Repaired aortic coarctation in adults—magnetic resonance imaging with velocity mapping shows distortions of anatomy and flow

1996 ◽  
Vol 6 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Philip J. Kilner ◽  
Tokuko Shinohara ◽  
Cynthia Sampson ◽  
Raad H. Mohiaddin ◽  
David N. Firmin ◽  
...  

AbstractMagnetic resonance velocity mapping of intraaortic flow was performed prospectively in adolescents and adults after coarctation repair. The aims were to assess the feasibility and clinical usefulness of the technique in this patient group, and to study flow velocity distributions in repaired regions. Twenty consecutive patients attending for follow-up after repair of aortic coarctation, aged 15–39, mean 25 years, were studied using a 0.5 tesla Picker magnetic resonance machine. Spin echo and cine imaging with phase velocity mapping, echo time 3.6 ms, were used to study anatomy and flow in the repaired region. Transcutaneous ultrasonic examination, with continuous wave Doppler velocity measurement was performed independently on the same day. Velocity maps, acquired successfully in all patients, showed asymmetry and nonhomogeneity of flow in relation to anatomical distortions of repaired regions. Magnetic resonance and Doppler measurements of peak velocity compared as follows: n=20, range 1.2–3.9 m/sec, mean 2.33 m/sec, mean of differences (Doppler-MR) 0.22 m/sec, standard deviation of differences ±0.27 m/sec. Localized velocity peaks adjacent to wall deformations were identified by magnetic resonance in five patients without significant restenosis. Magnetic resonance imaging with velocity mapping proved reliable and informative in follow-up assessment in adolescents and adults after surgical repair of aortic coarctation. There was satisfactory agreement between magnetic resonance and Doppler measurements of peak velocity. Velocity maps showed that localized velocity peaks may occur in limited parts of the stream adjacent to distorted aortic boundaries without stenosis. This could be a cause of overestimation of pressure gradients from peak velocity data, a possibility which requires further investigation.

1993 ◽  
Vol 41 (02) ◽  
pp. 107-111 ◽  
Author(s):  
H. Kaemmerer ◽  
P. Theissen ◽  
U. König ◽  
U. Sechtem ◽  
E. de Vivie

Neurosurgery ◽  
2006 ◽  
Vol 58 (6) ◽  
pp. 1081-1089 ◽  
Author(s):  
John Sinclair ◽  
Steven D. Chang ◽  
Iris C. Gibbs ◽  
John R. Adler

Abstract OBJECTIVE: Intramedullary spinal cord arteriovenous malformations (AVMs) have an unfavorable natural history that characteristically involves myelopathy secondary to progressive ischemia and/or recurrent hemorrhage. Although some lesions can be managed successfully with embolization and surgery, AVM size, location, and angioarchitecture precludes treatment in many circumstances. Given the poor outlook for such patients, and building on the successful experience with radiosurgical ablation of cerebral AVMs, our group at Stanford University has used CyberKnife (Accuray, Inc., Sunnyvale, CA) stereotactic radiosurgery (SRS) to treat selected spinal cord AVMs since 1997. In this article, we retrospectively analyze our preliminary experience with this technique. METHODS: Fifteen patients with intramedullary spinal cord AVMs (nine cervical, three thoracic, and three conus medullaris) were treated by image-guided SRS between 1997 and 2005. SRS was delivered in two to five sessions with an average marginal dose of 20.5 Gy. The biologically effective dose used in individual patients was escalated gradually over the course of this study. Clinical and magnetic resonance imaging follow-up were carried out annually, and spinal angiography was repeated at 3 years. RESULTS: After a mean follow-up period of 27.9 months (range, 3–59 mo), six of the seven patients who were more than 3 years from SRS had significant reductions in AVM volumes on interim magnetic resonance imaging examinations. In four of the five patients who underwent postoperative spinal angiography, persistent AVM was confirmed, albeit reduced in size. One patient demonstrated complete angiographic obliteration of a conus medullaris AVM 26 months after radiosurgery. There was no evidence of further hemorrhage after CyberKnife treatment or neurological deterioration attributable to SRS. CONCLUSION: This description of CyberKnife radiosurgical ablation demonstrates its feasibility and apparent safety for selected intramedullary spinal cord AVMs. Additional experience is necessary to ascertain the optimal radiosurgical dose and ultimate efficacy of this technique.


