Left ventricular filling patterns in patients with previous myocardial infarction measured by conventional cine cardiac magnetic resonance.

To explore left ventricular filling patterns in patients with a history of previous myocardial infarction (MI) using time-volume curves obtained from conventional cine-cardiac magnetic resonance (CMR) examinations. Consecutive patients with a history of previous MI who were referred for CMR evaluation constituted the study population, and a consecutive cohort of sex and age-matched patients with a normal CMR constituted the control group. The following CMR diastolic parameters were evaluated: peak filling rate (PFR), time to PFR (tPFR), normalised PFR adjusted for diastolic volume at PFR (nPFR), and percent RR interval between end systole and PFR. Fifty patients were included, 25 with a history of previous MI and 25 control. The mean age was 59.6 ± 13.9 years and 27 (54%) were male. Within the control group, age was significantly related to PFR (r = -0.53, p = 0.007), whereas among patients with previous MI age was not related to PFR (r = -0.16, p = 0.44). PFR (252.4 ± 96.7 ml/s vs. 316.0 ± 126.4 ml/s, p = 0.05) and nPFR (1.6 ± 1.2 vs. 3.3 ± 1.5, p < 0.001) were significantly lower in patients with previous MI, whereas no significant differences were detected regarding tPFR (143.0 ± 67.5 ms vs. 176.2 ± 83.9 ms, p = 0.13) and % RR to PFR (18.1 ± 9.7% vs. 20.6 ± 12.2%, p = 0.44). MI size was related to LV ejection fraction (r = -0.76, p < 0.001), PFR (r = -0.40, p = 0.004), nPFR (r = -0.52, p < 0.001) and left atrium area (r = 0.40, p = 0.004). Patients at the lowest PFR quartile (<200 ml/s) showed a larger MI size (Q1 26.5 ± 25.5%, Q2 15.5 ± 20.9%, Q3 6.3 ± 12.4%, Q4 8.8 ± 14.1%, p = 0.04). At multivariate analysis, MI size was the only independent predictor of the lowest PFR (p = 0.017). Infarct size has an impact on LV filling profiles, as assessed by conventional cine CMR without additional specific pulse sequences.

Signal density of left ventricular myocardial segments and impact of beam hardening artifact: implications for myocardial perfusion assessment by multidetector CT coronary angiography.

UNLABELLED: We sought to explore the normal myocardial signal density (SD) levels during multidetector computed tomography coronary angiography (MDCT-CA) acquisitions and evaluated the impact of beam hardening artifacts. BACKGROUND: Since myocardial perfusion by MDCT is based on the myocardial signal density (SD), it is pivotal to determine the normal values of myocardial SD and to identify potential mechanisms of misinterpretation of perfusion defects. In routine MDCT acquisitions, we commonly visualize a considerable SD drop at the posterobasal wall resembling perfusion defects, being attributed to beam hardening artifacts. Consecutive asymptomatic patients without history of coronary artery disease (CAD) and low probability of CAD who were referred for MDCT evaluation at our institution due to inconclusive or discordant functional tests constituted the study population. Perfusion defects were defined as a myocardial segment having a SD two standard deviations below the average myocardial SD for the 16 left ventricular American Heart Association (AHA) segments. Thirty six asymptomatic patients constituted the study population. Myocardial SD was evaluated in 576 American Heart Association (AHA) segments and 36 posterobasal segments. The mean myocardial SD at the posterobasal segment was 53.5 +/- 35.1 HU, whereas the mean myocardial SD at the basal, mid and apical myocardium was 97.4 +/- 17.3, with significant differences (p < 0.001) between posterobasal and all AHA segments. Posterobasal "perfusion defects" were identified in 26 (72%) patients. The only variable associated to the presence of posterobasal SD deficit was the heart rate (61.8 +/- 6.2 bpm vs. 56.3 +/- 8.1 bpm, p = 0.04), whereas body mass index, blood SD of the left and right ventricles, contrast-to-noise ratio, and the extent of atherosclerosis were not related to the presence of "perfusion defects". In an asymptomatic population with no history of coronary artery disease, a myocardial signal density deficit mimicking a perfusion defect is a common finding in the posterobasal wall and is not related to body mass index or scan quality.

Chronic myocardial infarction detection and characterization during coronary artery calcium scoring acquisitions.

