T1 Hypointense Research Articles

Proposing a quantitative MRI-based linear measurement framework for response assessment following stereotactic body radiation therapy in patients with spinal metastasis.

To provide evidence towards a quantitative response assessment framework incorporating MRI-based linear measurements for spinal metastasis that predicts outcome following stereotactic body radiation therapy (SBRT). Adult patients with de novo spinal metastases treated with SBRT between 2008 and 2018 were retrospectively assessed. The metastatic lesions involving the pedicles, articular processes, lamina, transverse process, spinous process and vertebral body at leach level were measured separately using linear measurements on pre- and all post-SBRT MRIs. The outcome was segment-specific progression (SSP) using SPINO guidelines which was dated to the first clinical documentation of progression, or the date of the associated MRI if imaging was the reason for progression. Random forest analysis for variable selection and recursive partitioning analysis for SSP probability prediction were used. Five Hundred Ninety-three spinal levels (323 patients) from 4081 MRIs were evaluated. The appearance of new T1 hypointensity and increase in Bilsky grade had an odds ratio (OR) of 33.5 and 15.5 for SSP, respectively. Compared to baseline, an increase of > 3mm in any lesion dimension, combined with a 1.67-fold increase in area, had an OR of 4.6 for SSP. The sensitivity, specificity, positive predictive value, negative predictive value, balanced accuracy and area under the curve of the training model were 96.7%, 89.6%, 28.6%, 99.8%, 93.2% and 0.905 and of the test model were 91.3%, 89.3%, 27.1% 99.6%, 90.3% and 0.933, respectively. With further refinement and validation in prospective multicentre studies, MRI-based linear measurements can help predict response assessment in SBRT-treated spinal metastases.

S3224 Pylephlebitis Presumed to Be Secondary to a Perforated Diverticulum

Introduction: Pylephlebitis is acute thrombosis of the portal system in the setting of intraabdominal infection. Diagnosis is challenging since symptoms may be nonspecific, but early identification and management with broad spectrum antibiotics is essential. We present a case of pylephlebitis presumed to be secondary to a perforated diverticulum. Case Description/Methods: A 63-year-old African American male with colonic diverticulosis presented with recurrent fevers and chills of two weeks duration. He immigrated from Benin 8 years ago but denied recent travel or sick contacts. On presentation, patient was febrile to 103.1F with tachycardia (107 beats/minute). Physical examination was normal. Labs revealed leukocytosis (15.9 K/uL) and mildly elevated liver enzymes with hyperbilirubinemia (1.4 mg/dL). Abdominal imaging revealed two hepatic abscesses with a multifocal occlusive thrombus in the right hepatic vein and a nonocclusive thrombus in the right portal vein. He underwent image guided aspiration of the abscesses and was started on intravenous (IV) antibiotics and heparin infusion. Fluid cultures grew Fusobacterium nucleatum and blood cultures had no growth. Due to concerns for colonic bacterial translocation, colonoscopy was performed which showed diffuse diverticulosis throughout the colon without evidence of diverticulitis. Upon clinical improvement, patient was discharged on a 4-week course of ceftriaxone/metronidazole with a 12-week course of apixaban. Repeat abdominal ultrasound a month after discharge showed interval improvement of hepatic abscesses and resolution of portal vein thrombus. (Figure) Discussion: Pylephlebitis is a rare condition but frequently associated with intra-abdominal infections, mainly diverticulitis which is the likely source in this patient. Inflammatory bowel disease and recent abdominal surgery have also been described as sources. Diagnosis is established via imaging confirming portal vein thrombosis in setting of an intraabdominal infection. Gram-negative organisms are most commonly isolated. The mainstay of therapy is broad spectrum antibiotics for 4-6 weeks. The role of anticoagulation (AC) is controversial as robust evidence is lacking. However, it has been proposed that AC prevents bowel ischemia and infarction secondary to thrombus extension. Despite the risk of sepsis and bowel infarction, morbidity and mortality rates have improved in recent years as imaging modalities have advanced and antibiotic options have diversified. AC should be considered on case-by-case basis.Figure 1.: A) 2.8 cm rim-enhancing abscess with rim-sign/double target sign (blue arrow) seen in axial view of segment 8; B) Associated T2 hyperintense, T1 hypointense linear filling defect consistent with thrombus along course of right hepatic vein branches (orange arrow) adjacent to abscess; C) Associated perfusional changes/wedge-shaped edema and T2 hyperintensity in liver parenchyma (green arrow).

