Bronchopulmonary sequestration: CT assessment

Computed tomographic (CT) scans of 24 bronchopulmonary sequestrations in 23 patients were reviewed. Seventeen sequestrations were diagnosed at surgery, three at angiography, and four on the basis of radiographic or CT findings combined with appropriate history. Sixteen sequestrations were intralobar, and eight were extralobar; 21 were posterobasal. Seventeen occurred on the left side and seven on the right. Anomalous systemic arterial supply was demonstrated by CT in 16 sequestrations. In the others, a systemic artery was not shown, presumably because of unfavorable orientation or small size of the vessel. The lung abnormalities shown by CT were classified into three types: A = cysts containing air or fluid (n = 8), or soft-tissue masses (n = 2); B = emphysematous lung surrounding cysts, and/or soft-tissue nodules (n = 13); and C = lung hypervascularity (n = 2). In only three cases did the chest radiograph show the emphysematous lung tissue. Such emphysematous lung has rarely before been reported as a CT finding, and lung hypervascularity has not, to the authors' knowledge, been reported. The authors conclude that CT can be helpful in the diagnosis and evaluation of bronchopulmonary sequestration. Characteristic manifestations are (a) a complex lesion containing solid or fluid components combined with emphysematous lung or (b) any basal lesion supplied by a systemic artery.     

Gallium uptake in myositis ossificans. Potential pitfalls in diagnosis

Seven cases of gallium uptake in myositis ossificans are described. Gallium scans are done frequently in paraplegics, quadriplegics, and comatose patients to look for occult infection. It is important to be aware of possible gallium uptake in myositis ossificans, particularly in the extremities, which is frequent in these patients. Gallium uptake may be present prior to any abnormalities seen on plain films or CT scans. It is important to correlate roentgenograms with abnormal gallium scans, particularly in the extremities, to avoid potential pitfalls in diagnosis and prevent unnecessary antibiotic treatment. A bone scan should be obtained whenever possible, particularly when roentgenograms are negative, to confirm the diagnosis.     

卵巢良性病变的CT表现

目的 提高对卵巢良性病变ＣＴ表现的认识。材料与方法 回顾性分析经手术病理证实的６６例共８０个卵巢良性肿块的ＣＴ及Ｂ超资料,讨论其ＣＴ表现特点及ＣＴ在诊断中的作用。结果 本组２５个功能性囊肿ＣＴ发现２３个;１８个卵巢子宫内膜异位囊肿,长径多与同侧的盆壁近科平行（１２／１８）,甚至大于横径达１．５倍（９／１８）;１５个囊腺瘤均呈边缘光滑的囊性肿块,其中浆液性囊腺瘤（ｎ＝９）密度均匀,多为单房（６／９）     

纵隔支气管源性囊肿的CT诊断探讨

目的　探讨纵隔支气管源性囊肿CT诊断及鉴别诊断。方法　回顾分析经病理证实 2 0例纵隔支气管源性囊肿CT表现。结果　 14例位于中纵隔气管旁 ,其中 12例位于右侧 ,2例位于左侧 ;5例位于右中纵隔隆突部支气管旁 ;左后纵隔食管旁 1例。呈圆形或卵圆形肿块 ,12例呈囊性密度 ,8例呈软组织密度 ,增强 5例囊内容物无强化 ,3例软组织密度病变强化后呈囊样低密度。结论　支气管源性囊肿多发于中纵隔气管旁 ,CT平扫加增强有助于诊断和鉴别诊断 ,结合临床资料多数可确诊。     

The CT and MR imaging features of carcinoma arising in thyroglossal duct remnants

BACKGROUND AND PURPOSE: Carcinoma arising in thyroglossal duct remnants is a well-described entity in the pathology and surgery literature, but it has little recognition in the radiology literature. Preoperative diagnosis may alter surgical management, although this diagnosis is rarely made. This study was undertaken to determine the radiologic features that might differentiate carcinoma from benign thyroglossal duct cysts. METHODS: Twenty-one cases of nonpediatric thyroglossal duct anomalies imaged at our institution during a 15-year period were reviewed retrospectively. The images were assessed for lesion wall thickness, enhancement, soft-tissue component, calcification, and loculation of the cystic component. Three additional cases of thyroglossal duct carcinoma obtained from outside institutions were reviewed for these features also. RESULTS: Six cases of thyroglossal duct carcinoma were reviewed. All cases of carcinoma had solid soft-tissue elements visible on CT scans or MR images, compared with three of 18 cases of benign thyroglossal duct cysts. The malignant component was seen as a small peripherally based mass in relation to a cyst, a solid mass in the expected course of the thyroglossal duct, or a complex invasive mass also in the midline of the neck. CT only revealed calcification in cases of carcinoma, within either the primary carcinoma mass or a metastatic node. CONCLUSION: Thyroglossal duct carcinoma should be suspected in an adult patient in the presence of a solid nodule or invasive features in association with a thyroglossal duct lesion visible on CT scans or MR images. The presence of calcification, which is seen best on CT scans, may be a specific marker for carcinoma.     

