T2 MRI Sequences Research Articles

Large Numbers for Small Children-Up to What Age Do Infants Benefit from a Longer Echo Time in Cerebral T2 MRI Sequences?

In newborns, white matter shows a high T2-weighted (T2w) signal in MRI with poor grey-white matter contrast. To increase this contrast, an extremely long echo time (TE) is used in the examination of children. It is not known up to what age this long TE should be used. The purpose of this study was to find up to what age a long TE should be used in infants. In the prospective study, 101 infants (0-18 months) underwent cranial MRI at 3 Tesla. T2-weighted Fast Spin Echo sequences with long TE (200 ms) and medium TE (100 ms) were used. The signal intensities of the cortex and white matter were measured and the grey-white matter contrast (MC) was calculated. A cut-off age was determined. The T2w sequences with long TE had a statistically significantly higher MC until the age of six months (medium TE: 0.1 ± 0.05, Long TE: 0.19 ± 0.07; p < 0.001). After the tenth month, the T2w sequence with medium TE provided significantly better MC (Medium TE: 0.1 ± 0.05; long TE: 0.05 ± 0.4; p < 0.001). The use of a long TE is only helpful in the first six months of life. After the tenth month of life, a medium TE should be favored as is used in adult brain MRI.

Volumetric Response and Survival of Patients With Bulky IDH-Mutated Grade 3 Glioma Managed With FET-FDG–Guided Integrated Boost IMRT

AimsDespite relatively favourable outcomes associated with IDH-mutant grade 3 gliomas, many patients present with diffuse non-enhancing disease involving multiple brain regions, prompting concern over both durable disease control and the morbidity associated with large volume radiation therapy. This study audits volumetric response, survival and functional outcomes in this ‘large volume’ subgroup that undergoes intensity modulated radiation therapy (IMRT). Materials and methodsFrom a prospective database of 187 patients with IDH-mutant grade 3 gliomas managed with IMRT between 2008 and 2020, recorded PTV was divided into quartiles. The top quartile, termed the ‘large volume cohort’ (LVC), was identified. IMRT involved FET-FDG guided integrated boost (59.4/54Gy in 33 fractions). Manual volumetric segmentation of baseline, four months and 13 months post-IMRT tumour were performed for T1, T2 and T1gd MRI sequences. The primary endpoint was volumetric reduction on the T1 and T2 sequences at 13 months and analysed with relapse-free survival (RFS) and overall survival (OS). Morbidity endpoints were assessed at year four post-IMRT and included performance status (ECOG PS) and employment outcomes. ResultsThe fourth quartile (LVC) identified 44 patients for whom volumetric analysis was available. The LVC had median PTV of 320cm3 compared to 186.2cm3 for the total group. Anaplastic astrocytoma and oligodendroglioma were equally distributed and tumour sites were frontal (54%), temporal (18%) and parietal lobes (16%).Median follow-up for survivors was 71.5 months. Projected 10-year RFS and OS in LVC was 40% and 62%, compared to 53% and 62% respectively in the overall cohort. The RFS (p = 0.06) and OS (p = 0.65) of the LVC was not significantly different to other PTV quartiles; however the impact of PTV volume reached significance when analysed as a continuous variable (RFS p < 0.01; OS p = 0.02).Median T1 volumes were 26.1cm3, 8.0cm3 and 5.3cm3 at months +0, +3 and +12, respectively. The corresponding T2 volumes were 120.8cm3, 29.1cm3 and 26.3cm3. The median T1 and T2 volume reductions were 77% (q1–3: 57–92%) and 78% (q1–3: 60–85%) at 13 months post-IMRT. Initial T2 volume was associated with worse RFS (p = 0.04) but not OS (p = 0.96). There was no association between median T2 volume reduction and RFS (p = 0.77).For patients assessable at year 4 post-IMRT, no late CTCAE Grade 3/4 toxicity events were recognised. 92% of patients were ECOG PS 0–1, 45% were employed at prior capacity and 28% were working with impairment. ConclusionPatients with large volume IDH-mutant Grade 3 glioma demonstrated significant tumour reduction post-IMRT, and good long-term outcomes with respect to survival and functional status. Although larger IMRT volumes were associated with poorer RFS, this was also associated with the initial volume of non-enhancing tumour.

