T1 Hypointense Research Articles

Haemorrhagic pituitary adenoma

Intra tumoral haemorrhage occurs frequently in pituitary macro adenomas. It can either manifest as pituitary apoplexy [1], a life threatening condition with sudden onset of headaches, nausea and vomiting; or as a silent recent or old haemorrhage. In the latter, like in our case, MR imaging is best to delineate these haemorrhagic changes. In fact, typical features are T1 and T2 hyperintensity (Figure 1A & 1B), persisting in fat saturated sequences (Figure 1C) with peripheral enhancement (Figure 1D). Usually a subsequent cystic change occurs, responsible for a fluid-fluid level (Figure 1E). Among the differential diagnosis of supra sellar masses, cystic craniopharyngiomas typically have calcifications although better appreciated on CT and a vividly enhancing solid component. Arachnoid cysts are very thin walled cystic supra sellar lesions with no solid or enhancing component, usually extending superiorly to the third ventricle and can be causing obstructive hydrocephalus. Rathke cleft cyst remains the most challenging differential, recent efforts were made to help make the correct diagnosis [2]. In that matter the classic appearance of a midline sellar and supra sellar lesion with fluid-fluid level, haemorrhagic changes and a T2 hypointense rim (Figure 1E) clinches the diagnosis of a haemorrhagic pituitary macroadenoma.

FRI425 BIUXX

Abstract Disclosure: D.M. Macedo: None. J. Casanova: None. A. Guerra: None. R. Francisco: None. Title: Hyperandrogenism due to post-menopausal ovarian stromal hyperplasia. Introduction: Severe and rapidly progressive installation of hyperandrogenism in women after menopause should be carefully investigated. Stromal hyperplasia of the ovaries, which etiology is not completely understood, is a rare and benign cause of excess androgen production. In addition to hyperandrogenism, it is usually associated with hyperinsulinism, obesity, metabolic syndrome and acanthosis nigricans. Clinical case: A 60 year old overweight female patient with a history of type 2 diabetes mellitus, dyslipidemia, polycystic ovarian syndrome and menopause at 53 years old, reported the recent onset of hirsutism on the face and back, alopecia and increased libido. The laboratory evaluation revealed: total testosterone 89.6ng/dL (<35.9), free testosterone 5.13pg/mL (<4.2), sex hormone-binding globulin 22.9nmol/L (18-144), LH 21.3mIU/mL (14-52), FSH 27.4mIU/mL (26-135) and E2 <19.0pg/mL. The remaining androgens did not show alterations and hypercortisolism was excluded. Abdominal and pelvic ultrasound was performed and revealed enlarged ovaries with homogeneous echotexture and reduced echogenicity. A pelvic MRI was also performed and showed solid lesions in both ovaries, with moderate T1 and T2 hypointensity, suspicious of bilateral androgen-producing ovarian tumors. After multidisciplinary discussion, the patient underwent total hysterectomy with bilateral oophorectomy. Histopathology was compatible with bilateral stromal hyperplasia of the ovaries. Three months after surgery, the patient presented with a reduction of the facial and back hirsutism and slight improvement in alopecia. The laboratorial evaluation revealed a marked reduction in total testosterone (18.0ng/dL) and free testosterone (1.07pg/mL). Conclusions: New-onset hyperandrogenism in postmenopausal women is very uncommon and a diagnostic challenge. After excluding iatrogenic causes, hypercortisolism or adrenal tumor, the differential diagnosis between virilizing ovarian tumor and bilateral stromal hyperplasia is difficult to establish. Although the imaging distinction is possible, the definitive diagnosis is histopathologic and total hysterectomy with bilateral oophorectomy should be performed. In this case, although MRI was suspicious of bilateral ovarian tumors, the definitive diagnosis was stromal hyperplasia of the ovaries. Three months after surgery, the patient presented marked clinical and biochemical improvement. Presentation Date: Friday, June 16, 2023

