in seven patients (88%) and upper lobes in three (38%). Pleural effusion was present in five (62%). Pleural thickening adjacent to the air-space consolidation was identified on the radiograph in four (50%) and CT scan in all eight. Cavitation or central areas of low attenuation not apparent on the radiograph were seen on the CT scan in five cases (62%). Hilar or mediastinal lymphadenopathy was identified on the radiograph in three cases (38%) and on the CT scan in six (75%). Chest-wall invasion occurred in only one case (12%). Thoracic actinomycosis is characterized on CT scans by air-space consolidation with adjacent pleural thickening. CT is superior to radiography in assessing the thoracic manifestations of actinomycosis.     

CNS complications of AIDS: CT and MR findings

AIDS is now a common disease, seen daily in large metropolitan medical centers. Neuroimaging techniques such as CT and MR are critical to the detection and diagnosis of CNS complications. Intracerebral infections are common. These infections frequently are caused by opportunistic organisms; less commonly, they are bacterial infections. The cranial imaging features on CT and MR are not pathognomonic, but their distribution or appearance (e.g., asymmetric target lesions of toxoplasmosis) may have predictive value in a known AIDS patient. The superior contrast resolution of MR makes it a more sensitive cross-sectional imaging tool for evaluating intracerebral abnormalities associated with a variety of infectious processes. Differential diagnoses still include metastatic disease, lymphoma, and infarcts. When MR is used as the initial cross-sectional imaging study, contrast-enhanced CT may still be necessary to further characterize a lesion. Currently, more experience exists with CT for follow-up of the AIDS patient with CNS manifestations. MR, particularly with gadolinium-DTPA as a contrast medium, will probably become the imaging method of choice.     

Lesions of the head and neck in patients with AIDS: CT and MR findings

The CT and/or MR findings were reviewed in 43 patients with head and neck disease; 27 had AIDS, 14 had AIDS-related complex, and two had positive human immunodeficiency virus serologies. Fourteen patients had infections, 15 had tumors, and 15 had benign lymphoid hyperplasia. Deep cervical infections were caused by bacterial and mycobacterial organisms, including Mycobacterium avium-intracellulare. Bacterial infections were clinically more virulent than they would be in immunocompetent patients. Neoplasms included Kaposi sarcoma, lymphoma, and squamous cell carcinoma. Benign lymphoid hyperplasia demonstrated enlargement of the cervical lymph nodes, adenoids, and tonsils. Although there was considerable overlap in the imaging characteristics of the various diseases seen, several distinguishing features were noted. Cellulitis, with infiltration and thickening of the subcutaneous fat, was typical of bacterial infections, but was uncommon with tumors or mycobacterial infections. Lymph nodes with necrotic centers were seen with Kaposi sarcoma, squamous cell carcinoma, and mycobacterial infection, but not with lymphoma or benign lymphoid hyperplasia. Benign adenoidal enlargement is usually symmetric with a flat anterior border, but bulky lesions indistinguishable from tumor were seen in two patients. It is important for radiologists to be aware of the spectrum of head and neck disease in patients with human immunodeficiency virus. The CT and MR assessment can guide biopsy and assist in planning therapy.     

Extra-cardiac findings at cardiac CT: experience with 1,764 patients

To investigate incidental extra-cardiac findings (ECF) at cardiac CT based on indication and impact on patient management. We retrospectively reviewed the reports of 1,764 patients who underwent a cardiac CT study between January 1, 2004 and December 31, 2006, including 463 calcium scorings (CS), 737 coronary CT angiograms (CTA), 341 pulmonary vein stenoses (PVS), and 223 bypass grafts (CABG). ECFs were categorized by type of examination, anatomical location and clinical significance. Comparisons were made between examination types to determine if incidental findings varied by indication. There were 507 ECFs with at least one ECF in 441 patients (25.0%). By examination, there was at least 1 ECF in 79/463 CS studies (17.1%), 196/737 CTAs (26.6%), 80/341 PVSs (23.4%) and 86/223 CABGs (38.6%). In 325 patients (18.4%), the findings were considered clinically important and occurred in 60/463 (12.9%) CSs, 149/737 (20.2%) CTAs, 56/341 (16.4%) PVSs and 60/223 (26.9%) CABGs. Differences between CABG and other indications and CTA vs. CS for incidental and clinically important findings were statistically significant (p < 0.05). Extra-cardiac findings requiring follow-up occur in 18% of patients and are significantly more frequent in coronary artery CTA and coronary artery bypass studies than in calcium scoring studies.