Fat Infiltration In Patients Research Articles

Study on the consistency between CT hounsfield units and MRI evaluation of preoperative cervical paraspinal muscular fat infiltration in patients undergoing ACDF

ObjectiveTo explore the feasibility of applying CT Hounsfield Units (HUs) for the assessment of preoperative paraspinal muscle fat infiltration (FI) in different segments in patients who underwent anterior cervical discectomy and fusion (ACDF). To compare the consistency of preoperative paraspinal muscle FI evaluations using MRI and those via CT HUs in patients who underwent ACDF surgery.MethodsNinety-five patients (45 males and 50 females, aged 37‒71 years) who received CT and MRI examinations and underwent ACDF surgery were retrospectively analyzed. In the axial T2-weighted MR images at the median level of the C3/4, C4/5, and C5/6 segments, regions of interests (ROIs) were delineated along the boundaries of the cervical multifidus (MF) and semispinalis cervicis (Scer) muscles. Using the threshold tool in ImageJ software, areas of fat tissue and intermuscular septa within the ROI were quantified. The effective cross-sectional area (ECSA) for each side was obtained by subtracting the areas of fat tissue and intermuscular septa from the total ROI area. The ratio of the fat tissue area to the CSA was then calculated to determine the initial FI value. The depth of subcutaneous fat from the midline spinous process to the epidermis at the median plane of the C4/5 intervertebral disc was measured. The initial FI values were then divided by the depth of fat to determine the post-correction FI value. Using the Picture Archiving and Communication System (PACS), at identical segments and planes, ROIs were delineated using the same method as in MRI under a standard soft tissue window (width of 500 HU, level of 60 HU). The CT HU values were measured within these defined areas. The CT HU values from both sides are summed to obtain the total HU value for the segment. According to whether the measurement results of two sets of data follow a normal distribution, Pearson’s test or Sperman’s test was used to analyze the correlation.ResultsOn MRI, a statistically significant difference was observed in the post-correction FI only at the C3/4 segment compared to the other two segments (P < 0.05). No significant difference in the post-correction FI between the C4/5 and C5/6 segments was noted (P > 0.05). The CT HU results showed a substantial discrepancy between C3/4 and C4/5 segments and between C3/4 and C5/6 segments (P < 0.05), whereas no statistically significant difference was found in the CT HU value between the C4/5 and C5/6 segments (P > 0.05). The consistency analysis revealed a relatively strong correlation between the post-correction FI and CT HU values of the C3/4 and C4/5 segments. Furthermore, a strong correlation was detected in the variations in the measurement outcomes at the C5/6 segment.ConclusionPatients requiring surgical treatment for the cervical spine exhibit varying degrees of FI in paraspinal muscles across different locations and segments. Evaluating the degree of FI in the paraspinal muscles of the cervical spine through CT HU values is feasible. There is considerable consistency between the post-correction FI assessed under MRI and the measurements of CT HU values in evaluating the FI of paraspinal muscles in the cervical spine.

Association of myosteatosis with short-term outcomes in patients with acute-on-chronic liver failure

Sarcopenia (low muscle mass, i.e., quantity) is associated with poor clinical outcomes in patients with acute-on-chronic liver failure (ACLF). In this study, we aimed to illustrate the clinical prognostic value of myosteatosis (muscle fat infiltration) for short-term mortality in patients with ACLF. We retrospectively enrolled consecutive patients with ACLF between January 2019 and January 2022. Computed tomography-based body composition analysis was performed at the third lumbar vertebral level to determine skeletal muscle radiation attenuation. Fine and Gray’s competing risk regression model, with liver transplantation as a competing risk, was used to assess the factors associated with 90-day mortality. A total of 431 patients with ACLF were included. Myosteatosis and sarcopenia were observed in 261 (60.6%) and 87 (20.2%) patients, respectively. Competitive risk regression showed that age (HR 1.021, 95% CI 1.000–1.043, P = 0.042), APASL ACLF Research Consortium (AARC) score (HR 1.498, 95% CI 1.312–1.710, P < 0.001), and sarcopenia (HR 1.802, 95% CI 1.062–3.060, P = 0.029) were independently associated with increased 90-day mortality. Subgroup analysis of male patients with HBV-ACLF revealed that myosteatosis (HR 2.119, 95% CI 1.101–4.078, P = 0.025) was promising prognostic factors for 90-day mortality after being adjusted for ascites, acute kidney injury, AARC score, and sarcopenia. Myosteatosis is predictive of short-term outcomes in male patients with HBV-ACLF. Our results emphasise the importance of focusing on muscle fat infiltration in patients with HBV-ACLF. Further studies are warranted to investigate the underlying mechanisms and potential therapies for myosteatosis.

