Natural history of colloid cysts of the third ventricle.

OBJECTIVE Colloid cysts are rare, histologically benign lesions that may result in obstructive hydrocephalus and death. Understanding the natural history of colloid cysts has been challenging given their low incidence and the small number of cases in most reported series. This has complicated efforts to establish reliable prognostic factors and surgical indications, particularly for asymptomatic patients with incidental lesions. Risk factors for obstructive hydrocephalus in the setting of colloid cysts remain poorly defined, and there are no grading scales on which to develop standard management strategies. METHODS The authors performed a single-center retrospective review of all cases of colloid cysts of the third ventricle treated over nearly 2 decades at Washington University. Univariate analysis was used to identify clinical, imaging, and anatomical factors associated with 2 outcome variables: symptomatic clinical status and presentation with obstructive hydrocephalus. A risk-prediction model was defined using bootstrapped logistic regression. Predictive factors were then combined into a simple 5-point clinical scale referred to as the Colloid Cyst Risk Score (CCRS), and this was evaluated with receiver-operator characteristics. RESULTS The study included 163 colloid cysts, more than half of which were discovered incidentally. More than half of the incidental cysts (58%) were followed with surveillance neuroimaging (mean follow-up 5.1 years). Five patients with incidental cysts (8.8%) progressed and underwent resection. No patient with an incidental, asymptomatic colloid cyst experienced acute obstructive hydrocephalus or sudden neurological deterioration in the absence of antecedent trauma. Nearly half (46.2%) of symptomatic patients presented with hydrocephalus. Eight patients (12.3%) presented acutely, and there were 2 deaths due to obstructive hydrocephalus and herniation. The authors identified several factors that were strongly correlated with the 2 outcome variables and defined third ventricle risk zones where colloid cysts can cause obstructive hydrocephalus. No patient with a lesion outside these risk zones presented with obstructive hydrocephalus. The CCRS had significant predictive capacity for symptomatic clinical status (area under the curve [AUC] 0.917) and obstructive hydrocephalus (AUC 0.845). A CCRS ≥ 4 was significantly associated with obstructive hydrocephalus (p < 0.0001, RR 19.4). CONCLUSIONS Patients with incidentally discovered colloid cysts can experience both lesion enlargement and symptom progression or less commonly, contraction and symptom regression. Incidental lesions rarely cause acute obstructive hydrocephalus or sudden neurological deterioration in the absence of antecedent trauma. Nearly one-half of patients with symptomatic colloid cysts present with obstructive hydrocephalus, which has an associated 3.1% risk of death. The CCRS is a simple 5-point clinical tool that can be used to identify symptomatic lesions and stratify the risk of obstructive hydrocephalus. External validation of the CCRS will be necessary before objective surgical indications can be established. Surgical intervention should be considered for all patients with CCRS ≥ 4, as they represent the high-risk subgroup.

ACR Appropriateness Criteria® pre-irradiation evaluation and management of brain metastases.

Pretreatment evaluation is performed to determine the number, location, and size of the brain metastases and magnetic resonance imaging (MRI) is the recommended imaging technique, particularly in patients being considered for surgery or stereotactic radiosurgery. A contiguous thin-cut volumetric MRI with gadolinium with newer gadolinium-based agents can improve detection of small brain metastases. A systemic workup and medical evaluation are important, given that subsequent treatment for the brain metastases will also depend on the extent of the extracranial disease and on the age and performance status of the patient. Patients with hydrocephalus or impending brain herniation should be started on high doses of corticosteroids and evaluated for possible neurosurgical intervention. Patients with moderate symptoms should receive approximately 4-8 mg/d of dexamethasone in divided doses. The routine use of corticosteroids in patients without neurologic symptoms is not necessary. There is no proven benefit of anticonvulsants in patient without seizures. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR appropriateness criteria management of vertebral compression fractures.

This is an updated review of management of vertebral compression fracture for both benign osteoporotic and malignant causes. Vertebral compression fracture radiologic imaging evaluation is discussed. A literature review is provided of current indications for vertebral augmentation with percutaneous vertebroplasty and kyphoplasty as well as medical management. Limitations and potential benefits of these procedures are discussed. Variant tables describing various clinical situations are also provided to assist in determining appropriate use of these treatments for patient care. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to formulate recommendations for imaging or treatment.

ACR Appropriateness Criteria Headache.