Intrauterine left ovarian torsion located in the right abdominal quadrant: Case report

In this article, we will share our case of intrauterine left ovarian torsion located entirely in the right half of the abdomen and its features. She was admitted to the pediatric surgery outpatient clinic due to an intra-abdominal mass lesion. In her history, it was learned that she had a known and unclear diagnosis of an intrauterine mass for seven months. Abdominal magnetic resonance imaging was performed for the cross-sectional evaluation of the lesion. In the right lower quadrant of the abdomen, 35x30 millimeter septated T1 hypointense T2 hyperintense nodular lesion without contrast enhancement and a collection of fluid around the lesion were seen, extending posterior to the cecum and inferiorly to the right adnexal region in the right lower quadrant of the abdomen. The mass was excised by performing salpingoopherectomy. Today, more intrauterine problems can be detected thanks to pregnancy follow-ups and fetal imaging, and intrauterine torsion is one of the fetal pathologies that should be considered. Although the common approach is excision, we think that with the development of early postnatal or fetal surgery opportunities in the future, it will be possible to treat these lesions without causing organ loss.

Head MRI imaging profile of meningioma according to WHO 2016 grading

Magnetic resonance imaging (MRI) of meningiomas is essential in predicting their histopathological grade. Meningiomas are the second most common central nervous system neoplasm in adults, usually benign, originating from arachnoid cap cells and categorized according to the WHO classification as benign (grade I), atypical (grade II), and anaplastic (grade III). The study aims to determine the head MRI imaging profile in preoperative meningioma patients confirmed by pathologic results according to WHO 2016 grading. A retrospective study was conducted from January 2017 to March 2022 with 30 samples of meningioma patients who underwent surgery. Preoperative head MRI and pathologic examination were done and tumor location, border, edge, and size were confirmed with pathology results according to WHO 2016 grading. Most patients were 41-50 years old, female (100%), mostly WHO grade I histopathology with transitional type. The most common locations were convexity meningiomas, with the most MRI characteristics of well-defined borders, regular edges, size 0-3 cm, with hypointense T1, hyperintense T2, hyperintense T2 FLAIR, restricted diffusion on DWI, type 2 DCE, homogeneous enhancement pattern, and the most feeding arteries originated from the meningeal artery.

Age, GH/IGF-1 levels, tumor volume, T2 hypointensity, and tumor subtype rather than proliferation and invasion are all reliable predictors of biochemical response to somatostatin analogue therapy in patients with acromegaly: A clinicopathological study

PurposeTo determine whether biochemical responses to long-acting forms of first-generation somatostatin analogue (SSA) therapy in patients with acromegaly could be predicted from baseline and postoperative hormone concentrations, and tumor radiological and histopathological characteristics. MethodsA total of 68 patients with acromegaly for whom postoperative SSA therapy was started were categorized according to their responses to treatment (SSA-responders vs. non-responders). The patients were compared based on their demographic characteristics, hormone levels, magnetic resonance imaging (MRI), and histopathological findings. Receiver-operating-characteristic (ROC) curves were constructed using the predictive factors that were significant in the univariate analysis to determinate the optimal cut-off values. ResultsThe SSA-responders were significantly older (p = 0.041). Lower GH at diagnosis (p = 0.036), the postoperative 1st-week GH level (p = 0.027), baseline GH, insulin-like growth factor-1 (IGF-1) and IGF-1% upper limit of normal (ULN) (p = 0.001, p = 0.006, p = 0.023, respectively) were associated with biochemical response. T2-hypointensity and lower tumor volume were more common in the SSA-responders (p = 0.018, p = 0.03, respectively). Compared to sparsely granulated somatotroph tumors, densely granulated somatotroph tumors and other PitNETs causing GH excess including mammosomatotroph and mixed somatotroph and lactotroph tumors were more likely to respond to SSA therapy (p = 0.026, p = 0.03, respectively). The cut-off values generated by ROC curve analysis were GH at diagnosis of ≤8.8 ng/mL, GH at baseline of ≤2.69 ng/mL, IGF-1 at baseline ≤461.5 ng/mL, IGF-1% ULN at baseline ≤180.4%, and tumor volume of ≤1.11 cm3 (all p < 0.05). There were no differences between the groups in terms of tumor invasiveness, proliferative activity (mitotic count per 2 mm2 and Ki-67 labeling index) and quantitative analyses of T2-weighted MRI. ConclusionThis study underscores that advanced age, low baseline GH and IGF-1 at diagnosis, low tumor volume, densely granulated tumor subtype, and T2 hypointensity may help predict biochemical response to SSA therapy in cases of acromegaly. These variables should be assessed with utmost attention for all patients prior to SSA treatment. In cases of possible resistance to SSA therapy, therapeutic activity should be monitored more closely and other therapies should be administered immediately in the event of poor response.