Detection of Multiple Sclerosis Lesions in Supra- and Infra-Tentorial Anatomical Regions by Double Inversion Recovery, Flair, and T2 MRI Sequences: A Comparative Study in Iraqi Patients

Background: In young adults, multiple sclerosis is a prevalent chronic inflammatory demyelinating condition. It is characterized by white matter affection, but many individuals also have significant gray matter involvement. A double-inversion recovery pulse (DIR) pattern was recently proposed to improve the visibility of multiple sclerosis lesions. Objective: To find out how well a DIR sequence, FLAIR, and T2-weighted pulse sequences can find MS lesions in the supratentorial and infratentorial regions. Methods: A total of 37 patients with established diagnoses of multiple sclerosis were included in this cross-sectional study. Brain MRI was done using double inversion recovery, T2, and FLAIR sequences. The number of lesions was counted and compared in the three sequences. Results: The DIR sequence detected more infratentorial lesions when compared to the T2 and FLAIR sequences. In the supratentorial region, DIR detected more lesions than T2 and FLAIR. Conclusion: The DIR sequence is highly superior to both the T2 and FLAIR sequences in depicting the lesions, regardless of their anatomical distribution. Moreover, the DIR sequence detected more multiple sclerosis lesions in the infratentorial region than the traditional T2W and FLAIR sequences.

CTNI-66. DECODING GLIOBLASTOMA SURVIVAL: UNRAVELING THE PROGNOSTIC POTENTIAL OF OLFACTORY FUNCTION IN A PROSPECTIVE OBSERVATIONAL STUDY

Abstract BACKGROUND Olfactory impairment is a common neurologic deficit among glioblastoma patients. We have previously shown that glioblastoma patients with reduced smell sensitivity had lower overall survival rates compared to those with normal olfactory function. A notable limitation in that study was the unequal distribution of prognostic factors between the two groups, and the absence of continuous olfactory assessments during treatment to investigate if therapy-associated neurotoxicity could be a contributing factor to diminished olfactory acuity. Question: Can Olfactory Function Serve as an Independent Prognostic Indicator in Glioblastoma Patients? METHODS This prospective, multicenter study is set to recruit 64 glioblastoma patients alongside 64 healthy controls. Stratification of participants will be based on prognostically relevant variables such as resection status, MGMT promoter methylation status, radiographic involvement of olfactory brain areas, olfactory function, age, and Karnofsky performance status scale. We will utilize Sniffing Sticks to evaluate olfactory function through identification and threshold tests, and this assessment will be carried out longitudinally throughout the therapy starting from tumor diagnosis. Infiltration of the olfactory brain areas will be scrutinized using coronal T2 and T1 MRI sequences. MRI images will be independently reviewed by two board-certified radiologists from distinct institutions, who are blinded to the patients' olfactory function status. Furthermore, quality of life data, neuropsychological testing, and psychosomatic screening will be performed at specific intervals throughout the study. Also, we'll examine next-generation sequencing results to investigate potential genetic associations with hyposmia in glioblastoma patients. RESULTS The first participant was enrolled in May 2023. Plans are underway to open a second study site in 2024, with the aim to complete recruitment by December 2025. Follow-up assessments will continue until December 2027. We anticipate that the final results of the study will be available in 2028.

Susceptibility-Weighted MRI Approximates Intraoperative Microelectrode Recording During Deep Brain Stimulation of the Subthalamic Nucleus for Parkinson's Disease

Deep brain stimulation of the subthalamic nucleus (STN-DBS) for Parkinson's disease can be performed with intraoperative neurophysiological and radiographic guidance. Conventional T2-weighted magnetic resonance imaging sequences, however, often fail to provide definitive borders of the STN. Novel magnetic resonance imaging sequences, such as susceptibility-weighted imaging (SWI), might better localize the STN borders and facilitate radiographic targeting. We compared the radiographic location of the dorsal and ventral borders of the STN using SWI with intraoperative microelectrode recording (MER) during awake STN-DBS for Parkinson's disease. Thirteen consecutive patients who underwent placement of 24 STN-DBS leads for Parkinson's disease were analyzed retrospectively. Preoperative targeting was performed with SWI, and MER data were obtained from intraoperative electrophysiology records. The boundaries of the STN on SWI were identified by a blinded investigator. The final electrode position differed significantly from the planned coordinates in depth but not in length or width, indicating that MER guided the final electrode depth. When we compared the boundaries of the STN by MER and SWI, SWI accurately predicted the entry into the STN but underestimated the length and ventral boundary of the STN by 1.2 mm. This extent of error approximates the span of a DBS contact and could affect the placement of directional contacts within the STN. MER might continue to have a role in STN-DBS. This could potentially be mitigated by further refinement of imaging protocols to better image the ventral boundary of the STN.

Evaluation of Sexual Side Effects in Patients after Chemoradiation and Brachytherapy for Gynecologic Cancers Involving the Lower Vagina and Bulboclitoris