THU104 An Atypical Case Of A Suprasellar Cyst: A Diagnostic Challenge

Abstract Disclosure: A. Chen: None. S. Zachariah: None. B. Wong: None. E. Owusu: None. A. Levitt: None. R. Todor: None. P. Kishore: None. Background: Cystic sellar masses may be challenging to diagnose on a clinical, imaging, and histopathological basis due to overlapping features. We report a case of a cystic sellar mass in which traditional imaging findings did not correspond to its histopathological findings. Clinical Case: A 37-year-old female presented with headaches and bilateral blurry vision for two months with acute worsening of left peripheral vision for one week. She denied irregular periods, hirsutism, or breast discharge. Ophthalmology evaluation found left temporal field vision loss but normal maculae/optic nerves. MRI pituitary exhibited 2.3 x 1.5 x 1.7 cm complex cystic suprasellar mass with partial rim enhancement, thought to represent a cystic macroadenoma. Initial tests were notable for negative HCG, prolactin 96.32 mIU/mL (n < 23.3 mIU/mL), TSH 9.440 uIU/mL (0.270-4.2 uIU/mL), normalized to 0.855 uIU/mL on repeat testing, FT4 0.748 ng/dL (n = 0.75 – 2.0 ng/dL). IGF-1, ACTH, AM cortisol, FSH, and LH were within normal limits. She was started on cabergoline prior to trans-nasal-sphenoid resection with cyst drainage of white and thick content. Histopathology exhibited a squamous epithelium-lined cyst with no columnar epithelium or mucin-containing cells, consistent with an epidermoid cyst (EC), although the differential included a Rathke’s cleft cyst (RCC). No pituitary tumor was noted. A re-evaluation of MRI in multidisciplinary rounds deemed epidermoid cyst unlikely, given that these present with restricted diffusion. Our patient had overall T2 hyperintensity with an associated T2 hypointense nodule and did not restrict diffusion [1]. After interdisciplinary discussion, including imaging and pathology review, it was felt that the most likely diagnosis was RCC with squamous metaplasia. After surgery, the patient's symptoms and visual function completely recovered, and follow-up imaging is scheduled. Conclusion: Differentiating RCC with squamous metaplasia from EC can be challenging since both may present with a squamous epithelial lining [2]. Rates of progression and recurrence vary amongst cysts; therefore, making an accurate diagnosis is essential for selecting management, predicting the likelihood of recurrence, and guiding postoperative surveillance. This case is unique in that radiologic features were more helpful than histopathology in determining the diagnosis and highlights the importance of collectively considering clinical, imaging, and histopathological features in making a final diagnosis.

FRI234 A Pregnancy With Two Special Surprises A Baby And A Nonhemorrhagic Adrenal Infarction During Pregnancy

Abstract Disclosure: S. Idriss: None. N. Barua: None. I. Jamal: None. A. Jabiev: None. Introduction: Unilateral Acute adrenal infarction (AAI) is a rare cause of acute abdomen in pregnancy, with a reported incidence of 1.3%. It usually presents with sudden, severe, and unremitting flank pain. The most common cause of AAI is adrenal vein thrombosis. We present a 26-year-old pregnant female who presents with right flank and back pain, found to have AAI without hemorrhage. Case: 26-year-old female Primigravida without significant past medical history presented to the emergency room at 33 weeks of gestation with sudden onset of RUQ flank and back pain. She was afebrile and normotensive. Physical exam was positive for right flank point tenderness. She underwent multiple investigations including an abdominal US which did not reveal an acute pathology. She was admitted and started on opioids which failed to control her pain. An abdominal MRI was obtained subsequently revealing 4.6cm right adrenal gland lesion suspicious for AAI without hemorrhage and normal left adrenal gland. The pain was poorly controlled warranting Dilaudid drip and repeat imaging/CT showed adrenal gland mass with density of 41-52 HU suspicious for lipid poor adenoma versus adrenal hematoma on CT scan. Initial AM Cortisol level was 46 ug/dl, then it trended down to 31.7. DHEAS was low at 94.2 ug/dl. Plasma metanephrines and normetanephrines were normal. Course was complicated with hypotension and worsening pain on day 10 of admission, repeat MRI showed increase in right adrenal lesion size and cystic transformation, containing some T2 hypointense septations and debris without notable intrinsic T1 hyperintensity to suggest blood products, and restricted diffusion which is a finding compatible with AAI. Repeat AM Cortisol and DHEAS were low at 12 and 61.3 respectively. Despite normal left adrenal gland, clinical picture was consistent with adrenal insufficiency and she was started on stress steroids. Thrombophilia workup was negative. She ultimately underwent c-section on day 13 of admission. She was discharged on physiologic dose of steroids with a pending repeat MRI and outpatient follow up. Discussion: Adrenal glands, especially with preexisting nodules are predisposed to micro-vascular thrombosis and infarction during procoagulable states. Pregnancy is a hypercoagulable state that predisposes patients to thrombotic events. The relative risk of thrombosis is 5-6 times higher in pregnant than non-pregnant females of the same age. Our patient had evidence of adrenal insufficiency and required steroid replacement. Anticoagulation was not started due to possible subtle hematoma on CT scan on initial imaging. Follow up imaging is planned. Conclusion: Adrenal infarction is a rare cause of abdominal pain during pregnancy, and if missed, it can result in devastating clinical consequences for the mother and the child. Adrenal insufficiency if found should be addressed to prevent circulatory collapse. Presentation: Friday, June 16, 2023

Role of Cavernous Sinus Extension and MRI T2 Hypointensity in the Extent of Resection following Trans-Sphenoidal Surgery for Giant Pituitary Adenomas.

