BACH1 promotes intervertebral disc degeneration by regulating HMOX1/GPX4 to mediate oxidative stress, ferroptosis, and lipid metabolism in nucleus pulposus cells.

BACKGROUND: Intervertebral disc degeneration (IDD) is a primary health problem worldwide that involves oxidative stress, ferroptosis, and lipid metabolism. However, the underlying mechanism remains unclear. We investigated whether the transcription factor BTB and CNC homology 1 (BACH1) affected IDD progression by regulating HMOX1/GPX4-mediated ferroptosis and lipid metabolism in nucleus pulposus cells (NPCs). METHODS: A rat IDD model was created to detect BACH1 expression in intervertebral disc tissues. Next, rat NPCs were isolated and treated with tert-butyl hydroperoxide (TBHP). BACH1, HMOX1, and GPX4 were knocked down, and oxidative stress and ferroptosis-related marker levels were examined. The binding of BACH1 to HMOX1 and of BACH1 to GPX4 was verified using chromatin immunoprecipitation (ChIP). Finally, untargeted lipid metabolism analysis was performed. RESULTS: An IDD model was successfully created, and BACH1 activity was found to be enhanced in the rat IDD tissues. BACH1 inhibited TBHP-induced oxidative stress and oxidative stress-induced ferroptosis in NPCs. Simultaneously, ChIP verified that BACH1 protein bound to HMOX1 and targeted the HMOX1 transcription inhibition to affect oxidative stress in NPCs. ChIP also verified that BACH1 bound to GPX4 and targeted the GPX4 inhibition to affect ferroptosis in NPCs. Finally, BACH1 inhibition in vivo improved IDD and affected lipid metabolism. CONCLUSIONS: The transcription factor BACH1 promoted IDD by regulating HMOX1/GPX4 to mediate oxidative stress, ferroptosis, and lipid metabolism in NPCs.

The Effect of Gut Microbiota on the Progression of Intervertebral Disc Degeneration.

OBJECTIVE: Intervertebral disc degeneration (IDD) is the main cause of back pain, and its treatment is a serious socio-economic burden. The safety and treatment of fecal microbiota transplantation (FMT) has been established. However, the relationship between FMT and IDD still unclear. We aimed to explore whether FMT plays a role in IDD to provide a reference for the treatment of IDD. METHODS: An experimental model of IDD was established using 2-month-old male Sprague-Dawley rats. FMT was performed by intragastric gavage of IDD rats with a fecal bacterial solution. Rat serum, feces, and vertebral disc tissue were collected after surgery for 2 months. The levels of TNF-α, IL-1ß, IL-6, matrix metalloproteinase (MMP)-3, MMP-13, Collagen II, and aggrecan in the serum or vertebral disc tissue were measured by an enzyme-linked immunosorbent assay, immunohistochemistry, quantitative real-time polymerase chain reaction, or western blotting. We also examined the pathology of the vertebral disc tissue using hematoxylin and eosin (HE) and safranin O-fast green staining. Finally, we examined the gut microbiota in rat feces using 16 S rRNA gene sequencing. RESULTS: We found that the expression of TNF-α, IL-1ß, IL-6, MMP-3, MMP-13, NLRP3 and Caspase-1 increased in the IDD group rats. In contrast, Collagen II and aggrecan levels were downregulated. Additionally, vertebral disc tissue was severely damaged in the IDD group, with disordered cell arrangement and uneven safranin coloration. FMT reversed the effects of IDD modeling on these factors and alleviated cartilage tissue damage. In addition, FMT increased the gut microbiota diversity and microbial abundance in rats treated with IDD. CONCLUSION: Our findings suggest that FMT has a positive effect in maintaining cellular stability in the vertebral disc and alleviating histopathological damage. It affects the diversity and abundance of gut microbiota in rats with IDD. Therefore, FMT may serve as a promising target for amelioration of IDD.

Pre-expanded muscle-sparing Latissimus Dorsi free flap: An ideal option for the reconstruction of extensive anterior knee contractures.

