Computed tomography of isodense subdural hematomas.

Eight cases of isodense subdural hematomas were evaluated by computed tomography (CT). CT demonstrated varying degrees of compression of a lateral ventricle, shift of the midline structures and, in some cases, obliteration of the subarachnoid sulci on the side of the lesion. Contrast enhancement was helpful in one case and demonstrated medial displacement of enhanced cortical margins away from the inner table of the skull. Two of the eight patients had no clear history of trauma.     

Computed tomography of isoattenuating subdural hematomas.

CT scans of 87 patients with subdural hematoma were compared to those of 393 patients with midline shift caused by other intracranial lesions with regard to attenuation changes in the lesion and the character of the ventricular deformity. Isoattenuating was exhibited by 25% of the subdural hematomas and 5% of the other lesions. In 70 to 80% of the isoattenuating hematomas, the diagnosis could be made on the basis of the characteristic ventricular deformity. Other diagnostic procedures are not necessary in these cases.     

Computed tomography in the evaluation of subdural hematomas.

Computed tomographic (CT) scans used in the diagnosis and management of subdural hematomas were analyzed with respect to their contribution to angiography and surgery. There has been a progressive increase in the use of CT in evaluating post-traumatic and postoperative subdural hematomas at the Mayo Clinic. At present, 40% of all patients undergo operation on the basis of the CT findings alone. False-positive diagnoses revealed at surgery have decreased to less than 4%. Erroneous negative interpretations have involved 10% of all patients whose diagnosis was subdural hematoma. Criteria for the interpretation of scans have been established.     

Computed tomography angiography: principles and clinical applications

Clinical applications of computed tomography (CT) angiography have increased with the improved technology of multidetector CT systems. Adequate contrast enhancement and the timing of image acquisition are key elements in producing technically adequate CT angiograms. This review article provides guidelines and protocols for four-, eight- and 16-channel multidetector systems in studies of the thoracoabdominal aorta, aortoiliac, and abdominal visceral vasculature, abdominal and extremity run-off studies, and carotid/cerebral CT angiography.     

Computed tomography features of recurrent ovarian carcinoma according to time to relapse

Background: Although the sites of recurrent ovarian cancer are individually described in the literature, patterns of recurrent disease are poorly understood.

Purpose: To describe CT patterns of disease in recurrent ovarian cancer. To emphasize common patterns, recognise subtle and unusual sites of recurrent disease.

Materials and Methods: We identified patients between 1981-2004 presenting with clinical recurrence or elevated CA 125 after complete primary clinical and radiological response. CT imaging at primary diagnosis, during and after treatment and at recurrence was retrospectively reviewed. Site, distribution, stage of disease and time to relapse was recorded.

Results: 400 patients were treated for ovarian cancer. 214(54%) achieved complete primary response. 161(75%) relapsed with complete imaging available in 67 patients. Of the 67 patients, 14 (21%) recurred within 1 year, 44 (66%) relapsed between 1-5 years. Therefore 87% of relapses occurred within 5 years following primary treatment. Five (8%) relapsed between 5-10 years and 4 (6%) relapsed after 10 years. Commonest pattern of relapse was pelvic mass in 35 (48%) patients, solitary in 15 (22%). 27 (45%) relapsed with peritoneal thickening, 27 (45%) had small or large bowel serosal disease, 22 (33%) had enlarged lymphadenopathy, 6 as sole manifestation of recurrence, 20 (30%) presented with unusual sites of recurrence: 6 splenic, 10 hepatic, 2 biliary, 3 brain and 2 muscle.

Conclusion: Our study is the first to describe common patterns of recurrence in ovarian cancer. Most frequent site is pelvis, followed by peritoneum, serosal surfaces and nodal disease. 30% presented with disease at 'unusual' sites.     

