Computed tomography of sacral and presacral lesions

Summary Forty-two patients with various sacral and presacral lesions were examined by computed tomography (CT). CT was sensitive in detecting intraosseous neoplasms and presacral soft tissue masses and in seven cases identified lesions not visible on plain films. The total extent of each lesion was readily determined using CT. However, CT is diagnostically nonspecific and differentiation between primary and secondary tumors of the sacrum is generally not possible from the CT appearance alone. CT is also of considerable use in the evaluation of several non-neoplastic conditions of the sacrum, including spinal dysraphism, anterior and internal meningocele and trauma.     

Computed tomography of orbital lesions

Summary During the first two years with the 160×160 matrix EMI scanner 144 consecutive patients referred with suspicion of orbital disease were subjected to 190 computed tomography (CT) examinations. The X-ray attenuation and enhancement patterns of the various lesions were analyzed. In general it was difficult to correlate these parameters with the histopathological features. Hemangiomas, however, showed little enhancement and meningiomas a large degree of enhancement, while malignancies, lymphomas and pseudotumors were mainly intermediate. With orbital Graves' disease a low preinjection attenuation and a large enhancement (with normal striated neck muscle as a reference) was found in the external eye muscles. The diagnostic accuracy of CT (n=143) was compared to that of A/scan ultrasonography (US, n=80) and carotid angiography (n=40). CT showed the highest accuracy of the three methods, but CT differed only statistically from carotid angiography.     

Computed tomography feature of synovial osteochondromatosis

Synovial osteochondromatosis in the knee joint is rarely a confusing diagnostic problem. Diagnosis depends on the clinical circumstances of the case and a radiologic interpretation which can exclude soft tissue tumors with calcifications and other malignant tumors characterized by the presence of multiple osteo-cartilaginous bodies. The relative value of computed tomography (CT) in the diagnosis of synovial osteochondromatosis is emphasized and the differential diagnosis discussed.     

Computed tomography for small acoustic neuromas

Summary The minimal size of acoustic neuromas detectable by computed tomography (CT) is, according to the available literature, 1.5 to 2 cm. The new otoneurosurgical technic using the transtemporal and translabyrinthine approach necessitates an early diagnosis of neuromas protruding 1 cm or less into the cerebellopontine angle cistern. This seemed impossible with the available CT equipment. Eight proven acoustic neuromas 1 cm or less in diameter, detected with CT, are reported. Diagnostic criteria are elaborated. The study shows that small cerebellopontine angle tumors can be detected by use of CT machines of the newer generation which perform scanning with thin and overlapping slices.     

Computed tomography for lesions of the craniovertebral region

Summary The images obtained by computed tomography constitute a new and interesting approach to lesions of the craniovertebral region. The criteria of basilar invagination must be systematically checked in routine examination. The main interest of CT scanning is the simultaneous view of the bony structures as well as the central nervous system in a completely innocuous way.     

Computed tomography and intracranial aspergillosis

Summary A case of aspergillosis of the central nervous system with multiple granulomas examined by computed tomography is reported. The findings are those of chronic mass lesions with and without calcium deposits. An associated cystic configuration probably is not specific for aspergillomas.     

Computed tomography of sternoclavicular joint lesions in spondylarthropathies

 To evaluate the computed tomography (CT) findings of inflammatory lesions of the sternoclavicular joints (SCJ) in spondylarthropathies. Design and patients. CT scans of the SCJs were obtained in 23 patients (group 1) with inflammatory SCJ lesions in spondylarthropathies. These scans were reviewed by four readers and compared with the CT scans of 23 matched controls (group 2). Each reader had to complete a 27-item grid. Results and conclusion. In the 23 patients of group 1, the mean number of observed signs was 5.3±4.2 higher (P<0.01) than in the group of 23 matched controls (2.4±1.6). Four signs were more frequently observed (P<0.05) in group 1: surrounded subchondral clavicular erosions and cysts, surrounded subchondral sternal cysts and sternal bone sclerosis. A cyst and/or an erosion was associated with hyperostosis and/or bone sclerosis in 9 of 23 patients in group 1. This association was not observed in group 2; the difference was significant (P<0.001). A cyst and/or an erosive lesion was observed 18 times in group 1 versus 11 times in group 2; the difference was significant (P<0.05). Conversely, signs of degenerative lesions (osteophytes, subchondral sclerosis, unevenness of joint surface) were no more frequently observed in controls than in group 1. This study emphasizes the diagnostic value of CT, in particular in the identification of inflammatory lesions, even when pre-existing degenerative disease is present.     