BACKGROUND: Extensive and complex contractures in the anterior knee area can pose a significant challenge for reconstruction due to insufficient skin and soft tissue coverage and poor cosmetic and functional outcomes using traditional methods. We presented our experience with pre-expanded muscle-sparing latissimus dorsi (LD) free flap as an alternative option for large-scale anterior knee reconstruction. METHODS: From January 2016 to December 2020, we applied this surgical technique in six patients with large postburn or post-traumatic contractures of the anterior knee. After tissue expansion of several months, the expanded muscle-sparing LD free flap was harvested and transferred to resurface the lesions. Operative procedures, postoperative complications, and long-term outcomes were evaluated. RESULTS: A total of six patients aged 7 to 32 years (mean: 20 years) were reconstructed successfully without any major complication. The flap ranged from 20 × 8 cm to 40 × 16 cm. All donor sites were primarily closed. Follow-up (range: 12 to 24 months) evaluation showed satisfactory results in both cosmetic and functional aspects. CONCLUSIONS: Pre-expanded muscle-sparing LD free flap is a reliable and effective choice for extensive anterior knee contracture reconstruction with satisfactory esthetic and functional outcome. It can provide substantial amount of soft tissue coverage with minimal complications and donor-site morbidity. Furthermore, it offers a good basis for next-step orthopedic surgery, such as total knee arthroplasty (TKA).

Necrotizing Fasciitis of the Breast: A Review of the Literature.

Background: Necrotizing fasciitis (NF) is a rare, rapidly progressing, and potentially fatal tissue infection involving subcutaneous tissue, superficial fascia, and the overlying skin. Breast NF is often misdiagnosed because of the thick breast tissue between the skin and deep fascia. Only early diagnosis followed by prompt antibiotic treatment and surgical therapy can prevent disastrous consequences. There are many case reports on breast NF, but a systematic review is lacking. Methods: Using PubMed and Scopus we performed a systematic review of the literature covering a period of 20 years. We reviewed articles with predisposing comorbidities (risk factors), triggering factors, laboratory examinations, culture of organisms, antibiotic treatment, surgical interventions, the presence of septic shock, and final outcome. We also performed statistical tests of all these factors in relation to death. Results: Forty cases identified from 38 articles were included in our literature review. Twenty-one cases (52.5%) were primary, whereas 15 cases (37.5%) occurred after surgery. In 15 cases (37.5%), the single organism responsible for NF was Streptococcus pyogenes, whereas mixed organisms were found in 17 cases (42.5%). Surgical debridement was performed in 39 (97.5%) cases. Septic shock was found in all five (12.5%) deceased cases and was associated with patient's mortality (p < 0.001). Conclusions: Breast NF is a rare, severe, and easily misdiagnosed complication. Breast NF could differ from that in other body regions in etiology pattern and clinical manifestations. Confirmed diagnosis of breast NF is based on the combination of clinical, cultural, laboratory, and imaging findings. Urgent subsequent treatments, including surgical debridement, antibiotic therapy, and reconstructive surgery, are critical for better prognosis and survival of patients.

Reliability of three-dimensional pseudo-continuous arterial spin labeling MR imaging for measuring visual cortex perfusion on two 3T scanners.

Cerebral blood flow (CBF) in the human primary visual cortex is correlated with the loss of visual function in neuro-ophthalmological diseases. Advanced three-dimensional pseudo-continuous arterial spin labeling (3D pCASL), as a non-invasive method to access the CBF, can be a novel measurement to detect the visual cortex. The objective of the study was to assess the intra- and inter-scanner reliability of 3D pCASL of the visual cortex in healthy adults and suggest the selection of different post-labeling delay times (PLDs). For this reason, 3D pCASL was conducted in two 3.0T MR three times with twelve healthy volunteers at an interval of 10-15 days. The 1st and 3rd tests were performed on scanner-1, and the 2nd test was performed on scanner-2. The value of the CBF was abstracted from the visual cortex with two PLDs. The intra- and inter-scanner reliability and reproducibility were evaluated with the intraclass correlation coefficient (ICC) and Bland-Altman plots. By estimating the mean value of the CBF in the visual cortex, the intra-scanner results demonstrated the higher reliability (ICC for PLD = 1.5 second presented at 0.743 compared with 0.829 for PLD = 2.5 seconds), and the Bland-Altman plots showed the reproducibility at a longer PLD. We conclude that the calibrated 3D pCASL approach provides a highly reproducible measurement of the CBF of the visual cortex that can serve as a useful quantitative probe for research conducted at multiple centers and for the long-term observation of the clinical effects of neuro-opthalmological diseases.