Computed tomography of cranial metastatic malignant melanoma: features, early detection and unusual cases

The cranial computed tomographic (CT) scans reported as showing metastatic disease in patients with malignant melanoma (MM) seen at the Westminster Hospital over a 5 year period were reviewed. Ninety-eight patients with intracranial metastatic MM were identified. Twelve had an initial scan which was reported as normal and particular attention was given to these to see if, in retrospect, any early features of metastatic disease were discernible. Fifty-eight cases showed the "typical" features of intracranial MM; the remainder were unusual in appearance, behavior, or site. Radiological regression was shown in only seven cases on follow-up scans; all but one of these patients had one or two large metastases. No significant lesion was thought to have been missed on a scan after the administration of intravenous contrast medium, but the lesions of three patients were difficult to discern on plain scans. Thus when MM metastasis is suspected, the use of the contrast-only scan is advocated.     

Computed tomography of hemangiomas and related soft-tissue lesions in children

The varied computed tomographic (CT) appearances of 19 hemangiomas and related soft-tissue lesions in 17 children were assessed retrospectively. Good CT-tissue correlation was obtained in 11 patients in whom histology was available. Although most cutaneous vascular lesions can be diagnosed by their characteristic clinical features, their extent may be difficult to assess clinically and at surgery. CT is important in defining the extent of these lesions as a guide for the surgeon, and for conservative follow-up. The often characteristic CT appearances also help in the diagnosis of the few patients with unusual clinical presentations.     

Dare to date: age estimation of subdural hematomas,literature, and case analysis

The age estimation of injuries, e.g., subdural hematomas (SDH), can play an important role in medicolegal cases. Various forensic textbooks provide tables of histomorphological changes in SDH in time. The analysis of these data showed that these tables employed different time intervals, although they were all based on only a single publication with a limited number of cases in some of the time periods. The present study aimed to add cases to the original article and to standardize the dating system of SDH. Results from two well-documented studies and 64 additional cases were analyzed, and the use of a number of immunohistochemical staining methods, which could support the histomorphological analysis of some of the changes, was proposed. The results showed that correct age estimation was achieved in approximately 95 % of the cases. Based on the cumulative data from the two published studies and the analysis of the additional cases, a simplified timing table was developed, and the potential pitfalls were addressed. This study shows that accurate age estimation of SDH is possible, provided that the rules established by this study are observed.     

Computed tomography of the nasopharynx and related spaces. Part II: Pathology

Malignant tumors of the nasopharynx were analyzed by region of origin and route of spread. Nasopharyngeal carcinomas produced early submucosal infiltration of the deglutitional muscle layer with enlargement of the levator palati muscle and lateral displacement of the parapharyngeal space. Serous otitis media was frequently associated, and the trigeminal nerve was occasionally involved. Intracranial extension via the foramen lacerum was frequent. Metastases to the infratemporal fossa produced early involvement of the masticatory muscle layer with medial displacement of the parapharyngeal space. Adenoid cystic carcinomas showed late but disproportionate involvement of the sphenoid sinus. Chordomas extended into the retropharyngeal soft tissues via the petro-occipital fissure. Maxillary sinus carcinomas, which were very large at the time of presentation and impinged on the nasopharynx, showed extensive destruction of the pterygoid plates.     

Computed tomography and lateral ventricular asymmetry: clinical and brain structural correlates

Asymmetry of the ventricles of the brain without an obvious cause is a common and intriguing radiologic finding. To understand this phenomenon better the authors conducted a 24-month study to compare clinical and structural manifestations of two groups of patients who had undergone head computed tomography (CT): group A comprised 249 patients with asymmetry of the lateral ventricles of the brain without space-occupying lesions, intracranial bleeding, recent infarction or trauma and group B comprised 266 patients with the above exclusion criteria but without ventricular asymmetry. The degree of ventricular asymmetry was classified as mild, moderate or severe, according to the ratio of the larger frontal horn diameter to the smaller one. The incidence of lateral ventricular asymmetry was 5.3%. The following clinical manifestations were more frequently present in group A: headaches (p = 0.002), seizures (p = 0.007) and positive human immunodeficiency virus (HIV) status (p = 0.02). Transient ischemic attacks were more prevalent in group B (p = 0.009). Independent predictors of headache were: younger age (p less than 0.001) and the degree of ventricular asymmetry (p = 0.02). Predictors of seizures were: younger age (p less than 0.001), ventricular asymmetry (p = 0.004) and the absence of septal deviation (p = 0.009). In group A, predictors of a higher degree of asymmetry were septal deviation (p less than 0.001) and older age (p = 0.008). The authors conclude that asymmetry of the lateral ventricles of the brain is a relatively common CT finding that has important clinical and brain structural correlates and deserves more attention in the field of imaging.     