Computed tomography of intrathecal thorotrast

Summary Thorotrast is distributed in the cerebral subarachnoid space in a distinctive manner. Computed tomography is an excellent method for demonstrating this distribution.     

Computed tomography of stress fracture

An athletic young female developed gradual onset of pain in the right leg. Plain radiographs demonstrated solid periosteal reaction in the tibia compatible with stress fracture. She stopped sport activites but her pain continued. Follow-up radiographs of the tibia revealed changes suspicious for osteoid osteoma. Computed tomography (CT) scan demonstrated periosteal reaction, but in addition, lucent fracture lines in the tibial cortex were evident. CT obviated the need for more invasive diagnostic procedures in this patient. In selected cases CT may be useful to confirm the diagnosis of stress fracture when plain radiographic or routine tomographic studies are not diagnostic.     

Computed tomography of intramuscular myxoma

Computed tomography (CT) was performed in seven patients with intramuscular myxoma. All lesions were well demarcated, of homogeneous appearance and attenuation values ranging from 10 to 60 (HU). The tumor size, as estimated at CT, correlated well with the size of the surgical specimen, which is in contrast to the findings in some high grade malignant sarcomas.     

Computed tomography evaluation of fatty tumors of the somatic soft tissues: Clinical utility and radiologic-pathologic correlation

The role of computed tomography (CT) in the evaluation of fatty tumors of the somatic soft tissues was investigated. Six surgically proven cases of fatty tumors were studied preoperatively by CT and standard radiographic means — conventional radiographs, xeroradiography, and angiography. Our case material included a simple lipoma, two infiltrative lipomas, an angiolipoma, and two liposarcomas. The radiologic-pathologic correlation was evaluated with respect to the various imaging modalities. The unique tissue characteristics of fatty tumors makes them particularly adaptable to CT scanning. In addition to its ability to define accurately tissue densities, the facility of CT in depicting depth, size, and extent of the lesion in the axial plane was found to be most useful in the preoperative evaluation of our case metarial.     

Diagnosis of sellar and parasellar lesions by computed tomography

Summary Suspected lesions in and around the sella were examined by CT in 129 cases. The diagnostic accuracy and various technical aspects of the method are described. The mean attenuation and enhancement after administration of contrast material are evaluated in craniopharyngiomas, chromophobe adenomas, meningiomas, aneurysms, dermoid cysts, an arachnoid cyst and a glioma. The choice of collimator and its use in relation to sellar dimensions, particularly the sellar depths, are emphasized.     

Computed tomography of cavernous sinus diseases

Summary We retrospectively analyzed CT scans of 21 cavernous sinus lesions in an attempt to discover CT findings helpful to the differential diagnosis. With the integration of various CT observations it was possible to categorize the lesions into inflammatory, vascular, benign neoplastic and malignant metastatic lesions with few exceptions. Four of 5 cases of septic cavernous sinus thrombophlebitis revealed unilateral or bilateral multiple irregular filling defects in the enhancing cavernous sinus with or without orbital inflammatory change. Four of 5 cases of carotid-cavernous fistula demonstrated unilateral or bilateral diffuse bulging and homogeneous enhancement of the cavernous sinus with obliteration of normal low densities of cranial nerves and gasserian ganglion. Dilatation and tortuosity of superior ophthalmic vein were also associated. Four of 5 cases of benign neoplastic lesion showed well-circumscribed enhancing masses confined to the cavernous sinus with pressure erosion or hyperostosis of adjacent bone. Five of 6 cases of malignant metastatic lesion showed changes suggesting malignancy such as destruction of adjacent bone or associated manifestations of intracranial spread. As compared with the axial scan, coronal scans proved to be more sensitive in detection of subtle cavernous sinus expansion, and superior in evaluation of intracavernous neural structures, relationships with the pituitary gland and changes in the skull base. Axial scans, however, were superior in detection of associated orbital and intracranial abnormalities. Scans in both projections are needed in the evaluation of most cavernous sinus diseases.     