[Quantitative measurement of carotid atherosclerotic plaque by high-resolution three- dimensional black-blood magnetic resonance imaging].

OBJECTIVE: To assess the value of high-resolution three-dimensional black-blood magnetic resonance imaging (3D-BB-MRI) in quantitative measurement of carotid atherosclerotic plaque by comparison with two-dimensional black-blood magnetic resonance imaging (2D-BB-MRI). METHODS: Forty patients were scanned with routine 2D and oblique-sagittal 3D-BB-MRI. The original oblique-sagittal 3D images were reformatted to an axial 2D-like dataset. Two experienced radiologists identified the interested slice in consensus for every patient (unilateral carotid artery) in 2D-BB-MRI images and matched the axial reformatted 3D images with 2D black-blood images. Plaque thickness (PT), lumen area (LA) and total vessel area (TVA) were measured, and lumen stenosis (LS) and normalized wall index (NWI) were calculated. RESULTS: There was no measurement difference between 2D-BB-MRI and reformatted 3D-BB-MRI (P>0.05), and these two methods had a good correlation (r<0.9). The Bland-Altman chart showed that 2D-BB-MRI and 3D-BB-MRI were in good agreement in the measurement of PT, LA and TVA. CONCLUSION: 3D-BB-MRI and 2D-BB-MRI have no obvious difference in quantitative measurement of the carotid plaques. 3D-BB-MRI can demonstrate the vessels and plaques by multiplanar reconstruction and thus have better performance in evaluating carotid atherosclerosis compared with 2D-BB-MRI.

[Scan time reduction with a small field-of-view quadruple inversion-recovery high-resolution contrast-enhanced MRI for carotid atherosclerosis].

OBJECTIVE: To reduce the acquisition time of carotid high-resolution contrast-enhanced magnetic resonance imaging (CEMRI), we designed a small field-of-view (FOV) quadruple-inversion-recovery (SF-QIR) T1WI and evaluated the image quality. METHODS: Twenty-four subjects with carotid plaque were enrolled in our study. All the subjects were imaged using the same 3.0T MRI by SF-QIR and standard rectangular FOV QIR (SrF-QIR) with identical parameters except for the phase-encoding step numbers and the RF excitation methods. Three independent readers qualitatively evaluated the differences between the two sequences in regard of the carotid outer wall border delineation, fibrous cap and lipid-rich necrotic core (LR-NC) border delineation, and diagnostic confidence. The quantitative measurements included maximal stenosis, wall area, LR-NC area, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). The inter-reader variability was assessed. RESULTS: The application of SF-QIR combined with orthogonal radio frequency excitation resulted in nearly half of the scan time with the SrF-QIR. Both qualitative and quantitative assessment by the readers revealed no significant differences between the two sequences except for SNR and CNR (Pgt;0.05). Since the mean loss of SNR with SF-QIR was 37.7%, SrF-QIR demonstrated a superior performance in SNR (P<0.001). CONCLUSION: The small FOV QIR sequence is effective in high-resolution CEMRI for evaluating carotid plaques and can effectively reduce the scan time and eliminate motion artifacts.

Comparison of carotid arterial morphology and plaque composition between patients with acute coronary syndrome and stable coronary artery disease: a high-resolution magnetic resonance imaging study.

The purpose of this study was to evaluate the differences in carotid arterial morphology and plaque composition between patients with acute coronary syndrome (ACS) and patients with stable coronary artery disease (SCAD). Twenty-eight patients (12 ACS patients and 16 SCAD patients) underwent carotid high-resolution MRI examination using a 3.0-Tesla (3.0T) MRI scanner. The indicators of carotid arterial morphology included the maximum total vessel area (Max-TVA), mean TVA, minimum lumen area (Min-LA), mean LA, maximum wall area (Max-WA), mean WA, maximum wall thickness (Max-WT), mean WT, maximum normalized wall index (Max-NWI), mean NWI, and maximum stenosis (Max-stenosis). The indicators of plaque composition included the prevalence and mean area percentage (%) of lipid-rich necrotic core (LRNC), calcification (Ca), intraplaque hemorrhage (IPH), and fibrous cap rupture (FCR). None of the indicators of carotid arterial morphology had significant differences (all P > 0.05) between the ACS and SCAD patients. The prevalence and plaque composition area percentage of LRNC, Ca, and IPH did not exhibit significant differences between the two groups. However, carotid plaques in the ACS patients presented a higher prevalence of FCR than SCAD patients (P < 0.05). This study revealed a similar carotid arterial morphology between ACS and SCAD patients. However, FCR is more common in carotid plaques with ACS than in those with SCAD. Ruptured carotid plaques may be a forewarning factor for those patients who are at high risk of ACS.

