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).

[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.

[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.

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.

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.

Differentiation of clinically benign and malignant breast lesions using diffusion-weighted imaging.

PURPOSE: To evaluate the value of diffusion-weighted imaging (DWI) in distinguishing between benign and malignant breast lesions. MATERIALS AND METHODS: Fifty-two female subjects (mean age = 58 years, age range = 25-75 years) with histopathologically proven breast lesions underwent DWI of the breasts with a single-shot echo-planar imaging (EPI) sequence using large b values. The computed mean apparent diffusion coefficients (ADCs) of the breast lesions and cell density were then correlated. RESULTS: The ADCs varied substantially between benign breast lesions ((1.57 +/- 0.23) x 10(-3) mm(2)/second) and malignant breast lesions ((0.97 +/- 0.20) x 10(-3) mm(2)/second). In addition, the mean ADCs of the breast lesions correlated well with tumor cellularity (P < 0.01, r = -0.542). CONCLUSION: The ADC would be an effective parameter in distinguishing between malignant and benign breast lesions. Further, tumor cellularity has a significant influence on the ADCs obtained in both benign and malignant breast tumors.