T2 Signal Hyperintensity Research Articles

Clinical and radiological outcomes with PEEK suture anchors used in rotator cuff repair: our experience confirm that a perianchor fluid signal on RM does not affect clinical outcome at one year of follow up.

Introduction / objectives:Osteolytic-type reactions of the perianchor bone which in magnetic resonance are manifested as hyperintensity of the signal in T2 images are reported in many studies. The doubt that this reaction of the bone could result in a loss of pull-out in the short and medium term and that it could therefore negatively affect tendon healing is the subject of an increasing number of studies. An osteolytic type signal around absorbable anchors can be explained by the metabilic processes in progress foreseen by the very nature of the material used, however this type of signal is also recognized around sutured implants or made of notoriously inert material. The objective of the present study is to evaluate and compare to the literature data the clinical and radiological results of a group of patients who underwent arthroscopic suture of a rotator cuff tear using polyetherketone (PEEK) suture anchors.Materials and methods:Twenty patients, aged between 44 and 73 years, who underwent arthroscopic repair of the rotator cuff for lesions smaller than 4 cm considered reparaible between August 2017 and January 2019, were enrolled in the present study. Patients were evaluated clinically with clinical examination, Constant scale and ASES scale pre and post surgery. MRI either pre and post operation at one year were evaluated to obtain data about tendon healing and evaluate bone reaction to PEEK anchors.Results:The mean lesion size was 16.8 mm +/- 7.8 mm and the mean tendon retraction was 15.6 mm +/- 14.9 mm. The mean increase in Constant and ASES scores at the one year-follow up was respectively 36.8 (p<0.01) and 47.2 (p<0.01). MRI analysis showed a tendon signal according to Sugaya classification of type 1 in the 25% of patients, type 2 in the 60% of cases and type 3 in the remaining 15% . Osteolysis was grade 0 in 65%, grade 1 in 30 % and grade 2 in 5% of cases. No anchors pull out or mobilization were reported.Conclusions:The presence of a T2 hyperintense signal osteolysis like on MRI control using PEEK anchors for the sutur of rotator cuff lesions does not find correlation whit the final clinical result of the procedure. Indeed, both patients with a major degree of osteolysis and those with degree 0 had an improvement both in terms of clinical and scores evaluation and in termsof tendon healing according to Sugaya’s score found in our cohort. (www.actabiomedica.it)

Pathogenic variants in NUBPL result in failure to assemble the matrix arm of complex I and cause a complex leukoencephalopathy with thalamic involvement

Disorders of the white matter are genetically very heterogeneous including several genes involved in mitochondrial bioenergetics. Diagnosis of the underlying cause is aided by pattern recognition on neuroimaging and by next-generation sequencing. Recently, genetic changes in the complex I assembly factor NUBPL have been characterized by a consistent recognizable pattern of leukoencephalopathy affecting deep white matter including the corpus callosum and cerebellum.Here, we report twin boys with biallelic variants in NUBPL, an unreported c.351 G > A; p.(Met117Ile) and a previously reported pathological variant c. 693 + 1 G > A. Brain magnetic resonance imaging showed abnormal T2 hyperintense signal involving the periventricular white matter, external capsule, corpus callosum, and, prominently, the bilateral thalami. The neuroimaging pattern evolved over 18 months with marked diffuse white matter signal abnormality, volume loss, and new areas of signal abnormality in the cerebellar folia and vermis. Magnetic resonance spectroscopy showed elevated lactate.Functional studies in cultured fibroblasts confirmed pathogenicity of the genetic variants. Complex I activity of the respiratory chain was deficient spectrophotometrically and on blue native gel with in-gel activity staining. There was absent assembly and loss of proteins of the matrix arm of complex I when traced with an antibody to NDUFS2, and incomplete assembly of the membrane arm when traced with an NDUFB6 antibody. There was decreased NUBPL protein on Western blot in patient fibroblasts compared to controls.Compromised NUBPL activity impairs assembly of the matrix arm of complex I and produces a severe, rapidly-progressive leukoencephalopathy with thalamic involvement on MRI, further expanding the neuroimaging phenotype.

Does the Diffusion Weighted Images and Subtration MRI of Hepatocellular Carcinoma has a Role in Predicting Outcome of Transarterial Chemoembolization?

