Coronal T2-weighted Magnetic Resonance Imaging Research Articles

Fatty infiltration of extraocular muscles on magnetic resonance imaging

ABSTRACT Purpose To investigate the prevalence of fatty infiltration in normal orbits using magnetic resonance imaging (MRI) and its impact on muscle diameters. Methods A retrospective analysis was conducted on normal orbits in patients who underwent coronal T1-weighted MRI. Fatty infiltration was defined by a hyperintense signal within the extraocular muscle. Fatty infiltration area was calculated by dividing the cross-sectional fat area by the sum of the muscle and fat area in the coronal plane. Muscle diameters were measured perpendicular to the muscle belly at their maximum and the mean diameters of the infiltrated muscles were compared with the non-infiltrated muscles. Results Seventy-six orbits from 76 participants with a mean age of 55.7 ± 18 years were included. Fatty infiltration in at least one muscle was seen in 57 (75%) of participants. When infiltration was present, inferior rectus was most commonly involved (98%). The area of fatty infiltration ranged from 6% to 42%, with 5 participants in the <10% group, 36 in the 10–20% group, 20 in the 20–30% group, 9 in the 30–40% group and 2 in the 40–50% group. Participants with fatty infiltration were significantly older (mean 61 ± 15 years vs 40 ± 16 years, p < .01) and had a higher proportion of males (56% vs 16%, p < .01). No significant difference in muscle diameters were found between infiltrated and healthy muscles. Conclusion Fatty infiltration of the extraocular muscles is a reasonably common finding in normal orbits, most commonly involves the inferior rectus muscle and is associated with increasing age.

Machine Learning-Based Perivascular Space Volumetry in Alzheimer Disease.

Impaired perivascular clearance has been suggested as a contributing factor to the pathogenesis of Alzheimer disease (AD). However, it remains unresolved when the anatomy of the perivascular space (PVS) is altered during AD progression. Therefore, this study investigates the association between PVS volume and AD progression in cognitively unimpaired (CU) individuals, both with and without subjective cognitive decline (SCD), and in those clinically diagnosed with mild cognitive impairment (MCI) or mild AD. A convolutional neural network was trained using manually corrected, filter-based segmentations (n = 1000) to automatically segment the PVS in the centrum semiovale from interpolated, coronal T2-weighted magnetic resonance imaging scans (n = 894). These scans were sourced from the national German Center for Neurodegenerative Diseases Longitudinal Cognitive Impairment and Dementia Study. Convolutional neural network-based segmentations and those performed by a human rater were compared in terms of segmentation volume, identified PVS clusters, as well as Dice score. The comparison revealed good segmentation quality (Pearson correlation coefficient r = 0.70 with P < 0.0001 for PVS volume, detection rate in cluster analysis = 84.3%, and Dice score = 59.0%). Subsequent multivariate linear regression analysis, adjusted for participants' age, was performed to correlate PVS volume with clinical diagnoses, disease progression, cerebrospinal fluid biomarkers, lifestyle factors, and cognitive function. Cognitive function was assessed using the Mini-Mental State Examination, the Comprehensive Neuropsychological Test Battery, and the Cognitive Subscale of the 13-Item Alzheimer's Disease Assessment Scale. Multivariate analysis, adjusted for age, revealed that participants with AD and MCI, but not those with SCD, had significantly higher PVS volumes compared with CU participants without SCD ( P = 0.001 for each group). Furthermore, CU participants who developed incident MCI within 4.5 years after the baseline assessment showed significantly higher PVS volumes at baseline compared with those who did not progress to MCI ( P = 0.03). Cognitive function was negatively correlated with PVS volume across all participant groups ( P ≤ 0.005 for each). No significant correlation was found between PVS volume and any of the following parameters: cerebrospinal fluid biomarkers, sleep quality, body mass index, nicotine consumption, or alcohol abuse. The very early changes of PVS volume may suggest that alterations in PVS function are involved in the pathophysiology of AD. Overall, the volumetric assessment of centrum semiovale PVS represents a very early imaging biomarker for AD.

Diameters of the optic sheath and superior ophthalmic vein can expand and contract at positional changes: a magnetic resonance imaging study.