Quantitative study of 3T MRI qDixon-WIP applied in pancreatic fat infiltration in patients with type 2 diabetes mellitus.

To investigate the application value of 3T MRI qDixon-WIP technique in the quantitative measurement of pancreatic fat content in patients with type 2 diabetes mellitus (T2DM). The 3T MRI qDixon-WIP sequence was used to scan the livers and the pancreas of 47 T2DM patients (experimental group) and 48 healthy volunteers (control group). Pancreatic fat fraction (PFF), hepatic fat fraction (HFF), Body mass index (BMI) ratio of pancreatic volume to body surface area (PVI) were measured. Total cholesterol (TC), subcutaneous fat area (SA), triglyceride (TG), abdominal visceral fat area (VA), high density lipoprotein (HDL-c), fasting blood glucose (FPC) and low-density lipoprotein (LDL-c) were collected. The relationship between the experimental group and the control group and between PFF and other indicators was compared. The differences of PFF between the control group and different disease course subgroups were also explored. There was no significant difference in BMI between the experimental group and the control group (P=0.231). PVI, SA, VA, PFF and HFF had statistical differences (P<0.05). In the experimental group, PFF was highly positively correlated with HFF (r=0.964, P<0.001), it was moderately positively correlated with TG and abdominal fat area (r=0.676, 0.591, P<0.001), and it was weakly positively correlated with subcutaneous fat area (r=0.321, P=0.033). And it had no correlation with FPC, PVI, HDL-c, TC and LDL-c (P>0.05). There were statistical differences in PFF between the control group and the patients with different course of T2DM (P<0.05). There was no significant difference in PFF between T2DM patients with a disease course ≤1 year and those with a disease course <5 years (P>0.05). There were significant differences in PFF between the groups with a disease course of 1-5 years and those with a disease course of more than 5 years (P<0.001). PVI of T2DM patients is lower than normal, but SA, VA, PFF, HFF are higher than normal. The degree of pancreatic fat accumulation in T2DM patients with long disease course was higher than that in patients with short disease course. The qDixon-WIP sequence can provide an important reference for clinical quantitative evaluation of fat content in T2DM patients.

Associations of Lumber Disc Degeneration With Paraspinal Muscles Myosteatosis in Discogenic Low Back Pain.

Accompanied with intervertebral disc (IVD) degeneration, increasing fat infiltration of paraspinal muscles may be related to discogenic low back pain (DLBP), but their relationship is still unclear and the classical animal models are not completely applicable. The purpose of this study was to assess the paraspinal muscle fat infiltration in patients with DLBP by quantitative MRI, and to develop a novel DLBP rat model to explore the potential relationship between DLBP paraspinal muscle fat infiltration and TNF-α levels. We measured the proton density fat fraction (PDFF) of the multifidus and erector spinae muscles of 70 DLBP patients and 36 healthy volunteers by using quantitative MRI IDEAL-IQ. In addition, we developed a DLBP experimental rat model by puncturing the L4/5 and L5/6 IVDs under the guidance of X-ray fluoroscopy. Then various behavioral experiments, MRI and pathological examination of IVDs were used to evaluate the performance of the DLBP animal model. The gait analysis, hot plate test, acetone test, grasping test and tail suspension test were used to evaluate the pain and muscle dysfunction in rats. Through quantitative MRI and histological examination, the degeneration of IVDs and fat infiltration in the muscles were observed in vivo and ex vivo. Enzyme linked immunosorbent assay detects the level of TNF-α in rat IVDs and paraspinal muscles. In the human study, compared with healthy volunteers, the PDFF of multifidus and erector muscles of DLBP patients increased significantly at L4/5 and L5/S1 levels (p<0.05). In the rat experiment, compared with control group and sham group, DLBP group had reduced gait score, shortened response time to cold and heat stimuli, prolonged bending time, and shortened struggling time. Rat lumbar MRI T2WI showed that the signal intensity of L4/5 and L5/6 IVDs were progressively decreased. Histological examination revealed that IVDs had increased collagen fibers, reduced nucleus pulposus, thickened annulus fibrosus, and distorted shape. The PDFF of multifidus muscle at L4/5 and L5/6 level in the DLBP group were more than that in other groups (p<0.05), and HE staining and oil red O staining of paraspinal muscles showed that the muscle bundle space of the DLBP group muscles increased, and the muscle tissues Increased lipid droplets. Finally, the expression of TNF-α in IVDs and paraspinal muscles in the DLBP group were significantly higher than that in the control group (p<0.05). It is reliable and feasible to establish a DLBP rat model by puncturing the lumbar IVDs under the guidance of X-ray fluoroscopy. The degeneration of lumbar IVDs with DLBP leads to the occurrence of fat infiltration of paraspinal muscles, which is related to the expression of TNF-α.