AbstractBackground: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and has a poor prognosis unless treated. Ablative therapies are promising treatment options for patients who are not eligible for surgery.Aim of Study: Is to evaluate the predictive values of diffusion-weighted imaging (DWI) and Subtration MRI in evaluating the efficacy of transcatheter arterial chemoembol-ization (TACE) in treatment of patients with hepatocellular carcinoma (HCC).Patients and Methods: This study included 30 patients with pathologically proven HCC (38 HCC lesions) who were referred to the Radiology Department of Ain Shams University Hospitals and National Liver Institute, Menofiya University for post therapeutic assessment after transarterial hepatic chemoembolization. The study was carried on over a period of 12 month (from August 2017 to August 2018). Patients' ages ranged from 59 to 73 with a mean of age 59.6 years. Of the 30 patients only 6 were females and 24 were males.Results: We found that dynamic study is the gold standard in detection of recurrent lesions. Well defined nodular en-hancement, thick irregular marginal enhancement or gross enlargement of the lesion with arterial phase enhancement and contrast wash out were considered positive for malignancy. Ill-defined persistent enhancement or well defined rim marginal enhancement were considered benign post ablation changes. We found that subtraction technique was essential in differ-entiation between the normal hyperintense T1 signal of the ablation zone and arterial enhancement of the lesion. The high signal intensity seen in T1 images post TACE was explained by haemorrhagic coagulative necrosis. Subtraction imaging is ideally suited for such a role where the unenhanced T1-weighted sequence is subtracted from the identical contrast enhanced sequence.Conclusion: We conclude that in evaluation of HCC after TACE, ADC calculated at DWI had weaker correlation to tumor necrosis degree than did findings with subtraction contrast-enhanced MRI. However, there was no difference between both methods in diagnosis of complete tumor necrosis.We suggest that whenever possible, gadolinium contrast enhancement and subtraction imaging be used for assessment of tumor necrosis after TACE.

Progressive Multifocal Leukoencephalopathy in a Patient with Multiple Myeloma Receiving Daratumumab and Pomalidomide

Background Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by reactivation of the polyomavirus John Cunningham (JCV) in the setting of immunosuppression. It has been described in patients with hematologic malignancies including multiple myeloma (MM), solid organ malignancies, granulomatous and inflammatory diseases, transplant recipients, lymphopenic patients (including patients with HIV) and with the use of certain drugs (rituximab, natalizumab). We present the first report to our knowledge of a patient with MM developing PML in association with daratumumab and pomalidomide therapy. Case Report A 63yo woman with relapsed/refractory IgA-Lambda MM on daratumumab and pomalidomide, presented to the emergency department after noticing difficulty putting her hair up in a ponytail. Her MM was diagnosed in 2003 and treated with steroids, high-dose melphalan and autologous stem cell transplant, maintenance therapy with thalidomide, switched to lenalidomide; upon relapse in 2010, she was treated with bortezomib, doxorubicin and dexamethasone, followed by bortezomib maintenance. Ten months prior to presentation, she relapsed and was started on daratumumab and pomalidomide, achieving an unconfirmed complete response (uCR), complicated by acquired hypogammaglobulinemia for the prior 8 months without infections. She developed progressive left arm weakness and gait instability; she denied any fevers, dysarthria, vision changes, headaches or seizures. On exam, she was alert and oriented; no cranial nerve abnormality; calculation, concentration and recall were intact; 4/5 strength in left upper extremity and 5/5 strength in all other extremities with preserved sensation and reflexes; coordination intact but a hemiparetic gait; rest of the exam was unremarkable. A brain MRI showed patchy and confluent areas of T2 hyperintense signal in the right greater than left cerebral hemispheres. She underwent a lumbar puncture which was positive for JCV by PCR (98 copies/mL) in her CSF and negative for neoplastic involvement by flow cytometry. The rest of her work-up was unremarkable. A diagnosis of PML was made and daratumumab and pomalidomide were discontinued. On follow-up brain MRIs four and eight weeks later, she had persistent extensive asymmetric patchy T2 hyperintense signal. Repeat LP revealed stable JCV in the CSF (95 copies/mL). Despite the lack of radiologic improvement, she had a remarkable clinical response with near resolution of neurologic symptoms and remains in an uCR. Discussion PML has been reported in association with multiple drugs used in the management of MM including corticosteroids, alkylating agents (cyclophosphamide, melphalan), immunomodulatory drugs (thalidomide, lenalidomide) and proteasome inhibitors (bortezomib, ixazomib), however, an association with pomalidomide or daratumumab has not yet been reported. In a clinical trial of daratumumab and pomalidomide for MM, a case of PML was reported, however, it was not considered to be related to these agents given that the patient received only one dose of daratumumab (Chari A. Blood 2017). PML has been reported in patients with primary hypogammaglobulinemia, however, it is not known whether acquired hypogammaglobulinemia - either due to MM or its therapy - is a risk factor for PML. Furthermore, the role for IVIG in the primary prevention or treatment of PML has not been clearly defined and warrants further study. The current treatment approach of PML remains the restoration of the host's adaptive immune response, including the discontinuation of immunosuppressive agents, unfortunately, evidence is lacking for any specific pharmacologic treatment. Recently, immune checkpoint inhibitors have shown clinical improvement or stabilization in small cohorts of patients with PML (NEJM 2019;380), however, given the safety concerns regarding their use in MM (KEYNOTE-183,-185) and the rapid clinical response seen in this case, no further therapy was instituted. This is the first report of pomalidomide and daratumumab as potential drugs associated with PML. Although it is not possible to ascertain their direct role in the reactivation of JCV, it should help clinicians recognize this potentially fatal complication in patients receiving either immunomodulatory drugs or anti-CD38 monoclonal antibodies, since prompt discontinuation may be life-saving. Disclosures Perry: Celgene: Speakers Bureau. Coleman:Gilead, Bayer, Celgene: Consultancy, Research Funding, Speakers Bureau; Kite Pharmaceuticals: Equity Ownership; Merck: Research Funding; Pharmacyclics: Speakers Bureau. Rossi:Janssen, Celgene, Amgen: Consultancy; BMS: Research Funding. Niesvizky:Takeda, Amgen, BMS, Janssen, Celgene: Consultancy, Research Funding.

