Subcutaneous granuloma annulare: MR imaging and literature review

Subcutaneous granuloma annulare (SGA) is little known to radiologists. Better knowledge of this lesion may prompt accurate diagnosis. A typical case is presented with plain radiography, ultrasound and MR imaging, and is confirmed by histology. When an otherwise healthy child presents with a rapidly growing, solitary, nontender, subcutaneous soft tissue mass, located on the scalp or extensor aspect of the limbs, that radiologically presents as an indistinct radiodense and hypoechoic mass, isointense to muscle on T1- and slightly hypointense to fat on T2-weighted MR images, without calcifications, bone involvement or extracompartmental invasion, SGA should be suspected. Received 5 June 1997; Revision received 29 October 1997; Accepted 8 January 1998     

Subcutaneous granuloma annulare: MR imaging findings

We present a case of subcutaneous granuloma annulare evaluated with MR imaging. The mass was poorly defined and showed thickened interconnecting strands with low signal intensity on T1- and T2-weighted MR images. When a poorly defined subcutaneous mass with low signal intensity on both T1- and T2-weighted MR images is observed in an otherwise healthy child, subcutaneous granuloma annulare should receive serious consideration. Subcutaneous granuloma annulare should be added to the list of tumors with short T2.     

Subcutaneous granuloma annulare: radiologic appearance

Objective. Granuloma annulare is an uncommon benign inflammatory dermatosis characterized by the formation of dermal papules with a tendency to form rings. There are several clinically distinct forms. The subcutaneous form is the most frequently encountered by radiologists, with the lesion presenting as a superficial mass. There are only a few scattered reports of the imaging appearance of this entity in the literature. We report the radiologic appearance of five cases of subcutaneous granuloma annulare. Design and patients. The radiologic images of five patients (three male, two female) with subcutaneous granuloma annulare were retrospectively studied. Mean patient age was 6.4 years (range, 2–13 years). The lesions occurred in the lower leg (two), foot, forearm, and hand. MR images were available for all lesions, gadolinium-enhanced imaging in three cases, radiographs in four, and bone scintigraphy in one. Results. Radiographs showed unmineralized nodular masses localized to the subcutaneous adipose tissue. The size range, in greatest dimension on imaging studies, was 1–4 cm. MR images show a mass with relatively decreased signal intensity on all pulse sequences, with variable but generally relatively well defined margins. There was extensive diffuse enhancement following gadolinium administration. Conclusion. The radiologic appearance of subcutaneous granuloma annulare is characteristic, typically demonstrating a nodular soft-tissue mass involving the subcutaneous adipose tissue. MR images show a mass with relatively decreased signal intensity on all pulse sequences and variable but generally well defined margins. There is extensive diffuse enhancement following gadolinium administration. Radiographs show a soft-tissue mass or soft-tissue swelling without evidence of bone involvement or mineralization. This radiologic appearance in a young individual is highly suggestive of subcutaneous granuloma annulare.     

Leukodystrophy in children: a pictorial review of MR imaging features.

Dysmyelinating diseases, or leukodystrophies, encompass a wide spectrum of inherited neurodegenerative disorders affecting the integrity of myelin in the brain and peripheral nerves. Most of these disorders fall into one of three categories-lysosomal storage diseases, peroxisomal disorders, and diseases caused by mitochondrial dysfunction-and each leukodystrophy has distinctive clinical, biochemical, pathologic, and radiologic features. Magnetic resonance (MR) imaging has become the primary imaging modality in patients with leukodystrophy and plays an important role in the identification, localization, and characterization of underlying white matter abnormalities in affected patients. MR imaging has also been extensively used to monitor the natural progression of various white matter disorders and the response to therapy. Although the MR imaging features of leukodystrophy are often nonspecific, systematic analysis of the finer details of disease involvement may permit a narrower differential diagnosis, which the clinician can then further refine with knowledge of patient history, clinical testing, and metabolic analysis.     

Subcutaneous panniculitis-like T-cell lymphoma: MRI features and literature review

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) represents a rare subclassification of peripheral T-cell lymphoma (PTCL). We present a case of a 21-year-old female who presented with a 1-month history of pain in the left buttock and hip, tender left inguinal lymph nodes, fevers, and night sweats. Percutaneous core needle biopsy was diagnostic for SPTCL with CD8+ cells positive for cytotoxic granules. Magnetic resonance imaging (MRI) features of SPTCL with a review of the literature are discussed.     