Risk Factor Analysis for Fat Infiltration in the Lumbar Paraspinal Muscles in Patients With Lumbar Degenerative Diseases.

IntroductionThis study aimed to investigate factors related to fat infiltration in patients with lumbar degenerative diseases (lumbar disc herniation and/or spinal stenosis), examining a wide range of potential risk variables.Materials and methodsWe studied consecutive adult patients who underwent posterior lumbar spinal surgery for degenerative diseases at our hospital between July 2013 and June 2017. Preoperative magnetic resonance imaging was used to evaluate the presence or absence of fat infiltration at the level of the L4-5 lumbar paraspinal muscles using Kjaer’s evaluation method. Patients without fat infiltration (0%–10%) were rated as grade 0, grade 1 for moderate fat infiltration (10%–50%), and grade 2 for severe fat infiltration (>50%). Patients were then divided into two groups: Group A (without fat infiltration, grade 0) and Group B (with fat infiltration, grade 1 or 2). Detailed patient clinical data were collected and analyzed.ResultsA total of 205 consecutive patients were enrolled; 54 (26.3%) patients were assigned to Group A and 151 (73.7%) to Group B. Logistic regression analysis revealed two independent risk factors for fat infiltration of the lumbar paraspinal muscles: female sex and older age (P < .001).DiscussionFat infiltration of the lumbar paraspinal muscles is reported to be associated with the development of pain and dysfunction of the lumbar region and postoperative complications of spinal instrumented fusion surgery. To the best of our knowledge, no previous studies have identified female sex and older age as independent risk factors for fat infiltration in the lumbar paraspinal muscles using multivariate analysis.ConclusionsFemale sex and older age were independent risk factors for fat infiltration in the lumbar paraspinal muscles. The results of the current study may provide useful information for the study of preventive measures for fat infiltration.

Relationship between fatty infiltration of paraspinal muscles and clinical outcome after lumbar discectomy

IntroductionCross sectional area (CSA) and fat infiltration (FI) are important parameters to assess paravertebral muscle atrophy. However, the relationship of muscular fat infiltration in patients with symptomatic lumbar disc herniation undergoing surgery remains unclear. Research questionDoes lumbar paravertebral muscle atrophy have prognostic value regarding the clinical outcome for patients with symptomatic lumbar disc herniation undergoing surgery? MethodsPatients over 18 years of age with lumbar disc herniation and radicular pain who underwent single-level discectomy were included. Multifidus, erector spinae and psoas cross-sectional area (CSA) and fatty infiltration (FI) were measured by ImageJ software at the levels of L3-L4, L4-L5 and L5-S1 from T2-weighted Magnetic Resonance axial images. Clinical status was assessed preoperatively and one-year after surgery with patient reported outcome measurements (PROMS), that included Numeric Rating Score for back and leg pain, Core Outcome Measurement Index (COMI), Oswestry Disability Index and EuroQoL-5D. Univariate and multiple linear regressions were performed. ResultsErector spinae FI was the only muscle-related factor that correlated to postoperative PROMS. Postoperative COMI was higher in patients with FI>30% (median: 4.4, IQR: 3.2) and lower when FI<15% (median: 1.2, IQR: 1.6) (Kruskal-Wallis, p ​< ​0.001). Male gender was associated with better outcome as well as erector spinae FI<15%, while FI >30% was related to worse postoperative status. ConclusionsIn the current study, increased fat infiltration of erector spinae muscles correlated to less favorable clinical outcomes following lumbar discectomies.