This study aimed to explore the diameters of the optic sheath (OSD) and superior ophthalmic vein (SOVD) in response to positional changes using magnetic resonance imaging (MRI). Fifty adult outpatients who presented to the hospital underwent thin-slice coronal T2-weighted MRI in the supine position followed by the prone position. The OS and SOV were well delineated in all the patients. The OSD in the anterior orbit was measured in the supine and prone positions on both sides. In addition, the SOVD in the anterior and posterior orbits was measured in the supine and prone positions on both sides. The OSD demonstrated an increase on both sides in 100% of the cases. The SOVD demonstrated an increase on both sides in 94% of the cases, whereas the remaining 6% demonstrated a decrease. The OSD measured at the anterior orbit and the SOVD at the anterior and posterior orbits significantly increased on both sides with positional changes from the supine to the prone position. OSD and SOVD may expand and contract in response to alterations in the intracranial pressure and venous flow patterns. MRI examination in the supine position combined with positional changes can help to better understand the OS and SOV as dynamic structures.

Evaluation of optic nerve by histogram analysis on MRI in patients with isolated optic neuritis

Objectives: We aimed to evaluate the Magnetic Resonance Imaging (MRI) histogram texture analyzis of the optic nerve by comparing patients of isolated optic neuritis with a healthy control group and to provide objective information without using contrast in the diagnosis of the disease. Methods: A total of 40 patients, including 20 patients with isolated optic neuritis (13 females, 7 males) and 20 healthy controls (11 females, 9 males), were included in the study. Non-contrast brain MR images of the patient and control groups were analyzed retrospectively. In the coronal T2-weighted MRI sequence of both groups, the Region of Interest (ROI) was placed in the extraocular anterior 1/3 of the optic nerve of both eyes. Numerical data were obtained using histogram analysis and the data were evaluated in the MATLAB program. The data were compared statistically. In addition, sensitivity and specificity were determined by Receiver Operating Characteristic (ROC) curve analysis. Results: As a result of histogram analysis, a significant difference was found between the mean values in the healthy and affected eye of the patients with isolated optic neuritis and the mean values of the control group (p &amp;lt; 0.05). A significant difference was found in standard deviation, minimum, maximum, median, variance values between both groups. ROC analysis was performed for mean value, AUC = 0.943 and when threshold value was selected as 354.258 Haunsfield Unit, two groups could be differentiated with 84.2% of sensitivity and 92.1% of specificity. We can say that patients with isolated optic neuritis also have histological effects on the clinically asymptomatic eye. Conclusions: Histogram analysis can be used in the diagnosis of the patients with isolated optic neuritis without the need to use contrast in their MRI. In addition, histological effect can be detected in the eye that does not show clinical symptoms with histogram analysis.

‘Haleem's Hen’: A Mnemonic for the Anatomy of Hindfoot Structures at the Level of Sustentaculum Tali on Coronal T1-Weighted Magnetic Resonance Images

Category: Hindfoot; Ankle Introduction/Purpose: Magnetic resonance anatomy of the hindfoot as seen at the level of the sustentaculum tali is intricate due to surrounding muscles, tendons, aponeurosis and ligaments. The objective of this work is to provide a mnemonic with illustrative figures to simplify this complex anatomical region on coronal T1-weighted magnetic resonance images (T1-MRIs). Methods: One hundred and twenty-four patients referred for foot and ankle complaints were scanned utilizing standard MRI imaging protocols for evaluation of the hindfoot. Only coronal T1-MRIs of the calcaneus at the level of sustentaculum tali of unremarkably reported patients were selected for the development of this mnemonic. T1- and T2-MRIs of an additional set of patients with hindfoot pathologies were selected to demonstrate how this mnemonic is adapted to identify specific pathologies. Results: Upon viewing the calcaneus with the adjacent anatomical structures on coronal T1-MRIs, the overall appearance resembles a ''Hen in the Nest with Four Eggs.'' The calcaneus represents the body of the hen, while the sustentaculum tali forms the head and neck. The posterior tibial tendon represents the crest of the hen, and the flexor digitorum longus and flexor hallucis longus tendons represent its beak and wattle, respectively. The peroneus brevis and peroneus longus tendons represent the tail, and the long plantar ligament represents the flexed legs of Haleem's hen. The plantar aponeurosis represents the hen's nest. Whereas the abductor hallucis, flexor digitorum brevis, abductor digiti minimi and quadratus plantae muscles are the four eggs. Pes planus, flexor digitorum brevis hemangioma, Baxter's neuropathy associated with chronic denervation abductor digiti minimi atrophy and peroneal tendonitis are some of the hindfoot pathologies that can be identified utilizing the mnemonic. Conclusion: The mnemonic, 'Haleem's Hen in the Nest with Four Eggs,' serves as a simplified phrase for orthopedic surgeons, radiologists and other physicians to easily recall the anatomy of the hindfoot when viewing it at the level of the sustentaculum tali on coronal T1-MRIs. In addition, this mnemonic could be particularly useful when utilized in medical education curriculum for residents, fellows, and medical students. Further research is required to validate this mnemonic as an educational tool in medical training and detail additional hindfoot pathologies that can be identified with it.