Giant pituitary adenomas (GPA) pose a significant neurosurgical challenge. In this study, we present an experience of 60 consecutive patients with GPA operated by trans-sphenoidal surgery (microscopic/endoscopic). The aim of this study was to elucidate preoperative factors predicting extent of resection (EOR) following transsphenoidal surgery for GPA. The study was a retrospective evaluation of 60 adult patients (>18 years) with GPA operated over a decade. The patients were analyzed for their clinical presentation, EOR, radiology, visual outcome, endocrinological outcome, and complications. The mean age of the cohort was 41.5 ± 13.3 years, mean tumor volume was 38.2 ± 19.1 cm3, and mean follow-up was 30.6 ± 21.7 months. Improvement in vision was seen in forty patients (66.7%), while another 16 (26.7%) had stable vision as prior to surgery. Duration of visual symptoms was found to be statistically significantly associated with postoperative improvement of vision (P = 0.001). Twenty-four patients (40.0%) underwent subtotal resection (STR), while the remaining 36 patients (60.0%) underwent either gross total or near-total resection. Factors associated with STR were retrosellar (P = 0.04), subfrontal (P = 0.02), Knosp 3,4 cavernous sinus extension (P = 0.03), and MRI T2 hypointensity (P = 0.02). During follow-up, eight patients (13.3%) had radiological evidence of growth of residual tumor. Most cases of GPA can be adequately handled by trans-sphenoidal surgery. The presence of retrosellar, subfrontal, cavernous sinus extensions, and T2 hypointensity should alert the surgeon for likelihood of STR, postoperative residual tumor hemorrhage and need for second-stage endonasal or transcranial surgery. However, utilization of extended endoscopic route has allowed good debulking of tumors having subfrontal and parasellar extensions, which was not possible previously using traditional microscopic transsphenoidal surgery.

Discal cysts and pseudocysts: Single center experience

IntroductionCurrent knowledge of intervertebral discal cysts is restricted to case reports and surgical case series, typically in young adult males presenting with back pain and radiculopathy. ObjectiveWe review our single-center experience to describe presentation, management, and outcomes of these rare lesions. MethodsWe performed a retrospective electronic search of our institution database using key words “discal cyst,” “disc cyst” and variations. Clinical presentation, imaging findings, management and outcomes were reviewed and tabulated. ResultsNine patients were identified (4 female), with mean age 49.1 years. Three patients had prior surgery at the level of the cyst. Seven patients presented with back pain, five with additional radiculopathy, one patient with radiculopathy alone, and one asymptomatic. Most discal cysts occurred at L5-S1, were left-sided, paracentral in location with a T2 hypointense rim and variable enhancement. One patient underwent primary cyst resection. Amongst 6 patients who underwent primary image-guided procedures, two had sustained pain relief, three proceeded to cystectomy, microdiscectomy and/or posterior decompressive surgery, and two were lost to follow-up. ConclusionOur retrospective cohort includes a wider age group with more heterogeneous clinical features, treatment approaches and response to therapy than that described in the literature. CT or fluoroscopy-guided steroid injection provided short-term symptomatic relief with several cases managed definitively with surgery. Further research is required to better understand and manage these rare lesions. Clinical impactDiscal cysts and pseudocysts occur in a wider range of patients and with more heterogenous presentations than previously described. Imaging-guided intervention can provide short-term symptomatic relief, but further research is required to optimize long-term management.

The Kinetics of Transtentorial Brain Herniation: Kernohan-Woltman Notch Phenomenon Revisited.

