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.     

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.     

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.     

Hepatic and splenic sarcoidosis: ultrasound and MR imaging

Two polypeptide antigens with molecular sizes of 34,000 daltons (34 kDa) and 38 kDa were separated from heated cells of a human clinical treponeme strain G7201 and Treponema denticola ATCC 35404, respectively. The rabbit polyclonal antisera against these antigens were produced and examined for their immunological reactions with the two heated antigens or intact spirochetal cells. Immunoblot analysis showed that the 34-kDa protein was also detected in T. denticola ATCC 35404 and ATCC 33520, and the 38-kDa protein was detected only in the two ATCC strains. Immunoelectron microscopy using the two rabbit antisera and protein A-gold complexes demonstrated that the 38-kDa protein antigen was present on the axial flagella of two T. denticola strains, and that the 34-kDa protein was located in the axial flagella of the G7201 cell, but neither in axial flagella nor on outer envelopes of the two ATCC strains cells, suggesting that the native 34-kDa axial flagellar protein of the G7201 strain may be different from that of T. denticola in terms of immunological reactivity.     

Chondroblastoma: classic and confusing appearance at MR imaging

PURPOSE: To define the characteristics of chondroblastoma at magnetic resonance (MR) imaging and the combination of findings that are diagnostic for chondroblastoma. MATERIALS AND METHODS: From January 1987 through December 1992, 22 patients with histologically confirmed chondroblastoma and prior MR imaging examinations were seen. Patients included 16 men and six women, aged 10-58 years (median, 17 years). Retrospective analysis of findings at MR imaging, plain radiography, computed tomography, and bone scanning was performed. RESULTS: Low to intermediate heterogeneous signal intensity, lobular internal architecture, and fine lobular margins were well defined with high-resolution T2-weighted (repetition time > or = 1,500 msec, echo time > or = 70 msec) MR imaging. Adjacent bone-marrow and soft-tissue edema and periosteal reactions were more dramatically demonstrated on MR images than on radiographs. Bone marrow edema was prominent in all but five cases. Obvious periosteal reaction and adjacent soft-tissue edema were visible in 17 cases. CONCLUSION: Knowledge of the MR imaging findings of chondroblastoma will allow accurate diagnosis and help avoid confusion with infection and aggressive neoplasms.     

Red degeneration of uterine leiomyoma: MR appearance

OBJECTIVE: Red degeneration (hemorrhagic infarction) of uterine leiomyoma can cause acute abdominal pain. This study was undertaken to identify MR features useful in diagnosing this rare complication of uterine leiomyoma. MATERIALS AND METHODS: Magnetic resonance imaging from five patients symptomatic for 7 to 20 days with pathologic confirmation of red degeneration was retrospectively evaluated and correlated with histopathologic findings. RESULTS: The lesions had a common MRI appearance: hyperintense rim on T1-weighted imaging (WI) and hypointense rim on T2-WI. These findings corresponded with numerous dilated vessels filled with red blood cells at the periphery of the lesion. The signal characteristics of the rim are best explained as an effect of abundant intracellular methemoglobin in these vessels. CONCLUSION: Recognition of these characteristics may help radiologists differentiate symptomatic red degeneration from other clinical conditions that need surgical interventions.     

Autoimmune pancreatitis: CT and MR characteristics

OBJECTIVE: Our goal was to elucidate the CT and MR imaging characteristics in patients with autoimmune pancreatitis, which is a reversible chronic pancreatitis with an autoimmune cause. CONCLUSION: On CT and MR imaging, a capsulelike rim, which is thought to correspond to an inflammatory process involving peripancreatic tissues, appears to be a characteristic finding of autoimmune pancreatitis. Also, diffuse pancreatic enlargement along with hypointensity on T1-weighted MR images and delayed enhancement on dynamic CT and MR studies are other features of this disorder.     

Kikuchi disease: CT and MR findings

Two cases of Kikuchi disease showed variable nodal enhancing features, including homogeneous enhancement and focal or extensive nodal necrosis on contrast-enhanced CT scans. At MR imaging, the area of central necrosis was isointense or hypointense on T1-weighted images and had a lower signal than nonnecrotic areas on T2-weighted images. The CT appearance of Kikuchi disease can be variable and can mimic not only lymphoma but various nodal diseases with nodal necrosis, including metastasis and tuberculosis.     

Wegener granulomatosis: CT and MR findings

PURPOSE: To demonstrate the spectrum of CT and MR imaging findings in patients with Wegener granulomatosis and to determine how often these findings could be attributed to either direct extension from paranasal or orbital disease sites, remote granulomas, or central nervous system (CNS) vasculitis. METHODS: We retrospectively reviewed the CT or MR studies of 15 patients with Wegener granulomatosis. RESULTS: Abnormal findings were seen in 7 patients (5 examined with MR imaging, 2 with CT). Findings included dural thickening and contrast enhancement (3 patients), infarcts (2 patients), regions of hyperintense signal on T2-weighted MR images (2 patients), and abnormal MR signal in the brain stem (2 patients). Three patients with imaging findings of dural enhancement and thickening were thought to have remote granulomatous lesions involving the dura. No patients had extension from sites external to the CNS or clinical findings suggestive of CNS vasculitis. CONCLUSION: The spectrum of CT and MR findings in Wegener granulomatosis includes dural thickening and enhancements cerebral infarction, and MR signal abnormalities in the brain stem and white matter. Presumed remote granulomatous lesions were the most common causes of CNS findings in this study. Complications related to non-CNS disease (eg, hypertension, endocarditis) also appear to have played a role in some patients.     