Síndrome de Percheron: reporte de caso

Introducción: La vascularización del tálamo fue descrita por Percheron en el siglo XX. La irrigación del tálamo proviene principalmente de las conexiones que establecen la arteria carótida interna y la arteria basilar, es decir, circulación vascular cerebral anterior y posterior. La arteria de Percheron, ante situaciones de isquemia, ocasiona lesión en el tálamo con injuria bilateral. Objetivo: Analizar caso clínico propuesto, literatura médica y evidencia científica actual relacionada. Metodología: Reporte descriptivo de un paciente de 45 años, ingresado en el Hospital General Guasmo Sur, Ecuador. Cuadro clínico de 20 horas de evolución previa al ingreso, caracterizado por deterioro del sensorio, se realizan neuroimágenes, compatibles con isquemia bitalámica, y revisión bibliográfica en la literatura mundial. Resultados: En TAC de cerebro inicial se visualiza imagen hipodensa bilateral en región talámica. En RMN evidencia lesiones en área de tálamo, hiperintensidad en Flair (Fluid Attenuated Inversion Recovery), T2 y DW (diffusion), hipointensidad en T1 y ADC (Apparent Diffusion Coefficient). Paciente cursa GOS (Glasgow Outcome Scale) 3 PTS. Discusión: Las lesiones bitalámicas son infrecuentes, la prevalencia oscila del 0,1 % al 0,6 %. Cabe destacar la relevancia diagnóstica, la mayor parte de ellas corresponde a un origen embólico. Conclusión: Cuadro clínico compatible con la tríada clásica de Percheron, que consiste en: parálisis vertical de la mirada, alteración cognitiva, coma. Los estudios de neuroimagen permiten dilucidar el infarto talámico paramediano, síndrome de Percheron.

Imaging features of juvenile xanthogranuloma.

Juvenile xanthogranuloma is rare in children and there are limited data on its imaging features. To analyze the computed tomography (CT) and magnetic resonance imaging (MRI) features of juvenile xanthogranuloma in children. A retrospective review was performed of clinical and radiographic data of histologically confirmed juvenile xanthogranuloma between January 2009 and June 2020. Fourteen children (4 girls, 10 boys; age range: 1day to 13years, mean age: 73months) were included in thestudy: 4/14 had CT only, 5/14 had MRI only and 5/14 had CT and MRI. Sites of extracutaneous juvenile xanthogranuloma involvement included subcutaneous soft tissue (8/14), liver (2/14), lungs (2/14), kidney (2/14), nose (2/14), pancreas (1/14), central nervous system (1/14) and greater omentum (1/14), mainly manifested as single or multiple nodules or masses in different organs. On CT, the lesions mainly manifested as an iso-hypo density mass with mild or marked enhancement. On MRI, the lesions mainly manifested as slightly hyperintense on T1 and slightly hypointense on T2, with decreased diffusivity and homogeneous enhancement. Juvenile xanthogranuloma was not included in the imaging differential diagnosis in any case. Juvenile xanthogranuloma mainly manifests as single or multiple nodules or masses in different organs. Slight hyperintensity on T1 and slight hypointensity on T2 with decreased diffusivity and homogeneous enhancement are relatively characteristic imaging findings of juvenile xanthogranuloma. Combined with its typical skin lesions and imaging features, radiologists should include juvenile xanthogranuloma in the differential diagnosis when confronted with similar cases.

Lesion-Specific Metabolic Alterations in Relapsing-Remitting Multiple Sclerosis Via 7 T Magnetic Resonance Spectroscopic Imaging.