1355 Accessory Spleen: An Unusual Pancreatic Mass Posing a Diagnostic Dilemma

INTRODUCTION: There are two main causes of accessory spleen; failure of fusion of the splenic anlage during the fifth week of fetal life and following autotransplantation after a splenectomy. They are structurally identical to the spleen and are most commonly found in the splenic hilum or pancreatic tail. Although rarely noted on radiograph due to low spatial resolution, their detection is increasing with more advanced modalities. This can result in the finding of a pancreatic mass that poses a diagnostic dilemma. CASE DESCRIPTION/METHODS: The patient is a 62-year-old man with a history of hepatitis B infection. On routine surveillance he had ultrasound findings of a liver calcification with inability to determine the presence of cirrhosis and a mildly elevated alpha-fetoprotein level. He was sent for an MRI, which revealed a 2.3 × 1.9 cm mass in the pancreatic tail showing mild hyperintense T2 signal and hypointense T1 signal. A CT from 2011 showed a slight contour bulge to the pancreatic tail in the same region, without appreciation of a discrete lesion. He underwent EGD with endoscopic ultrasound (EUS). A 21.4 × 13.7 mm well-circumscribed, homogeneous lesion was found in the pancreatic tail and biopsied. The pathology shows an immunohistochemical-staining pattern consistent with splenic tissue, confirming the diagnosis of an intrapancreatic accessory spleen (IPAS). No further intervention was needed and the patient was sent home. DISCUSSION: Pancreatic cancer has a 5-year survival rate of 9%, therefore it is imperative that all pancreatic masses are investigated thoroughly and promptly. In cases of an IPAS, its differentiation from a pancreatic mass is difficult as splenic tissue can mimic pancreatic tumors, especially on MRI. It is essential to differentiate between the two as IPAS are only clinical relevant when there is torsion, rupture, hemorrhage, or the patient carries a diagnosis of idiopathic thrombocytopenic purpura requiring the removal of all splenic tissue. Imaging modalities such as ultrasound, CT, MRI, and scintigraphy can aid in the diagnosis of IPAS. However, these have limitations and have not shown to provide a definitive diagnosis. EUS with fine needle aspiration is being increasingly used to characterize pancreatic lesions. In this case, it enabled adequate tissue sampling while avoiding unnecessary procedures. This case illustrates another use for EUS in an otherwise difficult diagnostic scenario.

2301 Hepatic Adenoma Misdiagnosed as Biliary Colic

INTRODUCTION: We present the case of a woman who presented on multiple occasions with abdominal pain attributed to biliary colic that was eventually diagnosed as a hemorrhagic hepatic adenoma. We emphasize the importance of keeping a wide differential diagnosis for a common gastrointestinal complaint, the importance of medication review, and the benefit of patient-centered care. CASE DESCRIPTION/METHODS: A 37 year old female presented to the emergency department with right upper quadrant pain. She had pain for the past month that was more severe and constant in the past week. She had no fevers, chills, vomiting, or diarrhea. Her only medication was ethinyl estradiol for endometriosis. Her pain had been attributed to biliary colic at prior clinic appointments. She had right upper quadrant tenderness without peritoneal signs. A complete blood count and complete metabolic panel were unremarkable. A CT scan showed a 4.9 × 3.9 × 3.9 cm hepatic mass, with subsequent MRI demonstrating intrinsic T1 hyperintense signal consistent with a hepatic adenoma with recent hemorrhage. The patient declined to stop her estrogen without further endometriosis therapy, so she underwent simultaneous laparoscopic liver wedge resection and robotic hysterectomy with bilateral salpingo-oopherectomy. She now has some minor residual pain but is doing well. DISCUSSION: Hepatic adenomas are uncommon liver tumors classically associated with oral contraceptive (OCP) use. The annual incidence is 1 in 1,000,000 in non OCP users, but increases to 30-40 per 1,000,000 in those with long term OCP use. The risk increases with both increasing dose and duration of therapy. OCPs not only increase the incidence of hepatic adenomas, but they tend to be larger, more numerous, and more likely to bleed in patients who take OCPs. In this case, premature closure by multiple providers led to anchoring on the diagnosis of biliary colic. The association between her use of ethinyl estradiol and the possibility of hepatic adenoma was not recognized until her adenoma had begun to bleed, which could have resulted in a catastrophic outcome. This highlights the need to keep a broad differential and perform an adequate medication review for patients that present with this common gastrointestinal complaint. Additionally, prioritizing the patient’s preference to control her endometriosis pain led to consultation with the appropriate surgical teams that ultimately led to a positive outcome for the patient.

