Leptomeningeal and calvarial sarcoidosis: CT and MR appearance

We report an unusual case of biopsy-proven combined leptomeningeal and calvarial sarcoidosis, as seen on CT and MRI. A solitary large thick plaque was present in the left hemisphere, with overlying bony infiltration and erosion and associated abundant vasogenic edema in the brain. The lytic lesion was visible on Scout digital radiography for CT slice positioning. The typical manifestations of CNS sarcoidosis, i.e., chronic leptomeningitis in the basilar cisterns and hypothalamic regions, were absent.     

CT appearance of pulmonary vasculitis in children

OBJECTIVE: The aim of this study was to determine whether a CT pattern that may represent early or subtle changes of pulmonary vasculitis in children exists. MATERIALS AND METHODS: High-resolution CT scans of the chest for 107 children were retrospectively reviewed by two radiologists who were unaware of the original study findings. Chest CT scans (conventional) for another 54 children who had symptoms or a diagnosis of vasculitis also were reviewed. RESULTS: We identified hazy or fluffy centrilobular, perivascular densities in 10 children, two of whom had small airways disease and eight of whom had vasculitis (Wegener's granulomatosis [n = 5], systemic lupus erythematosus [n = 1], scleroderma-polymyositis overlap syndrome [n = 1], and Churg-Strauss syndrome [n = 1]). The latter eight children underwent 35 scans, 17 of which were positive for these perivascular densities. All positive scans were associated with active disease of new onset (5/17) or with clinical exacerbation of preexisting systemic disease (12/17). The positive scans also were associated with an elevated erythrocyte sedimentation rate (13/17) and biopsy evidence of vasculitis from a variety of sites, including the lungs (n = 1), kidneys (n = 7), oropharynx (n = 5), skin (n = 9), lymph nodes (n = 1), and myocardium (n = 2). The single lung biopsy showed an angiocentric inflammatory-hemorrhagic process. Of the five patients who had positive scans, underwent therapy, and then had repeat studies, four patients had scans revert to normal in association with inactive disease. The remaining patient whose scan did not normalize failed to respond to treatment. CONCLUSION: The fluffy centrilobular pattern likely represents subtle changes of pulmonary vasculitis. In the appropriate clinical setting, such a finding may obviate the need for a lung biopsy.     

Primary intraosseous hemangioma of the orbit: CT and MR appearance

An 8-year-old girl had acute onset of blurred vision, proptosis, and lateral and vertical gaze palsies on the right. CT and MR examinations showed an expansile mass involving the greater wing of the right sphenoid bone. Pathologic analysis of the surgical specimen revealed a capillary hemangioma. The lesion was inhomogeneous but predominantly isointense with gray matter on T1-weighted images. On T2-weighted images the lesion was inhomogeneous with areas of both high and low signal intensity. The rim enhanced uniformly, and there was inhomogeneous enhancement of the bulk of the lesion.     

Normal appearance and size of the diaphragmatic crura in children: CT evaluation

PURPOSE: The objectives of the study were to document the normal CT appearance and size of the crura of the diaphragm in children. MATERIALS AND METHODS: The CT scans of 80 children (0-15 years) were reviewed. The children were divided into eight age groups. The maximal transverse diameters of the right and left crura were measured. They were normalized by comparison with the transverse and anterior-posterior diameters of the 12th thoracic vertebra (T12) and the transverse abdominal diameter at T12. The crura were also evaluated as to whether their contour was smooth or nodular. RESULTS: The diaphragmatic crura of smaller children appear large, relative to body size and the diameters of the T12 vertebral body, compared with those in older children. Crural width does not increase significantly with age. Additionally, the crura were found to have a greater tendency to be nodular in appearance in children under the age of 5 years than in older children. CONCLUSION: Diaphragmatic crura are more nodular and larger relative to body size in younger children.     