Fluid-Filled Dehiscences in the Anterior Cranial Fossa Floor: A Magnetic Resonance Imaging Study

To date, only limited information regarding the anterior cranial fossa floor (AFF) and the appearance of sites of dehiscence and potential channels has been available. We aimed to evaluate this region with thin section magnetic resonance imaging (MRI). A total of 65 patients underwent thin-sliced coronal T2-weighted MRI. The AFF was divided into 3 parts for analysis: the anterior, middle, and posterior. Dehiscences were identified in 84.6% of 65 patients with apparently transmitting channels. In 49.2% of the patients, the dehiscences were located in the anterior part, whereas they were located in the middle and posterior parts in 52.3% and 12.3%, respectively. The morphology and number of these dehiscences were highly variable. In 12.3%, channels in the dehiscences were distributed extradural. Statistically, dehiscences were more frequently identified on the left side in any part of the AFF. With thin-sliced, coronal T2-weighted MRI, dehiscences were frequently identified in the anterior two-thirds of the AFF. Further study is warranted to determine the role of AFF channels and dehiscences, including possibly for cerebrospinal fluid drainage.

"Haleem’s Hen"; A mnemonic for the anatomy of hindfoot structures at the level of sustentaculum tali on coronal T1-weighted magnetic resonance images

Magnetic resonance anatomy of the hindfoot as seen at the level of the sustentaculum tali is intricate due to surrounding muscles, tendons, aponeurosis and ligaments. The objective of this work is to provide a mnemonic with illustrative figures to simplify this complex anatomical region on coronal T1-weighted MR images (T1-MRIs).One hundred and twenty-four patients referred for foot and ankle complaints were scanned utilizing standard MRI imaging protocols for depiction of the hindfoot. Only coronal T1-MRIs of the calcaneus at the level of sustentaculum tali of unremarkably reported patients were selected for this work.Upon viewing the calcaneus with the adjacent anatomical structures on coronal T1-MRIs, the overall appearance resembles a “Hen in the Nest with Four Eggs’’. The calcaneus represents the body of the hen, while the sustentaculum tali forms the head and neck. The posterior tibial tendon represents the crest of the hen, and the flexor digitorum longus and flexor hallucis longus tendons represent its beak and wattle, respectively. The peroneus brevis and peroneus longus tendons represent the tail, and the long plantar ligament represents the flexed legs of Haleem’s hen. The plantar aponeurosis represents the hen’s nest. Whereas the abductor hallucis, flexor digitorum brevis, abductor digiti minimi and quadratus plantae muscles are the four eggs.The mnemonic, “Haleem’s Hen in the Nest with Four Eggs”, serves as a simplified phrase for radiologists and orthopedic surgeons to easily recall the anatomy of the hindfoot when viewing it at the level of the sustentaculum tali on coronal T1-MRIs.

Larger Acetabular Labrum Is Associated With Hip Dysplasia, Joint Incongruence, and Clinical Symptoms