Nontraumatic Spinal Cord Compression: MRI Primer for Emergency Department Radiologists.

The occurrence of acute myelopathy in a nontrauma setting constitutes a medical emergency for which spinal MRI is frequently ordered as the first step in the patient's workup. The emergency department radiologist should be familiar with the common differential diagnoses of acute myelopathy and be able to differentiate compressive from noncompressive causes. The degree of spinal cord compression and presence of an intramedullary T2-hyperintense signal suggestive of an acute cord edema are critical findings for subsequent urgent care such as surgical decompression. Importantly, a delay in diagnosis may lead to permanent disability. In the spinal canal, compressive myelopathy can be localized to the epidural, intradural extramedullary, or intramedullary anatomic spaces. Effacement of the epidural fat and the lesion's relation to the thecal sac help to distinguish an epidural lesion from an intradural lesion. Noncompressive myelopathy manifests as an intramedullary T2-hyperintense signal without an underlying mass and has a wide range of vascular, metabolic, inflammatory, infectious, and demyelinating causes with seemingly overlapping imaging appearances. The differential diagnosis can be refined by considering the location of the abnormal signal intensity within the cord, the longitudinal extent of the disease, and the clinical history and laboratory findings. Use of a compartmental spinal MRI approach in patients with suspected nontraumatic spinal cord injury helps to localize the abnormality to an epidural, intradural extramedullary, or intramedullary space, and when combined with clinical and laboratory findings, aids in refining the diagnosis and determining the appropriate surgical or nonsurgical management.Online supplemental material is available for this article.©RSNA, 2019.

Pituitary magnetic resonance imaging predictive role in the therapeutic response of growth hormone-secreting pituitary adenomas.

Growth hormone (GH)-secreting pituitary adenomas, responsible for the development of acromegaly, are the second most frequent type of secreting pituitary adenomas and are characterized by very variable T2-weighted signal intensity on pituitary magnetic resonance imaging (MRI). Previous data have demonstrated a correlation between T2-weighted tumor signal intensity and response to therapy with conventional somatostatin analogs (SSA) in patients with acromegaly. The aim of the current retrospective study was to investigate the correlation between the T2-weighted tumor signal on pituitary MRI and both biochemical and radiological response to first-line SSA therapy. Twenty-two naive patients with acromegaly were eligible for the study (14 females and 8 males, mean age ± SD: 58.8±15.74). A biochemical evaluation (GH and IGF-I levels) and an MRI assessment (volume and signal intensity analysis of adenoma) were conducted in each patient at diagnosis and after 12 months of SSA therapy. On diagnostic pituitary MRI, 16 (72.7%) adenomas were T2- hypointense and 6 (27.2%) T2-hyperintense. After 12 months of SSA therapy, IGF-I levels decreased by more than 50% from baseline in 62.5% of patients with T2-hypointense and 33.3% of patients with T2- hyperintense tumor signal, respectively (P=0.03). Moreover, GH levels decreased by more than 80% from baseline in 81.3% and 33.3% of patients with T2-hypointense and T2-hyperintense tumor signal (P=0.02). A significant tumor volume reduction (≥20%) was observed in 75% of the T2-hypointense and 33.3% of the T2-hyperintense adenomas (P=0.001). In naive patients with acromegaly, first-line SSA therapy is associated with a better biochemical response and greater tumor shrinkage in T2-hypointense compared to T2-hyperintense adenomas. Therefore, T2-weighted sequences of pituitary MRI can help to classify GH-secreting pituitary adenomas into a T2-hypointense and T2-hyperintense type and, therefore, to identify patients who can better respond to first-line SSA therapy.

Reader response: Neuronal intranuclear inclusion disease showing intranuclear inclusions in renal biopsy 12 years earlier.

