乳腺良恶性病变的CT鉴别诊断

目的评价多层螺旋CT在鉴别乳腺良恶性病变中的应用价值。方法 22例经手术或病理组织学证实的乳腺疾病患者,其中,恶性肿瘤14例(8例乳腺癌,3例导管癌及3例浸润癌)和良性病变8例(2例乳腺增生,4例乳腺纤维瘤,1例乳腺炎及1例男性乳房发育异常)均经16层螺旋CT(MSCT)扫描。4例又经对比增强CT扫描。对所有患者的CT表现进行了回顾性分析。结果 CT扫描证实,乳腺癌性病灶表现为不规则形肿块伴周边毛刺,病灶内钙化,局部皮肤凹陷,乳头内陷,腋窝淋巴结肿大。乳腺增生表现为乳腺组织中致密影,密度等同于周围腺体。乳腺纤维瘤表现为圆或椭圆形边缘光滑的肿块影,密度均匀,部分病灶有强化。乳腺炎表现为片状不规则致密影,边缘模糊,内见低密度脓肿形成。结论多层螺旋CT在乳腺良恶性病变的鉴别诊断中起重要作用。     

Differential diagnosis of submandibular cystic lesions by computed tomography

A retrospective analysis of 35 submandibular cystic lesions was undertaken to assess the usefulness of CT in their differential diagnosis. Lesions were analysed on the basis of extent, shape and density. It was found that all those lesions that extended into both the sublingual and the anterior part of the submandibular spaces could be diagnosed as ranulas (10/10) and all those limited to the posterior part as lateral cervical cysts (8/8). Those lesions that extended to the sublingual, but not the anterior part of the submandibular space, were dermoid cysts if they had a smooth margin (2/2), and probably ranulas when it was concave (4/5). Those lesions that extended into the anterior part of the submandibular but not the sublingual space were ranulas on the basis of a multilocular or concave margin (3/3), but if they had a smooth margin (3/7) they could not be differentiated from dermoid cysts (4/7). Although CT density was less valuable for the differential diagnosis, both ranulas and dermoid cysts could be excluded if it was similar to that of muscle.     

The diagnosis by computed tomography of brachial plexus lesions following radiotherapy for carcinoma of the breast

The region of the brachial plexus in the root of neck and axilla was examined by computed tomography (CT) in 62 patients attending the Royal Marsden Hospital. Forty-two of these patients had been treated by surgery and subsequent radiotherapy for carcinoma of the breast. Computed tomography was able to identify varying grades of abnormality that were ascribed to radiation fibrosis. Twenty-eight patients had neurological symptoms affecting the arm or hand on the treated side and CT changes were seen in 96%. The grading and significance of these CT abnormalities is discussed. The patients had been treated by two different radiotherapy techniques (three-field and four-field) which utilised either a large or small treatment fraction. The higher grades of abnormality on CT were seen in 57% of those treated with the large fraction size and 27% of those treated with the small fraction size. However, the changes on CT did not relate to the different radiotherapy techniques.     

Preoperative evaluation of bronchiectasis by computed tomography

A patient with known lingular bronchiectasis is presented for whom CT was used as the sole preoperative radiographic method to exclude disease in the remainder of the bronchial tree. The patient has remained symptom free for 12 months following lingulectomy. The potential of CT to obviate the need for bronchography in the preoperative staging of bronchiectasis is discussed.     

Dynamic low-dose three-dimensional computed tomography: a preliminary study

Three-dimensional (3D) computed tomographic reformations have been used successfully as an adjunct to standard axial computed tomography (CT) in the evaluation of disorders affecting areas of complex anatomy. The basic requirements for high-quality 3D reformations are an absence of patient movement and narrow-width transaxial sections. Speed of examination is an important factor in optimizing image quality. One hundred examinations were performed on an IGE CT 9800 scanner. For bone studies, 80 mAs and, for certain soft tissues, 140 or 200 mAs were employed with 120 kVp. The advantages of such a "low-dose" technique are significant reduction in patient skin dose and a faster examination. The main disadvantage is a reduction in signal-to-noise ratio. The image quality obtained in 3D presentations has nevertheless been sufficient to enable all bony abnormalities to be identified. Three-dimensional examinations are now being performed routinely using a dynamic mode and this "low-dose" technique.     

