Patterns of Intrathecal Ossification in Arachnoiditis Ossificans: A Retrospective Case Series.

Arachnoiditis ossificans is an uncommon end-stage appearance of chronic adhesive arachnoiditis. Imaging features of arachnoiditis ossificans are characteristic and should be diagnosed to avoid unnecessary intervention and guide prognosis and management. In this case series, we retrospectively analyzed CT and MR imaging of 41 patients to identify common patterns of intrathecal ossification and present the common etiologies. Thirty-two patients had a confirmed history of spinal instrumentation, 7 were discovered on imaging without prior surgical history, 1 had a history of ankylosing spondylitis, and 1 had trauma. The most frequent site of ossification was at the conus and cauda equina. Four patterns of ossification were identified, including central, nerve root encasing, weblike, and peripheral. Arachnoiditis ossificans is an important, likely under-recognized consideration in patients who present with back pain. Diagnosis can be made readily on CT; MR imaging diagnosis is also possible but may be challenging.

Cost-Effectiveness Analysis of 68Ga-DOTATATE PET/MRI in Radiotherapy Planning in Patients with Intermediate-Risk Meningioma.

BACKGROUND AND PURPOSE: While contrast-enhanced MR imaging is the criterion standard in meningioma diagnosis and treatment response assessment, gallium 68Ga-DOTATATE PET/MR imaging has increasingly demonstrated utility in meningioma diagnosis and management. Integrating 68Ga-DOTATATE PET/MR imaging in postsurgical radiation planning reduces the planning target volume and organ-at-risk dose. However, 68Ga-DOTATATE PET/MR imaging is not widely implemented in clinical practice due to higher perceived costs. Our study analyzes the cost-effectiveness of 68Ga-DOTATATE PET/MR imaging for postresection radiation therapy planning in patients with intermediate-risk meningioma. MATERIALS AND METHODS: We developed a decision-analytical model based on both recommended guidelines on meningioma management and our institutional experience. Markov models were implemented to estimate quality-adjusted life-years (QALY). Cost-effectiveness analyses with willingness-to-pay thresholds of $50,000/QALY and $100,000/QALY were performed from a societal perspective. Sensitivity analyses were conducted to validate the results. Model input values were based on published literature. RESULTS: The cost-effectiveness results demonstrated that 68Ga-DOTATATE PET/MR imaging yields higher QALY (5.47 versus 5.05) at a higher cost ($404,260 versus $395,535) compared with MR imaging alone. The incremental cost-effectiveness ratio analysis determined that 68Ga-DOTATATE PET/MR imaging is cost-effective at a willingness to pay of $50,000/QALY and $100,000/QALY. Furthermore, sensitivity analyses showed that 68Ga-DOTATATE PET/MR imaging is cost-effective at $50,000/QALY ($100,000/QALY) for specificity and sensitivity values above 76% (58%) and 53% (44%), respectively. CONCLUSIONS: 68Ga-DOTATATE PET/MR imaging as an adjunct imaging technique is cost-effective in postoperative treatment planning in patients with meningiomas. Most important, the model results show that the sensitivity and specificity cost-effective thresholds of 68Ga-DOTATATE PET/MR imaging could be attained in clinical practice.

Multimodality Imaging in Primary Progressive Aphasia.

Primary progressive aphasia is a clinically and neuropathologically heterogeneous group of progressive neurodegenerative disorders, characterized by language-predominant impairment and commonly associated with atrophy of the dominant language hemisphere. While this clinical entity has been recognized dating back to the 19th century, important advances have been made in defining our current understanding of primary progressive aphasia, with 3 recognized subtypes to date: logopenic variant, semantic variant, and nonfluent/agrammatic variant. Given the ongoing progress in our understanding of the neurobiology and genomics of these rare neurodegenerative conditions, accurate imaging diagnoses are of the utmost importance and carry implications for future therapeutic triaging. This review covers the diverse spectrum of primary progressive aphasia and its multimodal imaging features, including structural, functional, and molecular neuroimaging findings; it also highlights currently recognized diagnostic criteria, clinical presentations, histopathologic biomarkers, and treatment options of these 3 primary progressive aphasia subtypes.

CT-Guided C2 Dorsal Root Ganglion Radiofrequency Ablation for the Treatment of Cervicogenic Headache: Case Series and Clinical Outcomes.

Cervicogenic headache is a secondary headache syndrome attributable to upper cervical spine pathology. Osteoarthritis of the lateral atlantoaxial joint with resultant C2 dorsal root ganglion irritation is an important and potentially treatable cause of cervicogenic headache. In this case series, we present 11 patients with cervicogenic headache who underwent C2 dorsal root ganglion thermal radiofrequency ablation. Radiologists should be familiar with this efficacious procedure and technical considerations to avoid complications.

Urgent Liver Transplantation for Dietary Supplements: An Under-Recognized Problem.

BACKGROUND: The recent outbreak of acute liver failure caused by herbal/dietary supplements (HDS) in Hawaii prompted evaluation of those patients who underwent emergency liver transplantation (LT) for HDS in the United States. METHODS: We queried the Scientific Registry of Transplant Recipients (2003-2015) to identify patients who underwent urgent LT for acute hepatic necrosis (AHN) and identified those with HDS use. This group of patients was then characterized. RESULTS: Of 2408 adult cases, 625 were characterized as a drug-induced liver injury. The majority of cases (n = 300) were due to acetaminophen toxicity, but the fourth highest category was due to HDS (n = 21). Of these 21 cases caused by HDS, 13 did not list the specific agent responsible, mean age was 36 years, and all cases occurred after 2007. There probably are more cases because 25% of all LT cases in the study did not list a specific reason for liver failure and 20% of all drug-induced liver failure did not list a specific drug. CONCLUSIONS: Herbal/supplement use is the fourth most common cause of drug-induced AHN requiring LT, albeit an underestimation of the problem. Detailed questioning of patients and their support systems regarding herbal/supplement use and better reporting are imperative to further define this problem and identify products that have the potential to lead to liver failure.

Pseudotumor cerebri caused by isotretinoin.

A 16-year-old girl treated with isotretinoin at a dosage of 0.7 mg per kg each day experienced severe headaches and impaired night vision two months after the start of therapy. Bilateral papilledema and narrowing of the lateral ventricles of the brain were found. Pseudotumor cerebri and impaired night vision abated when isotretinoin was discontinued and systemic corticosteroids (dexamethasone) were administered.

Juvenile xanthogranuloma underneath a toenail.

A 1 1/2-year-old boy developed a dystrophic toenail shortly after trauma to the foot. At the age of three years, it was recognized that the nail deformity was caused by a subungual tumor. The tumor proved to be a juvenile xanthogranuloma. The lesion was solitary, and no systemic associations or visceral involvement were found.