Radiation toxicity to the bulboclitoris has not been previously investigated. This retrospective cohort study aims to report sexual side effects of patients who underwent radiotherapy for tumors involving the lower vagina, periurethra, and bulboclitoris (BC). Patients treated between 2017- 2022 for gynecologic cancer involving the low vagina were included. The high-risk clinical target volume (HR-CTV), bladder, rectum, and urethra were contoured on patient imaging during initial treatment planning. The BC was retrospectively contoured using T2 MRI sequences fused to the pre-treatment and brachytherapy CT simulation. Superiorly, the BC was defined as inferior to the pubic symphysis and attached to the suspensory ligament of the clitoris. Laterally, the crura extend on either side of the corpus. Inferiorly, the vestibular bulbs flank the urethra and vagina on either side, extending posteriorly to mid-vagina. Dosimetric data for the BC, vaginal morbidity using the CTCAE 4.0 for vaginal stenosis, and pain scoring of the BC were obtained via chart review. Patients underwent external beam radiotherapy (IMRT) to the pelvis and bilateral inguinal region (45 Gy in 25 fractions) followed by High Dose Rate Ir-192 interstitial brachytherapy in 5 fractions for a total dose of 25 Gy (22.5 - 27.5 Gy). Patients had a median age of 65 years (49-73) with tumors located in the lower vagina, near the BC and urethra. At the time of brachytherapy, in order to cover the HR-CTV, interstitial brachytherapy needles were placed within the BC structure with 58% (33% - 77%) of total interstitial needles placed within the bulbs of the BC. The mean pre-treatment volume of the BC was 16.6 cc (11.9 - 20.9 cc) and at brachytherapy was 12.66 cc (7.3 - 22.1 cc) with Table 1 summarizing radiation doses. At a median follow up of 19.6 months, all patients had a complete local response, with one patient deceased of metastatic disease. In the acute period, all patients reported severe pain in the clitoral glans region and dysuria that completely resolved after 2 years. Grade 1-2 vaginal stenosis occurred in all patients despite vaginal dilator usage. One patient reported decreased clitoral sensitivity and inability to achieve clitoral-mediated orgasm 5 months after radiotherapy. This study demonstrates that the BC receives a significant radiation dose during vaginal brachytherapy treatment which can cause clitoral pain and dysfunction. Further studies are needed to evaluate the dose response of the BC as well as explore methods to spare the organ during radiation therapy in order to minimize toxicity and preserve sexual function.

BRAIN TUMOR SEGMENTATION ON FLAIR MR IMAGES WITH U-NET

Brain tumors are among the illnesses that, if not treated promptly, can lead to death. It is extremely difficult to detect tumor tissue using only eye examination methods. As a result, Magnetic Resonance (MR) imaging is used to diagnose brain tumors. T1, T1c, T2, and FLAIR MRI sequences provide detailed information about brain tumors. If the segmentation procedure is performed correctly, patients' chances of survival improve. This paper describes an automated brain tumor segmentation for FLAIR sequences in MR images using U-NeT method. The study has been carried out on the BraTS 2018 data set. The models' correctness has been assessed using the binary accuracy, dice coefficient, and IOU assessment criteria. The results of the comparison between the tumor regions identified by the expert physicians and the tumor regions calculated by the U-Net model are as follows: The model has been completed with 99.26% accuracy, and the dice coefficient value, which expresses the similarity on the basis of pixels for the test data, has been found to be 73.99%. Furthermore, the IOU value of 0.59 demonstrated that the model provided accurate estimates for the study.

NIMG-80. A RADIOMICS-BASED MODEL PREDICTIVE OF OVERALL SURVIVAL IN GLIOBLASTOMA USING MULTI-INSTITUTIONAL PREOPERATIVE MRI SCANS

Abstract PURPOSE Though patients with glioblastoma generally have poor overall survival (OS), OS estimates range significantly. We sought to develop a radiomics-based model predictive of OS in glioblastoma using preoperative MRI scans to identify these differences and guide clinical care. METHODS The primary endpoint was OS, determined from the date of surgery to death or last follow-up. T1, FLAIR, T2, and post-contrast T1 (T1c) MRI sequences were obtained for all patients. Using HD-GLIO-AUTO, lesion segmentation yielded three masks corresponding to the regions of contrast enhancement, non-enhancement, and total volume. Radiomics features were extracted from each region from the T2 and T1c sequences independently (i.e. either from T2 or T1c) and in combination. Age at surgery and gender were also considered. The data was split into training (75%) and test (25%) sets, stratifying for age at surgery. Kaplan-Meier analysis and the Coxnet model were used. For Coxnet, Elastic Net was used as the penalty, with optimization of the L1 coefficient using 5-fold cross-validation and evaluation via the concordance index (C-index). RESULTS From 3 institutions, 383 patients were included. Median OS was 395 days: 346 patients died, and 37 were right-censored. Age &amp;gt; 65 years was predictive of decreased OS (p &amp;lt; 0.005), but gender was not (p=0.16). For the Coxnet model, the C-index was 0.67 (standard deviation: 0.01) considering T2 and T1c sequences for the total lesion volume, with a C-index of 0.65 for the test set. For the enhancing volume, the model had a C-index of 0.71 for the test set using T1c sequences. Overall, C-indices ranged from 0.62-0.71. CONCLUSIONS We present a novel radiomics-based model predictive of OS in glioblastoma across a multi-institutional dataset. Ongoing efforts will incorporate immediate postoperative imaging and IDH and MGMT status into the proposed model to further improve prognostic ability and help guide clinical decision-making.