To critically review recent literature in understanding the pathological consequences of transtentorial brain herniation resulting from unilateral expanding supratentorial mass lesions. Modern neuroimaging assists in understanding the consequences of transtentorial brain herniation with the development of the Kernohan-Woltman notch phenomenon. MRI studies in post-operative patients undergoing craniotomy and removal of expanding unilateral hemispheric mass lesions (usually an extradural or subdural hematoma) have shown striking findings in the contralateral crus cerebri suggestive of damage as a result of impact against the free margin of the opposite tentorium as suggested by Kernohan and Woltman nearly a century back in autopsy studies. MR changes include T1 hypointensity, T2 and fluid-attenuated inversion recovery (FLAIR) hyperintensity, DW1 hyperintensity with restriction of diffusion, presence of hypointensity in GRE sequences and evidence of axonal damage in the corticospinal tracts in the cerebral peduncle in diffusion tensor imaging and MR tractography. The pathological basis of such changes may be variable or a combination of several pathological processes, which may all be related to the impact/compression of the contralateral crus with the tentorial margin. These include contusion, compression, demyelination, and perhaps most importantly microvascular damage including microbleeds. The role of uncal herniation is debatable. It appears that as a result of massive lateral shift in the supratentorial compartment, there is a transient forceful impact of the opposite cerebral peduncle against the rigid tentorial border to induce one or more of the abovementioned phenomena to explain the imaging findings. The limitation of these studies is that most of them have been done in the post-operative periods and surgical manipulations can surely alter anatomical relationships between intracranial structures. The exact sequence of events happening intracranially in the face of rapidly expanding supratentorial mass lesions is largely unknown. Even with rapid progress in neuroimaging, documentation of such changes during life are difficult, principally for logistic reasons. Consequently, the very truth of the much taught about phenomenon of uncal herniation and the resultant Kernohan-Woltman notch phenomenon and the false localizing sign of unilateral motor weakness and contralateral pupillary dilation have been questioned. Animal experimentation and autopsy studies have not contributed much in our understanding of the actual process happening intracranially in such an emergent situation. The midbrain undoubtedly is the key structure bearing the brunt of the effect of brain shift which is more lateral than downward in cases with unilateral expanding lesions. Structural changes in the cerebral peduncles have now been visualized with modern neuroimaging. These alterations may result from the interplay of one or more factors which include compression, contusion, demyelination, and perhaps most importantly microvascular ischemia and hemorrhage resulting from a forceful yet transient impact of the cerebral peduncle with the tough tentorial margin. The last mentioned hypothesis would be in conformity with Kernohan and Woltman's concept of elastic deformation of the midbrain. In the present article an attempt is made to provide a historical account of the changing concepts in relation to brain herniation as systematically and chronologically as possible, and then, critically review recent neuroimaging observations with a view to hypothesize on the sequence of events during transtentorial brain herniation.

Development and validation of MRI-based scoring models for predicting placental invasiveness in high-risk women for placenta accreta spectrum.

To develop and validate MRI-based scoring models for predicting placenta accreta spectrum (PAS) invasiveness. This retrospective study comprised a derivation cohort and a validation cohort. The derivation cohort came from a systematic review of published studies evaluating the diagnostic performance of MRI signs for PAS and/or placenta percreta in high-risk women. The significant signs were identified and used to develop prediction models for PAS and placenta percreta. Between 2016 and 2021, consecutive high-risk pregnant women for PAS who underwent placental MRI constituted the validation cohort. Two radiologists independently evaluated the MRI signs. The reference standard was intraoperative and pathologic findings. The predictive ability of MRI-based models was evaluated using the area under the curve (AUC). The derivation cohort included 26 studies involving 2568 women and the validation cohort consisted of 294 women with PAS diagnosed in 258 women (88%). Quantitative meta-analysis revealed that T2-dark bands, placental/uterine bulge, loss of T2 hypointense interface, bladder wall interruption, placental heterogeneity, and abnormal intraplacental vascularity were associated with both PAS and placenta percreta, and myometrial thinning and focal exophytic mass were exclusively associated with PAS. The PAS model was validated with an AUC of 0.90 (95% CI: 0.86, 0.93) for predicting PAS and 0.85 (95% CI: 0.79, 0.90) for adverse peripartum outcome; the placenta percreta model showed an AUC of 0.92 (95% CI: 0.86, 0.98) for predicting placenta percreta. MRI-based scoring models established based on quantitative meta-analysis can accurately predict PAS, placenta percreta, and adverse peripartum outcome. These proposed MRI-based scoring models could help accurately predict PAS invasiveness and provide evidence-based risk stratification in the management of high-risk pregnant women for PAS. • Accurately identifying placenta accreta spectrum (PAS) and assessing its invasiveness depending solely on individual MRI signs remained challenging. • MRI-based scoring models, established through quantitative meta-analysis of multiple MRI signs, offered the potential to predict PAS invasiveness in high-risk pregnant women. • These MRI-based models allowed for evidence-based risk stratification in the management of pregnancies suspected of having PAS.

Role of magnetic resonance imaging in the diagnosis of placenta accreta.