Quantification of penile fat infiltration using the mDIXON Quant sequence: a pilot study on the correlation with penis hardness and erectile dysfunction.

The purpose of this study was to determine fat/water signal ratios using the mDIXON Quant sequence, quantitatively assess fat infiltration in the penis, and explore its possible relationship with penile hardness and erectile dysfunction. Routine pelvic MRI with the mDIXON Quant sequence was performed in 62 subjects, including 22 people in the normal group, 20 people in the normal erectile hardness group, and 20 people in the erectile dysfunction (ED) group. The fat/water signal ratio in the penis was measured using the mDIXON Quant sequence. Shear wave elastography was used to evaluate the hardness of the corpus cavernosa of the penis. The fat/water signal ratio of the corpus spongiosum was significantly lower than that of the corpus cavernosa in the normal group (p = 0.03) and ED group (p < 0.01). There was no significant difference in the fat/water signal ratios between the normal group and the normal erectile hardness group. Fat infiltration was significantly lower, and erectile hardness was significantly higher in the normal erectile hardness group than in the ED group, and the fat infiltration in the left and right corpus cavernosa was inversely proportional to the erectile hardness of the penis. This study suggests that mDIXON Quant can be used as a non-invasive, quantitative, and objective method for evaluating penile fat infiltration. This method could help diagnose penile fat infiltration in patients with erectile dysfunction and varying body mass indexes. Our results could also allow for a more accurate diagnosis and monitoring of erectile hardness function by quantitatively measuring penile fat infiltration. (1) The proton density fat fraction technology is a new tool for the objective, quantitative and non-invasive evaluation of penile fat infiltration. (2) The quantitative measurement of fat infiltration in the corpora cavernosa might help diagnose and monitor penile erection hardness and its function more accurately.

Regional variation of thigh muscle fat infiltration in patients with neuromuscular diseases compared to healthy controls.

Chemical shift encoding-based water-fat magnetic resonance imaging (CSE-MRI) measures a quantitative biomarker: the proton density fat fraction (PDFF). The aim was to assess regional and proximo-distal PDFF variations at the thigh in patients with myotonic dystrophy type 2 (DM2), limb-girdle muscular dystrophy type 2A (LGMD2A), and late-onset Pompe disease (LOPD) as compared to healthy controls. Seven patients (n=2 DM2, n=2 LGMD2A, n=3 LOPD) and 20 controls were recruited. A 3D-spoiled gradient echo sequence was used to scan the thigh musculature. Muscles were manually segmented to generate mean muscle PDFF. In all three disease entities, there was an increase in muscle fat replacement compared to healthy controls. However, within each disease group, there were patients with a shorter time since symptom onset that only showed mild PDFF elevation (range, 10% to 20%) compared to controls (P≤0.05), whereas patients with a longer period since symptom onset showed a more severe grade of fat replacement with a range of 50% to 70% (P<0.01). Increased PDFF of around 5% was observed for vastus medialis, semimembranosus and gracilis muscles in advanced compared to early DM2. LGMD2A_1 showed an early disease stage with predominantly mild PDFF elevations over all muscles and levels (10.9%±7.1%) compared to controls. The quadriceps, gracilis and biceps femoris muscles showed the highest difference between LGMD2A_1 with 5 years since symptom onset (average PDFF 11.1%±6.9%) compared to LGMD2A_2 with 32 years since symptom onset (average PDFF 66.3%±6.3%). For LOPD patients, overall PDFF elevations were observed in all major hip flexors and extensors (range, 25.8% to 30.8%) compared to controls (range, 1.7% to 2.3%, P<0.05). Proximal-to-distal PDFF highly varied within and between diseases and within controls. The intra-reader reliability was high (reproducibility coefficient ≤2.19%). By quantitatively measuring muscle fat infiltration at the thigh, we identified candidate muscles for disease monitoring due to their gradual PDFF elevation with longer disease duration. Regional variation between proximal, central, and distal muscle PDFF was high and is important to consider when performing longitudinal MRI follow-ups in the clinical setting or in longitudinal studies.

