Inadvertent embolic obstruction of abdominal aorta from left atrial thrombus after percutaneous mitral valvuloplasty

Inadvertent embolic obstruction of the distal abdominal aorta and left renal artery during a percutaneous mitral valvuloplasty procedure in a patient with mitral stenosis is reported. The embolism was from a left atrial thrombus which was detected by magnetic resonance imaging (MRI) but not by transesophageal echocardiography.     

核素心室显像对保留二尖瓣结构的二尖瓣替换术疗效评价

目的了解保留二尖瓣结构的二尖瓣替换术（ＭＶＲＰ）对术后早期心功能的影响及较常规二尖瓣替换术（ＣＭＶＲ）的优越性。方法３９例行二尖瓣替换术的二尖瓣关闭不全（ＭＩ）及二尖瓣狭窄（ＭＳ）病人手术前后进行核素心室显像。结果在ＭＩ病人中，保留组术后左室侧壁、侧壁近心尖、尖下壁局部射血分数（ｒＥＦ）较术前增高（Ｐ＜００１），术后侧壁、尖下壁ｒＥＦ较常规组改善更明显（Ｐ＜００５）；常规组术后左室间隔近基底ｒＥＦ明显下降（Ｐ＜００５）。保留组术后左室径线缩小明显，左室舒张末期容积及容积指数均较术前明显减小（Ｐ＜００５）。在ＭＳ病人中，保留组术后左室高峰充盈率较术前增高（Ｐ＜００５），术后相角程减少（Ｐ＜００５）。结论ＭＩ病人行ＭＶＲＰ有助于改善术后早期心功能，核素心室显像对二尖瓣替换术的疗效评价准确可靠，为一种有价值的无创性方法     

Magnetic resonance evaluation of anterior cruciate ligament repair using the patellar tendon double bone block technique

The magnetic resonance (MR) appearance of the anterior cruciate ligament reconstruction was determined in 20 clinically stable and 2 clinically unstable knees for a total of 22 examinations. All patients studied had undergone knee reconstruction using the patellar tendon as graft material. The reconstructed anterior cruciate ligament varies in appearance. It appeared as a thick, well-defined, low signal band on T1- and T2- weighted sagittal and coronal images in 14 of 22 examinations. The remaining 8 knees showed a graft having one or more thin and attenuated, low signal intensity bands in the sagittal and/or coronal plane. In 3 of these cases, the grafts appeared thicker in the coronal plane. All cases, including the two clinically unstable knees, showed no break in graft continuity. Arthroscopy confirmed an intact but lax graft in the clinically unstable knees.     

Magnetic resonance imaging of muscle injury

To further evaluate the role of magnetic resonance (MR) imaging in diagnosing and managing muscle injuries, eight patients with muscle pain or palpable masses were imaged. MR findings were correlated with clinical follow-up data. Increased signal was noted on T2-weighted images in torn and overused muscles. One extensively scarred muscle required surgical biopsy to exclude a fibrous tumor. Three partial muscle tears were treated conservatively. One complete musculotendinous junction tear required tendon transfer. MR studies noninvasively identified and staged various muscle injuries, thereby influencing management.     

外伤性二尖瓣关闭不全的外科治疗

目的 探讨外伤性二尖瓣关闭不全的临床特点、外科治疗方法及其手术效果.方法 回顾分析2000年12月-2007年11月收治的16例外伤性二尖瓣关闭不全外科手术治疗的临床病例.16例中术前心胸比例0.55±0.07,左心室射血分数为(51.2±23.2)%,按纽约心脏病学会(NYHA)心功能分级:Ⅰ～Ⅱ级者10例(63%).手术方法包括二尖瓣成形14例,二尖瓣置换术2例,并同期矫治合并病变.随访14例,随访时间(35.2±25.7)个月.结果 外伤至出现二尖瓣关闭不全症状的时间为(23.3±50.9)个月.随访时,13例二尖瓣成形者,二尖瓣血流正常4例,微量反流7例,少量反流2例.14例左心室射血分数为(66.8±9.0)%,较术前明显升高(P＜0.05).心功能NYHA Ⅰ～Ⅱ级者13例(93%),与术前比较,心功能NYHA Ⅰ～Ⅱ级者所占百数比明显增高(P＜0.01).结论 外伤性二尖瓣关闭不全可在外伤后即刻出现,亦可在外伤后数年逐渐出现.选择适当的手术时机,应用综合性二尖瓣成形术或者二尖瓣置换术,多能获得满意的中远期效果.     