To analyze the value of magnetic resonance imaging (MRI) in suspicious cases for prenatal detection of placenta accreta (PA). A total of 50 placental MRI exams performed on a 1.5T scanner were retrospectively reviewed by two radiologists in consensus.HASTE(half-Fourier acquisition single-shot turbo spin echo)and True-FISP (true fast imaging with steady-state precession) sequences were acquired. Findings from MRI were compared with the final diagnosis, which was determined by clinical findings at delivery and pathological examination of specimens. Of 50 pregnant women in the analysis, 33 required cesarean hysterectomy, and 17 underwent cesarean delivery.MRI signs such as myometrial thinning, loss of T2 hypointense interface(loss of retroplacental clear space on US), heterogenous intraplacental sign, and intraplacental T2 dark bands were more likely to be seen in this group. In this group, the cases that were finally clinically and pathologically confirmed were 12, 16, and 22 cases of placenta accreta vera, placenta increta, and placenta percreta respectively. MRI is particularly useful in cases where US is inconclusive and to assess the extent to which the placenta penetrates the uterine serosa and invades outward into surrounding tissues.MRI has become a routine examination for patients with suspected PA in clinical practice.

Magnetic resonance imaging in COVID-19-associated acute invasive fungal rhinosinusitis - Diagnosis and beyond.

The aim of the study was to evaluate the magnetic resonance imaging (MRI) features of acute invasive fungal rhinosinusitis (AIFRS) at presentation and on follow-up imaging when patients receive treatment with systemic antifungal therapy and surgical debridement. This is a retrospective analysis of imaging data from a cohort of patients diagnosed with AIFRS during the second wave of COVID-19 in single tertiary referral hospital in South India between March 2021 and May 2021 (n = 68). Final diagnosis was made using a composite reference standard which included a combination of MRI findings, clinical presentation, nasal endoscopy and intraoperative findings, and laboratory proof of invasive fungal infection. Analysis included 62 patients with "Definite AIFRS" findings on MRI and another six patients with "Possible AIFRS" findings on MRI and laboratory proof of invasive fungal infection. Follow-up imaging was available in 41 patients. The most frequent MRI finding was T2 hypointensity in the sinonasal mucosa (94%) followed by mucosal necrosis/loss of contrast-enhancement (92.6%). Extrasinosal inflammation with or without necrosis in the pre-antral fat, retroantral fat, pterygopalatine fossa, and masticator space was seen in 91.1% of the cases. Extrasinosal spread was identified on MRI even when the computed tomography (CT) showed intact bone with normal extrasinosal density. Orbital involvement (72%) was in the form of contiguous spread from either the ethmoid or maxillary sinuses; the most frequent presentation being orbital cellulitis and necrosis, with some cases showing extension to the orbital apex (41%) and inflammation of the optic nerve (32%). A total of 22 patients showed involvement of the cavernous sinuses out of which 10 had sinus thrombosis and five patients had cavernous internal carotid artery involvement. Intracranial extension was seen both in the form of contiguous spread to the pachymeninges over the frontal and temporal lobes (25%) and intra-axial involvement in the form of cerebritis, abscesses, and infarcts (8.8%). Areas of blooming on SWI were noted within the areas of cerebritis and infarcts. Perineural spread of inflammation was seen along the mandibular nerves across foramen ovale in five patients and from the cisternal segment of trigeminal nerve to the root exit zone in pons in three patients. During follow-up, patients with disease progression showed involvement of the bones of skull base, osteomyelitis of the palate, alveolar process of maxilla, and zygoma. Persistent hyperenhancement in the post-operative bed after surgical debridement and resection was noted even in patients with stable disease. Contrast-enhanced MRI must be performed in all patients with suspected AIFRS as non-contrast MRI fails to demonstrate tissue necrosis and CT fails to demonstrate extrasinosal disease across intact bony walls. Orbital apex, pterygopalatine fossa, and the cavernous sinuses form important pathways for disease spread to the skull base and intracranial compartment. While cerebritis, intracranial abscesses, and infarcts can be seen early in the disease due to the angioinvasive nature, perineural spread and skull base infiltration are seen 3-4 weeks after disease onset. Exaggerated soft-tissue enhancement in the post-operative bed after debridement can be a normal finding and must not be interpreted as disease progression.

Cortical morphological changes in multiple sclerosis patients: a study of cortical thickness, sulcal depth, and local gyrification index.