Clinical Y-view versus 3-dimensional assessments of intramuscular fat in patients with full-thickness rotator cuff tears

Rationale and Objectives.Recent evidence suggests an inhomogeneous distribution of intramuscular rotator cuff fat infiltration (FI) in a small sample of individuals with rotator cuff tears, yet clinically just a few slices at the scapular Y-view are used to evaluate FI in patients with rotator cuff tears. The purpose of this study was to determine if assessment of FI using the scapular Y-view is representative of the entire muscle in patients with full-thickness rotator cuff tears, and whether this varies by tear size. Materials and methodsPatients (N = 25) diagnosed with full-thickness rotator cuff tear and confirmed with magnetic resonance imaging (MRI) were included. Fat-water sequences were used to objectively quantify mean FI (%) in the entire 3D muscle and the mean from 3 slices at the Y-view. Mixed-model 2 × 2 ANOVAs were used to assess for differences between methods, and if results vary by tear-size. ResultsThere were no statistically significant differences between mean amount of FI of the entire 3D muscle and mean Y-view in the supraspinatus or infraspinatus muscles (p > 0.05). Additionally, this did not differ across tear size groups (p > 0.05). ConclusionResults of this study suggest FI assessed in the Y-view is not different (mean difference < 1.0%) from FI of the entire 3D muscle in patients with full-thickness rotator cuff tears. Therefore, the clinical utility of evaluating rotator cuff intramuscular fat infiltration with the Y-view is further supported in patients with full-thickness rotator cuff tears across tear sizes.

Morphologic Characteristics of the Deep Cervical Paraspinal Muscles in Patients with Single-Level Cervical Spondylotic Myelopathy

This study aimed to compare morphologic changes of deep paraspinal muscles at C4-7 in patients with C5-6 single-level cervical spondylotic myelopathy (CSM), and to evaluate the relationship between morphologic changes and the level of spinal cord compression. The study included 15 patients with C5-6 single-level CSM and 15 age- and sex-matched healthy subjects. Cross-sectional area (CSA) and functional CSA of the bilateral longus capitis (LCap), longus colli (LC), multifidus (MF), semispinalis cervicis (SSC), semispinalis capitis, splenius capitis, and splenius cervicis were measured on preoperative magnetic resonance images at C4-7, and calculated as ratios with respect to the corresponding vertebral body CSA. The mean maximum spinal cord compression was 22.30% in the CSM group. At the cranial level (C4-5), the CSM group had more fat infiltration in the MF and SSC (P < 0.05). At the spinal cord compression segment and caudal adjacent segment (C5-6 and C6-7), the degree of fat infiltration of all paravertebral muscles was aggravated, accompanied by atrophy of LCap, LC, and MF (P < 0.05). Compared between different levels, fat infiltration in the MF at C5-6 was greater than adjacent levels. In patients with C5-6 single-level CSM, fat infiltration and atrophy of deep paraspinal muscles, especially the Lcap, LC, and MF, mainly occurred in the level of spinal cord compression and caudal adjacent level. In the cranial adjacent segment, the degree of MF and SSC fat infiltration in patients with CSM was also aggravated. This may suggest that multiple mechanisms are involved in paraspinal muscles degeneration in CSM.

Prognostic value of perirenal and/or sinus fat infiltration in patients with pT3a renal cell carcinoma: A multicentre cohort study. LARCG Group