[Evaluation of atherosclerotic carotid plaque composition with magnetic resonance imaging using different sequences].

OBJECTIVE: To evaluate the capability of magnetic resonance imaging (MRI) using different sequences in displaying atherosclerotic carotid plaque composition. METHODS: Thirty-five patients received pre- and post-contrast carotid MRI examination on a 3.0T scanner. TOF, T(1)W, T(2)W, PDW and CE-T(1)W were used for identifying the positive and negative cases for the plaque composition (lipid-rich necrotic core, intraplaque hemorrhage and calcification), and their respective sensitivity, specificity and Cohens κ with 95% CI for displaying the components of the plaques were calculated. RESULTS: A total of 74 plaques were found in the 35 patients, and after exclusion of 6 plaques for a thickness below 3 mm, 68 plaques were included for the analysis. Lipid-rich necrotic core were found in 57 plaques, intraplaque hemorrhage in 30 plaques, and alcification in 43 plaques. CE-T(1)W was the optimal sequence for displaying lipid-rich necrotic core with a sensitivity of 100%, specificity of 90.9%, and κ value of 0.944. Both T(1)W and TOF reliably showed the intraplaque hemorrhage, but the former had a greater sensitivity (100%), specificity (92.1%), and κ value (0.911). Of all the 5 sequences, TOF was the best to show calcification with high sensitivity (100%), specificity (92%), and κ value (0.936). CONCLUSION: CE-T(1)W is the best sequence to show lipid-rich necrotic core with high sensitivity and specificity. T(1)W and TOF show a high level of agreement with the standard to show the intraplaque hemorrhage. TOF is more sensitive and accurate than the other sequences in displaying calcification. The combination of T(1)W, TOF and CE-T(1)W allows accurate evaluation of each component of the plaque.

[Oblique-sagittal black-blood contrast-enhanced magnetic resonance imaging in preoperative evaluation for carotid endarterectomy].

OBJECTIVE: To evaluate the value of oblique-sagittal black-blood contrast-enhanced magnetic resonance imaging (OB-CEMRI) in atherosclerotic carotid artery (CA) assessment before carotid endarterectomy (CEA). METHODS: Twenty-five patients with symptomatic atherosclerotic stenosis in the carotid artery (involving 26 arteries) were scheduled for CEA. OB-CEMRI and digital subtraction angiography (DSA) were conducted within 1 week prior to CEA, and two radiologists independently assessed the location of maximal lumen stenosis, plaque rupture, degree of maximal lumen stenosis and plaque involvement on DSA and OB-CEMRI images. The differences of DSA and the OB-CEMRI in analyzing the plaque conditions were assessed in comparison with matched histological sections of the excised specimens. RESULTS: Compared with the corresponding histological specimens, both DSA (κ=0.807) and OB-CEMRI (κ=0.812) showed a good consistency in defining the location of the maximal lumen stenosis. OB-CEMRI showed a better performance in detecting plaque rupture with higher sensitivity (90.0%) and specificity (83.3%) than DSA (40.0% and 66.7%, respectively). No significant difference was found between DSA and the OB-CEMRI in evaluating the degree of maximal lumen stenosis [(77.33∓3.79)% vs (76.02∓3.95)%, P=0.648]. Compared with the histological examination, OB-CEMRI appeared to underestimate the stenosis. The plaque extent on OB-CEMRI was larger than that on DSA (18.96∓4.96 mm vs 14.80∓3.78 mm, P=0.004), and similar to that by histological examination (18.13∓4.57 mm, P=0.506). CONCLUSIONS: OB-CEMRI allows noninvasive and objective detection of the location of the maximal lumen stenosis, plaque rupture, and plaque extent, though with a lower accuracy than DSA in the assessment of the maximal lumen stenosis. OB-CEMRI combined with DSA offers a more reliable means for preoperative evaluation of the carotid artery plaques for CEA.

