Matthew T. Whitehead

ACR Appropriateness Criteria Low Back Pain.

Most patients presenting with uncomplicated acute low back pain (LBP) and/or radiculopathy do not require imaging. Imaging is considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain. It is also considered for those patients presenting with red flags raising suspicion for serious underlying conditions, such as cauda equina syndrome, malignancy, fracture, and infection. Many imaging modalities are available to clinicians and radiologists for evaluating LBP. Application of these modalities depends largely on the working diagnosis, the urgency of the clinical problem, and comorbidities of the patient. When there is concern for fracture of the lumbar spine, multidetector CT is recommended. Those deemed to be interventional candidates, with LBP lasting for > 6 weeks having completed conservative management with persistent radiculopathic symptoms, may seek MRI. Patients with severe or progressive neurologic deficit on presentation and red flags should be evaluated with MRI. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (the RAND/UCLA Appropriateness Method and the Grading of Recommendations Assessment, Development, and Evaluation) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Interhypothalamic adhesion: A series of 13 cases

SUMMARY: Interhypothalamic adhesion is a newly described disease entity, characterized by an abnormal parenchymal band connecting the medial margins of the hypothalami across the third ventricle. Additional anomalies, including cleft palate, gray matter heterotopia, cerebellar hypoplasia, optic atrophy, hippocampal under-rotation, and white matter lesions, may coexist. The purpose of this clinical report is to describe the imaging findings from a series of 13 patients with interhypothalamic adhesions discovered on brain MR imaging.

Resective surgery for focal cortical dysplasia in children: a comparative analysis of the utility of intraoperative magnetic resonance imaging (iMRI).

PurposeSeizure freedom following resection of focal cortical dysplasia (FCD) correlates with complete resection of the dysplastic cortical tissue. However, difficulty with intraoperative identification of the lesion may limit the ability to achieve the surgical objective of complete extirpation of these lesions. Intraoperative magnetic resonance imaging (iMRI) may aid in FCD resections. The objective of this study is to compare rates of postoperative seizure freedom, completeness of resection, and need for reoperation in patients undergoing iMRI-assisted FCD resection versus conventional surgical techniques.MethodsWe retrospectively reviewed the medical records of pediatric subjects who underwent surgical resection of FCD at Children’s National Medical Center between March 2005 and April 2015.ResultsAt the time of the last postoperative follow-up, 11 of the 12 patients (92xa0%) in the iMRI resection group were seizure free (Engel Class I), compared to 14 of the 42 patients (33xa0%) in the control resection group (pxa0=xa00.0005). All 12 of the iMRI patients (100xa0%) achieved complete resection, compared to 24 of 42 patients (57xa0%) in the control group (pxa0=xa00.01). One (8xa0%) patient from the iMRI-assisted resection group has required reoperation, compared to 17 (40xa0%) patients in the control resection group.ConclusionOur results suggest that the utilization of iMRI during surgery for resection of FCD results in improved postoperative seizure freedom, completeness of lesion resection, and reduction in the need for reoperation.

ACR Appropriateness Criteria® Cerebrovascular Disease

Diseases of the cerebral vasculature represent a heterogeneous group of ischemic and hemorrhagic etiologies, which often manifest clinically as an acute neurologic deficit also known as stroke or less commonly with symptoms such as headache or seizures. Stroke is the fourth leading cause of death and is a leading cause of serious long-term disability in the United States. Eighty-seven percent of strokes are ischemic, 10% are due to intracerebral hemorrhage, and 3% are secondary to subarachnoid hemorrhage. The past two decades have seen significant developments in the screening, diagnosis, and treatment of ischemic and hemorrhagic causes of stroke with advancements in CT and MRI technology and novel treatment devices and techniques. Multiple different imaging modalities can be used in the evaluation of cerebrovascular disease. The different imaging modalities all have their own niches and their own advantages and disadvantages in the evaluation of cerebrovascular disease. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Osseous intramedullary signal alteration and enhancement in Sturge-Weber syndrome: an early diagnostic clue