To evaluate the association of labral length with acetabular morphology and clinical symptoms. Patients treated at our hip joint clinic between January 2015 and December 2018 were retrospectively enrolled in the study. Our sample included patients who received a diagnosis of one or more of the following: hip labral tear, femoroacetabular impingement (FAI), and developmental dysplasia of the hip. Patients with osteoarthritis and/or osteonecrosis were excluded. Bilateral labral length was measured as the distance from the acetabular rim to the edge of the labrum at the level of the central coronal T1-weighted magnetic resonance imaging scan cross-referenced to the axial plane (3- to 9-o'clock position). The lateral center-edge angle (LCEA) and acetabular roof obliquity (ARO) were evaluated with plain radiographs. An LCEA of 25° or less was defined as developmental dysplasia of the hip, whereas a positive crossover sign in the presence of an LCEA of 30° or greater, an LCEA greater than 40°, or acetabular inclination lower 0° was defined as pincer FAI. An alpha angle greater than 50° or head-neck offset lower 8 mm was considered cam FAI. The severity of hip symptoms was evaluated bilaterally using the Japanese Orthopaedic Association pain scale, on which hips scoring full points (i.e., a perfect score) were defined as asymptomatic whereas hips with all other scores were considered symptomatic. We used simple linear regression to examine the correlations of labral length with the LCEA and ARO. Labral length was also compared according to patient hip symptom status using the Mann-Whitney U test. The study included 102 patients (14 with bilateral symptoms and 88 with unilateral symptoms). Labral length was strongly correlated with the LCEA (r= -0.612, P < .001) and ARO (r= 0.635, P < .001). Additionally, patients with symptomatic hips had significantly larger labra (9.5 ± 3.0 mm) than those with asymptomatic hips (7.9 ± 2.1 mm, P= .004). Acetabular labral length is significantly greater in dysplastic, irregularly congruent, symptomatic hips. Level Ⅳ, retrospective cross-sectional study.

Quantitative evaluation of age-related changes to pelvic floor muscles in magnetic resonance images from 369 patients.

This study aimed to establish and validate a quantitative evaluation method for pelvic floor muscles using magnetic resonance images (MRI) and to examine the morphological change of pelvic floor muscles with aging. Data from 369 consecutive patients (163 men, 206 women; median age 58 years; range 17-92 years) who underwent coronal T2-weighted pelvic MRI at Osaka General Hospital between January 2016 and December 2016 were retrospectively examined. MRI of the levator ani muscle was evaluated. The MRI image blinded the patient information and was evaluated by a radiology specialist with 22 years of experience. In coronal T2-weighted MRI of the pelvis, the levator ani muscle was evaluated using the slice; it showed the most upward and downward convexity. We measured the thickness of the levator ani muscle, and the distance at the most convex part from a straight line connecting the origin and insertion of the levator ani muscle on both the left and right sides. Upward and downward convexity was recorded in positive and negative values, respectively. The levator ani muscle was able to be evaluated quantitatively in all cases. Both men and women showed thinning (men: mean 3.316 mm, r = -0.388, P < 0.0001; women: mean 3.947 mm, r = -0.359, P < 0.0001) and concavity (men: mean 1.412 mm, r = -0.362, P < 0.0001; women: mean 4.979 mm, r = -0.630, P < 0.0001) of the levator ani muscle with aging. A quantitative evaluation method for pelvic floor muscles using MRI was established. Aging was associated with morphological changes in the pelvic floor muscles in both men and women. Geriatr Gerontol Int 2019; 19: 834-837.

Value of Anterior Band of the Inferior Glenohumeral Ligament Area as a Morphological Parameter of Adhesive Capsulitis

Objective Thickened inferior glenohumeral ligament (IGHL) is considered as one of the major morphological parameters of adhesive capsulitis (AC). Previous studies reported that the anterior band of inferior glenohumeral ligament thickness (aIGHLT) is correlated with shoulder capsular contracture, luxatio erecta humeri, and AC. However, the thickness varies from the measured angle. To reduce this measurement error, we devised a new morphological parameter, called the anterior band of inferior glenohumeral ligament area (aIGHLA). Methods The aIGHL samples were collected from 54 patients with AC and from 50 control subjects who underwent shoulder magnetic resonance imaging (MRI) without any evidence of AC. Coronal T2-weighted MRI images were obtained at the shoulder level from each patient. We measured the aIGHLA and aIGHLT at the maximal view of the IGHL in the coronal plane using our picture archiving and communication system. The aIGHLA was measured at the whole cross-sectional area of the IGHL in the most hypertrophied segment of the coronal MR images. The aIGHLT was measured at the thickest point of the IGHL. Results The average aIGHLA was 55.58 ± 14.16 mm2 in the control group and 83.71 ± 28.45 mm2 in the AC group. The average aIGHLT was 3.47 ± 0.99 mm in the control group and 4.52 ± 1.02 mm in the AC group. AC patients showed significantly greater aIGHLA (p < 0.001) and aIGHLT (p < 0.001) than control subjects. Receiver operating characteristic (ROC) curve analysis showed that the optimal cut-off score of the aIGHLA was 63.37 mm2, with 79.6% sensitivity, 80.0% specificity, and AUC of 0.84 (95% CI, 0.76–0.92). The optimal cut-off point of the IGHLT was 3.81 mm, with 74.1% sensitivity, 74.0% specificity, and AUC of 0.77 (95% CI, 0.68–0.86). Conclusions Although the aIGHLA and aIGHLT were both significantly associated with AC, the aIGHLA was a more sensitive diagnostic parameter.