Differences of signal evolution of intraplaque hemorrhage and associated stenosis between symptomatic and asymptomatic atherosclerotic carotid arteries: an in vivo high-resolution magnetic resonance imaging follow-up study.

To evaluate the differences of signal evolution of intraplaque hemorrhage (IPH) and associated stenosis between symptomatic and asymptomatic atherosclerotic carotid arteries. Thirty-three carotid arteries (15 symptomatic and 18 asymptomatic plaques) with recent carotid IPH underwent serial high-resolution MRI examinations on a 3.0-Tesla (3.0T) MRI scanner over a period of 18 months. MR sequences included three-dimensional time-of-flight (3D-TOF), quadruple-inversion-recovery T1-weighted imaging (QIR T1 WI), proton density-weighted imaging (PDWI), and T2-weighted imaging (T2WI). The contrast-to-noise ratios (CNRs) of subsequent IPH during the follow-up period between symptomatic and asymptomatic carotid IPH showed a significant difference on 3D-TOF (P = 0.029), T1 WI (P = 0.005), and PDWI (P = 0.028), except for that on T2WI (P = 0.362). Compared with no significant signal intensity change of symptomatic IPH, CNRs of asymptomatic IPH exhibited a gradually descending trend on all contrast weighted images (P < 0.05). Compared with asymptomatic arteries, the degree of diameter stenosis associated with IPH increased significantly in the symptomatic atherosclerotic carotid arteries between baseline and the 18th month (10.53 ± 12.29% vs. 1.65 ± 7.74%, P = 0.017). Symptomatic and asymptomatic carotid IPH demonstrated different MRI signal evolution and associated carotid stenosis. Repeated carotid IPH may be more common in symptomatic plaques than in asymptomatic plaques and might produce a stronger stimulus for progression of atherosclerosis than one-time carotid IPH.

[Atherosclerotic area measurement in the vascular wall of the carotid artery: comparison between 16-slice computed tomography angiography and high-resolution magnetic resonance imaging].

OBJECTIVE: To assess the accuracy of computed tomography angiography (CTA) in quantifying atherosclerotic area in the vascular wall of the carotid artery in comparison with high-resolution magnetic resonance imaging (MRI). METHODS: Eighteen subjects (15 males and 3 females aged 63-/+8 years) with >or=50% stenosis in at least one carotid artery were enrolled in this study. CTA and high-resolution MRI scans (in-plane pixel size of 0.25 mmx0.25 mm for both) were conducted within 1 week on a multi-slice spiral CT scanner and a 1.5T MR scanner (Signa, GE Medical Systems), respectively. CTA images were matched with MR images with the carotid bifurcation as the mark. For each patient, multiple matched slices with carotid atherosclerotic plaques in the bilateral carotid arteries were selected to measure the outer wall boundary (OWB) area, lumen area and wall area. Bland-Altman analysis and Pearson correlation coefficients were used to analyze the correlations of the area measurements between CTA and high-resolution MRI. RESULTS: A wide range of lesion size (vascular wall area) was found in these patients. Strong correlations were noted between CTA and high-resolution MRI with the correlation coefficients for OWB area, lumen area and wall area of 0.98, 0.98 and 0.96, respectively. The mean differences between CTA and high-resolution MRI were 0.16-/+5.71 mm(2), 4.47-/+1.44 mm(2) and -4.31-/+5.73 mm(2) for OWB area, lumen area and wall area, respectively. CONCLUSION: Compared to high-resolution MRI, CTA is also a reliable method to measure carotid vascular wall area. CTA might become an alternative modality to high-resolution MRI for follow-up examination of patients with carotid artery atherosclerosis, especially in uncooperative patients or patients with contra-indications for MRI.

High-resolution MR study of the relationship between superficial calcification and the stability of carotid atherosclerotic plaque.