The study of predictive factors for the evolution of vestibular schwannomas.

The primary objective was to determine whether the analysis of textural heterogeneity of vestibular schwannomas on MRI at diagnosis was predictive of their radiological evolutivity. The secondary objective was to determine whether some clinical or radiological factors could also be predictive of growth. We conducted a pilot, observational and retrospective study of patients with a vestibular schwannoma, initially monitored, between April 2001 and November 2019 within the Oto-Neurosurgical Institute of Champagne Ardenne, Texture analysis was performed on gadolinium injected T1 and CISS T2 MRI sequences and six parameters were extracted: mean greyscale intensity, standard deviation of the greyscale histogram distribution, entropy, mean positive pixels, skewness and kurtosis, which were analysed by the Lasso method, using statistically penalised Cox models. Extrameatal location, tumour necrosis, perceived hearing loss < 2years with objectified tone audiometry asymmetry, tinnitus at diagnosis, were investigated by the Log-Rank test to obtain univariate survival analyses. 78 patients were included and divided into 2 groups: group A comprising 39 "stable patients", and B comprising the remaining 39 "progressive patients". Independent analysis of the texture factors did not predict the growth potential of vestibular schwannomas. Among the clinical or radiological signs of interest, hearing loss < 2years was identified as a prognostic factor for tumour progression with a significant trend (p = 0.05). This study did not identify an association between texture analysis and vestibular schwannomas growth. Decreased hearing in the 2 years prior to diagnosis appears to predict potential radiological progression.

Radiofrequency Neurotomy Does Not Cause Fatty Degeneration of the Lumbar Paraspinal Musculature in Patients with Chronic Lumbar Pain-A Retrospective 3D-Computer-Assisted MRI Analysis Using iSix Software.

The present study aimed (1) to analyze the relative paraspinal autochthonous intramuscular fat volume before and after radiofrequency neurotomy (RFN) and (2) to compare it to the contralateral non-treated side. Retrospective cohort study. Inselspital, University Hospital Bern, University of Bern. Twenty patients (59.60 ± 8.49 years; 55% female) with chronic low back pain, treated with RFN (L2/3-L5/S1) due to symptomatic facet joint syndrome (FCS) between 2008 and 2017 were included. All patients received a magnetic resonance imaging (MRI) of the lumbar spine before and at a minimum of 6 months after RFN. The absolute (cm3) and relative (%) paraspinal muscle and fat volume was analyzed three-dimensionally on standard T2-MRI sequences using a newly developed software (iSix, Osiris plugin). Both sides were examined and allocated as treated or non-treated side. A total of 31 treated and 9 non-treated sides (Level L2/3-L5/S1) were examined. There were no differences in the relative paraspinal intramuscular fat volume before and at a median of 1.4 [0.9 - 2.6] years after RFN (P = .726). We found no differences in the relative fat volume between the treated and non-treated side before (P = .481) and after (P = .578) RFN. Our study shows that there are no differences in the paraspinal muscle/fat distribution after RFN. RFN of the medial branches for FCS does not seem to cause fatty degeneration of the lumbar paraspinal muscles as a sign of iatrogenic muscle denervation.

Basilar artery dilatation relates to Alzheimer dementia, particularly among APOE4 non‐carriers

AbstractBackgroundBrain arterial dilatation has been associated with higher risk of dementia and cognitive decline in population‐based studies. Whether the association is related to brain amyloid or tau, pathological hallmarks of Alzheimer disease, is uncertain.MethodWe analyzed existing and de novo data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) regarding participants’ demographics, hypertension, dementia status, APOE4 genotype. We used composite PET measures of gray matter regions of beta amyloid (AV‐45) and neurofibrillary tangles (AV‐1451). We obtain de novo cross‐sectional carotid and basilar artery diameters using axial T2 MRI sequences. For cognitive outcomes, we used the Alzheimer's Disease Assessment Scale–Cognitive Subscale (ADAS‐Cog) and clinical dementia rating (ordinal CDR) scores. All models were adjusted for age, sex, years of education, APOE4 carrier status and hypertensionResultWe included 478 ADNI participants (56% men, mean age 77±7, 36% cognitively normal, 48 with mild cognitive impartment and 16% with dementia). Combined carotid and basilar artery diameters were not associated with ADAS‐13 cog score (B=0.07 per SD, P=0.46), ordinal CDR (B=0.13, P=0.32), amyloid (B=‐0.001, P=0.57) or tau (B=0.02, P=0.45). Stratifying by anterior versus posterior circulation artery showed that basilar artery diameters, but not carotid diameters, were associated with a higher ADAS‐13 cog score (B=0.17, P=0.01), higher CDR (0.25, P=0.009), but not with amyloid (B=0.01, P=0.46). The association between basilar artery diameters and CDR was stronger among APOE4 non‐carriers (B=0.37, P=0.004) than in carriers (B=0.05, P=0.70, P for the interaction 0.12).ConclusionBrain arterial dilatation is associated with poorer cognitive outcomes, and the association is stronger among APOE4 negative participants. Investigation of how brain arterial dilatation relates to dementia and whether such relationship interacts with amyloid and/or tau may reveal novel aspects of the vascular contributions to dementia.