IntroductionSturge-Weber syndrome (SWS) is a sporadic phakomatosis with variable intracranial involvement. Port-wine stain, choroidal angioma, and leptomeningeal angiomatosis typify the full disease spectrum. Disease manifestations generally evolve toward cerebral hemiatrophy and compensatory hemicalvarial enlargement. However, recognizable imaging correlates may be lacking early on. We have observed SWS-related marrow signal changes to be prevalent in patients of all ages. The purpose of this study is to evaluate bone marrow abnormalities in patients with Sturge-Weber syndrome.MethodsThe MR imaging database at an academic children’s hospital was queried for “Sturge-Weber” to build a cohort for retrospective analysis. Two board-certified neuroradiologists reviewed MR exams for abnormalities of the bone marrow, globes, susceptibility, and perfusion. A two-tailed Fisher’s exact test was applied to evaluate the association between variables.ResultsTwenty brain MR exams from 19 SWS patients, mean age 4.8 +/− 5.8xa0years (range 6xa0months–16xa0years), met the inclusion criteria. All patients with port-wine stains (18/20) had leptomeningeal enhancement, marrow T2 prolongation, and/or marrow enhancement ipsilaterally. Leptomeningeal enhancement was only present in 53xa0%. Eighty percent had unilateral bone marrow abnormalities. In 37xa0% (all <5xa0years), marrow abnormalities occurred without leptomeningeal angiomatosis. Thirty-five percent had facial bones involvement; 75xa0% of these had ipsilateral choroidal angiomas.ConclusionBone marrow signal abnormality and enhancement is common ipsilateral to the nevus flammeus in SWS. As this may be the sole brain MR abnormality in some patients, it may reflect mild phenotypes or an early disease manifestation, and could help stratify patients for early intervention.

Structural Brain Defects

Up to 14% of patients with congenital metabolic disease may show structural brain abnormalities from perturbation of cell proliferation, migration, and/or organization. Most inborn errors of metabolism have a postnatal onset. Abnormalities from genetic disease processes have a prenatal onset. Energy impairment, substrate insufficiency, cell membrane receptor and cell signaling abnormalities, and toxic byproduct accumulation are associations between genetic disorders and structural brain anomalies. Collective imaging patterns of brain abnormalities can provide clues to the underlying etiology. We review selected metabolic diseases associated with brain malformations and highlight characteristic clinical and imaging manifestations that help narrow the differential diagnosis.

ACR Appropriateness Criteria® Penetrating Neck Injury

In patients with penetrating neck injuries with clinical soft injury signs, and patients with hard signs of injury who do not require immediate surgery, CT angiography of the neck is the preferred imaging procedure to evaluate extent of injury. Other modalities, such as radiography and fluoroscopy, catheter-based angiography, ultrasound, and MR angiography have their place in the evaluation of the patient, depending on the specific clinical situation and question at hand. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Increased cerebral blood flow on arterial spin labeling magnetic resonance imaging can localize to seizure focus in newborns: A report of 3 cases

Arterial spin labeling (ASL) magnetic resonance imaging (MRI) can assess cerebral blood flow (CBF) without using radiolabeled tracers. It is unknown whether regional increases in CBF on ASL MRI correlate with seizure location in newborns. We report 3 newborns with focal seizures localized on continuous video electroencephalogram (cEEG), anatomical brain MRI, and ASL MRI. Each patient underwent pseudocontinuous ASL with segmented 3‐dimensional fast spin echo readout as part of standard care. Case 1 is a term male infant presenting with left temporal status epilepticus and recurrent cEEG seizures from an idiopathic large left intraventricular hemorrhage. ASL images demonstrated left mesial temporal lobe increased CBF. Case 2 is a late preterm male infant presenting with recurrent cEEG seizures due to focal right megalencephaly. Ictal EEG and ASL images coincided with the focal dysplasia. Case 3 is a dysmorphic term female infant with nonconvulsive partial status epilepticus identified by focal increased CBF of the left temporal lobe on ASL images. The area of increased CBF was within an area of extensive left hemisphere dysplasia. To our knowledge, this is the first report of regional increases in CBF on ASL MRI correlating with ictal cEEG in newborns.