MR imaging features of nasopharyngeal tuberculosis: report of three cases and literature review

The MR imaging appearances in three cases of nasopharyngeal tuberculosis are reported, and the findings are combined with three additional cases from a review of the literature. Two patterns of nasopharyngeal tuberculosis were identified. The first pattern is a discrete polypoid mass in the adenoids, and the second pattern is a more diffuse soft-tissue thickening of one or two of the walls of the nasopharynx. Extension outside the confines of the nasopharynx was not a feature, except in one case with early involvement of the prevertebral muscles.     

Orbital tumors in children: CT and MR imaging features

The purpose of the article is to review the CT and MR imaging features of orbital tumors in children. Tumors in children are usually different than those in adults. Clinical symptoms are usually non-specific. Clinical examination combined with US may be sufficient for diagnosis and follow-up of benign and superficial lesions. CT and/or MRI are needed for deep or malignant lesions. CT is valuable for osseous and/or calcified lesions. MR is advantageous because of its superior spatial resolution and non-ionizing nature. Malignant tumors correspond to about 20% of lesions and include primary tumors (retinoblastoma, rhabdomyosarcoma) and metastases. Benign pathology is more frequent (80%) with dermoid cyst corresponding to about 50% of orbital masses.     

MR imaging of malignant primary breast lymphoma: including diffusion-weighted imaging, histologic features, and a literature review

Objective

To investigate the magnetic resonance (MR) imaging characteristics of malignant primary breast lymphoma (PBL), including features on diffusion-weighted imaging (DWI).

Methods

The MR findings of three patients were reviewed retrospectively at our institutions. The signal intensity, shape, enhancement pattern, and DWI findings were examined and correlated with the histologic features. We also reviewed the MR findings of cases of PBL reported in the literature.

Results

The tumors in our cases showed early enhancement with penetrating vessels on early-phase dynamic MR images and a strong high signal intensity on DWI. The tumors had a cerebroid appearance and septal enhancement on delayed contrast-enhanced MR images, and we speculate that the fibrous tissue seen in the tumors may correspond to septal enhancement. After chemotherapy, all lesions decreased in size, while the ADCs were increased. All of the cases reported in the literature showed early or avid enhancement; this finding was similar to that observed in our cases.

Conclusions

Although based on a small number of cases, we suggest that strong enhancement with penetrating vessels in masses on early images of dynamic MR, strong high intensity on DWI, a cerebroid appearance, and septal enhancement are useful diagnostic clues for a diagnosis of PBL.     

小儿流行性乙型脑炎的MR成像及其扩散加权成像特征

目的探讨小儿乙型脑炎的MRI表现及其扩散加权成像（DWI）的特征。方法16例临床诊断符合小儿乙型脑炎的患者，均行头颅常规MRI和轴面DWI，其中7例在发病10d内检查，9例在10d后检查。观察患者脑DWI、T2WI序列的表现；同时测量感兴趣区的表观扩散系数（ADC）值，并将病灶的ADC值与其对应的发病持续时间作相关分析。结果脑部病变区主要呈稍长T1、长T2信号，丘脑受累最常见。16例患者中，15例丘脑受累，其中6例病变仅累及丘脑。7例10d内行MR检查者，病灶在DWI较T2WI信号高，而且病变范围更清楚，其中2例在DWI还显示了T2WI未能显示的病灶；9例发病10d后行MR检查者，T2WI显示病变较DWI清晰。丘脑病灶的ADC值与其病程呈正相关（r=0．84，P〈0．01）。结论 小儿乙型脑炎在MRI上常表现为较特征的丘脑受累，结合临床，DWI对乙型脑炎的早期诊断有一定帮助。     

MR imaging of the accessory soleus muscle appearance in six patients and a review of the literature

We examined seven ankles with an accessory soleus muscle to determine if the magnetic resonance (MR) imaging features were sufficient to allow accurate diagnosis of this anomalous muscle. We believe that the diagnosis of an accessory soleus muscle is unequivocal with MR imaging on the basis of morphology and signal intensity. Therefore, we suggest that this imaging method should be utilized in patients suspected of having a mass or with persistent swelling in the region of the ankle with or without pain, for the noninvasive diagnosis of this muscle and to better define the regional anatomy presperatively if surgery is being considered for relief of symptoms.     

