Computed tomography in acute posterior fossa infarcts

Thirty-one cases of acute posterior fossa infarcts are reported. CT evidence of obliterated posterior fossa cisterns and hydrocephalus indicates a grave prognosis due to brainstem compression. Progressive obliteration of posterior fossa cisterns may be used as an indicator for surgical decompression. Patients with intact posterior fossa cisterns had good recoveries without surgical treatment. CT can be used to diagnose the very early phase of an acute posterior fossa infarct and has prognostic value in predicting the outcome.     

Computed tomography in the diagnosis of renal masses

CT diagnosis of renal lesions proved to be highly efficient and reliable. This modality was most accurate in diagnosing renal cysts and the great majority of solid lesions. There was an indeterminate group (5% of cases studied) that included cysts, tumors and abscesses. This group requires additional investigation, but angiography is often not conclusive because of the avascular nature of these tumors. Other problem areas included cysts with apparently irregular margins and artifacts produced by the presence of contrast agent in the collecting systems.     

Computed tomography diagnosis of mesenteric masses.

The computed tomographic findings of 30 mesenteric masses are presented. To delineate the mesentery accurately, oral contrast material must fill the entire small bowel. Of the masses, 23 were secondary to non-Hodgkin's lymphoma. These masses were irregular in shape and homogeneous in their tissue attentuation. Two of the 23 had a normal lymphangiogram in the upper paraaortic area. Both lymphangiography and CT were necessary to define the extent of disease in such patients. The six mesenteric metastases were irregular in shape. Four of these had areas of decreased attentuation eccentrically located within the mass which may be secondary to necrosis. One mesenteric cyst had a circular shape with smooth, sharp borders, and a centrally located area of decreased attenuation.     

跨中、后颅窝轴外肿瘤及肿瘤样病变的影像学诊断

目的：提高对跨中、后颅窝轴外肿瘤及肿瘤样病变的影像学认识。方法：60例经病理证实的跨中、后颅窝轴外肿瘤及肿瘤样病变按位置分为中央型和外侧型，后者又分中颅窝型、后颅窝型及骑跨型，分析各型构成情况及影像学特征。结果：中央型12例，脊索瘤5例，垂体瘤3例，鼻咽癌2例，颅咽管瘤、脑膜瘤各1例。外侧型48例，三叉神经肿瘤14例，脑膜瘤12例，表皮样囊肿11例，硬膜型海绵状血管瘤4例，皮样囊肿、转移瘤各2例，血管外皮瘤、颈静脉球瘤、鼻咽癌各1例。多数病变可根据影像学特点做出诊断并明确范围。结论：按位置特征对跨中、后颅窝轴外肿瘤及肿瘤样病变分型．有助于定性诊断及范围描述，有较高的临床应用价值。     

Computed tomography of ovarian masses

A retrospective analysis of CT images in 138 histologically proven ovarian masses in 100 patients was undertaken to evaluate the usefulness and limitation of CT in the diagnosis of ovarian tumors. Benign masses were purely cystic in 98 (94.2%) and had solid component (including thickened walls, thickened septa, papillary projections) in five of 104 lesions (4.8%) on CT. These five masses, which are classified as benign solid tumors, could not be differentiated from malignant tumors by either the size of the solid portion or the intensity of contrast enhancement. In the malignant tumors a solid portion was detected in 32 of 34 tumors (94%). When a solid component is detected in an ovarian mass, the mass should be considered malignant although a few cases will be benign solid tumors. In Krukenberg tumors, which were all of gastric origin, the solid component was so large that it occupied more than one-half the mass. Therefore, if the solid portion of the ovarian mass is large on CT, upper gastrointestinal study should be performed to rule out Krukenberg tumor.     

Computed tomography of non-functioning adrenal masses

Incidental finding of non-functioning adrenal masses is not uncommon in patients undergoing abdominal CT. In a 4-year period, adrenal masses were detected as an accessory finding in 38 patients. The diagnosis was confirmed either histologically or in follow-up studies. This global series consists of 6 adenomas, 4 carcinomas, 1 pheochromocytoma, 1 ganglioneuroma, 23 metastases, 1 lymphoma, 1 histiocytoma, 1 myelolipoma. The Authors point out the parameters for the pathologic assessment of adrenal masses: size, contours and fine-needle biopsy appear to be the most reliable features.     