Reply regarding lesional perfusion abnormalities on arterial spin labeling in Leigh disease

Dear Editor, We thank Drs. Finsterer and Zarrouk-Mahjoub [1] for their interest in our article [2], and we welcome the opportunity to provide clarification. The authors raised questions and concerns as to diagnostic criteria, associations between genetic defects and perfusion changes, and external factors that may alter brain blood flow such as seizures, strokes, anesthetics and other medications [1]. Herein, we contribute to the comments regarding our recent report and discuss the context of our findings. It is well known that Leigh disease can be a phenotype of several different genetic defects [3]. While many specific causitive gene mutations have been firmly established, some are of less certain pathogenicity, ranging to include “variants of unknown clinical significance.” We retrospectively identified and analyzed 15 brain MR exams from 8 subjects with clinically, radiographically and genetically confirmed Leigh disease [2]. All patients met clinical dignostic criteria for Leigh disease based on the following: symmetrical deep gray nuclear and/or brainstem lesions on MRI, clinical findings suggestive of mitochondrial dysfunction, and lactate elevation in the blood, cerebral spinal fluid (CSF), or brain on MR spectroscopy. Genetic confirmation revealed various pathogenic mitochondrial and nuclear gene mutations as well as several variants of unknown significance, but was highly suspicious for causitive defects based on the clinical picture (Table 2 in our article) [2]. Unfortunately the sample size of each gene defect was too small to make reasonable judgments regarding potential correlation(s) between the specific genetic abnormalities and types of brain perfusion changes, though no such correlations were identified. Further studies are warranted in this regard. All patients underwent propofol sedation to prevent/ mitigate the effect of motion artifact on MR image quality per age-based division protocol. Propofol has been shown to decrease cerebral blood flow in children and adults [4, 5]. While decreased cerebral cortical perfusion is an expected finding in children sedated with propofol [4], focal/regional hyperor hypoperfusion in the cerebral deep gray nuclei sparing the cortex would be atypical, especially when coinciding with structural brain lesions and/or diffusion alteration as was seen in the vast majority of our patients. Furthermore, the arterial spin-labeling (ASL) perfusion signal in the Leigh cohort sedated with propofol differed significantly with the ASL perfusion signal from age-matched normal exams from nonLeigh patients also acquired under propofol sedation [2]. As for the previously reported propofol-induced connectivity alterations in the brain, these are of questionable validity [5]. All eight studies cited by Song and Yu [5] used parametric statistical methods to analyze functionalMRI (fMRI) data that have been shown to be flawed [6]. None of our patients developed signs or symptoms of propofol infusion syndrome. Although the effects of propofol on ASL perfusion signal have yet to be thoroughly defined, it is clear that pathological ASL perfusion changes are quite common in Leigh patients and tend to correlate with disease activity. * Matthew T. Whitehead MWhitehe@childrensnational.org

Normal Developmental Globe Morphology on Fetal MR Imaging.

BACKGROUND AND PURPOSE: Age-dependent structural changes of the globes occur during gestation. The posterolateral globe margins bulge outward, and the eyes are conical in early gestation. Later, the globes are ellipsoid. The purpose of this study was to establish normal developmental fetal globe morphology. MATERIALS AND METHODS: The fetal MR imaging data base at an academic childrens hospital was queried for all brain MRIs performed during 8 years. Motion artifacts, brain/craniofacial/globe malformations, and chromosomal defects were exclusion criteria. Two board-certified neuroradiologists evaluated each examination for globe shape (elliptic/nonelliptic) and hyaloid visibility. Logistic regression was used to evaluate correlations among variables. Age-specific cut-points for globe shape and hyaloid visibility were chosen to optimize specificity. RESULTS: We identified 1243 examinations from 1177 patients. Six hundred eighty-two examinations met the inclusion criteria (17–39 weeks). Receiver operating characteristic analysis showed that age was highly predictive of globe shape (area under the curve = 0.99) and fetal vasculature visibility (area under the curve = 0.94). Nonelliptic globes were universal up to 22 weeks. Thereafter, globes gradually assumed an elliptic shape, present in nearly all patients 29 weeks and older (sensitivity, 81%; 95% CI, 76%–85%; specificity, 99%; 95% CI, 98%–100%). The hyaloid vasculature was visible in most patients up to 19 weeks and occasionally in those at 20–24 weeks, but never in those 25 weeks and older (sensitivity, 69%; 95% CI, 65%–72%; specificity, 100%; 95% CI, 95%–100%). CONCLUSIONS: Physiologic nonspheric globe shapes are normal up to 29 weeks gestation and should not be misinterpreted as pathologic. Thereafter, globes are generally elliptic. The timing of this process coincides with the resolution of the primary vitreous and may be related.