Multiple sclerosis (MS) is a disease that progresses not only with demyelination but also with neurodegeneration. One of the goals of drug treatment in MS is to prevent neurodegeneration. Cortical thickness (CT), sulcal depth (SD), and local gyrification index (LGI) are indicators related to neurodegeneration. The aim of this study is to investigate changes in CT, SD, and LGI in patients with relapsing-remitting MS (RRMS). T1 images of 74 RRMS patients and 65 healthy controls were used. T1 hypointense areas in RRMS patients were corrected using fully automated methods. CT, SD, and LGI were calculated for each patient. RRMS patients showed widespread cortical thinning, especially in bilateral temporoparietal areas, decreased SD in bilateral supramarginal gyrus, superior temporal gyrus, postcentral gyrus, and transverse temporal gyrus, and decreased LGI, especially in the left posterior cingulate gyrus and insula. The decrease in cortical thickness was associated with the number of attacks and lesion volume. EDSS was related to CT in the right lingual, inferior temporal, and fusiform gyrus. The LGI was correlated with T2 lesion volume in bilateral insula, with EDSS in the right insula and transverse and superior temporal gyri, and with the number of attacks in the right paracentral gyrus and pre-cuneus. However, SD did not show any correlation with EDSS, T2 lesion volume, or the number of attacks. Our results demonstrate widespread cortical thinning, decreased sulcal depth in local areas, and decreased gyrification in folds in RRMS patients, which are related to clinical parameters.

Imaging findings in carcinomatous encephalitis secondary to malignant melanoma

BackgroundThe case of disseminated cancer cell spreading throughout the brain is called “miliary metastases” or “carcinomatous encephalitis”, a very rare and critical condition (primarily associated with lung and breast cancer) in which there are multiple plaque with a perivascular distribution, made of punctate lesions spread in all the brain. To our knowledge this represents the fourth case of melanotic miliary brain metastases described in the literature, also associated with melanin content of the lesions that is already evident on unenhanced T1-weighted images.Case presentationA 75-year-old patient with history of metastatic cutaneous melanoma (BRAF V600E mutate, PD-L1 negative) in treatment with dabrafenib and trametinib after 9 years from the diagnosis developed severe cognitive-motor slowing. Contrast-enhanced brain MRI showed miliary enhancing intra-axial brain lesions involving supra- and sub-tentorial regions and also the perivascular spaces, characterized by a bright appearance on unenhanced T1-weighted images without signal hypointensity in T2*-weighted images, as for melanotic pattern. Thus, the radiological diagnosis of “carcinomatous encephalitis” was made. Neurological examination showed an alert and cooperative subject with increased reaction time in verbal and motor responses. No ocular motility disturbances were found, and there were no motor or sensory deficits in the four limbs. The finger-to-nose test was normal, and no coordination deficit was found bilaterally. Blood tests and body temperature demonstrated no signs of ongoing infection. Electroencephalography showed slow and punctate abnormalities in bilateral fronto-temporal regions, with left prevalence. Corticosteroid therapy was started during hospitalization, improving the clinical picture. The patient was then discharged after 4 days in good clinical conditions with the indication to start second-line treatment with ipilimumab and nivolumab and to perform a whole-brain irradiation.ConclusionsBrain MRI plays a crucial role for the non-invasive diagnosis of carcinomatous encephalitis and for the differential diagnosis with other pathologies. Awareness of the existence of this disorder even in patients with melanoma is necessary to avoid diagnostic delays. Miliary brain metastases should be suspected in all melanoma patients with new neurological findings and contrast-enhanced MRI should be performed to assess the real burden of the disease.

P.086 Unusual case of Aspergillosis presenting as a skull base lesion

Background: Fungi are ubiquitous microorganisms. Sinonasal fungal infections range from an acute fulminant to a chronic indolent clinical course. Fungal infections are common in immunocompromised patients, diabetics, and those with hematological malignancies. We present an unusual case of chronic invasive fungal sinusitis presenting as an anterior skull base lesion. Methods: A 42-year-old patient was referred with a history of right-sided proptosis. Prompt CT and MR imaging revealed a large right sinonasal erosive mass, predominantly T2 hypointense with heterogeneous enhancement. It extended into the right anterior skull base and invaded the right frontal lobe. The mass also invaded into the right extra-conal orbital fat, right pterygopalatine fossa, and right sphenopalatine foramen. Results: In view of the imaging findings, a biopsy was performed which confirmed fungal elements and chronic inflammation. Subsequently, a right-sided endoscopic endonasal resection of the sinonasal mass with resection of the right orbital component and debulking of the anterior skull base component was performed. Culture specimen grew aspergillosis. Conclusions: Extra-sinus invasion in fungal sinusitis is not uncommon. These cases may mimic other pathologies, e.g., tumors, with potential delay in treatment. Sound knowledge of the imaging appearances of this entity is imperative to ensure a good outcome.

Predicting disease progression and the need for tumor-directed treatment in tectal plate gliomas.