Computed tomography of chest wall masses

The authors argue that CT is superior to other imaging techniques for the examination of the bones and soft tissues of the chest wall. They also note the importance of CT in planning therapy for lesions involving these structures. In support of these theses they present computed tomograms showing 26 different types of lesion involving the chest wall ranging from sternal fracture to malignant fibrous histiocytoma. Malignant neoplasms involving the chest wall by metastasis or direct extension from the breast, lung or mediastinum are emphasized.     

Computed tomography of cystic neck masses

Computed tomography (CT) of the neck has been primarily applied to the assessment of malignant disease with few reports describing its utility in benign conditions. The authors report 13 cases of cystic neck masses evaluated by CT. Pathological conditions included brachial cleft cyst, laryngocele, thyroglossal duct cyst, cavernous lymphangioma, necrotic lymphadenopathy, and asymmetric jugular veins. Computed tomography was helpful in correctly predicting the etiology by determining the exact location of these masses in relation to the normal anatomic structures in the neck.     

Computed tomography of benign ovarian masses

Although ultrasound is the primary imaging modality for evaluating benign gynecologic pelvic masses, CT may provide diagnostic information regarding ovarian masses that are discovered fortuitously. The relatively infrequent use of CT in evaluating the adnexa has resulted in a paucity of literature regarding the CT characteristics of benign ovarian masses. The CT appearances of 24 benign ovarian masses are presented. Pathologic diagnoses were ovarian cyst (nine), endometrioma (five), teratoma (three), serous cystadenoma (two), mucinous cystadenoma (two), thecoma (one), cystadenofibroma (one), and Brenner tumor (one). Benign ovarian cysts have characteristic homogeneous water density and smooth walls on CT. Single internal septations and slight wall irregularity are also common features, but soft-tissue mural or septal nodules are uncommon. Computed tomography can be diagnostic in evaluating cystic teratomas. Other benign ovarian masses exhibit a spectrum of CT appearances that is often nonspecific, and surgical or biopsy proof may be necessary to exclude malignancy.     

Computed tomography of the infratemporal fossa in primary jaw pathology

Due to the anatomical relationship of the jaws to the infratemporal fossa this area is readily involved in pathological processes of the jaw. Conventional radiographs play a limited role in demonstrating this region. A variety of primary diseases of the jaws, namely hereditary, developmental, infective, benign and malignant tumours with extension into the infratemporal fossa, are presented. Computed tomography is an excellent method for showing both osseous and soft-tissue components which include bony destruction, new bone formation, soft tissue calcification, inflammatory and malignant processes affecting the muscles and fat in the infratemporal fossa.     

Computerised axial tomography in posterior fossa lesions

The author found that 191 patients out of the first 6000 examined by the EMI brain scanner had lesions in the posterior fossa. Appearances in acoustic tumours, meningiomas, astrocytomas, haemangioblastomas, medulloblastomas, gliomas of the brain stem and metastases are described.     

Computed tomography of intracerebral leukemic masses.

Five patients with differing types of leukemia had clinical symptoms of a localized intracerebral leukemic mass. Computed tomography (CT) demonstrated a mass of equal or increased density relative to normal brain; a zone of surrounding edema was variable. In each case, the mass showed evidence of relatively uniform contrast enhancement. CT appearance of leukemic masses is consistent and quite different from the findings in other central nervous system complications of leukemia and its aggressive treatment.     

Computed tomography of cardiac and pericardiac masses

Cardiac and paracardiac masses include benign and malignant tumors and nontumoral mass lesions. Metastatic tumors are far more common than primary cardiac tumors. Although echocardiography and magnetic resonance imaging (MRI) are the most frequently used imaging examinations, multidetector computed tomography (MDCT) is often used to evaluate these masses, particularly when MRI is contraindicated. MDCT is not only fast but also has high spatiotemporal resolution, multiplanar reconstruction capabilities, and a wide field of view, providing detailed evaluation of cardiac and paracardiac masses and adjacent structures, including the lungs. Knowledge of the characteristic and atypical imaging appearances is essential for thorough evaluation of these masses. In this pictorial review, the CT appearances of the most common cardiac and paracardiac masses are discussed and illustrated.