We thank Motoki et al.1 for completing the information about the workup; we agree with the final conclusion that FMR1 premutation would be necessary to distinguish these disorders. However, we do not share the opinion that the absence of the typical MRI findings of T2 signal hyperintensity in middle cerebellar peduncles (MCPs), the lack of ataxia, or neurodegenerative disorders in family history lead to exclude clinically fragile X-associated tremor/ataxia syndrome (FXTAS; FMR1 gene premutation) in favor of a neuronal intranuclear inclusion disease diagnosis in this patient. Despite that the MCP hyperintensity was postulated as 1 major criterion of FXTAS,2 the mentioned criteria need revision,3 because of the phenotypic variability of premutation carriers, that ranges from mild tremor and cognitive impairment to ataxia with or without typical MRI findings, even associated non-neurologic disorders.

Noncontrast vestibular schwannoma surveillance imaging including an MR cisternographic sequence: is there a need for postcontrast imaging?

The purpose of this study was to evaluate the use of a noncontrast MRI protocol that includes a cisternographic sequence (CISS/FIESTA/3D DRIVE) compared to a protocol that includes a gadolinium-enhanced sequence in order to determine whether a noncontrast approach could be utilized to follow vestibular schwannomas. A total of 251 patients with vestibular schwannomas who underwent MRI of the temporal bones that included both cisternographic sequence and postcontrast T1 imaging between January 2000 and January 2016 for surveillance were included in this retrospective study. The size of the vestibular schwannomas was independently assessed on a noncontrast MR cisternographic sequence and compared to size measurements on a postcontrast sequence. The evaluation of intralesional cystic components (identified as T2 signal hyperintensity) and hemorrhagic components (identified with intrinsic T1 hyperintensity) on noncontrast MR sequences was compared to evaluation on postcontrast MR sequences to determine whether additional information could be derived from the postcontrast sequences. Additionally, any potentially clinically significant, incidentally detected findings on the postcontrast T1 sequences were documented and compared with the detection of these findings on the precontrast images. No significant difference in vestibular schwannoma size was found when comparing measurements made on the images obtained with the MR cisternographic sequence and those made on images obtained with the postcontrast sequence (p = 0.99). Noncontrast MR images were better (detection rate of 87%) than postcontrast images for detection of cystic components. Noncontrast MR images were also better for identifying hemorrhagic components. No additional clinically relevant information regarding the tumors was identified on the postcontrast sequences. Based on the results of this study, a noncontrast MR protocol that includes a cisternographic sequence would be sufficient for the accurate characterization of size and signal characteristics of vestibular schwannomas, obviating the need for gadolinium contrast administration for the routine surveillance of these lesions.

Prevalence of pituitary cysts in children using modern magnetic resonance imaging techniques.

Pituitary pars intermedia/Rathke cleft cysts or cyst-like structures are commonly encountered in children undergoing brain magnetic resonance imaging (MRI), especially when examinations include thin-section, high-resolution sequences. To determine the prevalence of pituitary cystic lesions in children at our institution using modern MRI technique, to assess for associated endocrinopathy and to address the need for follow-up. We retrospectively reviewed 232 consecutive 1.5- and 3-T brain MRIs in children ages 0-18years (mean: 8.3±5.3years). We evaluated 3-D volumetric T1 spoiled gradient echo (SPGR) and axial T2-weighted sequences. Pituitary glands were evaluated for the presence, size and signal characteristics of cysts. Cyst volumes were measured in three orthogonal planes. Endocrine abnormalities were documented from the medical record. Pituitary cysts were present in 57.7% of children (n=134), with a mean linear measurement of 3.6±1.17mm (range: 0.4 to 12.3mm). The overwhelming majority of cysts were hyopointense on T1-W images (n=121, 90%) and isointense on T2-W images relative to the adenohypophysis (n=106, 79%). T1 hyperintense and T2 hypointense signals were present in a minority, 6.7% and 8%, respectively. Most cysts were occult on post-contrast T1-W images (n=24, 77%). Endocrine abnormalities were present in 2/134 (1.5%) of children with cysts (these were unrelated to the pituitary gland) versus 1/98 (1%) children without cysts (P=0.7). More often than not, pituitary cysts/cyst-like structures can be found incidentally in children using modern MRI techniques. Follow-up is not typically required if there are no associated symptoms or excessive size.

A rare case of spinal epidural sarcoidosis: case report and review of the literature

Sarcoidosis is a rare systemic disease characterized by growth and organization of inflammatory cells in a granuloma. Granulomas can localize in any parts of the human body. The main localization is represented by lungs, lymph nodes, eyes and skin. Any organ, however, can be affected. Central nervous system (CNS) represents a rare localization of sarcoidosis, in fact, only 1% of patient with sarcoidosis present brain and/or spinal cord localization of the granulomas associated with this disease. This condition takes the name of Neurosarcoidosis. Its diagnosis and management pose a significant challenge, as its clinical manifestation and appearance in imaging studies are difficult to distinguish from more common lesion of the spinal cord. In this paper, we present the case of a 45-year-old woman who presented back pain associated with neurologic signs of myelopathy. Spinal cord MRI documented a T2 hyperintense signal around medullary conus. She underwent a gross total removal of the lesion. Histopathological examination revealed spinal sarcoidosis. Next total body CT scan did not show other localization of the disease. The aim of the present paper is to report a very rare case of spinal epidural sarcoidosis, actually only five cases have been described, without other localization of the disease. The present article underlines the difference between this forms of spinal sarcoidosis compared to intradural extramedullary and intramedullary spinal sarcoidosis.