Magnetic resonance spectroscopic imaging (MRSI) of the brain enables in vivo assessment of metabolic alterations in multiple sclerosis (MS). This provides complementary insights into lesion pathology that cannot be obtained via T1- and T2-weighted conventional magnetic resonance imaging (cMRI). The aims of this study were to assess focal metabolic alterations inside and at the periphery of lesions that are visible or invisible on cMRI, and to correlate their metabolic changes with T1 hypointensity and the distance of lesions to cortical gray matter (GM). A 7 T MRSI was performed on 51 patients with relapsing-remitting MS (30 female/21 male; mean age, 35.4 ± 9.9 years). Mean metabolic ratios were calculated for segmented regions of interest (ROIs) of normal-appearing white matter, white matter lesions, and focal regions of increased mIns/tNAA invisible on cMRI. A subgroup analysis was performed after subdividing based on T1 relaxation and distance to cortical GM. Metabolite ratios were correlated with T1 and compared between different layers around cMRI-visible lesions. Focal regions of, on average, 2.8-fold higher mIns/tNAA than surrounding normal-appearing white matter and with an appearance similar to that of MS lesions were found, which were not visible on cMRI (ie, ~4% of metabolic hotspots). T1 relaxation was positively correlated with mIns/tNAA ( P ≤ 0.01), and negatively with tNAA/tCr ( P ≤ 0.01) and tCho/tCr ( P ≤ 0.01). mIns/tCr was increased outside lesions, whereas tNAA/tCr distributions resembled macroscopic tissue damage inside the lesions. mIns/tCr was -21% lower for lesions closer to cortical GM ( P ≤ 0.05). 7 T MRSI allows in vivo visualization of focal MS pathology not visible on cMRI and the assessment of metabolite levels in the lesion center, in the active lesion periphery and in cortical lesions. This demonstrated the potential of MRSI to image mIns as an early biomarker in lesion development.

A Novel Variant of the Short-Chain Enoyl-CoA Hydratase-1 Gene Presenting with a Mild Phenotype: The Second Case Report from India

AbstractA 9-year-old girl presented with asymmetric abnormal twisting movements affecting her left side more than the right side, initially action induced, but later persistent. Examination revealed generalized persistent dystonia with choreoathetosis and right partial tonic ocular tilt reaction. Brain magnetic resonance imaging showed T1 and T2 fluid-attenuated inversion recovery (FLAIR) hypointense and T2 hyperintense signal changes in bilateral globus pallidi. Clinical exome sequencing revealed compound heterozygous variatnts in enoyl-CoA hydratase-1 (ECHS1) gene: a novel pathogenic variant in exon 6, chr10:g.133366045G &gt; A (p.Gln224Ter) and a likely pathogenic variant in exon 5, chr10:g.133366990G &gt; A (p.Ala173Val). Metabolic testing and arterial lactate levels were normal. She was treated with valine restricted diet, trihexiphenidyl, clonazepam, N-acetyl cysteine and mitochondrial cocktail, without significant improvement over the 6 months follow-up period.

Radiological Features for Outcomes of MOGAD in Children: A Cohort in Southwest China.

BackgroundStudies suggested that myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD) are an isolated group of diseases that are different from multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD). The proportion of individuals with MOGAD is higher among children. However, limited data are available on autoimmune antibodies and neuroimaging features in children with MOGAD.MethodsThis study retrospectively reviewed 42 children with MOGAD. The clinical, neuroradiological, and cerebrospinal fluid data were compared according to courses and radiological results.ResultsOf the 42 patients, 28 suffered a monophasic course and 14 had a relapsing course. During the follow-up magnetic resonance imaging (MRI), 21 patients had a well-resolved brain condition and another 21 patients showed slight improvement with marked residuals. Most patients with relapse had cortical lesions and a leukodystrophy-like MRI pattern (all p < 0.05). Children with poor radiological outcomes have confluent and hazy lesions that involve both cortexes, white matter lesion of >2 cm, and a leukodystrophy-like pattern, as well as cerebral lesions with T1 hypointensity or enhancement and spinal lesions (all p < 0.05). The multivariable logistic regression analysis used the aforementioned differential features and showed cerebral enhancement and a leukodystrophy-like pattern as the most effective variations associated with poor radiological outcomes of MOGAD with an area under the curve of 0.875.ConclusionMOGAD in children have some radiological features suggestive of clinical courses and radiological outcomes. A good understanding of these differential features can help to give early warnings of disease recurrence or poor radiological improvement and develop subsequent therapeutic strategies.