Relative value of computed tomography and hypocycloidal tomography in the diagnosis of pituitary microadenoma a radio-surgical correlative study

Summary The relative value of a second generation CT scanner and complex motion polytomography are compared in 36 patients undergoing transsphenoidal surgery due to clinical and biological evidence of pituitary hypersecretion. CT findings of focal glandular hypodensity in 17 patients and upward convexity of the sellar contents in 15 patients suggested the presence of a pituitary microadenoma. Complex motion tomographic findings suggesting a microadenoma were found in 21 of 32 cases and included bulging of the sellar floor or localized thinning of the lamina dura. Selective transsphenoidal adenomectomy was performed on 34 of the 36 patients and the preoperative location based on CT scanning data was positively correlated with surgical results in 75% of the cases. When there is a strong clinical suspicion of pituitary hypersecretion both CT and polytomography may suggest the existence and location of a microadenoma. CT should be the radiographic technique of choice since it produces accurate information as to the size and density of the pituitary gland.Orginal presentation: 9th Congress of the European Society of Neuroradiology, Brussels, 12–13 September 1980.     

Computed tomography in ophthalmology

Summary The practical value of density measurements with computed tomography of orbital lesions is demonstrated.     

Perfusion characterization of liver metastases from endocrine tumors: Computed tomography perfusion

AIM: To assess prospectively parameters of computed tomography perfusion (CT p) for evaluation of vascularity of liver metastases from neuroendocrine tumors.METHODS: This study was approved by the hospital’s institutional review board. All 18 patients provided informed consent. There were 30 liver metastases from neuroendocrine tumors. Patients were divided into three groups depending on the appearance of the liver metastases at the arterial phase of morphological CT (hyperdense, hypodense and necrotic). Sequential acquisition of the liver was performed before and for 2 min after intravenous injection of 0.5 mg/kg contrast medium, at 4 mL/s. Data were analyzed using deconvolution analysis to calculate blood flow (BF), blood volume (BV), mean transit time (MTT), hepatic arterial perfusion index (HAPI) and a bi-compartmental analysis was performed to obtain vascular permeability-surface area product (PS). Post-treatment analysis was performed by a radiologist and regions of interest were plotted on the metastases, normal liver, aorta and portal vein.RESULTS: At the arterial phase of the morphological CT scan, the aspects of liver metastases were hyperdense (n = 21), hypodense (n = 7), and necrotic (n = 2). In cases of necrotic metastases, none of the CT p parameters were changed. Compared to normal liver, a significant difference in all CT p parameters was found in cases of hyperdense metastases, and only for HAPI and MTT in cases of hypodense metastases. No significant difference was found for MTT and HAPI between hypo- and hyperdense metastases. A significant decrease of PS, BV and BF was demonstrated in cases of patients with hypodense lesions PS (23 ± 11.6 mL/100 g per minute) compared to patients with hyperdense lesions; PS (13.5 ± 10.4 mL/100 g per minute), BF (93.7 ± 75.4 vs 196.0 ± 115.6 mL/100 g per minute) and BV (9.7 ± 5.9 vs 24.5 ± 10.9 mL/100 g).CONCLUSION: CT p provides additional information compared to the morphological appearance of liver metastases.     

Computed tomography in the diagnosis and differential diagnosis of glioblastomas

Summary The CT patterns of 295 glioblastomas examined with pre- and postcontrast scans using an EMI scanner mark I (Matrix 160/160) have been reviewed and compared with the CT appearances of other brain tumors, metastases and abscesses. There is a great variety of CT patterns with glioblastomas. However, a garland-shaped CT appearance, representing a subgroup of ring-shaped lesions, seems to be most typical for glioblastomas since it was observed in 19% of ring-shaped glioblastomas but in only one out of 172 metastases and in no case of an astrocytoma grade II or an abscess in our series. The initial CT diagnosis, based on the CT finding, the patient's history and the clinical data, was correct in 69.8% of the glioblastomas, 41 recurrent glioblastomas included. In 12% of the cases the presence of a glioblastoma was within differential diagnosis. These results lead to the conclusion that in many cases additional diagnostic methods, such as serial scintigraphy and/or cerebral angiography, are required for a reliable differential diagnosis.     

Computed tomography in Alexander's disease

Summary A case of biopsy proven Alexander's disease is described with extensive low density lesions in both frontal lobes, which in our experience, and on survey of the literature have not been described previously.     

Computed tomography in Alexander's disease

Summary Two cases of biopsy-proven Alexander's disease are described with computed tomographic changes which, in our experience and on survey of the literature, have not occurred in any other condition. Such changes in a child with a progressive condition consistent with Alexander's disease, strongly support the diagnosis.