Cervical ecchordosis physaliphora: CT and MR features

We report a case of cervical ecchordosis physaliphora in an elderly man who presented with hemihypoaesthesia and contralateral hemiparesis. MRI showed a well defined, non-enhancing extradural mass lesion on the dorsal surface of the odontoid process of the axis. The lesion was of intermediate signal intensity on T1 weighted images and of low signal intensity on T2 weighted images. CT showed a small bony defect on the adjacent cortex of the odontoid process. Recognition of the imaging features of ecchordosis physaliphora is helpful in suggesting the diagnosis and differentiating the lesion from chordoma.     

Localized pleural mesothelioma: CT and MR findings

A case of localized pleural mesothelioma inducing hypoglycemic coma is presented. CT and MR findings are described. T1-weighted MR images demonstrated the mass of slightly high signal intensity with lesions of signal void. Varying degrees of T2 shortening were shown on T2-weighted MR images. Coronal MR imaging was useful for assessing the relationship between the diaphragm and lesions in the lower chest.     

CT urography and MR urography

CT urography and MR urography are an evolving concept and developing technique. As the technology matures, CT urography will combine the ultimate diagnostic capabilities of intravenous urography and CT. In the near future, many intravenous urograms will be replaced by CT urography to evaluate patients with hematuria and other genitourinary conditions. MR urography currently serves as an alternative imaging technique to intravenous urography and CT urography for children and pregnant women and for patients with contraindications to iodinated contrast media.     

The CT findings of pulmonary sarcoidosis

Virtually every subspecialty in medicine in one way or another deals with angiogenesis-associated physiological or pathological processes and, without exception, every organ system in the body has many diseases in which angiogenesis is an important component. This in itself makes the study of angiogenesis mandatory, in both basic science and clinical settings. Yet the study of angiogenesis does not require this justification. As a biological process it is extraordinarily rich, touching on virtually every aspect of modern cell biology, making it almost impossible for molecular biologists, biochemists and morphologists to ignore. Considerable therapeutic benefit can now be obtained through positive or negative manipulation of the angiogenic process, and this is due in large part to the rapid transfer to the clinical setting of knowledge acquired through a cell biological approach.     

The MR appearance of the infrapatellar plica

OBJECTIVE: Our purpose is to describe the MR appearance and clinical relevance of the infrapatellar plica of the knee and to assess possible imaging pitfalls resulting from lack of recognition of this normal structure. Seven patients--four from our institution and three from our teaching file from outside institutions--were selected because they displayed the imaging features of the infrapatellar plica. CONCLUSION: The infrapatellar plica is readily appreciated on sagittal MR images of the knee as a low-signal-intensity structure in the intercondylar notch just anterior to the anterior cruciate ligament (ACL). The infrapatellar plica is important to recognize for the following reasons: It may be confused with an intact ACL because of its proximity and similar signal characteristics; it may pose difficulty to the arthroscopist when attempting to move instruments from the medial to lateral compartments of the knee; it can block clear visualization of the ACL during arthroscopy; and it can impair retrieval of loose bodies in the intercondylar notch. Familiarity with the infrapatellar plica should allow one to differentiate this normal structure from other structures in the knee and aid in preoperative planning.     

MR imaging of muscular sarcoidosis after steroid therapy

The nodular type of muscular sarcoidosis has been known to show characteristic MR findings: however, MR imaging features after steroid therapy have not been reported. A 48-year-old man with nodular type of muscular sarcoidosis is reported. Prior to steroid therapy, axial MR images showed peripheral increased signal intensity and central star-shaped decreased signal intensity. Coronal images showed an inner stripe of decreased signal intensity and outer stripes of increased signal intensity. After steroid therapy, axial images showed only the central star-shaped area of decreased signal intensity. Coronal images showed only the inner stripe of decreased signal intensity. It is important to know that the central area will continue to exist after steroid therapy.     

Aggressive angiomyxoma: findings on CT and MR imaging

OBJECTIVE: Aggressive angiomyxoma is a benign tumor affecting the pelvis and perineum, predominantly in women. Because of its variable presentation as a soft mass in the vulva, perianal region, buttock, or pelvis, the tumor is often clinically misdiagnosed and initial surgery is usually unsuccessful in extirpating it. This study describes the imaging features of these tumors. CONCLUSION: Aggressive angiomyxomas display unusual growth patterns of translevator extension with growth around perineal structures. Both CT and MR imaging show the transdiaphragmatic extent of these tumors. High signal intensity on T2-weighted MR images may reflect the myxomatous stroma of these tumors.