Microsurgical Management of a Spinal Dural Arteriovenous Fistula With Shared Blood Supply to the Artery of Adamkiewicz: 3-Dimensional Operative Video.

The presented case is of a 65-yr-old gentleman referred for thoracic myelopathy. He developed bilateral, nondermatomal foot dysesthesia 14 mo prior to presentation, which progressed to numbness below the L3 level. He reported progressive gait instability, bilateral lower extremity weakness, and required a cane for ambulation. He subsequently developed urinary incontinence, while bowel function was spared. The neurological examination upon presentation revealed lower extremity strength was reduced to 4/5 in all major muscle groups bilaterally, while sensation and proprioception were reduced below the L3 level. Patellar and Achilles reflexes were not elicited and clonus was absent. Gait was unsteady and slow. The patient was not able to perform heel, toe and tandem gait. MRI revealed abnormal T2 hyper-intense signal and spinal cord expansion from T6 through the conus medullaris. Angiography revealed a dural arteriovenous fistula (dAVF) originating from the left T9 radicomedullary pedicle, which also supplied the Artery of Adamkiewicz (AoA). The patient underwent T8-10 laminectomies. Prior to disconnection of the fistula, an aneurysm clip was applied to the fistulous point and an indocyanine green video angiogram was completed to show that the fistula no longer opacified, but that the AoA remained patent, which was later confirmed with angiography. As of discharge, the patient's motor exam had improved substantially, though his sensory deficits persisted. This case demonstrates that surgical disconnection is requisite in the treatment of spinal dAVF that have a shared blood supply with the AoA, as embolization risks spinal cord infarction. The patient consented to presentation of this case in a de-identified fashion.

Data mining: Seasonal and temperature fluctuations in thyroid-stimulating hormone

Subacute combined degeneration of the spinal cord (SACD) is a rare neurologic disorder manifesting progressive symptoms of paresthesia and spastic paralysis. Herein we present an autopsy case of SACD caused by folic acid and copper deficiency. A 16-year-old male presented with gradually worsening unsteady gait, and bladder and rectal dysfunction. He had a medical history of T-cell acute lymphoblastic leukemia (T-ALL), diagnosed 1.5 years previously. The patient had undergone chemotherapy, including methotrexate, as well as allogeneic bone mallow transplantation. Laboratory tests revealed normal vitamin B12 and methylmalonic acid concentration, but reduced serum copper, ceruloplasmin and folic acid concentrations. Magnetic resonance imaging revealed symmetrical T2 signal hyperintensities in the posterior and lateral spinal cord. The patient was treated with oral copper, oral folate, and intravenous vitamin B12. A month after this treatment, the patient’s symptoms were unchanged, and 2 months later he died of acute adrenal insufficiency. The pathological findings of the spinal cord were compatible with SACD. Because SACD is usually reversible with early treatment, it should be suspected in high-risk patients undergoing chemotherapy or those who are malnourished with characteristic symptoms of SACD, even in young patients.

Diagnostic Accuracy of High-Resolution Black-Blood MRI in the Evaluation of Intracranial Large-Vessel Arterial Occlusions

3D high-resolution black-blood MRI or MR vessel wall imaging allows evaluation of the intracranial arterial wall and extraluminal pathology. We investigated the diagnostic accuracy and reliability of black-blood MRI for the intraluminal detection of large-vessel arterial occlusions. We retrospectively identified patients with intracranial arterial occlusions, confirmed by CTA or DSA, who also underwent 3D black-blood MRI with nonenhanced and contrast-enhanced T1 sampling perfection with application-optimized contrasts by using different flip angle evolution (T1 SPACE) sequences. Black-blood MRI findings were evaluated by 2 independent and blinded neuroradiologists. Large-vessel intracranial arterial segments were graded on a 3-point scale (grades 0-2) for intraluminal baseline T1 hyperintensity and contrast enhancement. Vessel segments were considered positive for arterial occlusion if focal weak (grade 1) or strong (grade 2) T1-hyperintense signal and/or enhancement replaced the normal intraluminal black-blood signal. Thirty-one patients with 38 intracranial arterial occlusions were studied. The median time interval between black-blood MRI and CTA/DSA reference standard studies was 2 days (range, 0-20 days). Interobserver agreement was good for T1 hyperintensity (κ = 0.63) and excellent for contrast enhancement (κ = 0.89). High sensitivity (100%) and specificity (99.8%) for intracranial arterial occlusion diagnosis was observed with either intraluminal T1 hyperintensity or contrast-enhancement imaging criteria on black-blood MRI. Strong grade 2 intraluminal enhancement was maintained in >80% of occlusions irrespective of location or chronicity. Relatively increased strong grade 2 intraluminal T1 hyperintensity was noted in chronic/incidental versus acute/subacute occlusions (45.5% versus 12.5%, P = .04). Black-blood MRI with or without contrast has high diagnostic accuracy and reliability in evaluating intracranial large-vessel arterial occlusions with near-equivalency to DSA and CTA.