Pulsatile masses surrounding vascular prostheses: real-time US color flow imaging

A prospective evaluation of color flow mapping and real-time ultrasound was performed to determine if pseudoaneurysms could be distinguished from other causes of masses surrounding vascular grafts of the lower extremities. Twelve palpable pulsatile masses were imaged. Diagnoses were confirmed at angiography (n = 11), computed tomography (n = 7), aspiration biopsy (n = 5), and operative intervention (n = 6). A swirling pattern of blood flow was seen in six of seven cases of pseudoaneurysm. Lack of flow signals was noted in four of the five collections representing hematoma (n = 2) or infection (n = 2). The seventh case was later shown to be an infected, thrombosed pseudoaneurysm. The single false-positive diagnosis was made early in the series when the flow signals detected were due to transmitted arterial pulsations. The authors conclude that color Doppler flow imaging is useful in the differential diagnosis of pulsatile masses associated with prosthetic grafts. Prosthetic graft pseudoaneurysms have a specific appearance of swirling blood flow arising from a wide neck and are distinguishable from traumatic or iatrogenic pseudoaneurysms of the native vascular tree.     

CT diagnosis of unsuspected pneumothorax after blunt abdominal trauma

Review of abdominal CT scans for evaluation of blunt abdominal trauma yielded 35 cases of pneumothorax, 10 of which had not been diagnosed before CT by clinical examination or plain radiographs. Of the 10 cases initially diagnosed on CT, seven required tube thoracostomy for treatment of the pneumothorax. CT detection of pneumothorax is especially important if mechanical assisted ventilation or general anesthesia is used. Demonstration of pneumothorax requires viewing CT scans of the upper abdomen (lower thorax) at lung windows in addition to the usual soft-tissue windows.     

Bronchogenic cysts in the adult: diagnostic criteria derived from the correct use of standard radiography and computed tomography

PURPOSE: This study was undertaken to identify the radiographic and computed tomography patterns allowing a diagnosis of bronchogenic cyst. MATERIALS AND METHODS: We retrospectively reviewed chest radiographs and CT scans of 21 adults (ten men and 11 women, age range 18-74 years) with a histologically confirmed diagnosis of bronchogenic cyst. RESULTS: Sixteen cysts were located in the mediastinum and five in the lungs. On chest radiography, mediastinal cysts appeared as sharply marginated rounded areas of increased opacity; intrapulmonary cysts also exhibited an air-fluid interface. CT confirmed these morphological features in all cases. In addition, analysis of attenuation values allowed the subdivision of mediastinal cysts into three groups: fluid density (four cases), air density (two cases) and soft-tissue density (ten cases). CONCLUSIONS: All bronchogenic cysts were visualised on chest radiography, but the findings were nonspecific and required further characterisation by CT. The CT findings proved to be diagnostic when cystic attenuation values were evident. When soft-tissue attenuation values were demonstrated, a confident diagnosis was not possible, and other solid lesions had to be considered. In such cases, magnetic resonance imaging may be helpful to ascertain the cystic nature of the lesions.     

下肢动脉瘤的MDCTA诊断

目的:探讨MDCTA在下肢动脉瘤病变中的诊断价值.方法:回顾分析了18例临床诊断下肢动脉瘤病例的四排螺旋CTA影像.三种不同的重组后处理方式包括MIP,VR及CPR,以及横断位图像均被用于回顾性分析.结果:18位患者中共检出真性动脉瘤15例(23个),假性动脉瘤3例.MDCTA较好地显示了所有瘤腔及腔壁的血栓.其中8例真性动脉瘤和3例假性动脉瘤均经手术证实.结论:下肢动脉MDCTA成像技术安全可靠,在下肢动脉瘤病变的影像学诊断中有着较好的诊断价值,能够基本替代创伤性的血管造影.     

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.     

The value of MDCT in diagnosis of splenic artery aneurysms

OBJECTIVE: To evaluate the clinical value of multiple detector computed tomography (MDCT) in the diagnosis and planning the treatment of splenic aneurysms. METHODS: Eight cases with splenic artery aneurysms (SAA) were retrospectively reviewed. Sixty four-slice spiral CT scans were performed. Intravenous contrast material was injected at 4ml/s, and arterial and venous phase images were obtained. Subsequently, arterial phase images were analyzed and made for CT angiography. The diagnosis was made by using axial and reconstructive images. All of the patients were also performed Doppler color echocardiography. RESULTS: All patients showed splenic artery and splenic artery aneurysms clearly with CT arterial phase images. Among them, six patients had splenic artery aneurysms, one had giant splenic artery aneurysms (GSAA) and one had splenic artery pseudoaneurysms. Ultrasound examination only diagnosed six of them. CONCLUSION: MDCT is a noninvasive and valuable method in diagnosis of splenic artery aneurysms and has high value in determination of treatment plan.     