In this study, we have aimed to evaluate the relationship between the shape and location of superficial calcification and the presence of fibrous cap rupture and intraplaque hemorrhage in atherosclerotic carotid plaque. Sixty-three patients with carotid stenosis underwent contrast-enhanced high resolution MR examinations with a 3-T MR scanner and 226 slices with superficial calcification were evaluated in the study. The shape of superficial calcification was categorized as the irregular type (dotted/arcuated) and patchy type and the location of superficial calcification was categorized as the marginal type and central type. Intraplaque hemorrhage and fibrous cap rupture depicted on the same slice as superficial calcification were identified. The chi-squared test was used for statistical analysis. A total of 149 slices (65.9%) with intraplaque hemorrhage and 107 slices(47.3%)with fibrous cap rupture were detected. There were 191 slices with irregular type (dotted/arcuated) calcification and 166 slices with marginal type calcification. Irregular superficial calcification was found more frequently accompanied with intraplaque hemorrhage as compared to the patchy type (73.8 vs. 22.9%, P < 0.0001); there was a significant difference between the marginal type and the central type for the accompaniment of intraplaque hemorrhage (72.9 vs. 46.7%, P < 0.05). However, there was no significant difference between different shapes and locations of superficial calcification that accompanied with fibrous cap rupture (P > 0.05). This study showed that superficial calcification is an important factor for determination of instability of atherosclerotic carotid plaque. The shape and location of superficial calcification are important features associated with the occurrence of intraplaque hemorrhage.

Lower fractional anisotropy at the anterior body of the normal-appearing corpus callosum in multiple sclerosis versus symptomatic carotid occlusion.

INTRODUCTION: Not uncommonly, differentiating multiple sclerosis (MS) from ischemic cerebral vascular disease is difficult based on conventional magnetic resonance imaging (MRI). We aim to determine whether preferential occult injury in the normal-appearing corpus callosum (NACC) is more severe in patients with MS than symptomatic carotid occlusion by comparing fractional anisotropy (FA) from diffusion tensor imaging (DTI). METHODS: Eighteen patients (eight men, ten women; mean age, 38.6 years) with MS and 32 patients (24 men, eight women; mean age, 64.0 years) with symptomatic unilateral internal carotid occlusion were included. DTI (1.5 T) were performed at corpus callosum which were normal-appearing on fluid-attenuated inversion recovery MRI. Mean FA was obtained from the genu, anterior body, posterior body, and splenium of NACC. Independent-sample t test statistical analysis was performed. RESULTS: The FA values in various regions of NACC were lower in the MS patients than symptomatic carotid occlusion patients, which was statistically different at the anterior body (0.67 +/- 0.12 vs 0.74 +/- 0.06, P = 0.009), but not at genu, posterior body, and splenium (0.63 +/- 0.09 vs 0.67 +/- 0.07, P = 0.13; 0.68 +/- 0.09 vs 0.73 +/- 0.05, P = 0.07; 0.72 +/- 0.09 vs 0.76 +/- 0.05, P = 0.13). CONCLUSION: MS patients have lower FA in the anterior body of NACC compared to patients with symptomatic carotid occlusion. It suggests that DTI has potential ability to differentiate these two conditions due to the more severe preferential occult injury at the anterior body of NACC in MS.

Feasibility of whole body diffusion weighted imaging in detecting bone metastasis on 3.0T MR scanner.

OBJECTIVE: To evaluate the feasibility of whole body diffusion weighted imaging (DWI) in bone metastasis detection using bone scintigraphy as comparison. METHODS: Forty-five patients with malignancy history were enrolled in our study. All the patients received the whole body DWI and bone scintigraphy scan within 1 week. The magnetic resonance (MR) examination was performed on 3.0T MR scanner using embedded body coil. The images were reviewed separately by two radiologists and two nuclear medicine physicians, who were blinded to the results of the other imaging modality. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the two techniques for detecting bone metastasis were analyzed. RESULTS: A total of 181 metastatic lesions in 77 regions of 34 patients were detected by whole body DWI, and 167 metastatic lesions in 76 regions of 31 patients were identified by bone scintigraphy. The patient-based sensitivity and PPV of whole body DWI and bone scintigraphy were similar (89.5% vs. 81.6%, 97.1% vs. 91.2%), whereas, the patient-based specificity and NPV of whole body DWI were obviously higher than those of bone scintigraphy (85.7% vs. 57.1%, 60.0% vs. 36.4%). Ten regions negative in scintigraphy but positive in whole body DWI, mainly located in spine, pelvis, and femur; nine regions only detected by scintigraphy, mainly located in skull, sternum, clavicle, and scapula. The region-based sensitivity and specificity of whole body DWI were slightly higher than those of bone scintigraphy (89.5% vs. 88.4%, 95.6% vs. 87.6%). CONCLUSION: Whole body DWI reveals excellent concordance with bone scintigraphy regarding detection of bone metastasis, and the two techniques are complementary for each other.