Characterization of intramuscular calf vein thrombosis on routine knee MRI.

Literature regarding intramuscular calf vein thrombosis (IMCVT) or infrapopliteal deep vein thrombosis (DVT) evaluation by magnetic resonance imaging (MRI) is limited, particularly with regard to routine unenhanced knee examinations. We attempt to correlate routine unenhanced MRI findings with ultrasound evaluations of the lower extremity deep venous system. The radiology information system was searched, yielding a total of 67 patients who had undergone both routine knee MRI and duplex ultrasound examinations within 14days. The MRI examination findings recorded were the presence and pattern of edema, segmental vein dilation, intraluminal signal on fluid-sensitive sequences, and abnormal hyperintense signal on axial T1-weighted sequences. The presence and extent of thrombus more centrally (i.e., intramuscular calf vein thrombosis with or without extension into the popliteal vein) was reassessed on ultrasound. When comparing patients with positive (n = 13) and negative (n = 54) ultrasound, there were significant differences in each of these parameters: perivascular edema, intramuscular edema, focal vein dilation, and abnormal fluid-sensitive signal. In the subset of patients with popliteal extension of the intramuscular calf vein thrombosis compared with those without any deep vein thrombosis, there was a statistically significant increase in peripopliteal edema, abnormal fluid-sensitive signal, and abnormal hyperintense T1 signal. Imaging findings on routine unenhanced MRI have a high rate of concordance with duplex ultrasound performed through the calf in the detection of intramuscular calf vein thrombosis.

Global Burden Related to Nitrous Oxide Exposure in Medical and Recreational Settings: A Systematic Review and Individual Patient Data Meta-Analysis.

The risk of adverse effects of nitrous oxide (N2O) exposure is insufficiently recognized despite its widespread use. These effects are mainly reported through case reports. We conducted an individual patient data meta-analysis to assess the prevalence of clinical, laboratory, and magnetic resonance findings in association with N2O exposure in medical and recreational settings. We calculated the pooled estimates for the studied outcomes and assessed the potential bias related to population stratification using principal component analysis. Eighty-five publications met the inclusion criteria and reported on 100 patients with a median age of 27 years and 57% of recreational users. The most frequent outcomes were subacute combined degeneration (28%), myelopathy (26%), and generalized demyelinating polyneuropathy (23%). A T2 signal hyperintensity in the spinal cord was reported in 68% (57.2–78.8%) of patients. The most frequent clinical manifestations included paresthesia (80%; 72.0–88.0%), unsteady gait (58%; 48.2–67.8%), and weakness (43%; 33.1–52.9%). At least one hematological abnormality was retrieved in 71.7% (59.9–83.4%) of patients. Most patients had vitamin B12 deficiency: vitamin B12 <150 pmol/L (70.7%; 60.7–80.8%), homocysteine >15 µmol/L (90.3%; 79.3–100%), and methylmalonic acid >0.4 µmol/L (93.8%; 80.4–100%). Consistently, 85% of patients exhibited a possibly or probably deficient vitamin B12 status according to the cB12 scoring system. N2O can produce severe outcomes, with neurological or hematological disorders in almost all published cases. More than half of them are reported in the setting of recreational use. The N2O-related burden is dominated by vitamin B12 deficiency. This highlights the need to evaluate whether correcting B12 deficiency would prevent N2O-related toxicity, particularly in countries with a high prevalence of B12 deficiency.

Increased signal in the proximal patellar tendon: normal or pathologic?

To determine the clinical significance of T2 signal hyperintensity in the proximal patellar tendon seen on MRI of the knee. MRIs of 100 patients who underwent MRI of the knee between 1 May 2018 and 15 July 2018 were retrospectively evaluated. All examinations were performed on 3-Tesla MRI scannerswith a dedicated knee coil and in accordance with our institution's standard knee MRI protocol. The presence of increased T2 signal was assessed on both sagittal and axial T2-weighted fat-saturated images. The amount of increased signal in the proximal patellar tendon on T2-weighted images was characterized as: none, mild, moderate, or severe. A corresponding chart review of the referring physicians' notes was performed to determine the presence of clinical symptoms of patellar tendinopathy. Patellar tendinopathy was considered present if the clinical notes described tenderness on palpation of the inferior patellar pole, infrapatellar tenderness, or patellar tendinosis/tendinitis. The majority(66%) of knee MRIs demonstrated the presence of increased T2 signal in the proximal patellar tendon. Only 4.5% of these patients had associated clinical findings of patellar tendinopathy. Although increased T2 signal in the proximal patellar tendon is a common finding, only in rare cases are there associated clinical symptoms. Thus, increased T2 signal in the proximal patellar tendon may not be a pathological finding in the absence of clinical findings of patellar tendinopathy.