Radiological Features of IgG4-Related Disease in the Head, Neck, and Skull Base

Background: IgG4-related disease (IgG4-RD) is increasingly recognized as a multisystemic, chronic inflammatory process characterized by histologic fibrosis with IgG4-positive plasma cell infiltration. Objectives: The purpose of this study was to characterize the imaging features of patients diagnosed with IgG4-RD in the head and neck, especially the skull base. Methods: Our study evaluated CT and MR imaging features of IgG4-RD in the head, neck, and skull base. Images from 15 patients were retrospectively evaluated for the location, signal intensity, morphology, size, boundary, and pre- and post-contrast MRI performances. Results: The lesions presented as irregular shaped, localized masses, distributed in skull base regions; 93.3% of the lesions were isointensity in T1WI (14/15). A total of 80% of the lesions were iso-hypointense in T2WI (12/15); 60% of the lesions got homogeneous enhancement (9/15); and 46.7% of the patients had cranial nerves dysfunction (7/15). The most likely involved cranial nerve was trigeminal nerves (5/15); 60% of the patients had osteolytic bone destruction or sclerosis (9/15). Conclusion: Typical radiological features of IgG4-RD included T1 isointensity and T2 hypointensity, homogeneous and gradual enhancement pattern in MRI, easy cranial nerve invasion, dura involvement but the absence of brain edema, and the presence of bone remodeling without destruction, blurred lesion boundaries.

BI-RADS 3 Assessment on MRI: A Lesion-Based Review for Breast Radiologists.

Unlike mammography and US, limited data exist to establish well-defined criteria for MRI findings that have a ≤2% likelihood of malignancy. Therefore, determining which findings are appropriate for a BI-RADS 3 assessment on MRI remains challenging and variable among breast radiologists. Emerging data suggest that BI-RADS 3 should be limited to baseline MRI examinations (or examinations with less than two years of prior comparisons) performed for high-risk screening and only used for masses with all of the typical morphological and kinetic features suggestive of a fibroadenoma or dominant enhancing T2 hypointense foci that is distinct from background parenchymal enhancement and without suspicious kinetics. This article presents an updated discussion of BI-RADS 3 assessment (probably benign) for breast MRI using current evidence.

Acquired cystic disease subtype renal cell carcinoma (ACD-RCC): prevalence and imaging features at a single institution.

Acquired cystic kidney disease (ACKD) is commonly seen in patients with end-stage renal disease (ESRD), and patients with ACKD have an increased risk of renal cell carcinoma (RCC). Acquired cystic disease-associated RCC (ACD-RCC) was incorporated into the 2016 World Health Organization Classification. This study aims to describe the imaging features of ACD-RCC, which are not well reported previously. Retrospective review of patients with ACKD who underwent total nephrectomy for concern of a renal mass between 2016 and 2021 yielded 122 nephrectomies in 107 patients. Pathology reports were searched for type and subtype of mass. In ACD-RCC subtypes, imaging studies were evaluated for modality and contrast enhancement (CE). Imaging findings assessed included cystic/solid nature, unenhanced CT (NECT) attenuation, enhancement characteristics [non-enhancing (< 10 HU difference), equivocal (10-20 HU), enhancing (> 20 HU)], subjective MRI enhancement, T1 and T2 signal intensity, restricted diffusion, ultrasound (US) echogenicity, and subjective CEUS enhancement. 148 masses were identified, 122 (82%) of which were malignant and 26 (18%) benign. The three most common tumors were clear cell RCC (n = 47), papillary RCC (n = 35), and ACD-RCC (n = 21). Of the 21 cases of ACD-RCC, 16 had preoperative imaging: CT (15: 6 NECT only, 2 CECT only, 7 combined NECT and CECT), MRI (4), CEUS (5). Ten of these tumors were solid/mostly solid and 6 mixed cystic/solid. On NECT, the average attenuation was 35 HU (range 13-52). Of those with multiphasic CTs, 1 was non-enhancing, 3 were equivocal, and 3 enhanced. All 3 masses imaged with CE-MRI showed enhancement. All 4 tumors evaluated by MRI demonstrated T2 hypointensity and restricted diffusion. All five masses enhanced on CEUS. ACD-RCC subtype was the third most common renal neoplasm in ACKD patients. Our findings found that no single imaging feature is pathognomonic for ACD-RCC. However, ACD-RCCs are typically solid masses with most demonstrating equivocal or mild enhancement on CT. T2 hypointensity and restricted diffusion were the most common MRI features.