Most patients presenting with uncomplicated, nontraumatic, primary headache do not require imaging. When history, physical, or neurologic examination elicits "red flags" or critical features of the headache, then further investigation with imaging may be warranted to exclude a secondary cause. Imaging procedures may be diagnostically useful for patients with headaches that are: associated with trauma; new, worse, or abrupt onset; thunderclap; radiating to the neck; due to trigeminal autonomic cephalgia; persistent and positional; and temporal in older individuals. Pregnant patients, immunocompromised individuals, cancer patients, and patients with papilledema or systemic illnesses, including hypercoagulable disorders may benefit from imaging. Unlike most headaches, those associated with cough, exertion, or sexual activity usually require neuroimaging with MRI of the brain with and without contrast to exclude potentially underlying pathology before a primary headache syndrome is diagnosed. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Automated classification of radiology reports to facilitate retrospective study in radiology.

Retrospective research is an import tool in radiology. Identifying imaging examinations appropriate for a given research question from the unstructured radiology reports is extremely useful, but labor-intensive. Using the machine learning text-mining methods implemented in LingPipe [1], we evaluated the performance of the dynamic language model (DLM) and the Naïve Bayesian (NB) classifiers in classifying radiology reports to facilitate identification of radiological examinations for research projects. The training dataset consisted of 14,325 sentences from 11,432 radiology reports randomly selected from a database of 5,104,594 reports in all disciplines of radiology. The training sentences were categorized manually into six categories (Positive, Differential, Post Treatment, Negative, Normal, and History). A 10-fold cross-validation [2] was used to evaluate the performance of the models, which were tested in classification of radiology reports for cases of sellar or suprasellar masses and colloid cysts. The average accuracies for the DLM and NB classifiers were 88.5% with 95% confidence interval (CI) of 1.9% and 85.9% with 95% CI of 2.0%, respectively. The DLM performed slightly better and was used to classify 1,397 radiology reports containing the keywords "sellar or suprasellar mass", or "colloid cyst". The DLM model produced an accuracy of 88.2% with 95% CI of 2.1% for 959 reports that contain "sellar or suprasellar mass" and an accuracy of 86.3% with 95% CI of 2.5% for 437 reports of "colloid cyst". We conclude that automated classification of radiology reports using machine learning techniques can effectively facilitate the identification of cases suitable for retrospective research.

ACR Appropriateness Criteria® follow-up and retreatment of brain metastases.

Multiple options for retreatment are available, which include whole-brain radiation therapy, stereotactic radiosurgery, surgery, chemotherapy, and supportive care. Size, number, timing, location, histology, performance status, and extracranial disease status all need to be carefully considered when choosing a treatment modality. There are no randomized trials examining the retreatment of brain metastases. Repeat whole-brain radiation has been examined in a single-institution experience, showing the potential for clinical responses in selected patients. Local control rates as high as 91% using stereotactic radiosurgery for relapses after whole-brain radiation are reported. Surgery can be indicated in progressive and/or hemorrhagic lesions causing mass effect. The role of chemotherapy in the recurrent setting is limited but some agents may have activity on the basis of experiences on a smaller scale. Supportive care continues to be an important option, especially in those with a poor prognosis. Follow-up for brain metastases patients is discussed, examining the modality, frequency of imaging, and imaging options in differentiating treatment effect from recurrence. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of the current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR Appropriateness Criteria(®) myelopathy.

Myelopathy is a problem that requires imaging to distinguish among numerous specifically treatable causes. The first priority is to determine mechanical stability after trauma. Next, it is crucial to distinguish intrinsic disease from extrinsic compression-for example, by epidural abscess. Osteophytes or disc extrusions and metastatic compression are the most common causes of extrinsic lesions. Imaging approaches rely on clinical features such as pain, fever, trauma, and pattern of progression. CT is preferred initially in acute trauma and MRI in all other circumstances. Contrast-enhanced MRI is added when tumor or infection is suspected or with slow or stepwise progression, especially when pain is not prominent. Vascular imaging is used when arteriovenous malformation, fistula, or occlusive disease is suspected. Because the treatment of myelopathy is often complex, treatment planning may require more than one imaging study or sequential examination to assess interval change. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR Appropriateness Criteria® on cerebrovascular disease.

Stroke is the sudden onset of focal neurologic symptoms due to ischemia or hemorrhage in the brain. Current FDA-approved clinical treatment of acute ischemic stroke involves the use of the intravenous thrombolytic agent recombinant tissue plasminogen activator given <3 hours after symptom onset, following the exclusion of intracerebral hemorrhage by a noncontrast CT scan. Advanced MRI, CT, and other techniques may confirm the stroke diagnosis and subtype, demonstrate lesion location, identify vascular occlusion, and guide other management decisions but, within the first 3 hours after ictus, should not delay or be used to withhold recombinant tissue plasminogen activator therapy after the exclusion of acute hemorrhage on noncontrast CT scans. MR diffusion-weighted imaging is highly sensitive and specific for acute cerebral ischemia and, when combined with perfusion-weighted imaging, may be used to identify potentially salvageable ischemic tissue, especially in the period >3 hours after symptom onset. Advanced CT perfusion methods improve sensitivity to acute ischemia and are increasingly used with CT angiography to evaluate acute stroke as a supplement to noncontrast CT. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Osseous metaplasia late in the course of nephrogenic systemic fibrosis.