Correlation of Appearance of MRI Perinidal T2 Hyperintensity Signal and Eventual Nidus Obliteration Following Photon Radiosurgery of Brain AVMs: Combined Results of LINAC and Gamma Knife Centers

A wide variety of radiologic changes occur within and adjacent to the nidus of arteriovenous malformations (AVMs) after stereotactic radiosurgery (SRS). Our objective was to study the magnetic resonance imaging(MRI)-defined changes following photon radiosurgery of AVMs and specifically to correlate the appearance of a perinidal T2 hyperintensity signal with the eventual angiographic obliteration of an AVM nidus in response to SRS treatment. This retrospective study was conducted on 62 patients with brain AVMs who received photon SRS treatments between 2004 and 2017, using either a technique based on a linear accelerator at the Alexandria LINAC Radiosurgery Center in Egypt (21 patients/AVMs) or a technique based on a gamma unit at the Koto Memorial Gamma Knife Center in Japan (41 patients/AVMs). All patients included in the study had serial clinical and radiologic follow-ups for ≥ 2 years after SRS treatments. In the combined study series of 62 patients/AVMs treated with photon SRS, the follow-up MRIs revealed that 50 AVMs (80.6%) showed nonvisualized nidus and 12 AVMs (19.4%) showed decreased nidus size. Radiation-induced changes, defined as appearance of perinidal T2 hyperintensities in post-SRS MRIs, occurred in 34 patients (54.8%). Of the 35 patients with available follow-up angiographic studies, 30 AVMs (85.7%) demonstrated complete nidus obliteration at a mean of 36 months (range: 8-66 months) after SRS. Of the 30 AVMs with both MRI evidence of a nonvisualized nidus and angiographic verification of complete nidus obliteration, 20 AVMs (66.7%) were associated with prior MRI evidence of the appearance of a perinidal T2 hyperintensity signal at an average of 12 months (range: 6-45 months) after SRS. Of the five AVMs with both MRI evidence of decreased nidus size and angiographic verification of partial nidus obliteration, four AVMs (80%) showed perinidal T2 hyperintensity signal on post-SRS follow-up MRIs. Lower Spetzler-Martin grade (p = 0.013), smaller AVM volume (p = 0.017), and appearance of post-SRS perinidal T2 hyperintensity signal (p = 0.007) were the statistically significant independent predictors of AVM obliteration. The appearance of perinidal T2 hyperintensity signal in the post-SRS MRIs had a sensitivity of 66.7%, a specificity of 20%, and an overall accuracy of 60% in predicting the eventual obliteration of the AVM nidus. The present study may help improve our current understanding of the mechanisms behind the radiation-induced tissue changes following AVM SRS. Because the SRS-induced hemodynamic changes within the AVM nidus initiate the cascade of the subsequent formation of perinidal vasogenic brain edema, the appearance of perinidal high T2 signal in the follow-up MRIs after SRS would be a valuable indicator of the AVM response to SRS. The development of perinidal hyperintensity was the strongest predictive factor of AVM obliteration (p = 0.007), with relatively high sensitivity (66.7%) and accuracy (60%) and fairly low specificity (20%), as a prognostic sign of eventual complete angiographic obliteration of the AVM nidus following SRS.

Radiation myelitis after durvalumab administration following chemoradiotherapy for locally advanced non-small cell lung cancer: an illustrative case report and review of the literature

A 69-year-old man with stage IIIB lung adenocarcinoma received durvalumab following chemoradiotherapy. The prescribed dose was 50 Gy in 2 Gy fractions, and the maximum spinal cord dose was 40 Gy. After three cycles of durvalumab, he experienced bladder and rectal disturbance, muscle weakness in the lower limbs, and sensory loss in the lower body. Magnetic resonance imaging revealed T2 signal hyperintensity involving the thoracic spinal cord. As the thoracic spinal cord with T2 signal hyperintensity matched with the irradiated site, the patient was diagnosed with radiation myelitis. This case report shows the clinical and radiographic features of a case of locally advanced non-small cell lung cancer that demonstrated radiation myelitis following durvalumab administration. The time of onset was very early and the influence of durvalumab was suspected as the cause of myelitis.