ETMR-01. Management of CNS tumor with BCOR internal tandem duplication with multimodalities therapy: Surgery, Intensive Chemotherapy, and Radiation

The 2021WHO CNS tumor classification includes CNS tumors with internal tandem duplications in the BCL6 corepressor (BCOR) gene as a new entity of CNS embryonal tumors labelled high-grade neuroepithelial tumors with BCOR alterations (HGNET-BCOR) are characterized by genetic aberrations in the BCOR gene located at Xp11.4, leading to increased expression of BCOR mRNA and distinct DNA methylation profiles. currently no agreement on the optimal strategy to manage these rare tumors, which mostly occur in young children These tumors are usually treated as high grade glioma HGG with upfront radiation therapy with poor outcome. We report 2.5 years old boy presenting with headache and vomiting. MRI showed a well-defined left cerebellar mass, hyperintense in T2 and hypointense in T1, with restricted diffusion and no spinal CSF seeding metastases. He underwent gross surgical resection of the tumor initial pathological diagnosis was epithelioid high grade malignant neoplasm. Brain tumor methylation classifier analysis of resected tumor tissue confirmed a CNS tumor with BCOR internal tandem duplication (WHO grade 4). The patient was treated per COG ACNS0334 (3 induction cycles of vincristine, cyclophosphamide, cisplatin, etoposide, HDMTX, followed by consolidation with 3 cycles of carboplatin and thiotepa with autologous hematopoietic stem cell rescue). MRI brain before the start of chemotherapy showed a small recurrent mass within the surgical cavity. post-induction MRI detected stable-sized residual lesion in the surgical cavity; however, post-consolidation MRI showed complete resolution of the residual mass. The patient subsequently received craniospinal irradiation (36 Gy [CSI]) with a boost to the tumor bed up to 54 GY. By the time of writing this report our patient is still in complete remission. Our case showed that this aggressive brain tumor may respond well to intensive multimodalities therapy Further case studies and international prospective trials are needed to optimize the clinical management of these rare tumors.

NFB-04. Evaluating focal areas of signal intensity (FASI) in children with neurofibromatosis type-1 (NF1) treated with selumetinib on PBTC-029B

BACKGROUND: Focal Areas of Signal Intensity (FASI) are T2 hyperintense benign lesions in children with NF1. They can mimic the appearance of low-grade glioma (LGG). Selumetinib has shown efficacy in treatment of NF1-associated LGG but treatment effects on FASI have not yet been described. METHODS: Patients with NF1-associated LGG treated with selumetinib on Stratum 3 of PBTC-029B were compared to age-matched untreated children with NF1-associated LGG at Cincinnati Children’s Hospital Medical. FASI were defined by published criteria as T2 hyperintense lesions lacking mass effect, enhancement or T1 hypointensity. Lesion size was determined by cross-product of perpendicular measures in LGG and 1-3 FASI per subject. When multiple FASI were present, the sum of FASI cross-products was used. Change between baseline and the latest available measure within 4 months of control was assessed, insuring that selumetinib-treated subjects were still receiving therapy. RESULTS: Fifteen age-matched pairs were assessed (2.8-16.9 years and 60% were male). Initial FASI size was not different between groups (p=0.98; median [IQR]: 138.7mm2 [88.4-182.0] for treated subjects versus 121.6mm2 [79.6-181.9] for untreated subjects). Lesion change was measured over mean follow up of 18.9 + 5.9 months. Spider plots show decreased LGG size over time during treatment, but there was no consistent change in size among treated or untreated FASI. Comparing FASI size between paired timepoints showed no difference in change from baseline for treated subjects versus for untreated subjects (two-sided test; p=0.08). In subjects who received selumetinib, there was no correlation between change in LGG and change in FASI (r=-0.04, p=0.88). Using RANO criteria for FASI lesions, 2/30 (6.7%) subjects had partial response, 26/30 (86.7%) subjects had stable disease, and 2/30 (6.7%) subjects had progressive disease. CONCLUSIONS: While the sample size was limited, treatment with selumetinib did not reduce overall FASI size in children with NF1 and LGG.