Mucocele of a giant inferior turbinate concha bullosa mimics a nasal mass: case report

BackgroundThe concha bullosa is a pneumatized nasal turbinate commonly middle turbinate but that of the inferior turbinate is an uncommon entity. A giant inferior conchal pneumatization with mucocele formation is not reported in the literature till now.Case presentationA 17-year-old female patient presented with bilateral severe nasal obstruction. Anterior rhinoscopy and endoscopic examination revealed a giant mass which filled the left nasal cavity completely, pushing the septum to the contralateral side. The paranasal sinus CT showed a mass in the left nasal cavity ballooning the whole nasal cavity with compression of the nasal septum to the right side. MRI was done and the lesion was hyperintense in T2 MRI sequences and hypointense in T1 sequences consistent with a cystic lesion. The patient was consented and prepared for endoscopic resection under general anesthesia. The lesion was completely separated from the nasal septum and the orbit but attached to the lateral nasal wall at the site of origin of the inferior turbinate. Conchoplasty was done and patient follow-up for 9 years is excellent with complete disappearance of all patient symptoms.ConclusionsConcha bullosa of the inferior turbinate should be considered in the differential diagnosis of nasal tumors, nasal cystic lesions, and preoperative evaluation of endoscopic sinus surgery. Also, a systematic approach for dealing with nasal lesions with thorough examination and radiological review will be of great value in decision-making. The anatomy of the paranasal should be thoroughly examined prior to endoscopic sinus surgery to develop treatment strategies and to prevent possible complications.

Abstract P731: Genetic Knockout of Cd38 Protects Mice Against Ischemic Brain Injury

Introduction: CD38 is an ectoenzyme that is present on the cellular membranes of endothelial cells and subtypes of inflammatory cells. We have shown that ischemia/reperfusion (I/R) in the heart triggers CD38 activation that in turns leads to NADPH depletion and endothelial nitric oxide synthase (eNOS) impairment. This cascade results in worsening of ischemic injury secondary to endothelial dysfunction. We hypothesize that a similar paradigm exists in acute ischemic stroke and that loss of CD38 function is protective against cerebral I/R injury. Methods: Middle cerebral artery occlusion (MCAO) was performed for 60 minutes in 15 week-old CD38 knockout mice (KO) n=12 and wild type (WT) mice n=12. Stroke volume was calculated using T2 MRI sequences obtained at 48 hours post MCAO. Percentage of brain infarction volume compensated for swelling (IFV) was calculated by manual segmentation of the stroke area and non-affected cerebral hemisphere. Following brain MRI, H&amp;E staining and immunohistochemistry assessment of superoxide radicals (DHE fluorescence) nitric oxide (NO) (DAF fluorescence), eNOS expression, CD38 expression and microglia activation (Iba1) were performed. (P&lt;0.05) was considered significant in statistical testing. Results: CD38 KO mice had a smaller IFV as % of the normal contralateral hemisphere volume compared to WT (19.6±3 vs 33.5±9, P=0.001). Both western blotting and immunohistology confirmed lack of CD38 expression in CD38 KO mice. CD38 expression was 55% higher in the ipsilateral stroke side compared to the contralateral stroke side in WT mice (P=0.0105). Compared to WT mice, CD38 KO had 45% lower superoxide levels (P&lt;0.001), 50% higher NO levels (P&lt;0.05) and 46% lower Iba-1 expression with more significance in ipsilateral side (P&lt;0.01) than contralateral side (P&lt;0.05). While eNOS expression was 40% lower in WT vs CD38 KO, this did not reach statistical significance. Conclusions: Thus, genetic deletion of CD38 is protective against cerebral ischemia with reduced superoxide production and preserved NO production, likely through the protection conferred against NADPH depletion. These results suggest that inhibition of CD38 could serve as a potent therapeutic approach to protect against acute ischemic stroke and related brain I/R injury.