Diagnosis of ruptured intracranial dermoid cyst: value MR over CT

The CT and MR findings of seven patients with pathologically proved ruptured dermoid cysts were reviewed to analyze the MR characteristics and to see if MR evaluation had significant advantages over CT. In six cases, both CT and MR identified fatty material in the CSF spaces. Hemorrhage complicated preoperative diagnosis in one case. Patterns of extraaxial fat distribution were as follows: intraventricular fat/CSF levels (three patients), generalized subarachnoid spread (six patients), and localized subarachnoid spread with sulcal widening (one patient). There was no correlation between fat distribution and clinical symptoms. MR showed the vascular involvement better than CT did in five of seven cases, and showed extension of the cysts into the skull base in two cases. Signal intensity of the solid mass was low on T1-weighted MR images and inhomogeneously high on T2-weighted images, which correlated pathologically with the presence of crystal cholesterol, hair, sebaceous glands, and epithelial cells in all cases. On MR, brain parenchyma showed little edema or other reaction to the masses, which were typically large. The value of MR over CT in the examination of ruptured dermoid cysts is the conspicuity of the extent of subarachnoid spread, involvement of the extraaxial structures, and evidence of vascular compromise, which can obviate angiography. MR had no advantage over CT in making the initial diagnosis of ruptured dermoid, but it would be the preferred preoperative study.     

Suprasellar arachnoid cysts: 1. CT recognition

Suprasellar arachnoid cysts are basal midline masses that represent a rare but surgically remediable cause of hydrocephalus and neurologic deficits. These cysts represent a diagnostic challenge and often go unrecognized for many years. The authors review the computed tomographic (CT) findings in seven patients with documented suprasellar arachnoid cysts and define previously undescribed diagnostic criteria. These cysts usually can be differentiated from cystic midline neoplasms by their CT density, homogeneity, and location as well as by their lack of fat, lack of calcification, and absence of contrast enhancement. Accurate distinction from marked third-ventricular enlargement secondary to obstructive hydrocephalus and from third-ventricular ependymal cysts can be made on the basis of basal cisternal expansion, distinctive mass effect and displacement, the characteristic shape and contour of the apparent "third ventricle," and the appearance of structures at the foramen of Monro. Although metrizamide CT ventriculography and cisternography allow confirmation of the diagnosis and evaluation of cerebrospinal fluid dynamics, these definitive studies will not be obtained unless the cysts are first suspected by their conventional CT appearance.     

Problematic renal masses in ultrasonography and computed tomography

The diagnosis of renal masses is based upon the contribution of ultrasonography (US) and computed tomography (CT), which enable the recognition of these lesions with high diagnostic accuracy. However, a number of diagnostic difficulties exist in the definition of the nature of the mass, both for cystic and solid lesions, and to a lesser extent in the identification of the mass. "Complicated" cystic masses, such as calcified cysts, hemorrhagic cysts, inflammatory cysts, abscesses, and cystic tumors may be difficult to diagnose with US and sometimes with CT. CT is helpful in most of these cases because it enables the evaluation of the calcifications and the density of the fluid content. CT is also helpful in cases of cystic tumors because it shows the enhancement of septae within the masses. Problems with solid masses are the identification of small renal tumors and the definition of the benign or malignant nature of the mass. Although both techniques enable the recognition of most tumors, even if small in diameter, they are still limited in defining the pathological structure of the tumor.     

CT and MR imaging of intralabyrinthine schwannoma: report of two cases and review of the literature

Two cases of intralabyrinthine schwannoma were studied with computed tomography (CT) and magnetic resonance (MR) imaging. On CT scans, a soft-tissue mass was identified in the round window niche in both cases. Widening of the basilar turn of the cochlea and characteristic erosion of the promontory were noticed in one case. Preoperative MR imaging (performed in only one case) revealed a soft-tissue mass in the labyrnth, extending into the round window niche. Findings at CT and MR imaging are discussed, and a differential diagnosis is given. The literature is reviewed. The authors' findings suggest that CT and MR imaging may prove very valuable in the previously difficult preoperative diagnosis of these tumors. In the setting of progressive sensorineural hearing loss, atypical Meniere disease, or recurrent vertigo, the presence of a mass in the labyrinth or labyrinthine windows- delineated on CT or MR images, despite a normal internal auditory canal, cerebellopontine angle, or brain stem - is highly suggestive of intralabyrinthine schwannoma.     