Osseous metaplasia has recently been described in several cases of nephrogenic systemic fibrosis, sometimes in association with unusual clinical features such as painful hyperkeratotic spicules, palpable bony masses, and disease regression. Some authors have suggested that it may mainly occur late in the disease course or even be a marker for involuting nephrogenic systemic fibrosis. Here, we present a 27-year-old woman with a 7-year history of nephrogenic systemic fibrosis, who developed cutaneous osseous metaplasia.

ACR Appropriateness Criteria: single brain metastasis.

Single brain metastasis represents a common neurologic complication of cancer. Given the number of treatment options that are available for patients with brain metastasis and the strong opinions that are associated with each option, appropriate treatment for these patients has become controversial. Prognostic factors such as recursive partitioning analysis and graded prognostic assessment can help guide treatment decisions. Surgery, whole brain radiation therapy (WBRT), stereotactic radiosurgery or combination of these treatments can be considered based on a number of factors. Despite Class I evidence suggestive of best therapy, the treatment recommendation is quite varied among physicians as demonstrated by the American College of Radiology's Appropriateness Panel on single brain metastasis. Given the potential concerns of the neurocognitive effects of WBRT, the use of SRS alone or SRS to a resection cavity has gained support. Since aggressive local therapy is beneficial for survival, local control and quality of life, the use of these various treatment modalities needs to be carefully investigated given the growing number of long-term survivors. Enrollment of patients onto clinical trials is important to advance our understanding of brain metastasis.

Enlarged vestibular aqueduct in pediatric sensorineural hearing loss.

OBJECTIVE: Comparison of the Cincinnati criteria (midpoint >0.9 mm or operculum >1.9 mm) to the Valvassori criterion (midpoint > or =1.5 mm) for enlarged vestibular aqueduct (EVA) in pediatric cochlear implant patients. STUDY DESIGN: Cohort study. SUBJECTS: One hundred thirty pediatric cochlear implant recipients. METHODS: We reviewed temporal bone CT scans to measure the vestibular aqueduct midpoint and opercular width. RESULTS: The Cincinnati criteria identified 44 percent of patients with EVA versus 16 percent with the Valvassori criterion (P < 0.01). Of those with EVA, 45 percent were unilateral and 55 percent were bilateral using Cincinnati criteria; 64 percent were unilateral and 36 percent bilateral using Valvassori criterion (P < 0.01). The Cincinnati criteria diagnosed 70 ears with EVA classified as normal using the Valvassori criterion (P < 0.01); 59 lacked another medical explanation for their hearing loss. CONCLUSION: The Cincinnati criteria identified a large percentage of pediatric cochlear implant patients with EVA who might otherwise have no known etiology for their deafness.

Evaluation of intraaxial enhancing brain tumors on magnetic resonance imaging: intraindividual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine for visualization and assessment, and implications for surgical intervention.

OBJECT: The goal in this article was to compare 0.1 mmol/kg doses of gadobenate dimeglumine (Gd-BOPTA) and gadopentetate dimeglumine, also known as gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA), for enhanced magnetic resonance (MR) imaging of intraaxial brain tumors. METHODS: Eighty-four patients with either intraaxial glioma (47 patients) or metastasis (37 patients) underwent two MR imaging examinations at 1.5 tesla, one with Gd-BOPTA as the contrast agent and the other with Gd-DTPA. The interval between fully randomized contrast medium administrations was 2 to 7 days. The T1-weighted spin echo and T2-weighted fast spin echo images were acquired before administration of contrast agents and T1-weighted spin echo images were obtained after the agents were administered. Acquisition parameters and postinjection acquisition times were identical for the two examinations in each patient. Three experienced readers working in a fully blinded fashion independently evaluated all images for degree and quality of available information (lesion contrast enhancement, lesion border delineation, definition of disease extent, visualization of the lesion's internal structures, global diagnostic preference) and quantitative enhancement (that is, the extent of lesion enhancement after contrast agent administration compared with that seen before its administration [hereafter referred to as percent enhancement], lesion/brain ratio, and contrast/noise ratio). Differences were tested with the Wilcoxon signed-rank test. Reader agreement was assessed using kappa statistics. Significantly better diagnostic information/imaging performance (p < 0.0001, all readers) was obtained with Gd-BOPTA for all visualization end points. Global preference for images obtained with Gd-BOPTA was expressed for 42 (50%), 52 (61.9%), and 56 (66.7%) of 84 patients (readers 1, 2, and 3, respectively) compared with images obtained with Gd-DTPA contrast in four (4.8%), six (7.1%), and three (3.6%) of 84 patients. Similar differences were noted for all other visualization end points. Significantly greater quantitative contrast enhancement (p < 0.04) was noted after administration of Gd-BOPTA. Reader agreement was good (kappa > 0.4). CONCLUSIONS: Lesion visualization, delineation, definition, and contrast enhancement are significantly better after administration of 0.1 mmol/kg Gd-BOPTA, potentially allowing better surgical planning and follow up and improved disease management.