Tectal plate gliomas are rare, slow-growing tumors of the midbrain that are discovered predominantly in the pediatric population. Because of their indolent nature, treatment mainly consists of observation and management of hydrocephalus. Unfortunately, a subset of tectal gliomas may exhibit tumor enlargement and disease progression. Currently, there are no established guidelines for predicting future progression of tectal gliomas or the need for tumor-directed treatment. In this paper, the authors present a large case series of tectal plate gliomas with the aim of determining early indicators of tumor progression and the need for tumor-directed treatment in a pediatric population, along with providing their experience in treating progressive tumors. A retrospective chart review of 170 patients diagnosed with tectal plate glioma from a single institution, of whom 67 were pediatric patients (≤ 18 years of age), was performed. Univariate analysis was used to determine statistically significant predictors of symptomatic disease progression requiring eventual tumor-directed therapy. The median patient age of the full cohort was 24 years (range 0-73 years). Compared with the pediatric population, the adult population had more instances of incidental lesions (p < 0.001) and lower rates of hydrocephalus (50% vs 84%, p < 0.001). Of the pediatric patients who had ≥ 5 years of follow-up (n = 51), 12 (24%) experienced radiological progression and 13 (25%) required treatment for their tumor. The 1-year, 5-year, and 10-year radiographic progression-free survival (PFS) rates were 98%, 90%, and 86%, respectively. In univariate analysis, lesion involvement of the pons, moderate T1 hypointensity, and moderate contrast enhancement on baseline radiology were significantly associated with worse radiographic PFS. Alternatively, significant predictors of requiring tumor-directed treatment included extraocular eye movement abnormalities at presentation, involvement of the lesion beyond the tectum on baseline radiology, moderate T1 hypointensity, moderate contrast enhancement, and an increase in total lesion size during progression. At the most recent follow-up, 94% of the patients had stable/nonprogressive disease, 2% had progressive disease, and 4% died of tumor progression. Patients who demonstrate radiographic progression may not necessarily experience clinical/symptomatic progression or require tumor-directed treatment. Certain patient presentation characteristics and baseline radiographic features may be predictive of worse radiographic PFS or the need for future tumor-directed treatment in the pediatric population. Typically, the natural history of these lesions lends to excellent long-term survival, even in patients who experience clinical progression, should appropriate treatment be initiated.

Pathophysiology of multiple sclerosis damage and repair: Linking cerebral hypoperfusion to the development of irreversible tissue loss in multiple sclerosis using magnetic resonance imaging.

Reduced cerebral perfusion has been observed in multiple sclerosis (MS) and may contribute to tissue loss both acutely and chronically. Here, we test the hypothesis that hypoperfusion occurs in MS and relates to the presence of irreversible tissue damage. In 91 patients with relapsing MS and 26 healthy controls (HC), gray matter (GM) cerebral blood flow (CBF) was assessed using pulsed arterial spin labeling. GM volume, T1 hypointense and T2 hyperintense lesion volumes (T1LV and T2LV, respectively), and the proportion of T2-hyperintense lesion volume that appears hypointense on T1-weighted magnetic resonance imaging (T1LV/T2LV) were quantified. GM CBF and GM volume were evaluated globally, as well as regionally, using an atlas-based approach. Global GM CBF was lower in patients (56.9 ± 12.3 mL/100 g/min) than in HC (67.7 ± 10.0 mL/100 g/min; p < 0.001), a difference that was widespread across brain regions. Although total GM volume was comparable between groups, significant reductions were observed in a subset of subcortical structures. GM CBF negatively correlated with T1LV (r = -0.43, p = 0.0002) and T1LV/T2LV (r = -0.37, p = 0.0004), but not with T2LV. GM hypoperfusion occurs in MS and is associated with irreversible white matter damage, thus suggesting that cerebral hypoperfusion may actively contribute and possibly precede neurodegeneration by hampering tissue repair abilities in MS.

Magnetic resonance imaging features of parotid mucoepidermoid carcinoma: a retrospective analysis

Background: Parotid mucoepidermoid carcinoma (P-MEC) is the most common of malignant salivary gland tumors and its accurate preoperative diagnosis is crucial for better management and prognostication. This becomes even more critical because in most cases P-MEC is difficult to distinguish from other common benign parotid lesions including abscess both clinically and radiologicall, but where management is entirely different. MRI could prove a vital cog in the wheel in this whole endeavor. This study aims to analyse the various MRI features in parotid mucoepidermoid carcinoma and the control group of non-MEC benign parotid masses which will aid in better distinguish between the two entities thereby coming to a confident diagnosis which will aid in management planning and better prognosis. Methods: This retrospective study was conducted at Sree Uthradom Thirunal Academy of Medical Science (SUTAMS), Thiruvananthapuram, India from July 2021 to July 2022 after obtaining Institutional Ethical committee approval. An informed consent was obtained from all patients before conduct of MRI imaging. The various MRI findings was applied in 60 patients in age bracket of 45-90 yrs with HPE proven parotid gland tumors. The cohort was divided into 2 groups: MEC (n=30) and non–MEC (n=30) as a control group. Results: Logistic regression analysis identified presence of cystic component (p&lt;0.001), T1 hypointense signal (p&lt;0.001), T2 hyperintense signal (p&lt;0.001), heterogeneous post contrast enhancement (p&lt;0.001) and perineural invasion (p=0.002) as characteristic MRI features of parotid MEC that aided in its accurate distinction from other non-MEC lesions of parotid. Conclusions: MRI can be a valuable tool for reliably distinguishing parotid mucoepidermoid from other parotid lesions.