Time-resolved contrast-enhanced MR angiography of intracranial lesions.

PURPOSE: To determine if contrast-enhanced (CE) MRI of intracranial lesions benefits from time-resolved MR angiography (MRA) during contrast agent injection. MATERIALS AND METHODS: For 126 patients with suspected intracranial lesions undergoing routine CE MRI at 3.0T (N = 88) or 1.5T (N = 38), time-resolved CE MRA (three-dimensional [3D] time-resolved imaging of contrast kinetics [TRICKS]) was performed during injection of the routine gadolinium (Gd) dose of 0.1 mmol/kg. Time to peak (TTP) enhancement of lesions as well as time to internal carotid artery (ICA), middle cerebral artery (MCA), superior sagittal sinus (SSS), and jugular vein enhancement were measured. Source and maximum intensity projection (MIP) images were reviewed to delineate the spatial relationship of lesions and the vasculature. RESULTS: In 61 patients (48%), additional important findings were detected on time-resolved MRA that were not seen on the routine CE protocol, including aneurysms (N = 6), arteriovenous malformations (N = 7), ICA stenoses (N = 2), vascular anomalies (N = 18), and relationships between lesions and vessels (N = 28). In addition, tumor TTP correlated with glioma grade (r = 0.87) and discriminated epithelial from nonepithelial meningiomas (P = 2.6 x 10(-5)). MRA added eight minutes to the total exam time. CONCLUSION: Time-resolved MRA performed during contrast agent injection adds information to the routine brain CE MRI examination of intracranial lesions with only a small time penalty and no additional risk to the patient.

Diffusion-weighted magnetic resonance imaging in diagnosis of Creutzfeldt-Jakob disease.

BACKGROUND: Creutzfeldt-Jakob disease (CJD), a rare disease, is uncharacterized by computed tomography (CT) and magnetic resonance imaging (MRI). This study was aimed to evaluate the diffusion-weighted MRI (DWI) manifestations of CJD and to discuss their diagnostic value. METHODS: The findings of T(1)-weighted MRI (T(1)WI), T(2)-weighted MRI (T(2)WI), DWI and post-contrast MRI in 5 patients (3 patients with biopsy-proven CJD and 2 patients with clinically-proven CJD) were retrospectively analyzed in this study. RESULTS: Four out of the 5 patients had cerebral atrophy of various degrees. One patient showed symmetric high signal intensity at the bilateral globus pallidus and the head of the caudate nucleus, with very high signal in the cerebral cortex on the DWI. This patient only had symmetric slightly high signal at the bilateral globus pallidus and putamen on T(2)WI. One patient had high signal intensity at the basal ganglia and cerebral cortex on DWI, but abnormal T(2) signal intensity at the bilateral paraventricular white matter on MRI. Two patients presented with widely gyri-like high signal intensity at the cortex on DWI, but routine MRI showed bilateral paraventricular long T(2) signal intensity in 1 patient and no abnormal findings in another. No abnormalities were shown by both routine MRI and DWI in the last patient. CONCLUSIONS: DWI is more sensitive than its conventional counterpart in the depiction of CJD. DWI is more sensitive to detect cortical abnormal signal intensity in CJD not detected by T(2)WI.

Comparison of symptomatic and asymptomatic atherosclerotic carotid plaque features with in vivo MR imaging.