Computed tomography of pineal, parapineal, and histologically related tumors

Thirty-one of 32 pineal and related tumors were diagnosed by computed tomography (CT). There were 7 germinomas, 4 primary pineal tumors, 4 embryonal cell carcinomas, one teratoma, one epidermoid, one primitive neuroectodermal tumor, 8 astrocytomas and 6 lipomas. Histologic confirmation was obtained in 22. The CT characteristics allow differentiation of benign tumors such as teratomas and epidermoids from malignant germinal lesions such as germinoma and embryonal cell carcinoma. Abnormal calcification occurs most frequently in the primary pineal tumors, pineoblastoma and pineocytoma. The CT characteristics and consideration of the patient's age and sex often lead to histologic prediction and better treatment planning.     

Computed tomography and the clinical picture of suicidal CO poisoning

Cranial CT is important to exclude the presence of a mass in the cavum cranii in case of an unclear suicide attempt, particularly a traumatic mass. It can be helpful also in cases of carbon monoxide intoxications.     

Age determination of subdural hematomas with CT and MRI: A systematic review

Objectives

To systematically review the literature on dating subdural hematomas (SDHs) on CT and MRI scans.

Methods

We performed a systematic review in MEDLINE, EMBASE and Cochrane to search for articles that described the appearance of SDHs on CT or MRI in relation to time between trauma and scanning. Two researchers independently screened the articles, assessed methodological quality and performed data extraction. Medians with interquartile ranges were calculated. Differences were tested with a Mann–Whitney U or Kruskal–Wallis H test.

Results

We included 22 studies describing 973 SDHs on CT and 4 studies describing 83 SDHs on MRI. Data from 17 studies (413 SDHs) could be pooled. There were significant differences between time intervals for the different densities on CT (p < 0.001). Time interval differed significantly between children and adults for iso- and hypodensity (p = 0.000) and hyperdensity (p = 0.046). Time interval did not differ significantly between abused and non-abused children. On MRI, time intervals for different signal intensities on T1 and T2 did not differ significantly (p = 0.108 and p = 0.194, respectively).

Conclusions

Most time intervals of the different appearances of SDHs on CT and MRI are broad and overlapping. Therefore CT or MRI findings cannot be used to accurately date SDHs.     

Computed tomography of intracerebral hematomas. II. Radionuclide and transmission CT studies of the perihematoma region.

Transmission CT studies of 40 patients with intracerebral hematomas were used for an analysis of the perihematoma region. Nineteen of these patients had radionuclide studies. In the brain adjacent to an intracerebral hematoma, the patterns of pertechnetate uptake on scintillation scans and contrast enhancement on transmission CT resemble those observed in cerebral infarctions. The healing of the perihematoma region proceeds similarly to that of infarcts. The brain about the hematoma is ischemic tissue which behaves much like cerebral infarction not related to hematomas.     

Computed tomography in urothelial tumors of renal pelvis and related filling defects

Our study includes 12 patients. Of these, six had transitional cell carcinoma, three patients with stones and three patients with blood clots. With the use of computed tomography we were able to arrive at a reasonable staging and diagnosis of the filling defects. Computed tomography is not sufficiently sensitive to recognize microscopic invasion. Reactive fibrosis and postobstructive inflammatory changes can mimic tumor invasion on computed tomography, and in such cases staging will not be accurate.     

Computed tomography of cerebral infarction: Hemorrhagic,contrast enhancement,and time of appearance

Large confluent petechial hemorrhages and/or hemorrhage within infarcts may be seen on CT scan. Small petechial hemorrhages are not resolved by current equipment and techniques. Elevation of absorption values of an infarct following contrast media primarily occurs in the first month after onset, and may be occasionally confused with a tumor. Sequential CT changes in infarcts correlate well with established pathologic changes. Cerebral infarction may be seen on CT scan in some cases as early as 24–48 hr after its onset.