Clinical impact of mitral calcium volume in patients undergoing transcatheter aortic valve implantation

BackgroundMitral annular calcification (MAC) has been associated with mitral valve (MV) disease and cardiovascular events in patients undergoing transcatheter aortic valve implantation (TAVI). We aimed to investigate the incidence and impact of mitral calcium volume (MCV) quantified by multidetector computed tomography (MDCT) on MV function and clinical outcomes after TAVI.MethodsConsecutive patients with exploitable echocardiography and MDCT performed during TAVI screening were enrolled in this retrospective analysis. Mitral calcium was assessed visually and measured using a semi-automatic tool developed for the aortic valve in an off-label fashion.ResultsMCV >0 mm³ was found in 65% of the 875 included patients. Patients with calcification were older (82 ± 6 versus 81 ± 7; P = 0.002) and had high prevalence of renal dysfunction (69% versus 61%; P = 0.017) and mitral stenosis (25% versus 4%, P < 0.001). MCV correlated well with visual MAC severity (r = 0.94; P < 0.001), but showed a greater predictive value for mitral stenosis (AUC = 0.804 vs. 0.780, P = 0.012) , while it was not a predictor of mitral regurgitation (AUC = 0.514). Correlations were found between MCV and echocardiographic parameters including MV area, mean transmitral gradient, and pressure half-time (P < 0.001 for all). MCV did not impact on cardiovascular mortality or new permanent pacemaker implantation after TAVI.ConclusionsCalcification of the mitral apparatus is common in TAVI candidates and results in mitral stenosis in 25% of the patients. Increasing MCV predicts mitral stenosis, but had no impact on clinical outcomes following TAVI.Clinical trial registrationNCT01368250.     

Magnetic resonance imaging of acute pulmonary embolism

Pulmonary embolism (PE) is a very common and potentially life-threatening disease. In comparison with CT, the clinical relevance of magnetic resonance imaging (MRI) for the assessment of PE is low. Nevertheless, as there are some potential advantages of MRI over CT (e.g. radiation free method, better safety profile of MR contrast media, capability of functional imaging). In certain patient, groups MRI might therefore be considered as a valuable alternative in the assessment of suspected PE. This article reviews the relevant MRI techniques for the evaluation of PE and gives an overview of the current literature for contrast-enhanced MR angiography of PE.     

二尖瓣狭窄合并左心房血栓患者的经皮二尖瓣球囊成形术

目的　评价经皮二尖瓣球囊成形术 (PBMV)治疗风湿性二尖瓣狭窄合并左心房血栓的临床疗效和安全性。方法　 2 7例风湿性二尖瓣狭窄合并左心房血栓患者进行PBMV ,19例食管超声心动图 (TEE)有左心房内新鲜血栓者术前经华法令抗凝治疗 3～ 6个月。结果　 2 7例风湿性二尖瓣狭窄合并左心房血栓患者进行PBMV均成功。 19例TEE有左心房内新鲜血栓者 ,PBMV术前经华法令抗凝治疗后 ,TEE复查示 9例左心房血栓消失 ,10例左心房内血栓明显缩小 ,机化为高强回声团块的陈旧性血栓 ;5例经胸心脏超声发现左心房陈旧性血栓 ,未行TEE也未予华法令治疗者 ,术中 1例发生脑栓塞。其余患者均无并发症发生。结论　对风湿性二尖瓣狭窄伴有心房纤维颤动患者 ,PBMV前应常规行TEE检查 ;二尖瓣狭窄伴左心房血栓者经充分抗凝治疗后行PBMV是安全可行的。     

一步法治疗中重度二尖瓣狭窄的研究(附492例报告)

目的　研究一步法经皮球囊扩张术治疗中重度二尖瓣狭窄 15年的经验及长期随访的情况。方法　摒弃传统的三步法 ,采用一步法经皮经房间隔穿刺球囊扩张治疗二尖瓣狭窄。本组共 4 92例风湿性心脏病二尖瓣狭窄患者 ,其中男 15 6例 ,女 336例 ,年龄 4 1 2±10 5岁(15～ 6 8岁 )。结果　 4 92例二尖瓣球囊扩张术手术时间 36 5± 12 1min ,成功率 98 2 % (4 83/ 4 92 ) ,术后二尖瓣口面积从 0 89±0 18cm2 增加至 2 2 1± 0 4 1cm2 。 10 5例随访 8～ 98个月 ,二尖瓣再狭窄率为 11 4 % (12 / 10 5 ) ,远期死亡率为 2 9% (3/ 10 5 )。结论　一步法经皮球囊扩张术治疗重症二尖瓣狭窄成功率高 ,近远期疗效均佳。     