PURPOSE: To retrospectively determine if in vivo magnetic resonance (MR) imaging can simultaneously depict differences between symptomatic and asymptomatic carotid atherosclerotic plaque. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for this HIPAA-compliant study. Twenty-three patients (21 men, two women; mean age, 66.1 years +/- 11.0 [standard deviation]) with unilateral symptomatic carotid disease underwent 1.5-T time-of-flight MR angiography and 1.5-T T1-, intermediate-, and T2-weighted MR imaging. Both carotid arteries were reviewed. One observer recorded quantitative and morphologic information, which included measurement of the area of the lumen, artery wall, and main plaque components; fibrous cap status (thick, thin, or ruptured); American Heart Association (AHA) lesion type (types I-VIII); and location (juxtaluminal vs intraplaque) and type of hemorrhage. Plaques associated with neurologic symptoms and asymptomatic plaques were compared with Wilcoxon signed rank and McNemar tests. RESULTS: Compared with asymptomatic plaques, symptomatic plaques had a higher incidence of fibrous cap rupture (P = .007), juxtaluminal hemorrhage or thrombus (P = .039), type I hemorrhage (P = .021), and complicated AHA type VI lesions (P = .004) and a lower incidence of uncomplicated AHA type IV and V lesions (P = .005). Symptomatic plaques also had larger hemorrhage (P = .003) and loose matrix (P = .014) areas and a smaller lumen area (P = .008). No significant differences between symptomatic and asymptomatic plaques were found for quantitative measurements of the lipid-rich necrotic core, calcification, and the vessel wall or for the occurrence of intraplaque hemorrhage or type II hemorrhage. CONCLUSION: This study revealed significant differences between symptomatic and asymptomatic plaques in the same patient.

Combined MR spectroscopic imaging and diffusion tensor MRI visualizes corticospinal tract degeneration in amyotrophic lateral sclerosis.

Motor neuron damage and cortical spinal tract (CST) degeneration are pathological features of amyotrophic lateral sclerosis (ALS). We combined whole-brain diffusion tensor imaging (DTI) and three-dimensional magnetic resonance spectroscopic imaging (MRSI) to study the CST at different locations. Eight ALS patients were compared with normal controls. Fractional anisotropy (FA) and mean diffusivity (MD), and the ratio of N-acetyl-aspartate (NAA) to creatine (Cr) were measured at various locations in the CST, including the subcortical white matter (SWM), centrum semiovale (CS), periventricular white matter (PV), posterior limb of the internal capsule (PIC) and cerebral peduncle (CP). Patients showed significantly lower FA than controls in the CST, including the SWM, CS, PV and PIC. Although there was a trend towards elevated MD in ALS patients, this did not reach statistical significance. NAA/Cr ratios were also decreased in ALS patients compared with normal controls, with significant differences in the SWM and PV but not in PIC. Combined whole-brain DTI and MRSI can detect axonal degeneration in ALS. Measurements of FA obtained in the SWM, CS, PV and PIC, and NAA/Cr ratios in the SWM and PV yield the most robust results.

MR imaging of meningeal carcinomatosis by systemic malignancy.

OBJECTIVE: To investigate the magnetic resonance (MR) features of meningeal carcinomatosis, and to improve the ability in understanding and diagnosing meningeal carcinomatosis by MR findings. METHODS: Eleven cases with proven meningeal carcinomatosis were studied by conventional and Gd-DTPA enhanced MR imaging. The enhancement patterns and features, as well as the types of meningeal involvement, were retrospectively analyzed. RESULTS: Conventional MR imaging showed no evident meningeal abnormalities. After the administration of Gd-DTPA, abnormal pia mater enhancement was detected in 9 cases, demonstrating as the continuous, thin, and lineal high signal intensity on the brain surface that could descend into the sulci. The abnormal pial enhancement occurred on the cortical surfaces of cerebellum, brainstem, and cerebrum. No abnormal enhancement in the subarachnoid space was found. Abnormal dura-arachnoid enhancement was seen in 3 cases, showing as the continuous, thick, and curvilineal high signal intensity over the convexities or in the tentorium without extension into the cortical sulci. Cerebral dura-arachnoid involvement was found in all 3 cases and one of them also showed abnormal enhancement in cerebellar dura-arachnoid and tentorium. Of the 11 cases, 9 with pial involvement had abnormal cerebrospinal fluid (CSF) results, 2 involving only the dura-arachnoid had normal CSF results. CONCLUSION: Meningeal carcinomatosis could be well demonstrated by Gd-DTPA enhanced MR imaging, and its type could be differentiated by the enhancement features. Combined with the clinical information, Gd-enhanced MR imaging may lead to the diagnosis and guide the therapy of meningeal carcinomatosis.