Intra-Arterial Infusion of Magnetic Nanoparticle-Based Theragnostic Agent to Treat Colorectal Cancer Liver Implants in Rats

Introduction: Nowadays, surgical excision remains the gold standard to treat liver metastases of colorectal cancer (CRCLM). However, as more than 50% of patients are not eligible for surgery, other alternatives such as percutaneous or intravascular interventional therapies (thermal ablation, chemoembolization, or radioembolization), are quite relevant. Recently, the use of magnetic nanoparticles (MNPs) has been suggested as an adjuvant for these therapies, as they could increase their necrotising effect on the tumour while reducing doses and exposure times of thermal therapies. To investigate the potential curative effect of these compounds, animal models are needed, both for the development of experimental interventional procedures and for MNPs toxicity and distribution assessment. Herein, we describe both an experimental infusion procedure in CRCLM-bearing rats and analytical and histological methods to evaluate MNPs deposits in the tissue. Methods: Eighteen male WAG/RijHsd rats were subjected to intrahepatic injection of 250,000 colorectal cancer cells. Twenty-eight days later, half of the tumour-positive animals (n = 6) were administered with MNPs while the other half (n = 6) did not receive any injection and were used as control. Under microscope magnification, the splenic artery was carefully and completely dissected, and a catheter was inserted through the splenic artery to the common hepatic artery where 1 mL MNPs suspension was administered in 5 min; then STIR, DP*, and T2 MRI sequences were obtained (and signal intensity measured) and both tumour and liver tissue samples were collected for elemental and histological analyses. Conclusion: Our method for selective administration of MNPs is reproducible and well-tolerated and it fairly mimics the approach used in clinical practice when intravascular interventional therapies are applied.

Diagnostic value of 3D-FLAIR magnetic resonance sequence in detection of white matter brain lesions in multiple sclerosis

BackgroundMS is common demyelinating disease in which standard T2 and 2D-FLAIR MRI sequences play important role in its diagnosis. Recently, 3D-FLAIR sequence is used and has a role that is evaluated compared to standard sequences.ResultsThis study was performed on 20 selected MS patients. Brain MRI was performed using routinely used T2 and 2D FLAIR sequences, and 3D-FLAIR sequence was added. 3D-FLAIR images were reformatted, and all images were blindly analyzed. Lesions were counted in each sequence and classified according to their location into supratentorial lesions including periventricular, deep white matter, and juxta-cortical, and infratentorial lesions and relative comparison of lesion number on 3D-FLAIR versus 2D-FLAIR and T2 imaging, respectively, were expressed as percentage gain or a loss.3D-FLAIR sequence showed significantly more lesions compared to 2D FLAIR and T2 sequences in all locations with relative ratio of 29% and 41%, respectively, in periventricular region; 22% and 30%, respectively, in deep WM; 180% and 147%, respectively, in juxta-cortical region; and 80% and 13%, respectively, in infratentorial region.Conclusion3D-FLAIR sequence is of greater sensitivity than standard 2D-FLAIR and T2 sequences in MS brain lesions depiction, and it is recommended to be included in MR protocol of MS.

Abstract WP323: Genetic Knockout of CD38 in Mice Protects Against Ischemic Stroke With Smaller Infarct Volumes and Decreased Motor Impairment

Introduction: Endothelial dysfunction is an important mediator of post ischemic injury of the heart and brain following ischemia/reperfusion (I/R). We have reported that CD38 activation in heart I/R models leads to NADPH depletion with endothelial nitric oxide synthase (eNOS) impairment, loss of endothelial-mediated coronary dilatation and increased myocardial infarction. While CD38 knockout or inhibition prevents this dysfunction and decreases myocardial infarction, the role of CD38 in ischemic stroke remains uncertain. Hypothesis: We hypothesize that loss of CD38 expression and activity through gene knockout is protective with smaller infarct volume. Methods: 15 week-old male CD38 knock out (KO) n=12 and wild type (WT) mice n=12 underwent middle cerebral artery occlusion (MCAO) for 60 minutes. Stroke volume was calculated using T2 MRI sequences on a 9.4 T MRI system acquired 48 hours post stroke with images analyzed using Osirix software. The ratios of the stroke volume to the affected hemisphere volume and the compensated swelling infarction volume percentage of normal hemisphere were calculated using established methods. Open field test to measure motor impairment was performed at baseline and 48 hours post stroke (KO, n=12, WT n=6). Statistical analysis was completed in STATA using Man-Whitney U test and T-test to compare infarct volumes and cognitive parameters. Values are shown as mean ± SD. P value &lt; 0.05 was considered significant. Results: At 48 hours, brain MRI showed a smaller percentage of cerebral hemisphere affected by stroke in CD38 KO compared to WT (25.9±3.7 vs 41.1±9.4, respectively P=0.0001) and a smaller percentage of compensated swelling infarction volume of normal hemisphere in KO mice compared to WT (19.6±3 vs 33.5±9, respectively P=0.0001). Open field test showed significant post stroke motor impairment in WT compared to CD38KO mice (distance travelled 1.8±1 m vs 4.7±3 m, P=0.04, respectively and average speed 0.006±0.003 m/s vs 0.016±0.01m/s, P=0.04, respectively). Conclusions: Infarct volumes are smaller and motor impairment is decreased in CD38 KO mice compared to WT demonstrating that gene knockout of CD38 confers neuroprotection against acute ischemic brain injury.