肾上腺肿瘤的CT诊断(附46例分析)

目的:探讨肾上腺肿瘤在CT上的表现特点,以提高对该部位肿瘤的认识。方法:收集46例肾上腺肿瘤,回顾分析CT特征,对照病理结果进行讨论。结果:46例中,皮质腺瘤21例,多数较小,边缘光滑,轻度强化;转移瘤7例,单侧或双侧,密度均匀或不均匀;嗜铬细胞瘤6例,肿块一般较大,密度不均,增强后实质部分强化明显;髓性脂肪瘤6例,瘤内脂肪组织为其特征;皮质腺癌3例,较大肿块,直径一般大于7 cm,密度不均;肾上腺囊肿2例,边缘光滑,均匀水样密度的囊性占位,增强扫描无强化;非何杰金淋巴瘤1例,双侧发生,软组织密度肿块,强化较均匀。结论:肾上腺肿瘤CT表现各有特征,结合临床表现和生化检查可作出较为正确的诊断。     

Soft-tissue masses: diagnosis using MR imaging

The MR images of 112 soft-tissue masses of various causes were retrospectively reviewed. Pathologic diagnosis by biopsy was available in 96 cases. Diagnosis in the remaining 16 cases was established by characteristic radiographs, CT scans, and/or arteriograms, in conjunction with appropriate history and clinical follow-up. All masses were evaluated with both T1-weighted, 300-600/20-30 (TR/TE), and T2-weighted, 2000/80-100, images. They were reviewed to determine (1) if these images were sufficiently unique to allow a preoperative diagnosis based exclusively on the MR appearance and (2) if benignity vs malignancy could be predicted on the basis of the analysis of the MR image characteristics of the lesion. Concerning the latter, attention was directed to the margins of the lesions, to the impact of the lesion on the surrounding tissues (edema, infiltration, etc.), and to the intensity and homogeneity of the MR signal of the lesion. MR images were sufficiently characteristic to allow a specific diagnosis in 27 (24%) of the 112 cases (10 lipomas, eight hemangiomas, six pigmented villonodular synovitis, two hematomas, and one arteriovenous malformation). MR was incapable of reliably distinguishing between benign and malignant soft-tissue tumors.     

Imaging characteristics of cystic adventitial disease of the peripheral arteries: presentation as soft-tissue masses

OBJECTIVE: Our purpose was to identify the characteristic imaging features of cystic adventitial disease of the peripheral arteries. CONCLUSION: Patients with cystic adventitial disease of the peripheral arteries often present for evaluation of soft-tissue masses involving the extremities. Noninvasive imaging reveals a characteristic appearance allowing confident diagnosis.     

Imaging strategies in the evaluation of soft-tissue hemangiomas of the extremities: correlation of the findings of plain radiography,angiography, CT,MRI, and ultrasonography in 12 histologically proven cases

Twelve patients with the histologic diagnosis of soft-tissue hemangioma of the extremities (nine intramuscular, two subcutaneous, and one synovial) were evaluated in a retrospective study using plain film radiography (n = 12), angiography (n = 8), computed tomography (CT; n = 4), magnetic resonance imaging (MRI; n = 3), and ultrasonography (US; n = 2). In eight of nine intramuscular lesions, the plain film demonstration of phleboliths suggested the diagnosis, while the plain radiographs were normal in three. Angiograms showed the pathognomonic features of soft-tissue hemangioma in six patients. MRI was characteristic in all three patients: The lesion demonstrated intermediate signal intensity on T1-weighted spin echo images and extremely bright signal on T2-weighting. US showed a hypoechoic soft-tissue mass in one case and a mixed echo pattern in the other. In one case, a central echogenic focus with acoustic shadowing consistent with a calcified phlebolith was identified, and one lesion exhibited increased color flow and low resistance arterial Doppler signal. CT showed a nonspecific mass in one of four cases and a mass with phleboliths in three. If a deep hemangioma is suspected, we recommend initial imaging with plain radiography followed by MRI. US may be useful in confirming the presence of a mass in doubtful cases or if MRI is unavailable. CT offers no distinct advantage over the combined use of plain radiography and MRI. Although angiography demonstrated the pathognomonic features in all six deeply situated lesions, because of its invasiveness it should be reserved chiefly for those patients undergoing surgical resection.     

Computed tomography of localized pleural mesothelioma

The computed tomographic (CT) features of six pathologically proven cases of fibrous mesothelioma were reviewed. There were no pathognomonic CT characteristics, but in all cases CT suggested or supported the preoperative diagnosis. CT findings included well delineated, often lobulated, noncalcified soft-tissue masses in close relation to a pleural surface, associated crural thickening, and absence of chest wall invasion. An obtuse angle of the mass with respect to the pleural surface was not particularly useful. Rather, a smoothly tapering margin was more characteristic of a pleural lesion.