Carotid-anterior cerebral artery anastomosis: MR angiographic features and literature review

Carotid-anterior cerebral artery anastomosis is a rare anomaly of the anterior part of the circle of Willis. We report here magnetic resonance (MR) angiographic findings in 2 patients with this anomaly. MR angiographic source images are useful in evaluating the anatomical details of this anomaly. Including the 2 present cases, 27 patients with this anomaly have been reported in the English-language literature. Thirty anomalous arteries were found in the 27 patients (R/L/bilateral=22/2/3). The reason for the right-sided predominance is unknown.     

MR imaging of uterine adenosarcoma: case report and literature review

We report a case of uterine adenosarcoma demonstrated on magnetic resonance (MR) imaging. A 74-year-old woman with a large uterine mass underwent MR examination before total abdominal hysterectomy. Imaging revealed a markedly enlarged uterus with thin myometrium occupied by a large polypoid mass. The mass contained solid components with low intensity on T(1)-weighted images and high intensity on T(2)-weighted images compared to the myometrium and areas of small cysts.     

Retroclival ecchordosis physaliphora: MR imaging and review of the literature

BACKGROUND AND PURPOSE: Ecchordosis physaliphora (EP), found in about 2% of autopsies, is a clinically inconspicuous notochordal remnant appearing at the dorsal wall of the clivus. To our knowledge, a systematic review of its MR features does not exist. The aim of this study was to describe the MR imaging findings of incidentally found retroclival EP with special respect to its differentiation from intradural chordomas.METHODS: We reviewed 300 consecutive 1.5-T MR imaging studies that included thin-section transverse T2-weighted images of the skull base for the presence of a retroclival EP. In cases in which an EP was identified, two neuroradiologists observed MR signal intensity characteristics, contrast enhancement, size, form, stalk of EP, and signal intensity changes of the adjacent clivus.RESULTS: Five cases with retroclival EP were found (incidence, 1.7%). In all cases, the ecchordoses was hyperintense on T2-weighted images and hypointense on T1-weighted images. Contrary to the reported findings in chordomas, none of the lesions showed contrast enhancement. In four cases, there were signal intensity changes in the adjacent clivus. A stalklike connection between clivus and EP was seen in three patients.CONCLUSION: Because of the benign character of EP and the difficulties in its histopathologic differentiation from chordomas, precise knowledge of the radiologic characteristics of EP is important. On the basis of these five cases and a review of literature, contrast enhancement and the presence of clinical symptoms seem to be highly reliable parameters in the differential diagnosis of intradural chordoma and EP.

Ecchordosis physaliphora (EP) is a small, gelatinous tissue that is considered an ectopic notochordal remnant (1–4). This tissue is located in midline of the craniospinal axis, reaching from the dorsum sellae to the sacrococcygeal region. Intracranial EP is typically found intradurally in the prepontine cistern, where it is attached to the dorsal wall of the clivus via a small pedicle (1, 2, 5). Ecchordoses in this region are usually asymptomatic and found in about 2% of autopsies (1, 6, 7). Only a few reports in the literature provide the detailed radiologic features of a retroclival EP (4–6, 8), with none in neuroradiology journals, to our knowledge. The purpose of this study was to describe the MR imaging findings of five cases of asymptomatic retroclival EP.On the basis of the cases reported in the literature and the current knowledge about remnants of the notochord, there is no significant foundation for defining criteria to distinguish simple notochordal remnants from their aggressive counterparts (i.e., chordomas). Such criteria would be helpful in identifying cases that require further procedures, such as follow-up or surgery.     

MR imaging of benign fatty tumors in children: report of four cases and review of the literature

This study correlates the magnetic resonance imaging characteristics with the pathologic findings in rare benign fatty soft tissue tumors in four children. A review of the literature is presented. Two cases of infiltrating lipoma displayed bright signal on both T1- and T2-weighted images, similar to that observed in subcutaneous fat. Histological study revealed extensive muscle infiltration by mature fat, with some areas of total fatty replacement. The case of facial lipomatosis revealed an extensive process of fatty invasion of adjacent soft tissue and osseous deformity by mass effect of the tumor. This lesion was bright on T1- and T2-weighted images. Histopathologic examination showed widespread invasion of squamous mucosa and skeletal muscle. The single case of lipoblastoma involved the presacral region and right buttock. This lesion, although bright on both T1 and T2 weighting, was relatively hypointense to subcutaneous fat on T1. Microscopic examination revealed a well-encapsulated fatty mass made up of cells ranging from lipoblasts to mature lipocytes. In childhood, when fatty lesions are almost always benign, a morphologic characterization by magnetic resonance may be sufficient basis on which to make critical therapeutic judgements.     