Fuzzy volumetric delineation of brain tumor and survival prediction

A novel three-dimensional detailed delineation algorithm is introduced for Glioblastoma multiforme tumors in MRI. It efficiently delineates the whole tumor, enhancing core, edema and necrosis volumes using fuzzy connectivity and multi-thresholding, based on a single seed voxel. While the whole tumor volume delineation uses FLAIR and T2 MRI channels, the outlining of the enhancing core, necrosis and edema volumes employs the T1C channel. Discrete curve evolution is initially applied for multi-thresholding, to determine intervals around significant (visually critical) points, and a threshold is determined in each interval using bi-level Otsu’s method or Li and Lee’s entropy. This is followed by an interactive whole tumor volume delineation using FLAIR and T2 MRI sequences, requiring a single user-defined seed. An efficient and robust whole tumor extraction is executed using fuzzy connectedness and dynamic thresholding. Finally, the segmented whole tumor volume in T1C MRI channel is again subjected to multi-level segmentation, to delineate its sub-parts, encompassing enhancing core, necrosis and edema. This was followed by survival prediction of patients using the concept of habitats. Qualitative and quantitative evaluation, on FLAIR, T2 and T1C MR sequences of 29 GBM patients, establish its superiority over related methods, visually as well as in terms of Dice scores, Sensitivity and Hausdorff distance.

Evaluation of tumor coverage after MR-guided prostate focal laser ablation therapy.

Prostate cancer is the most common noncutaneous cancer among men in the USA. Focal laser thermal ablation (FLA) has the potential to control small tumors while preserving urinary and erectile function by leaving the neurovascular bundles and urethral sphincters intact. Accurate needle guidance is critical to the success of FLA. Multiparametric magnetic resonance images (mpMRI) can be used to identify targets, guide needles, and assess treatment outcomes. In this study, we evaluated the location of ablation zones relative to targeted lesions in 23 patients who underwent FLA therapy in a phase II trial. The ablation zone margins and unablated tumor volume were measured to determine whether complete coverage of each tumor was achieved, which would be considered a clinically successful ablation. Preoperative mpMRI was acquired for each patient 2-3 months preceding the procedure and the prostate and lesion(s) were manually contoured on 3T T2-weighted axial images. The prostate and ablation zone(s) were also manually contoured on postablation 1.5T T1-weighted contrast-enhanced axial images acquired immediately after the procedure intraoperatively. The lesion surface was nonrigidly registered to the postablation image using an initial affine registration followed by nonrigid thin-plate spline registration of the prostate surfaces. The margins between the registered lesion and ablation zone were calculated using a uniform spherical distribution of rays, and the volume of intersection was also calculated. Each prostate was contoured five times to determine the segmentation variability and its effect on intersection of the lesion and ablation zone. Our study showed that the boundaries of the segmented tumor and ablation zone were close. Of the 23 lesions that were analyzed, 11 were completely covered by the ablation zone and 12 were partially covered. A shift of 1.0, 2.0, and 2.6mm would result in 19, 21, and all tumors completely covered by the ablation zone, respectively. The median unablated tumor volume across all tumors was 0.1 with an IQR of 3.7 , which was 0.2% of the median tumor volume (46.5 with an IQR of 46.3 ). The median extension of the tumors beyond the ablation zone, in cases which were partially ablated, was 0.9mm (IQR of 1.3mm), with the furthest tumor extending 2.6mm. In all cases, the boundary of the tumor was close to the boundary of the ablation zone, and in some cases, the boundary of the ablation zone did not completely enclose the tumor. Our results suggest that some of the ablations were not clinically successful and that there is a need for more accurate needle tracking and guidance methods. Limitations of the study include errors in the registration and segmentation methods used as well as different voxel sizes and contrast between theregistered T2 and T1 MRI sequences and asymmetric swelling of the prostate postprocedurally.

Elite Rowers Demonstrate Consistent Patterns of Hip Cartilage Damage Compared With Matched Controls: A T2* Mapping Study.