Tumor to Cerebellar Peduncle T2-Weighted Imaging Intensity Ratio Fails to Predict Pituitary Adenoma Consistency.

Object The consistency of pituitary macroadenomas affects the complexity of surgical resection. On T2-weighted (T2W) imaging, the intensity ratio of the tumor to the cerebellar peduncle (tumor to cerebellar peduncle T2-weighted imaging intensity [TCTI] ratio) correlates with meningioma consistency. We aimed to determine the correlation of this radiographic finding with pituitary macroadenoma consistency and to determine whether it can be used for preoperative planning. Methods We performed a retrospective evaluation of 196 patients with macroadenomas who underwent endoscopic transsphenoidal resection from January 2012 to June 2017. Macroadenoma consistency was determined by one senior neurosurgeon at the time of surgery. Axial and coronal T2W magnetic resonance imaging images were evaluated retrospectively, and adenoma size, Knosp grade, suprasellar extension and TCTI were calculated. Results The mean TCTI ratio was 1.70 (95% confidence interval [CI]: 1.65-1.75). Intraoperatively, 140 (71.4%) adenomas were classified as soft and 48 (24.5%) as fibrous. Gross total resection was achieved in 66.7% of fibrous adenomas and in 86.4% of soft adenomas ( p = 0.007). The mean ratio was 1.68 (95% CI: 1.62-1.74) for soft tumors and 1.76 (95%CI: 1.67-1.84) for fibrous tumors. There was no difference in the mean TCTI ratio between groups. Lactotroph and somatotroph adenomas had a lower mean TCTI ratio compared with other functioning and nonfunctioning adenomas with a mean TCTI of 1.52 compared with 1.77. Conclusions In this retrospective cohort study, we found that the TCTI ratio does not correlate with tumor consistency. We also noted that the TCTI ratio is increased in prolactin and growth hormone-secreting adenomas.

Distinguishing Depressive Pseudodementia from Alzheimer Disease: A Comparative Study of Hippocampal Volumetry and Cognitive Tests

Background and Aim: Depressive pseudodementia (DPD) is a condition which may develop secondary to depression. The aim of this study was to contribute to the differential diagnosis between Alzheimer disease (AD) and DPD by comparing the neurocognitive tests and hippocampal volume. Materials and Methods: Patients who met criteria of AD/DPD were enrolled in the study. All patients were assessed using the Wechsler Memory Scale (WMS), clock-drawing test, Stroop test, Benton Facial Recognition Test (BFRT), Boston Naming Test, Mini-Mental State Examination (MMSE), and Geriatric Depression Scale (GDS). Hippocampal volume was measured by importing the coronal T1-weighted magnetic resonance images to the Vitrea 2 workstation. Results: A significant difference was found between the AD and DPD groups on the WMS test, clock-drawing test, Stroop test, Boston Naming Test, MMSE, GDS, and left hippocampal volume. A significant correlation between BFRT and bilateral hippocampal volumes was found in the AD group. No correlation was found among parameters in DPD patients. Conclusions: Our results suggest that evaluation of facial recognition and left hippocampal volume may provide more reliable evidence for distinguishing DPD from AD. Further investigations combined with functional imaging techniques including more patients are needed.

A ganglion cyst of the temporomandibular joint.

A ganglion cyst of the temporomandibular joint.

Analysis of Potential Determinants of a Reduced Intercarotid Distance in Patients Undergoing Endoscopic Transsphenoidal Surgery