2021 ◽  
Vol 49 (3) ◽  
pp. 737-746
Author(s):  
Yiwen Hu ◽  
Yuyang Zhang ◽  
Qianru Li ◽  
Yuxue Xie ◽  
Rong Lu ◽  
...  

Background: Cartilage degeneration is a common issue in patients with chronic lateral ankle instability. However, there are limited studies regarding the effectiveness of lateral ligament surgery on preventing talar and subtalar joint cartilage from further degenerative changes. Purpose: To longitudinally evaluate talar and subtalar cartilage compositional changes using magnetic resonance imaging T2* mapping in anatomic anterior talofibular ligament (ATFL)–repaired and ATFL-reconstructed ankles and to compare them with measures in asymptomatic controls. Study Design: Cohort study; Level of evidence, 3. Methods: Between January 2015 and December 2016, patients with chronic lateral ankle instability who underwent anatomic ATFL repair (n = 19) and reconstruction (n = 20) were prospectively recruited. Patients underwent 3.0-T magnetic resonance imaging at baseline and 3-year follow-up. As asymptomatic controls, 21 healthy volunteers were recruited and underwent imaging at baseline. Talar dome cartilage was divided into (1) medial anterior, central, and posterior and (2) lateral anterior, central, and posterior. Posterior subtalar cartilage was divided into (1) central talus and calcaneus and (2) lateral talus and calcaneus. Ankle function was assessed using the American Orthopaedic Foot & Ankle Society scores. Results: There were significant increases in T2* values in medial and lateral posterior and central talus cartilage from baseline to 3-year follow-up in patients who underwent repair. T2* values were significantly higher in ATFL-repaired ankles at follow-up for all cartilage regions of interest, except medial and lateral anterior and lateral central, compared with those in healthy controls. From baseline to 3-year follow-up, ATFL-reconstructed ankles had a significant increase in T2* values in lateral central and posterior cartilage. T2* values in ATFL-reconstructed ankles at follow-up were elevated in all cartilage regions of interest, except medial and lateral anterior, compared with those in healthy controls. ATFL-repaired ankles showed a greater decrease of T2* values from baseline to follow-up in lateral calcaneus cartilage than did ATFL-reconstructed ankles ( P = .031). No significant differences in American Orthopaedic Foot & Ankle Society score were found between repair and reconstruction procedures (mean ± SD, 19.11 ± 7.45 vs 16.85 ± 6.24; P = .311). Conclusion: Neither anatomic ATFL repair nor reconstruction could prevent the progression of talar dome and posterior subtalar cartilage degeneration; however, ankle function and activity levels were not affected over a short period. Patients who underwent ATFL repair exhibited lower T2* values in the lateral calcaneus cartilage than did those who underwent reconstruction.


Author(s):  
Shinya Ito ◽  
Akihiro Isotani ◽  
Kyohei Yamaji ◽  
Kenji Ando

Abstract Background  Löffler endocarditis is a condition characterized by cardiac infiltration of eosinophils. Cardiac magnetic resonance imaging (MRI) is a modality for the diagnosis of myocardial damage. Case summary  This is the case of a 77-year-old man with acute decompensated heart failure who was admitted. Transthoracic echocardiography showed preserved left ventricular (LV) systolic function along with LV thrombi attached to the septo-apical wall and the posterior wall, consistent with Löffler endocarditis. Cardiac MRI revealed obliteration of the LV apex and partial filling of the LV cavity, as well as near circumferential subendocardial late gadolinium enhancement (LGE) in the mid- and apical segments. T2-weighted images showed a near circumferential high-intensity area of the LV subendocardial muscle in the mid- and apical segments. High-dose corticosteroids and intravenous heparin were initiated, followed by maintenance warfarin therapy. At 18 months, follow-up cardiac MRI revealed the disappearance of the LV thrombi, and a reduction of LGE, as well as high-intensity areas in the T2-weighted images. Discussion  The high-intensity area of T2-weighted images indicate the presence of subendocardial oedema. Eosinophil-mediated heart damage evolves through three stages: (i) acute necrotic, (ii) thrombotic, and (iii) fibrotic stages. Since the deposition of toxic eosinophil granule proteins and eosinophil infiltration injured the endocardium, the first-line treatment for Löffler endocarditis is corticosteroid therapy. In this case, LGE in the subendocardium and the high-intensity area in the T2-weighted images were reduced at 18 months. High-intensity areas of T2-weighted images in the acute phase might indicate the possibility of therapeutic response to corticosteroid therapy.


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