Rowing exposes the femoral head and acetabulum to high levels of repetitive abutment motion and axial loading that may put elite athletes at an increased risk for developing early hip osteoarthritis. Do elite rowers demonstrate characteristic hip cartilage lesions on T2 MRI sequences compared with asymptomatic individuals who do not row? This study included 20 asymptomatic rowers (mean age, 23 ± 3 years; nine females, 11 males) who had a minimum of 5 years of intensive (≥ 12 hours/week) training. The recruiting of the rowers took place from the central German federal rowing base, which has inherent intense training and selection requirements to declare these athletes as "elite rowers." We investigated one hip per study participant. MRI was performed on a 3-T scanner. The protocol included standard sequences, a double-echo steady-state sequence, and a multiecho data image combination sequence with inline T2 calculation (= the decay of transverse magnetization arising from molecular interactions [T2] and inhomogeneities in the magnetic field resulting from tissue susceptibility-induced field distortions and variations in the magnet itself), which detects changes in water content and the disruption of collagen structure. Although extrinsic and intrinsic influences on the T2 values including diurnal effects, MR technic-derived variations, and anatomic-related regional disparities need to be taken into account, low T2 values well below 20 ms indicate cartilage degeneration. Cartilage was morphologically analyzed in the anterior, anterosuperior, superoanterior, superior, superoposterior, posterosuperior, and posterior regions of the hip and graded as follows: Grade 0 = normal; Grade 1 = signal changes; Grade 2 = cartilage abrasion; Grade 3 = cartilage loss. Labrum was classified as follows: Grade 0 = normal; Grade 1 = partial tear; Grade 2 = full-thickness tear; Grade 3 = labrum degeneration. The T2 measurement was done through a region of interest analysis. For reliability assessment, morphologic evaluation and T2 measurement were performed by two observers while one observer repeated his analysis with a time interval > 2 weeks. Intra- and interobserver reliability was determined using κ analysis and intraclass correlation coefficients. Control T2 data were derived from a previous study on 15 hips in 15 asymptomatic volunteers of similar ages (seven males and eight females) who were not competitive rowers with similar MR hardware and imaging sequences. Compared with the control group of asymptomatic volunteers who were not competitive rowers, we noted a high level of labrum and cartilage degeneration in the cohort of elite rowers. In the group of elite rowers, cartilage degeneration was noted in all hips. Regarding the acetabular cartilage, 271 zones could be evaluated. Of those, 44% (120 of 271) were graded normal, 6% (15 of 271) revealed signal alteration, 45% (122 of 271) demonstrated cartilage abrasion, and 5% (14 of 271) were noted to have full-thickness cartilage loss. Morphologic cartilage degeneration in the femoral head was less frequent. T2 values were lower than the control hips in all zones except for the posterior central acetabular zone (global T2 acetabular: 20 ± 6 ms, range, 9-36 ms, 95% confidence interval [CI], 19-21 ms versus 25 ± 5 ms, range, 14-44 ms, 95% CI, 24-25 ms, p < 0.001; global T2 femoral: 23 ± 7 ms, range, 9-38 ms, 95% CI, 22-24 ms versus 27 ± 5 ms, range, 17-45 ms, 95% CI, 26-28 ms, p < 0.001). The difference in T2 between the two study groups was superior in the peripheral zone of the anterosuperior region (16 ± 3 ms; range, 10-22 ms, 95% CI, 15-18 ms versus 26 ms ± 5 ms, range, 18-38 ms, 95% CI, 24-29 ms, p < 0.001). We found signs of hip cartilage degeneration to a much greater degree in elite rowers than in asymptomatic controls. Although causation cannot be inferred, this is concerning, and future investigations including controlled longitudinal studies both on elite and nonelite athletes with sufficient cohort size are warranted to clarify our findings. Level III, therapeutic study.

Evaluation of osseous cervical foraminal stenosis in spinal radiculopathy using susceptibility-weighted magnetic resonance imaging.

The aim of this study was to evaluate the diagnostic performance of susceptibility-weighted magnetic resonance imaging (SW-MRI) for the evaluation of osseous foraminal stenosis (FS) of the cervical spine compared to conventional MRI-sequences, using computed tomography (CT) as a reference standard. Twenty-one patients with suspected radiculopathy of the cervical spine were prospectively included. CT and MRI data sets were available for all patients. As standard of reference, 280 neuroforamina of the cervical spine, including 58 foraminal stenosis, were identified on sagittal CT images. T1-, T2-, and SW-MRI of the cervical spine were performed. The presence of foraminal stenosis was assessed on sagittal views in all sequences. Sensitivity and specificity were calculated and differences in detection rate and severity scoring of foraminal stenosis between the different sequences were tested. CT was used as reference standard for all analysis. Fifty-six of 58 osseous foraminal stenosis could be correctly identified on SW-MR magnitude images. SW-MRI achieved a sensitivity of 96.6% and specificity of 99.5% for the identification of foraminal stenosis. In comparison, conventional T1-weighted MRI sequences achieved a sensitivity and specificity of 43.1% and 100% respectively. T2-weighted MRI sequences achieved a sensitivity and specificity of 65.5% and 99.1%, respectively. The overall detection rate was significantly (p < 0.05) higher on SW-MRI and there was no significant difference (p > 0.05) in severity scoring compared to CT. T1- and T2-weighted MRI underestimated the degree of foraminal stenosis. Intermodality and interobserver agreements were highest for SW-MRI. SW-MRI enables the reliable detection of osseous foraminal stenosis of the cervical spine in patients with spinal radiculopathy with a higher sensitivity compared to conventional T1- and T2-MRI sequences, with CT as a reference standard. • Susceptibility-weighted magnetic resonance imaging enables the reliable detection of osseous foraminal stenosis of the cervical spine with CT as a reference standard. • This could be relevant for younger patients in order to prevent unnecessary radiation exposure. • This may also facilitate a one-stop-shop approach and speed up diagnostic work-up.