Multiple sclerosis of the spinal cord: magnetic resonance appearance

OBJECTIVE: To determine the MR appearance of spinal cord multiple sclerosis (MS) plaques in patients presenting with myelopathy by using a high-field (1.5 T) imager. MATERIALS AND METHODS: We studied 119 patients who underwent high-field (1.5 T) MR studies of the spinal cord for evaluation of myelopathy. All 119 patients were thought to have possible findings of spinal cord MS at the time of the MRI interpretation. RESULTS: Sixty-four plaques were studied in 47 patients with clinically definite MS and adequate quality MRI. Of these patients 68% had a single spinal cord plaque, 19% had two plaques, and 13% had three or more plaques. Sixty-two percent of the plaques occurred in the cervical spinal cord and most frequently involved the posterior (41%) and lateral (25%) aspects of the spinal cord. None of the 64 lesions involved the entire thickness of the spinal cord. The lesion length varied from 2 to 60 mm, with 84% of the lesions < 15 mm in length. The spinal cord diameter was unchanged in 84% of plaques, enlarged at the level of the lesion in 14%, and atrophic in 2%. Just over half (55%) of the plaques enhanced with intravenously administered gadolinium. Of the patients who received synchronous head and spinal cord examinations on the same day, 24% had normal findings on the MR study of the head. Follow-up spinal cord studies were available in nine patients. New lesions developed in two patients, while previously described lesions resolved. In three patients only new lesions developed. In four patients no change occurred in the existing number of cord plaques. CONCLUSION: Spinal cord demyelinating plaques present as well-circumscribed foci of increased T2 signal that asymmetrically involve the spinal cord parenchyma. Knowledge of their usual appearance may prevent unnecessary biopsy. An MR examination of the head may confirm the imaging suggestion of spinal cord demyelinating disease, because up to 76% of patients have abnormal intracranial findings. In the remaining 24% of cases in which the clinical diagnosis is not certain and MR findings in the head are negative, a follow-up spinal cord study is recommended, because these lesions evolve and change over time.     

Neonatal meningitis and multiple brain abscesses due to Citrobacter diversus

We report a fatal sporadic case of neonatal Citrobacter diversus meningitis with rapid clinical progression. At autopsy, multiple brain abscesses and abscesses in the spinal cord had complicated purulent meningitis. Septic omphalitis was identified as the most likely portal of entry.     

Appendiceal and peri-appendiceal air at CT: prevalence, appearance and clinical significance

AIM: Appendiceal air has been reported as both a sign of appendicitis and of a normal appendix both at plain radiography and computed tomography (CT). It is the aim of this investigation to determine the prevalence, range of appearances, and significance of appendiceal and peri-appendiceal air at CT. PATIENTS AND METHODS: Appendiceal CT scans of 100 patients with proven appendicitis and 100 patients with a normal appendix were reviewed for the presence of appendiceal and peri-appendiceal air. All cases were correlated with surgical and pathological findings or clinical follow-up. RESULTS: In 100 CT cases of appendicitis, appendiceal and/or peri-appendiceal air was present in one or more forms in 31% of cases. When present, it appeared as intraluminal air bubbles (38.7%) or air-fluid levels (22.6%), appendolith air (41.9%), intramural air (16.1%), peri-appendiceal air bubbles (12.9%), or extraluminal air-fluid level(s) (29.0%). Intramural and extraluminal air correlated with perforation in 60% and 100%, respectively. In 100 CT cases of a normal appendix, air was present in 57%. It was always intraluminal and appeared as small bubbles of air (52.6%), a tubular-shaped air collection (43.9%), or as an air-fluid level (3.5%). The appendiceal lumen was either airless (43%), or minimally (32%), moderately (18%), or completely filled with air (7%). CONCLUSION: Air is a common finding at appendiceal CT in both the normal and inflamed appendix. Intraluminal air is seen in both appendicitis and normal appendices, and cannot be presumed to indicate a patent lumen and thus a normal appendix. Appendolith, intramural and peri-appendiceal air appear diagnostic of appendicitis.     