Objectives: (1) Evaluate the anatomic variability of the distance between the internal carotid arteries (ICA) at the paraclival, intracavernous, and paraclinoid segments in normal variants and in patients with sellar or parasellar lesions. (2) Identify clinicopathologic factors associated with a reduced intercarotid distance (ICD) and identify subgroups at higher risk for ICA injury during endoscopic skull base surgery. Methods: A retrospective case-control study was performed at an academic tertiary care center. The smallest distance between the ICAs at the paraclival, intracavernous. and paraclinoid segments on coronal T2-weighted magnetic resonance imaging was measured in patients with sellar or parasellar tumors and in nontumor controls. Factors such as demographic profiles, cephalometric measurements, tumor dimensions, and sphenoid configuration were assessed as potential predictors of the ICD. Results: In total, 154 cases and 34 controls were analyzed. Patients with growth hormone (GH) secreting adenomas had a markedly reduced ICD at the paraclival segment as compared to controls (1.59 cm and 1.77 cm, respectively; P = .02; 95% confidence interval [CI] [0.03-0.32]). The paraclinoid ICD was reduced in patients with a planum sphenoidale meningioma (1.09 cm and 1.33 cm, respectively; P = .04; 95% CI [0.01-0.45]). The transverse dimension of pituitary adenomas was linearly correlated to the ICD ( P &lt; .001). No narrowing of the ICD was associated with sphenoid configuration or cephalometric measurements. Conclusions: Patients with a GH secreting adenoma or planum sphenoidale meningioma had a reduced ICD. Identifying these populations can help surgeons recognize constraints imposed by a reduced ICD to endoscopic access of the skull base and avoid inadvertent ICA injury.

Sacroiliitis in Behçet Syndrome

33-year-old woman presented with inflammatory low back pain for 1 year, recurrent painful oral aphthous, and genital ulcers for 6 months with remaining tissue scarring, extensive pseudofolliculitis on the upper and lower limbs, fever, weight loss, and bilateral anterior uveitis. Seven months later, the pa- tient presented bilateral panuveitis. She had no abdominal pain, diarrhea, anemia, or other symptoms that suggested inflam- matory intestinal disease. Human leukocyte antigen B27 and antinuclear antibody tests were negative. The patient was diag- nosed with Behcet disease according to the International Study Group criteria. 1 Most symptoms were resolved with corticoste- roid eye drops, oral corticosteroids, colchicine, and methotrexate, but the low back pain alleviated only with nonsteroidal anti- inflammatory drugs. After 4 years of follow-up, there is no back pain or skin or eye disease on this treatment. Radiography has not been performed again. Radiography of the sacroiliac joints did not show abnor- malities. After gadolinium administration, coronal T1-weighted magnetic resonance imaging of the sacroiliac joints demonstrated left joint space enhancement indicative of synovitis (Figure, arrows). Edema of the sacral surface of the adjacent sacroiliac joint (Figure, open arrow) and sclerosis of the iliac surface (Figure, asterisk) were also observed, indicating sacroiliitis. Behcet disease, a systemic vasculitis of unknown etiology, is characterized by relapsing episodes of oral and genital ulcers, skin lesions, and ophthalmological disease. It can also affect the vascular, gastrointestinal, and neurological systems. 1Y4 Rheu- matic manifestations have been described in 45% of patients with Behcet syndrome, ranking second after skin and mucosal mani- festations. Inflammatory arthralgia is the most common mani- festation (81% of cases), and sacroiliitis is uncommon (7.5% of cases). 1Y5 Some authors have described a high prevalence of sacroiliitis in patients with Behcet disease, but others have found no association between these conditions. 5 The main reason for these differing results could be a high degree of interobserver variation in interpreting radiographs of the sacroiliac joints. In our case, sacroiliitis was demonstrated by magnetic resonance imaging, the most sensitive method for the detection and early diagnosis of this condition. Joint involvement can be an early manifestation of Behcet syndrome, potentially causing significant

Renal Cell Carcinoma: Role of MR Imaging in the Assessment of Muscular Venous Branch Invasion