Head and neck imaging: the role of CT and MRI.

High-resolution computed tomography (CT) and magnetic resonance imaging (MRI) have become indispensable tools for the evaluation of conditions involving the head and neck. Complex anatomic structures and regions, such as the orbit, skull base, paranasal sinuses, deep spaces of the neck, larynx, and lymph nodes, require that the radiologist be familiar with the imaging modalities available and their appropriate applications. The purpose of this article is to review the techniques of CT and MRI and the roles they play in clinical practice, including head and neck disorders.

Desmoplastic fibroma of the mandible in an infant.

We report the CT and MR imaging findings of a case of a desmoplastic fibroma of the mandible in a 6-month-old girl who presented with a rapidly enlarging facial mass and who represents one of the youngest reported children with this rare tumor. Although imaging is non-specific and these lesions are best distinguished histologically, the desmoplastic fibroma should be considered when there is an occurrence of any bubbly or cystic expansile mandibular lesion presenting in childhood.

Tortuous vertebral artery injury complicating anterior cervical spinal fusion in a symptomatic rheumatoid cervical spine.

STUDY DESIGN: A case report of a 60-year-old patient with rheumatoid arthritis who sustained injury of a tortuous vertebral artery after anterior cervical spinal fusion is reported. The literature relevant to this topic is reviewed. OBJECTIVE: To report the surgical injury of a tortuous vertebral artery resulting from rheumatoid arthritis and to stress the value of cross-sectional imaging in identifying this anomaly before surgery in these patients. BACKGROUND DATA: Rheumatoid arthritis causes well-known bony complications such as atlantoaxial and subaxial subluxation and spinal stenosis with spinal cord compression. Less emphasized is vertebral artery loop formation and vascular compression. Anomalous vertebral artery position could jeopardize otherwise successful anterior diskectomy and corpectomy in these patients. METHODS: A 60-year-old man with rheumatoid arthritis sustained a vertebral artery injury during anterior corpectomy, which resulted in cerebral and cerebellar infarction. RESULTS: Computed tomography and magnetic resonance imaging and angiography confirmed the medially deviated vertebral artery. A computed tomography scan confirmed the cerebral infarction that resulted from dissection and injury of the artery at the time of surgery. CONCLUSION: The patient with rheumatoid arthritis of the cervical spine could have associated tortuosity of the vertebral artery, mandating a thorough awareness of vascular anatomy before surgical decompression. Cross-sectional imaging effectively locates the position of the vertebral arteries and should be carefully studied before anterior cervical spinal fusion in these patients.

MR imaging features of craniodiaphyseal dysplasia.

We report the magnetic resonance (MR) imaging findings in a 4-year-old girl with characteristic radiographic and computed tomography (CT) features of craniodiaphyseal dysplasia. MR imaging exquisitely depicted cranial nerve compression, small foramen magnum, hydrocephalus, and other intracranial complications of this syndrome. A syrinx of the cervical spinal cord was demonstrated. We suggest that MR imaging become a routine component of the evaluation of these patients.

Fast magnetic resonance imaging in steady-state precession (true FISP) in the prenatal diagnosis of a congenital brain teratoma.

Teratomas are the most common congenital intracranial tumor. Although fetal magnetic resonance (MR) imaging is becoming more popular for prenatal diagnosis, only 2 cases of congenital intracranial teratoma have been reported, and these cases relied on half-Fourier single-shot turbo spin echo (HASTE) imaging. We report the first known case of congenital intracranial teratoma diagnosed by means of a fast imaging in steady-state precession (true FISP) MR sequence. True FISP can be obtained in almost 20 seconds and provides superior contrast resolution compared with HASTE.

Imaging the treated oral cavity and oropharynx.

Cross-sectional imaging has become essential in the evaluation of the treated oral cavity and oropharynx. The purpose of this paper is to review the imaging guidelines for the evaluation of this region and to detail the typical changes encountered on imaging following surgical and radiation treatment for cancer.