特殊情况的左房室瓣球囊扩张术疗效分析

目的　分析和总结伴有特殊情况的左房室瓣狭窄球囊扩张术(PBMV)的临床疗效和安全性。方法　收集我院自1986年12月至2 0 0 5年1月施行的2 30 0例风湿性心脏病左房室瓣狭窄(MS)病例,其中有特殊情况者6 2 1例。包括非单纯MS(合并左房室瓣关闭不全或主闭)者32 8例;非单纯的MS伴巨大左房者15例;巨大左房者10 6例;左房血栓者5 2例;巨大左房及左房血栓者4例;PBMV或左房室瓣闭式分离术后者79例;PBMV或左房室瓣闭式分离术后非单纯的MS者34例;妊娠大咯血者2例。采用Inoue球囊技术。结果　手术成功率98.5 % ,失败率0 .2 % ;发生严重并发症8例,并发症为1.3% ,其中急性左心衰2例,低心排1例,脑栓塞2例,心脏压塞3例。因急性左心衰、低心排、心脏压塞、脑栓塞造成的死亡各1例。结论　随着操作技巧的不断完善,许多伴有特殊情况的PBMV可安全、有效的接受手术。但术前一定要全面评价瓣膜、心功能、血栓情况     

Magnetic resonance imaging in patients with pancreatitis: evaluation of signal intensity and enhancement changes

PURPOSE: To evaluate the utility of unenhanced and enhanced T1-weighted fat-suppressed (T1-FS) magnetic resonance imaging (MRI) in detecting pancreatitis. MATERIALS AND METHODS: 1.5-T MRI was performed in 25 patients with acute and 23 patients with chronic pancreatitis and in 20 control subjects without known pancreatic disease. T1-FS spin-echo and contrast-enhanced arterial-predominant (DYN1) and portal-predominant (DYN2) fast multiplanar spoiled gradient-echo (FMPSPGR) sequences were evaluated. These three sets of images were evaluated both subjectively for decreased or heterogeneous signal intensity (rating scale, 0-3) and objectively (region of interest (ROI)) in the head, body, and tail of the pancreas, in each patient. RESULTS: Good correlation between subjective assessment and objective data was demonstrated. The T1-FS sequence showed an abnormality with greater frequency (T1-FS > DYN1, 81/144 scores; T1-FS = DYN1, 63/144 scores; T1-FS < DYN1, 0/144 scores) and magnitude (average subjective score, 2.48 vs. 1.74; P < 0.0003) than that of the contrast-enhanced FMPSPGR (decreased or heterogeneous enhancement). The overall sensitivity and specificity of MRI was 92% and 50%, respectively. On the basis of signal intensity and enhancement, MRI was not able to differentiate acute from chronic pancreatitis. CONCLUSION: MRI was highly sensitive for disease detection, particularly using the T1-FS sequence, but using the sequences described, was not able to differentiate acute from chronic pancreatitis.     

经皮二尖瓣球囊成形术治疗合并重度肺动脉高压的二尖瓣狭窄远期疗效评价

目的　评价经皮二尖瓣球囊成形术 (PBMV)治疗合并重度肺动脉高压的二尖瓣狭窄 (MS)的远期疗效。方法　对 30例合并重度肺动脉高压的二尖瓣狭窄患者进行严格的PBMV术后随访 ,包括超声心动图、胸片 ,临床心功能评价。平均随访时间 (6 .4± 1.4 )年。结果　二尖瓣口面积 (MVA)由术前的 (1.19± 0 .32 )cm2 增至术后的 (1.99± 0 .4 5 )cm2 (P <0 .0 1) ;随访 5年以上 ,MVA逐渐减小至(1.4 4± 0 .4 2 )cm2 ,较术后明显减小 ,P <0 .0 1;16例发生再狭窄 ,再狭窄率 5 3.3%。平均肺动脉压(PAMP)由术前的 (6 5 .3± 14 .1)mmHg降至术后的 (40 .0 3± 12 .6 9)mmHg ,P <0 .0 1;PBMV术心功能改善 1个级别以上者占 93.3% ,术后 5年以上随访心功能仍维持在Ⅰ～Ⅱ级而未再次行介入或换瓣手术者占 73.3%。结论　PBMV术对合并重度肺动脉高压的MS患者也有较为满意的远期疗效 ,作为一种良好姑息疗法可明显缓解此类重症患者的临床症状。     

Proximal coronary artery stenosis: Three-dimensional MRI with fat saturation and navigator echo