PRIMARY STERNAL OSTEOMYELITIS IN A CHILD: A CASE REPORT

TYPE: Case Report TOPIC: Pediatrics INTRODUCTION: Primary sternal osteomyelitis which develop without any contiguous focus of infection is a rare condition, that too in children. MRI and biopsy are required for diagnosis. Rarity of the condition often results in delayed diagnosis and treatment. CASE PRESENTATION: A 9 year old boy , who was otherwise normal, presented with high fever - 9 days, followed by painful limitation of movement of right upper limb.O/E- Sick and toxic child..Tender, firm swelling, 2 x 2cm ,over the sterno-chondral junction of 2nd and 3rd rib with signs of inflammation.Rest of physical examination WNL. Investigation revealed anemia, polymorphonuclear leucocytosis with elevated ESR and CRP. Cultures were sterile. USG revealed collection below Rt sternoclavicular joint which yielded a dry tap . CECT showed non enhancing collection with no cortical defect in sternum. MRI revealed T2 hyperintensity and T1 hypointensity showing diffusion restriction of sternum suggestive of bone marrow edema.CT-guided sternal biopsy confirmed sternal osteomyelitis. Patient responded to Meropenem and Vancomycin after nonresponse to Cloxacillin and cefotaxime.Treatment continued for 4 weeks and patient recovered completely. DISCUSSION: Primary sternal osteomyelitis is diagnosed after exclusion of other sources of infection. Close proximity to vital organs can complicate the condition. Early recognition, identification of the causal organism, and early initiation of culture-driven intravenous antibiotic therapy is crucial in determining outcome. Staphylococcus aureus,coagulase negative staphylococcus, group B streptococcus, and other streptococcus species are most commonly implicated organisms.Nearly half requires surgical debridement and resection. CONCLUSIONS: Early diagnosis and appropriate treatment results in complete recovery of sternal osteomyelitis DISCLOSURE: Nothing to declare. KEYWORD: sternal osteomyelitis

P.079 MT-TA: A mitochondrial genome cause of developmental and epileptic encephalopathy

Background: MT-TA (OMIM 590000), one of 22 mitochondrial transfer-RNA (mt-tRNA) genes, encodes the mt-tRNA for alanine. Pathogenic variants in mt-tRNA genes affect the translation of respiratory chain complexes I, III, and IV; which leads to mitochondrial dysfunction and a clinically variable phenotype. MT-TA pathogenic variants have been described in only seven patients, all of whom had isolated myopathy Methods: Case report. Results: Our patient initially presented with drug-resistant West syndrome, later evolving towards a Lennox Gastaut phenotype. Although she had hypotonia, serum creatine kinase and electromyography were normal. Brain-MRI showed bilateral symmetric hypointense T1, hyperintense T2-fluid-attenuated-inversion-recovery and restricted-diffusion signal changes in the dentate nuclei. Mitochondrial genome testing identified a previously published pathogenic variant in MT-TA (m.5591G&gt;A) with 14% blood heteroplasmy and 16% urine heteroplasmy. The variant was absent in serum sampled from the patient’s mother Conclusions: Our case extends the phenotypic spectrum of MT-TA variants to include developmental and epileptic encephalopathy, in the apparent absence of muscle disease. We hypothesize that our patient may have the greatest degree of heteroplasmy in brain tissue; however, animal models and induced pluripotent stem cell (iPSC) models are needed to identify the precise mechanism by which MT-TA dysfunction results in variable phenotypes with variable degrees of heteroplasmy.

Radiomics on Gadoxetate Disodium-enhanced MRI: Non-invasively Identifying Glypican 3-Positive Hepatocellular Carcinoma and Postoperative Recurrence