To assess diagnostic performance and interreader agreement of tumor-to-sinus distance measurements and visual assessment of renal sinus fat invasion at T2-weighted magnetic resonance (MR) imaging as predictors of muscular venous branch invasion (MVBI) in patients with renal cell carcinoma (RCC). The institutional review board approved this retrospective study and waived the informed consent requirement. The study was HIPAA compliant. A total of 186 consecutive patients underwent preoperative 1.5-T MR imaging; 188 RCCs were identified. Blinded to histopathologic information, two readers independently measured the tumor-to-sinus distance and assessed renal sinus fat invasion on transverse and coronal T2-weighted MR images. Interreader agreement (intraclass correlation coefficient, Cohen κ) and performance characteristics of imaging tests were calculated. Histopathologic findings served as the standard of reference. Histopathologic findings indicated MVBI in 35% (66 of 188) of tumors. At imaging, all tumors with MVBI had a tumor-to-sinus distance of 0 mm. All tumors with renal sinus fat invasion at imaging had MVBI. Sensitivity and specificity for the detection of renal sinus fat invasion were 100% (95% confidence interval [CI]: 92%, 100%) and 94% (95% CI: 89%, 98%). In the absence of renal sinus fat invasion at imaging, a tumor-to-sinus distance of 0 mm was associated with MVBI in 21% (18 of 86) of cases. Interreader agreement for quantitative (intraclass correlation coefficient = 0.92; 95% CI: 0.89, 0.94) and qualitative (κ = 0.89; 95% CI: 0.81, 0.96) assessments was excellent. Tumor-to-sinus distance measurements and the assessment of renal sinus fat invasion at T2-weighted MR imaging can be used reliably to rule out MVBI in patients with RCC.

Identification of the human medial temporal lobe regions on magnetic resonance images

The medial temporal lobe (MTL) plays a key role in learning, memory, spatial navigation, emotion, and social behavior. The improvement of noninvasive neuroimaging techniques, especially magnetic resonance imaging, has increased the knowledge about this region and its involvement in cognitive functions and behavior in healthy subjects and in patients with various neuropsychiatric and neurodegenerative disorders. However, cytoarchitectonic boundaries are not visible on magnetic resonance images (MRI), which makes it difficult to identify precisely the different parts of the MTL (hippocampus, amygdala, temporopolar, perirhinal, entorhinal, and posterior parahippocampal cortices) with imaging techniques, and thus to determine their involvement in normal and pathological functions. Our aim in this study was to define neuroanatomical landmarks visible on MRI, which can facilitate the examination of this region. We examined the boundaries of the MTL regions in 50 post-mortem brains. In eight cases, we also obtained post-mortem MRI on which the MTL boundaries were compared with histological examination before applying them to 26 in vivo MRI of healthy adults. We then defined the most relevant neuroanatomical landmarks that set the rostro-caudal limits of the MTL structures, and we describe a protocol to identify each of these structures on coronal T1-weighted MRI. This will help the structural and functional imaging investigations of the MTL in various neuropsychiatric and neurodegenerative disorders affecting this region.

The Risk Factors of Symptomatic Communicating Hydrocephalus After Stereotactic Radiosurgery for Unilateral Vestibular Schwannoma: The Implication of Brain Atrophy

To identify the effect of brain atrophy on the development of symptomatic communicating hydrocephalus (SCHCP) after stereotactic radiosurgery (SRS) for sporadic unilateral vestibular schwannomas (VS). A total of 444 patients with VS were treated with SRS as a primary treatment. One hundred eighty-one patients (40.8%) were male, and the mean age of the patients was 53±13 years (range, 11-81 years). The mean follow-up duration was 56.8±35.8 months (range, 12-160 months). The mean tumor volume was 2.78±3.33 cm3 (range, 0.03-23.30 cm3). The cross-sectional area of the lateral ventricles (CALV), defined as the combined area of the lateral ventricles at the level of the mammillary body, was measured on coronal T1-weighted magnetic resonance images as an indicator of brain atrophy. At distant follow-up, a total of 25 (5.6%) patients had SCHCP. The median time to symptom development was 7 months (range, 1-48 months). The mean CALV was 334.0±194.0 mm2 (range, 44.70-1170 mm2). The intraclass correlation coefficient was 0.988 (95% confidence interval [CI], 0.976-0.994; p<0.001). In multivariate analysis, the CALV had a significant relationship with the development of SCHCP (p<0.001; odds ration [OR]=1.005; 95% CI, 1.002-1.007). Tumor volume and female sex also had a significant association (p<0.001; OR=1.246; 95% CI, 1.103-1.409; p<0.009; OR=7.256; 95% CI, 1.656-31.797, respectively). However, age failed to show any relationship with the development of SCHCP (p=0.364). Brain atrophy may be related to de novo SCHCP after SRS, especially in female patients with a large VS. Follow-up surveillance should be individualized, considering the risk factors involved for each patient, for prompt diagnosis of SCHCP.

Paget's Disease of the Calcaneus Causing Right Foot Pain

"Paget's Disease of the Calcaneus Causing Right Foot Pain." Baylor University Medical Center Proceedings, 25(2), pp. 161–162

Radiology Quiz Case 3

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