The purpose of this study was to compare the diagnostic value of MR angiography (MRA) with conventional contrast angiography in coronary artery disease. Thirty-five patients underwent MRA and coronary angiography within 4 hours. Of these, three patients were investigated twice: once before and once after balloon angioplasty. The pulse sequence was a cardiac-triggered, single-slab, three-dimensional gradient-echo sequence, employing a spin-echo navigator echo measurement to track the variation of the diaphragm during the scan. The following segments of the coronary arteries were included in this prospective study: left main coronary artery, proximal and middle left anterior descending, proximal and middle left circumflex, proximal and middle right coronary artery, and intermediate branch, if present. In total, 176 segments were classified as normal or having a stenosis of less than 50% and as having a stenosis of more than 50%. Five patients were excluded because of lack of cooperation. Over all, 45 of 54 stenoses were detected and interpretable by MRA. Sensitivity, specificity, and positive and negative predictive values of MRA for detecting significant stenoses were 83%, 94%, 87%, and 93%, respectively. MRA identified significant stenoses within the major coronary arteries with a high degree of accuracy. Sensitivity and specificity are higher compared with exercise tests or scintigraphy or top of the precise localization.     

二尖瓣脱垂的CT表现

目的了解二尖瓣脱垂的CT表现并探讨CT诊断二尖瓣脱垂的可行性。方法对25例经手术或心脏超声证实的二尖瓣脱垂患者的64层CT心脏图像进行分析。结果所有25例患者均可见收缩期二尖瓣叶突人左心房,并超过瓣环平面2mm。其他CT表现包括瓣叶增厚超过2mm（14例）和腱索断裂（3例）。结论二尖瓣脱垂具有特殊的CT表现,CT能够可靠地诊断二尖瓣脱垂。     

风湿性心脏病二尖瓣狭窄伴严重肺动脉高压的球囊扩张术疗效

目的　评估风湿性心脏病二尖瓣狭窄 (风心二狭 )伴严重肺动脉高压的经皮球囊导管二尖瓣扩张术疗效 ;以超声多普勒检查观察术后近期的肺动脉压变化。方法　 4 2例风心二狭伴严重肺动脉高压 (肺动脉收缩压≥ 75mmHg)患者以标准Inoue技术行经皮二尖瓣扩张术 ,并测定随访期临床心功能和多普勒超声肺动脉收缩压的变化。结果　 39例扩张术成功 (93% )。术后二尖瓣瓣口面积自 (0 .83±0 .12 )cm2 增至 (1.75± 0 .11)cm2 ,肺动脉收缩压自 (85± 7)mmHg降至 (6 1± 13)mmHg(P值均 <0 .0 0 1)。3例并发严重二尖瓣返流 ,其中 1例行二尖瓣置换术。在平均 6个月的随访中 ,39例成功扩张者 ,尽管二尖瓣瓣口面积无显著改变 ,但临床心功能明显改善 ,肺动脉收缩压进一步降低。结论　风心二狭伴严重肺动脉高压患者行经皮球囊导管扩张术安全、有效。术后短期内肺动脉收缩压继续减低 ,临床心功能进一步改善。     

Low-field magnetic resonance imaging in the evaluation of mechanical and biological heart valve function

Magnetic resonance imaging (MRI) has been frequently considered unsafe for patients with ferromagnetic implants: risks to be considered include induction of electric current, heating and dislocation of the prosthesis. Previous in vitro and in vivo studies have indicated the possibility of performing MRI examinations on patients with prosthetic heart valves. The aim of our study was to verify the presence of artifacts at the level of the prosthetic heart valve in vivo using a low-field MR unit (0.2 T) and to define the possibility of a functional analysis of the valve in patients with biomedical or mechanical prostheses. We evaluated 14 patients surgically treated for implantation of nine biological and seven mechanical aortic and mitral valves. A low-field MR unit (0.2 T) was employed using cine-MR technique on long- and short-axis view. The images were acquired on planes parallel and perpendicular to the valvular plane. Semiquantitative analysis with double-blind evaluation for definition of the extent of the artifact was performed. Three classes of artifacts were distinguished from minimal to significant. The examinations showed the presence of minimal artifacts in all biological heart valves and moderate artifacts in mechanical valves giving good qualitative data on blood flow near the valve. Analysis of the flow behind the valve showed signs of normal function in 13 prostheses and pathological findings in the remaining three. In these latter cases, MRI was able to define the presence of a pathologic aortic pressure gradient, mitral insufficiency and malpositioning of the mitral valve causing subvalvular turbulence. Nevertheless, we believe that the application of velocity-encoding cine-MR is more promising than semiquantitative analysis of artifacts.     