Differential diagnosis of low-attenuation splenic lesions on computed tomography

A retrospective computed tomography evaluation of proved low-attenuation splenic lesions in nontraumatic cases was done. Computed tomography was able to distinguish cystic from solid lesions. Although computed tomography examination is sensitive in the detection of low-attenuation lesions, the computed tomography findings alone are not helpful in differentiation of different low-attenuation lesions. Associated computed tomography findings in other organs and clinical findings are more helpful than the size, shape, and computed tomography attenuation of the lesions. Splenic lesions may be the only metastatic manifestation in some cancer patients. A thin needle aspiration may be done to document the nature of the pathologic lesion in problematic cases.     

Preoperative assessment of focal liver lesions: multidetector computed tomography challenges magnetic resonance imaging

PURPOSE: To investigate prospectively multidetector computed tomography (CT) (MDCT) and magnetic resonance (MR) imaging (MRI) in the preoperative assessment of focal liver lesions. MATERIAL AND METHODS: Multiphasic MDCT and conventional gadolinium-enhanced MRI were performed on 31 consecutive patients prior to hepatic surgery. All images were blindly analyzed as consensus reading. Lesion counts and their relation to vascular structures and possible extrahepatic disease were determined. The data from the MDCT and MRI were compared with the results obtained by intraoperative ultrasound (IOUS) and palpation. Histopathologic verification was available. RESULTS: At surgery, IOUS and palpation revealed 45 solid liver lesions. From these, preoperative MDCT detected 43 (96%) and MRI 35 (78%) deposits. MDCT performed statistically better than MRI in lesion detection (P=0.008). Assessment of lesion vascular proximity was correctly determined by MDCT in 98% of patients and by MRI in 87%. Statistical difference was found (P=0.002). IOUS and palpation changed the preoperative surgical plan as a result of extrahepatic disease in 8/31 (26%) cases. In MDCT as well in MRI extrahepatic involvement was suspected in two cases. CONCLUSION: MDCT was superior to MRI and nearly equal to IOUS in liver lesion detection and in the determination of lesion vascular proximity. However, both techniques fail to reliably detect extrahepatic disease.     

Preoperative diagnosis of the Mirizzi syndrome: limitations of sonography and computed tomography

Preoperative recognition of the Mirizzi syndrome permits avoidance of several serious pitfalls at surgery. The typical diagnostic signs of the Mirizzi syndrome are (1) dilatation of the common hepatic duct above the level of (2) a gallstone impacted in the cystic duct, with (3) normal duct width below the stone. Since jaundice is the leading clinical symptom, sonography and computed tomography (CT) are now the primary radiologic tests. The syndrome does not regularly have typical features, however, and therefore cannot be detected routinely on sonography or CT. Direct cholangiography is often necessary, especially since a cholecystobiliary fistula secondary to stone penetration into the common bile duct can be demonstrated only by cholangiography. On the other hand, direct cholangiography should follow either sonography or CT because these imaging methods are superior for demonstrating extraluminal signs of malignancy, which is the most important differential diagnosis. The findings at preoperative examinations (sonography, six; CT, four; endoscopic retrograde cholangiography, five) in seven patients with surgically confirmed Mirizzi syndrome are analyzed retrospectively.     

Lymphaticopleural fistula: diagnosis by computed tomography

A case of lymphaticopleural fistula demonstrated by CT following lymphography is presented. Computed tomography can depict the course and location of the fistula as well as the chylous nature of the effusion.     

计算机体层激光乳腺摄影在乳腺病变中的应用

目的探讨计算机体层激光乳腺摄影（CTLM）诊断乳腺良恶性病变的可行性。方法对91例乳腺疾病病人的93个病变乳腺逐一进行CTLM检查,最后诊断均经病理证实。观察不同病变的CTLM表现,并将CTLM所见与临床检查提示的病变位置和病理诊断对照分析。结果成功获得84例病人的86个乳腺CTLM影像,检查成功率为92．5％（扫描层数≥6）。其中,恶性病变的乳腺扫描成功率为88．7％,良性病变成功率为100％（P〉0．05）。与乳腺良性肿瘤比较,恶性肿瘤在CTLM影像中表现出更常见（P〈0．01）和更明显（P〈0．01）的吸光增加。结论通过观察乳腺病变区域对激光的吸收情况。CTLM可以提供乳腺病变血管生成和血流多少的相关信息。     

Evalation of renal masses by ultrasound and computed tomography: A preliminary study

Computed tomography (CT) and ultrasound were performed on fifty-two patients with renal masses. Both modalides were able to correctly demonstrate the renal mass with an equal degree of accuracy. Since renal ultrasound is a well established, economical and noninvasive technique, it should be the diagnostic procedure of choice to determine whether or not a mass demonstrated by intravenous urography is cystic or solid. However, if faster scanning times as well as lower patient cost could be accomplished, more widespread use of CT as a diagnostic modality for differentiation of renal masses could result.     