Introduction and objectivesThe objective of this study is to evaluate overall survival (OS), cancer-specific survival (CSS), relapse-free survival, local and distant (LRFS and DRFS, respectively) rates in patients with pT3a renal cell carcinoma (RCC) considering the perirenal and/or sinus fat infiltration (FI) as prognostic factors. Materials and methodsRetrospective cohort of patients with pT3a RCC who underwent radical or partial nephrectomy. The data were extracted from the LARCG (Latin American Renal Cancer Group) database. The demographic, clinical, pathological and surgical variables were evaluated. FI was divided into 4 groups (vein, perirenal, sinus and both fats infiltration). The Kaplan Meier and Cox regression curves were performed. Results293 patients were included in the study. The mean age was 61.4 years. The median follow-up was 21 months (r: 1–194). CSS, RFS, LRFS and DRFS estimated at 3 years in the group of both fats’ infiltration were 53.1, 45.1, 58.7 and 51.6 months, respectively, and always statistically lower than the rest (p<0.005). In the multivariate analysis, the infiltration of both fats significantly increased specific mortality, overall and local relapse with respect to vein infiltration (HR: 4.5, 2.42 and 8.08, respectively). The Fuhrman grade and renal pelvis infiltration were independent predictors of CSS and RFS. ConclusionsInfiltration of both fats increases the risk of overall and local relapse in pT3a RCC. In the same way, it is associated with a lower cancer-specific survival and should be considered as a factor of poor prognosis.

Development of 3D method to assess intramuscular spatial distribution of fat infiltration in patients with rotator cuff tear: reliability and concurrent validity

BackgroundIntramuscular fat infiltration is a critical factor in surgical decision-making and is the most important factor used to prognosticate surgical repair outcomes in patients with rotator cuff tears. Quantitative 3D assessment of total rotator cuff fat infiltration in patients with rotator cuff tears has been realized. However, a reproducible method to evaluate 3D spatial distribution of rotator cuff intramuscular fat has not been established. The objective of this study was to establish the reproducibility, change detectable beyond error, and concurrent validity of a semi-automated method to evaluate the 3D spatial distribution of fat infiltration and muscle volume in patients with rotator cuff tears.MethodsThirteen consecutive patients diagnosed with symptomatic rotator cuff pathology and 3.0 T MRI confirmation at a single center were included. Fat-water imaging was used to quantify 3D intramuscular fat (%fat) in sagittal oblique sequences and intramuscular spatial distribution with the semi-automated technique. Each rotator cuff muscle was manually segmented yielding %fat in four axial intramuscular quartile-regions (superior-inferior; Q1–4) and three sagittal (medial/ intermediate/ lateral) regions. Reliability and concurrent validity of %fat and whole muscle volume were calculated with intraclass correlation coefficients (ICC).ResultsIntra-rater reliability for intramuscular sagittal divisions (ICC = 0.93–0.99) and axial divisions (ICC = 0.78–0.99) was good/excellent. Inter-rater reliability for %fat (ICC = 0.82–0.99) and volume (ICC = 0.92–0.99) was good/excellent. Concurrent validity with commercialized software showed good/excellent agreement (ICC = 0.66–0.99).ConclusionsA new semi-automated method to assess 3-dimensional intramuscular distribution of fat infiltration in patients with rotator cuff tears using advanced MR imaging demonstrates high intra and inter-rater reliability and good concurrent validity. Minimal detectable change thresholds established facilitate clinical interpretation for future clinical application of this technique to assess change and treatment efficacy in patients with rotator cuff tears.

Frailty is associated with intramuscular fat infiltration in patients with colorectal cancer

Rationale: Emerging evidence suggests that intramuscular fat infiltration is associated with muscle weakness and poor function. We aimed to investigate whether intramuscular fat infiltration is associated with frailty in patients with colorectal cancer.

Paper #61 - Quantifying variation in intramuscular fat infiltration in patients with rotator cuff tears

Paper #61 - Quantifying variation in intramuscular fat infiltration in patients with rotator cuff tears

Paraspinal muscle asymmetry and fat infiltration in patients with symptomatic disc herniation