Computed tomography as a guide in the diagnosis and follow-up of brain abscesses

The diagnosis and follow-up of 20 cases of intracranial abscess are analyzed, with particular attention to the role of computed tomography (CT). the differential diagnosis of the CT appearance is presented, and the value of clinical and laboratory findings is discussed. Of special interest is the potential effect of steroids on CT findings as well as the frequent observation of a residual enhancing focus seen on the scan obtained at hospital discharge.     

Distribution and contrast enhanced CT appearance of abdominal tuberculous lymphadenopathy

PURPOSE: To clarify the contrast enhanced CT features and anatomic distribution of the disseminated vs non-disseminated tuberculosis (TB) involving abdominal lymph nodes. MATERIALS AND METHODS: The contrast enhanced CT findings of abdominal lymphadenopathy in 25 patients, including disseminated TB associated with miliary TB of the lung (n = 5) and non-disseminated TB (n = 20), were retrospectively evaluated in a blind review to assess our criteria of morphology, density and location of the involved lymphadenopathy. RESULTS: The enhancement patterns of disseminated TB were not different from those of non-disseminated TB. Ninety-six percent of the patients had peripheral rim enhancement, and 60% showed a multilocular appearance. The enlarged lymph nodes of TB were less than 4 cm in diameter. Lymphadenopathy caused by hematogenous dissemination often accompanied splenic involvement showing multiple low-density foci in the spleen. The predominant sites of lymphadenopathy of disseminated TB were hepatoduodenal ligamentous, hepatogastric ligamentous, mesenteric, and both upper and lower portions of the retroperitoneal lymph nodes, whereas non-disseminated TB mainly involved hepatoduodenal ligamentous, hepatogastric ligamentous, mesenteric and upper retroperitoneal lymph nodes, excluding the lower retroperitoneal lymph nodes. By combining contrast enhancement patterns and the anatomic distribution of lymphadenopathy shown on the contrast enhanced CT images, reviewers made a correct diagnoses of tuberculosis in 94%, of cases, with a specificity of 95% and sensitivity of 92%. CONCLUSION: Contrast enhanced CT patterns correlate well with the pathologic features of tuberculous lymphadenopathy. A different anatomic distribution between disseminated and non-disseminated TB involving the lower retropentoneal lymph nodes was recognized in this study.     

Early advanced hepatocellular carcinoma: evaluation of CT and MR appearance with pathologic correlation

PURPOSE: To determine the computed tomographic (CT) and magnetic resonance (MR) imaging appearances of early advanced hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty-seven surgically resected cases of early advanced HCC were studied with CT, CT during arterial portography, CT arteriography, and MR imaging. RESULTS: The sensitivity of standard CT (unenhanced, early, and late CT combined) for the detection of early advanced HCC was 81%, while that of standard MR imaging (T1- and T2-weighted MR imaging combined) was 83%. A nodule-in-nodule appearance was identified in approximately one-third to one-half of cases. Signal behavior of early and advanced components of early advanced HCC followed the expected behaviors of isolated early HCC and isolated advanced HCC, respectively. Tumor size was accurately estimated with standard CT and standard MR imaging. CONCLUSION: More research must be performed to ascertain whether any relationship exists between the different types of HCC and the clinical outcome.     