Bullous lesions detected by computed tomography

An analysis was made of bullous emphysema detected by plain chest radiography and computed tomography (CT). Bullous lesions were detected in 43 of 214 patients who had thoracic CT as a further assessment of their pulmonary, pleural, and mediastinal abnormalities. Plain chest radiography failed to detect the bullous lesions in 17 (39.5%) out of the 43 patients. Bullous lesions unrecognizable on plain radiographs ranged from 1.0 to 2.0 cm in size, were few in number, and were situated on the mediastinal side of the lung in many patients. CT is a sensitive method for detecting bullous lesions. Therefore, we consider it necessary to perform CT when needle biopsy for a previously known pulmonary lesion is taken into account, because knowledge of coexisting bullous lesions may be useful in preventing the occurrence of severe pneumothorax as complication.     

Volumetric cine imaging for cardiovascular circulation using prototype 256-detector row computed tomography scanner (4-dimensional computed tomography): a preliminary study with a porcine model

This is a preliminary demonstration of volumetric cine imaging of cardiovascular circulation in domestic pigs using a prototype 256-detector row computed tomography (CT) scanner. The scan range is approximately 120 mm in the craniocaudal direction, with a 0.5-mm slice thickness. The thin sections can be used to create cine loops in multiple planes. Thus, the 256-detector row CT scanner overcomes some of the limitations of present helical CT methods.     

Comprehensive evaluation of patients with haematuria on multi-slice computed tomography scanner: protocol design and preliminary observations

An imaging protocol with a multi-slice CT scanner that allows comprehensive assessment of patients with haematuria is described. This protocol allows evaluation of the kidneys, ureters and bladder in a single examination using CT. This approach should streamline the diagnostic work-up of patients with haematuria.     

Preoperative evaluation of abdominal aortic aneurysms by computed tomography

A prospective, preoperative study was conducted of 50 electively repaired abdominal aortic aneurysms comparing the CT and angiographic findings with those described at surgery. CT demonstrated all 50 aneurysms and correctly identified their proximal extent in relation to the takeoff of the renal arteries in 47 patients (94%), while angiography detected 48 aneurysms (96%) and their correct relation to the renal arteries in all (100%). CT correctly identified 40 (98%) of 41 patients with two renal arteries, but only two (29%) of seven with three and none of two patients with four arteries. Common iliac artery involvement or lack thereof was accurately predicted in 42 (84%) of the 50 patients and internal iliac artery aneurysms found in one (33%) of three patients. It was concluded that CT is not sufficiently accurate for documenting location and patency of the renal arteries to allow its routine substitution for angiography in patients undergoing preoperative assessment of abdominal aortic aneurysms.     

Positron-emission computed tomography of the pancreas: a preliminary study.

Twenty-seven patients with suspected pancreatic disease were examined with emission computed tomography (ECT) with 11C-labeled amino acids. Of 24 patients with known clinical outcome, there were 1 false positive and 2 false negative results. One finding of interest was the increased concentration of radiopharmaceutical that accurately delineated the presence and extent of 4 pancreatic carcinomas and 1 lymphoma. In the normal subjects ECT reliably identified the pancreas. Disadvantages of ECT include the need for a cyclotron and high-quality hot chemistry laboratory, and the relatively long scanning time. The advantage of ECT is that it offers a unique opportunity to image biologic activity of the pancreas.     

Analytical study of the performance of a multilayer positron computed tomography scanner

The image-forming performance of multilayer positron tomographs for extended sources is evaluated analytically. The analysis is simplified by "rotation transform," by which three-dimensional photon detection problems are solved by two-dimensional treatment. Event rates of singles, unscattered true coincidence, and a single- and double-scattered coincidence are formulated for a uniform cylinder phantom as functions of various design parameters. Angle factors for Compton scattering and other parameters used in the evaluation are presented. Scatter components in projections and their effect on the reconstructed images are also evaluated. The scatter component in the reconstructed image depends critically on the detector ring radius, phantom radius, method of attenuation correction, etc. When the director radius is relatively small (40 or approximately 45 cm in diameter), the scatter/true ratio at the image center of a 20 cm diameter phantom may be larger than the scatter/true ratio in the event rates. Comparison with experimental data obtained with a head positron tomograph, POSITOLOGICA, showed reasonable agreement both in the total coincidence rates and in the scatter components in the images for a cylindrical phantom of 20 cm in diameter.