To investigate asymmetry in size and composition of the multifidus and erector spinae in patients with posterolateral disc herniation and concordant radicular symptoms, and determine whether symptom duration is associated with degree of asymmetry. Thirty-three patients diagnosed with posterolateral disc herniation at L4-L5 verified on imaging and concordant leg pain were included. Multifidus and erector spinae cross-sectional area (CSA), functional cross-sectional area (FCSA, fat-free area), signal intensity and ratio of FCSA to total CSA were measured bilaterally from T 2-weighted axial magnetic resonance imaging (MRI) at L3-L4, L4-L5, L5-S1 and S1 levels. No side-to-side differences in multifidus CSA, FCSA, and ratio of FCSA/CSA reached statistical significance at any spinal level. The multifidus signal intensity at L5-S1 was significantly greater (more fatty infiltration) on the side of the disc herniation. The erector spinae FCSA (lean muscle mass) at L5-S1 was found to be significantly smaller on the side of the herniation and the ratio of FCSA/CSA was smaller (more fatty infiltration) on the side of the herniation at L4-L5 and L5-S1. The degree of muscle asymmetry was not associated with symptoms duration. There was no significant asymmetry of the multifidus at spinal level above, same or level below the disc herniation. Instead, variations in muscle composition were observed, with greater fat infiltration on the side and at spinal levels adjacent to the disc herniation. Muscle asymmetry was not correlated with symptom duration.

Chemical shift magnetic resonance imaging is helpful in detecting hepatic steatosis but not fibrosis in patients with nonalcoholic fatty liver disease (NAFLD)

Background & Aim: Imaging modalities have a role in the diagnosis of patients with nonalcoholic fatty liver disease. Aim of the present study was to evaluate the role of chemical shift magnetic resonance imaging in assessing hepatic steatosis and fibrosis in patients with nonalcoholic fatty liver disease.Methods: Chemical shift magnetic resonance imaging was done in 10 biopsy proven patients (7 females, mean age 41 ± 9.2 years) with nonalcoholic fatty liver disease. Objective measurements of signal intensity (SI) were done and a ratio was calculated (SI out-of-phase liver/ SI out-of-phase kidney)/ (SI in-phase liver/ SI in-phase kidney). A lower ratio indicated a higher signal drop and hence higher fat content. The ratio was correlated with hepatic steatosis on histology (< 33% and > 33%). Patients were classified as having histological NASH or no NASH and MRI was assessed in diagnosing hepatic fi-brosis as seen on liver histology.Results: Six patients had > 33% hepatic steatosis on histology. Five patients (50%) had evidence of histological NASH. MRI was not helpful in differentiating patients with and without his-tological NASH. One patient amongst NASH patients did not have fibrosis, one had stage 1, 2 had stage 2 and one had stage 4 fibrosis. SI ratio ranged between 0.350.69 in 6 patients with steatosis > 33% and was in the range of 0.69-1.20 in four patients with steatosis < 33% on histology. Fibrotic changes seen in 4 patients on biopsy were not detected on MRI.Conclusion: Chemical shift MRI provides objective data on fat infiltration in patients with NAFLD without giving information about hepatic fibrosis.

Prognostic implication of capsular invasion without perinephric fat infiltration in localized renal cell carcinoma

Objectives To analyze the prognostic value of capsular invasion without perinephric fat infiltration in patients with localized renal cell carcinoma (RCC) Stage pT1-pT2N0M0. Methods A total of 288 patients with RCC (conventional type) confined to the kidney (pT1-pT2N0M0) who underwent radical nephrectomy from January 1993 to November 2004 at our institution were included in our study. The disease of all patients was staged according to the 2002 TNM classification system. Pathologic findings, including T stage, nuclear grade, and capsular invasion, were retrospectively reviewed. Disease-specific survival was compared according to the capsular invasion. Results Tumor invasion of the renal capsule was identified in 108 (37.5%) of the 288 patients. Of the 230 patients with Stage pT1, 78 (33.9%) had lesions invading the renal capsule and 30 (51.7%) of 58 patients with Stage pT2 had capsular invasion. Involvement of the renal capsule was associated with a worse pT stage ( P = 0.015). The 5-year disease-specific survival rate for patients with no capsular invasion versus with capsular invasion was 91.8% versus 84.3%, respectively ( P = 0.132). For patients with pT1 tumors, the 5-year disease-specific survival rate was 95.6% for patients without capsular invasion and 92.6% for those with capsular invasion ( P = 0.299). For patients with pT2 tumors, the 5-year disease-specific survival rate was 90.5% for patients without capsular invasion and 73.8% for those with capsular invasion ( P = 0.031). Conclusions Renal capsular invasion is associated with a worse stage in localized RCC. Patients with Stage pT2 RCC and capsular invasion appear to have a worse prognosis than those with equivalently staged RCC without capsular invasion.