Susceptibility-weighted MR imaging: a review of clinical applications in children

Susceptibility-weighted imaging (SWI) is a high-spatial-resolution 3D gradient-echo MR imaging technique with phase postprocessing that accentuates the paramagnetic properties of blood products such as deoxyhemoglobin, intracellular methemoglobin, and hemosiderin. It is particularly useful for detecting intravascular venous deoxygenated blood as well as extravascular blood products. It is also quite sensitive to the presence of other substances such as iron, some forms of calcification, and air. We have used this technique in the past several years to study a wide variety of pediatric neurologic disorders. We present a review with selected case histories to demonstrate its clinical usefulness in the improvement of the following: 1) detection of hemorrhagic lesions seen in various conditions, including traumatic brain injury and coagulopathic or other hemorrhagic disorders; 2) detection of vascular malformations such as cavernous angiomas, telangiectasias, or pial angiomas associated with Sturge-Weber syndrome; 3) demonstration of venous thrombosis and/or increased oxygen extraction in the setting of infarction, hypoxic/anoxic injury, or brain death; 4) delineation of neoplasms with hemorrhage, calcification, or increased vascularity; and 5) depiction of calcium or iron deposition in neurodegenerative disorders. SWI has provided new understanding of some of these disease processes. It is hoped that as SWI becomes more widely available, it will provide additional diagnostic and prognostic information that will improve the care and outcome of affected children.     

Spontaneous intracranial hypotension: a study of six cases with MR findings and literature review

Spontaneous intracranial hypotension is clinically characterized by orthostatic headache and other symptoms caused by low cerebrospinal fluid pressure due to leakage of cerebrospinal fluid from dural punctures or other medical causes. The other symptoms are mainly due to traction of the cranial and spinal nerves owing to descent of the brain caused by low cerebrospinal fluid pressure. Magnetic resonance imaging is very useful in the diagnosis because of its characteristic findings. We describe the MRI findings in six cases that had variable clinical presentation.     

Panner''s disease: X-ray, MR imaging findings and review of the literature

Panner's disease, avascular necrosis of the capitellum, was first described on X-ray examination of the elbow. It represents a major threat to the elbow joint integrity, and it is important to diagnose early. Panner's disease occurs most commonly in young children who play baseball, and in competitive gymnasts. Although considered a rare entity, it probably is underdiagnosed. We present the X-ray and MR imaging findings in a young boy with Panner's disease. The MR imaging findings in Panner's disease have not been previously reported.     

Deltoid contracture: MR imaging features

AIM: To describe the magnetic resonance imaging (MRI) features of deltoid contracture and compare these findings with the operative and histological findings and to determine the utility of MRI for diagnosis and treatment planning. PATIENTS AND METHODS: Retrospective review of clinical and imaging in six patients with deltoid contracture, as well as the operative and histological findings of four operated patients. RESULTS: Magnetic resonance imaging clearly demonstrated the intramuscular fibrous bands of the deltoid as a homogeneously hypointense area with distinctive margins on T1-, T2- and T2*-weighted images. Operative findings were exactly consistent with the findings observed by MRI. CONCLUSION: Deltoid contracture is best evaluated with MRI which facilitates visualization of the intramuscular fibrous bands being pathognomonic of this entity and may provide information useful in treatment planning.     

Hemifacial spasm: MR imaging features

MR imaging was used to evaluate the relationship of the root exit zone of the seventh cranial nerve to surrounding vascular structures in 13 patients with clinically documented hemifacial spasm and in 70 asymptomatic patients. MR imaging clearly demonstrated the course of the seventh nerve from the root exit zone of the brainstem to the internal auditory canal and its relationship to the surrounding vertebrobasilar system. The presence of a vascular structure at the root exit zone of the seventh nerve was identified in all 13 patients with hemifacial spasm. In the 70 asymptomatic patients, examination of 140 seventh nerves revealed that 21% had contact by a vascular structure at the root exit zone of the seventh nerve. Our results indicate that although neurovascular contact may be asymptomatic, MR demonstration of a vascular structure at the root exit zone of the seventh cranial nerve in a patient with hemifacial spasm may implicate neurovascular compression as the cause of symptomatology. This finding may alter therapeutic management. Because of the inherent limitations of CT in the visualization of posterior fossa structures, MR imaging should be considered the initial screening procedure in the assessment of patients with hemifacial spasm.