Rapidly Resolving Orbital Pseudotumor in Systemic Lupus Erythematosus

Rapidly Resolving Orbital Pseudotumor in Systemic Lupus Erythematosus

Classification and neuroimaging of ependymal tumors.

Ependymal tumors arise from the ependymal cell remnants of the cerebral ventricles, the central canal of the spinal cord, or the filum terminale or conus medullaris, although most pediatric supratentorial ependymomas do not exhibit clear communication or abutment of the ventricles. In this article, we discuss the classification, imaging characteristics, and clinical settings of these tumors. The WHO 2021 classification system has categorized ependymal tumors based on histopathologic and molecular features and location, in which they are grouped as supratentorial, posterior fossa (PF), and spinal. The supratentorial tumors are defined by either the ZFTA (formerly RELA) fusion or the YAP1 fusion. Posterior fossa tumors are divided into group A and group B based on methylation. On imaging, supratentorial and infratentorial ependymomas may arise from the ventricles and commonly contain calcifications and cystic components, with variable hemorrhage and heterogeneous enhancement. Spinal ependymomas are defined by MYCN amplification. These tumors are less commonly calcified and may present with the "cap sign," with T2 hypointensity due to hemosiderin deposition. Myxopapillary ependymoma and subependymoma remain tumor subtypes, with no change related to molecular classification as this does not provide additional clinical utility. Myxopapillary ependymomas are intradural and extramedullary tumors at the filum terminale and/or conus medullaris and may also present the cap sign. Subependymomas are homogeneous when small and may be heterogeneous and contain calcifications when larger. These tumors typically do not demonstrate enhancement. Clinical presentation and prognosis vary depending on tumor location and type. Knowledge of the updated WHO classification of the central nervous system in conjunction with imaging features is critical for accurate diagnosis and treatment.

Calcifications in Cerebral Infarcts: Report of Two Cases

Calcification in cerebral infarcts has been reported as an uncommon finding. CT hyperdensity in an infarct can also be due to hemorrhagic transformation and in MRI can be mimicked by cortical laminar necrosis seen as gyriform T1 hyper and T2 hypointensities. Susceptibility-weighted imaging (SWI) with phase image has been reported to differentiate calcification and hemorrhage. We report 2 cases of cerebral infarcts with a review of the literature. The first patient showed early gyriform calcification 10 days after the onset and showed partial resolution of the calcification on follow-up. The second patient showed plaque-like calcification within perisylvian infarct that was confirmed by SWI phase imaging.

The T1 Ratio of Marrow (TROM) as a Novel Tool to Identify Metastatic from Nonmalignant Marrow Lesions of the Spine: A Pilot Study.

Objective The purpose of this study was to analyze quantitative values of normal and abnormal marrow on T1-weighted images of spine, to propose a ratio for T1 values of abnormal to normal vertebrae, and to assess whether this ratio could be helpful in predicting presence of neoplastic lesions in the spine. Materials and Methods One-hundred randomly selected magnetic resonance imagings of lumbar spine without infection, fracture, and tumor were selected to form normal cohort. A second cohort of 100 metastasis of lumbar spine was identified. Ratio of T1 value of vertebral body to the T1 value of the inferior vertebral body was performed for normal cohort from D11 to L5. Ratio of T1 value of metastasis to adjacent normal vertebral body was done for metastatic cohort. Data was analyzed using standard t -test and kappa was performed for intra- and inter-observer reliability. Results A decline in T1 value of abnormal to normal marrow was seen in patients with metastasis that was statistically significant. We call this the T1 ratio of marrow (TROM). The sensitivity and accuracy with the cutoff value of TROM at 0.7 (92% sensitivity, 97.1% accuracy) are better than at 0.6 (75% sensitivity, 96.2% accuracy) or 0.5 (47% sensitivity, 93.2% accuracy). A subset analysis of the other T1 hypointense benign lesions including atypical hemangiomas and focal marrow hyperplasia, however, revealed overlapping TROM values with the metastatic cohort. Conclusion Using the TROM on T1-weighted images could not confidently differentiate malignant from benign T1 hypointense lesions of the spine.