Dynamic computed tomographic assessment of the mitral annulus in patients with and without mitral prolapse

ObjectivesTo obtain 3D CT measurements of mitral annulus throughout cardiac cycle using prototype mitral modeling software, assess interobserver agreement, and compare among patients with mitral prolapse (MP) and control group.BackgroundPre-procedural imaging is critical for planning of transcatheter mitral valve (MV) replacement. However, there is limited data regarding reliable CT-based measurements to accurately characterize the dynamic geometry of the mitral annulus in patients with MV disease.MethodsPatients with MP and control subjects without any MV disease who underwent ECG-gated cardiac CT were retrospectively identified. Multiphasic CT data was loaded into a prototype mitral modeling software. Multiple anatomical parameters in 3D space were recorded throughout the cardiac cycle (0–95%): annular circumference, planar-surface-area (PSA), anterior-posterior (A-P) distance, and anterolateral-posteromedial (AL-PM) distance. Comparisons were made among the two groups, with p < 0.05 considered statistically significant. Interobserver agreement was assessed on ten patients using intraclass correlation coefficient (ICC) among 4 experienced readers.ResultsA total of 100 subjects were included: 50 with MP and 50 control. Annular dimensions were significantly higher in the MP group than control group, with circumference (144 ± 11 vs. 117±8 mm), PSA (1533 ± 247 vs. 1005 ± 142 mm²), A-P distance (38 ± 4 vs. 32±2 mm), and AL-PM distance (47 ± 4 vs. 39±3 mm) (all p < 0.001). Substantial size changes were observed throughout the cardiac cycle, but with maximal and minimal sizes at different cardiac phases for the two groups. The interobserver agreement was excellent (ICC≥0.75) for annular circumference, PSA, A-P- and AL-PM distance.ConclusionA significant variation in the mitral annular measures between different cardiac phases and two groups was observed with excellent interobserver agreement.     

Magnetic resonance angiography of the peripheral arteries: current status

Comprehensive imaging of the peripheral vasculature has traditionally only been possible with catheter angiography. With the introduction of time-of-flight magnetic resonance angiography (TOF MRA), non-invasive imaging of the peripheral arteries became a clinical reality; however, widespread adoption of TOF MRA did not occur due to long scan times and artefacts which precluded its use as a screening tool. Contrast-enhanced MRA, an extremely time-efficient technique with minimal associated artefacts, addresses most of the limitations of non-contrast techniques. Numerous technological advances, including bolus detection, optimized 3D volume placement, improved k-space filling mechanisms and the evolution from single-station to multi-location moving-table contrast-enhanced MRA, have facilitated the development of non-invasive evaluation of the peripheral vascular tree with contrast-enhanced techniques. Electronic Publication     

超声心动图在二尖瓣置换术后远期心功能不全病因诊断中的应用

 目的探索超声心动图在二尖瓣置换(MVR)术后远期心功能不全病因诊断中的作用。方法超声随访44例MVR患者术后3个月～13.5a,并根据手术的远期效果,分为心功能不全组(A组)和康复组(B组)。除注意人工瓣和自然瓣的病变外,还分析了这2组手术前后左房、左室内径及左室射血分数(EF)的差异。结果超声显示A组二尖瓣位单组或伴主动脉瓣位双组人工瓣异常5例,其它自然瓣明显病变11例。术后A组的左室内径明显大于B组(P＜0.05),EF值明显小于B组(P＜0.01)。超声心动图提供的信息为36.4％心功能不全代偿期和66.7％失代偿期患者诊断出了导致心功能障碍的主要原因。结论MVR手术前后超声检查对术后远期心功能不全的诊断具有实用价值。     

Magnetic resonance imaging of pituitary adenomas

Today, MR is the only method needed for the morphological investigation of endocrine-active pituitary adenomas. In acromegaly and Cushings syndrome, the therapeutic attitude is directly dictated by MR data. We present the MR aspect of pituitary adenomas according to size, sex, age, endocrine activity and a few particular conditions such as hemorrhagic pituitary adenomas, pituitary adenomas during pregnancy, cavernous sinus invasion and postsurgical changes. When an intrasellar mass extending out of the sella turcica is detected, the goal of the MR examination is to indicate precisely the origin of the tumor, its extension in relation to the various surrounding structures, its structure and its enhancement in order to help in the differential diagnosis. Demonstration of very small pituitary adenomas remains a challenge. When SE T1- and Turbo SE T2-weighted sequences are non-diagnostic, enhanced imaging becomes mandatory; half-dose gadolinium injection, delayed sequence, dynamic imaging can be of some help.