Uncomplicated asthma in adults: comparison of CT appearance of the lungs in asthmatic and healthy subjects

A study was undertaken to define the computed tomographic (CT) appearance of the lungs in subjects with uncomplicated asthma and to compare the prevalence of bronchial dilatation at CT in asthmatic and healthy subjects. Clinical features, pulmonary physiologic findings, chest radiographs, and high-resolution CT scans of 48 asthmatic subjects were reviewed. Forty-one (85%) of the 48 asthmatic subjects were undergoing bronchodilator therapy, 28 (58%) were undergoing steroid therapy, and 21 (44%) were cigarette smokers. Twenty-seven healthy control subjects underwent limited high-resolution CT. At selected CT levels, any bronchus with an internal diameter greater than that of the accompanying pulmonary artery was considered dilated. In the asthmatic subjects, 153 (36%) of 429 bronchi evaluated met criteria for bronchial dilatation compared with 37 (26%) of 142 bronchi in the control group (P < .05). Because bronchial dilatation demonstrated at CT did not correlate with clinical data, the authors conclude a bronchus larger in diameter than the adjacent vessel is not sufficient evidence to diagnose cylindric bronchiectasis.     

Multiple symmetric lipomatosis in the Chinese: ultrasound, CT and MR imaging

We report four cases of multiple symmetric lipomatosis in the Chinese population. We believe that multiple symmetric lipomatosis in the Chinese is not uncommon and may be related to the increasing incidence of alcoholism. The ultrasound appearances of these lipomatous masses are presented for the first time. Heterogeneous echogenic masses with fine fibrous strands that insinuate around fascial planes, lymph nodes and vascular tissues are typical findings. Unlike diseases affecting the Western population, multiple symmetric lipomatosis in the Chinese appears to be limited to the head and neck.     

CT appearance of the normal and abnormal breast with mammographic correlation

Mammography is the preferred technique to evaluate the breast but computed tomography (CT) performed for extramammary disease often images breast tissue. We reviewed studies of patients who underwent both CT and mammography to identify abnormalities that were visible with both techniques. The CT appearance of the normal breast, breast cancer, and several other abnormalities is demonstrated in this study. CT may occasionally allow for a precise diagnosis of a previously unsuspected breast lesion but a mammogram is usually required.     

An unusual CT and MR appearance of a posterior fossa dermoid

A study was made of the effect of transcutaneous diaphragmatic electrostimulation (2 mA, 0.3 ms, 20-30 V) on the external respiratory function in 12 asthmatic patients with respiratory insufficiency. The course comprised 7 daily sessions for 20 min. The improvement in respiratory function parameters was observed in the majority of the patients. The effect of electrostimulation was related to the quantity of the procedures.     

Spatiotemporal appearance of developing LHRH neurons in the rat brain

To obtain insight into the development of the heterogeneous intracerebral populations of luteinizing hormone-releasing hormone (LHRH) neurons, their spatiotemporal appearance was examined at different stages in normal rat embryos, in nasal epithelial explants in vitro, and in intrauterine nasal-operated embryos. Following the appearance of nerve cell adhesion molecule in the nasal placode at embryonic day (E) 12.5, LHRH neurons, generated in the nasal placode at E13.5, penetrated the forebrain vesicle (FV) by E14.5-15.5. After E16.5, as the FV elongated to form the olfactory bulb, the migrating neurons traversed posteriorly through the interhemispheric space to penetrate the septopreoptic (S-P) area. By E18.5, LHRH neurons were detected in the preoptic-diagonal band (P-D) area as well as in the S-P region, along with some scattered extrahypothalamic LHRH neurons. To determine the source of these neurons, we separately cultured dissected parts of E12.5 nasal pit epithelium. Neuronal generation was predominantly from the medial wall epithelium (NAP), but some LHRH neurons originated in the roof epithelium. Cocultures of the NAP (E12.5) with the FV, median eminence-arcuate complex, Rathke's pouch, mesencephalon, or medulla oblongata from E14.5 embryos revealed the ability of LHRH cells to penetrate all of these tissues. Uni- or bilateral nasal destruction was conducted at E16.5 or E15.5, respectively, and examined at E18.5 and E21.5. In the operated embryos, most LHRH neurons were present in the P-D system and some in the S-P area. This finding suggests that the neurons generated before E15.5 are primarily predisposed to form the P-D system, whereas those derived afterward form the S-P system.