To investigate the impact of preoperative gadoxetate disodium (EOB) MRI-based radiomics on predicting glypican 3 (GPC3)-positive expression and the relevant recurrence-free survival (RFS) of HCC ≤ 5 cm. Between January 2014 and October 2018, 259 patients with solitary HCC ≤ 5 cm who underwent hepatectomy and preoperative EOB-MRI were retrieved. Multivariate logistic regression was implemented to identify independent predictors for GPC3. By combining five feature selection strategies and three classifiers, 15 GPC3-oriented radiomics models could be constructed, the best of which with independent clinicoradiologic predictors was integrated into the comprehensive nomogram. GPC3 was an independent risk factor of postoperative recrudescence for HCC. Alpha-fetoprotein >20 ng/mL, homogenous T2 signal and hypointensity on hepatobiliary phase were independently related to GPC3-positive expression in the clinicoradiologic model. With 10 features selected by support vector machines-recursive feature elimination, logistic regression-based classifier achieved the best performance among 15 radiomics models. After five-fold cross-validation, our comprehensive nomogram acquired better average area under receiver operating characteristic curves (training and validation cohorts: 0.931 vs. 0.943) than the clinicoradiologic algorithm (0.738 vs. 0.739) and the optimal radiomics model (0.943 vs. 0.931). Net reclassification indexes further demonstrated the superiority of GPC3 nomogram over clinicoradiologic and radiomics algorithms (46.54%, p < 0.001; 7.84%, p=0.207). Meanwhile, higher radiomics score significantly shortened the median RFS (from >77.9 to 48.2 months, p=0.044), which was analogue to that of the histological GPC3-positive phenotype (from >73.9 to 43.2 months, p < 0.001). Preoperative EOB-MRI radiomics-based nomogram satisfactorily distinguished GPC3 status and outcomes of solitary HCC ≤ 5 cm.

Evolution of Myocardial Tissue Injury: A CMR Study Over a Decade After STEMI

BackgroundIn patients with a first ST-segment elevation myocardial infarction (STEMI), the multi-annual evolution of myocardial tissue injury parameters, as assessed by cardiac magnetic resonance (CMR), has not yet been described. ObjectivesThis study examined myocardial tissue injury dynamics over a decade after STEMI. MethodsSequential CMR examinations (within the first week after STEMI, and at 4, 12, months, and 9 years thereafter) were conducted in 74 patients with STEMI treated with primary percutaneous coronary intervention. Left ventricular function, infarct size (IS), and microvascular obstruction (MVO) were assessed at all time points. T2∗, T2, and T1 mapping (n = 59) were added at 9-year scan to evaluate the presence of iron and edema within the infarct core, respectively. ResultsIS decreased progressively and significantly between all CMR time points (all P < 0.001), with an average reduction rate of 5.8% per year (IQR: 3.5%-8.8%) and a relative reduction of 49% (IQR: 39%-76%) over a decade. MVO was present in 61% of patients at baseline, but was not present at the follow-up examinations. At 9-year CMR, 17 of 59 (29%) patients showed iron deposition within the infarct core, whereas 82% had persistent edema. Persistent iron and edema were associated with greater IS on any occasion (all P < 0.001), as well as the presence of MVO (P < 0.001). Patients with persistent iron and edema showed a lower relative regression of IS (P = 0.005 and P = 0.032, respectively) and greater end-systolic volumes over a decade (all P < 0.012 and P > 0.023, respectively). A T1 hypointense infarct core without evidence of T2∗ iron deposition (14 of 59 [24%] patients) was attributed to lipomatous metaplasia of the infarct. ConclusionsThe evolution of IS is a dynamic process that extends well beyond the first few months after STEMI. Persistence of iron and edema within the infarct core occurs up to a decade after STEMI and is associated with initial infarct severity and poor infarct healing.

Predicting disease activity in patients with multiple sclerosis: An explainable machine-learning approach in the Mavenclad trials.

Multiple sclerosis (MS) is among the most common autoimmune disabling neurological conditions of young adults and affects more than 2.3 million people worldwide. Predicting future disease activity in patients with MS based on their pathophysiology and current treatment is pivotal to orientate future treatment. In this respect, we used machine learning to predict disease activity status in patients with MS and identify the most predictive covariates of this activity. The analysis is conducted on a pooled population of 1935 patients enrolled in three cladribine tablets clinical trials with different outcomes: relapsing–remitting MS (from CLARITY and CLARITY‐Extension trials) and patients experiencing a first demyelinating event (from the ORACLE‐MS trial). We applied gradient‐boosting (from XgBoost library) and Shapley Additive Explanations (SHAP) methods to identify patients' covariates that predict disease activity 3 and 6 months before their clinical observation, including patient baseline characteristics, longitudinal magnetic resonance imaging readouts, and neurological and laboratory measures. The most predictive covariates for early identification of disease activity in patients were found to be treatment duration, higher number of new combined unique active lesion count, higher number of new T1 hypointense black holes, and higher age‐related MS severity score. The outcome of this analysis improves our understanding of the mechanism of onset of disease activity in patients with MS by allowing their early identification in clinical settings and prompting preventive measures, therapeutic interventions, or more frequent patient monitoring.