BACKGROUND: Hypoenhanced regions on multidetector CT (MDCT) coronary angiography correlate with myocardial hyperperfusion. In addition to a limited capillary density, chronic myocardial infarction (MI) commonly contains a considerable amount of adipose tissue. OBJECTIVE: We explored whether regional myocardial hypoenhancement on contrast-enhanced MDCT could be identified with standard coronary artery calcium (CAC) scoring acquisitions with noncontrast CT. METHODS: Consecutive patients with a history of MI who were referred for contrast-enhanced MDCT from November 2006 until March 2009 were studied. Noncontrast CT for CAC scoring was also performed. The correlation between regional myocardial hypoenhancement on contrast-enhanced CT and regional myocardial hypoattenuated areas on noncontrast CT was defined. RESULTS: Eighty-three patients (mean age, 61.5+/-12.5 years; n=67; 81% male) with previous MI were studied. A total of 1411 myocardial segments were evaluated. Two hundred thirty-nine segments (17%) showed myocardial hypoenhancement by MDCT and 140 segments (9.6%) by CAC. On a patient level, noncontrast CT showed a sensitivity, specificity, positive predictive value, (PPV) and negative predictive value (NPV) of 66% (95% CI, 0.53-0.77), 100% (95% CI, 0.76-1.00), 100% (95% CI, 0.90-1.00), and 41% (95% CI, 0.26-0.58), respectively, to detect myocardial hypoenhancement. On a per segment level, noncontrast CT showed a sensitivity, specificity, PPV, and NPV of 58% (95% CI, 0.51-0.64), 100% (95% CI, 0.99-1.00), 99% (95% CI, 0.94-1.00), and 92% (95% CI, 0.90-0.93), respectively, to detect myocardial hypoenhancement. CONCLUSIONS: Our findings suggest that chronic MI can be detected with standard CAC scoring acquisitions.

Early assessment of myocardial viability by the use of delayed enhancement computed tomography after primary percutaneous coronary intervention.

OBJECTIVES: We sought to explore the relationship between established parameters of reperfusion and the extent of myocardial damage measured by the delayed enhancement (DE) of iodinated contrast by multidetector computed tomography (MDCT) immediately after primary percutaneous coronary intervention (PCI). BACKGROUND: Early detection of myocardial viability should be valuable for risk stratification of patients with reperfused acute myocardial infarction (AMI). METHODS: Consecutive patients without a history of previous AMI who underwent primary PCI for an ST-segment elevation AMI were examined by DE-MDCT without an additional contrast injection immediately after completion of PCI. No medication was administrated to lower the heart rate. Dose modulation lead to an approximate mean radiation dose of 5.5 mSv. RESULTS: Thirty patients constituted the study population. Mean age was 61.4 +/- 15.6 years, 24 (80%) were men, and 4 (13%) were diabetic. Although post-procedural Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 was achieved in all patients, DE was detected in 14 (47%) patients. Age, sex, hypertension, diabetes, smoking history, serum creatinine levels, and pain duration were not associated with the presence of DE. Door-to-balloon time (DE 70.3 +/- 33.6 min vs. non-DE 98.3 +/- 70.7 min, p = 0.19) and lesion crossing time (DE 18.6 +/- 11.4 min vs. non-DE 16.4 +/- 9.6 min, p = 0.58) did not differ between groups. The TIMI myocardial perfusion grade (0 to 1 vs. 2 to 3) after stent implantation and electrocardiogram ST-segment resolution (<50% or >/=50%) were associated with the presence of DE (p = 0.001 and p = 0.02, respectively). Pre-discharge left ventricular ejection fraction was lower in DE than in non-DE patients (44.6 +/- 12.4% vs. 54.1 +/- 10.3%, respectively, p = 0.05). Hospitalization days (DE 5.6 +/- 3.8 vs. non-DE 4.8 +/- 1.0, p = 0.41) and 6-month cardiac events (DE 3 of 14 vs. non-DE 1 of 16, p = 0.22) did not differ between groups. CONCLUSIONS: Early detection of myocardial viability immediately after primary PCI by the use of DE-MDCT is related to clinical and angiographic parameters of myocardial reperfusion.

Modified scan protocol using multislice CT coronary angiography allows high quality acquisitions in obese patients: a case report.

Nearly every cardiovascular functional imaging technique has difficulties in dealing with obese patients and MSCT-CA is not an exception. Excluding such large portion of the coronary population remains a grim limitation of the technique and requires thus a comprehensive re-evaluation. In this report, we show that excellent image quality could be achieved in a morbidly obese patient with the aid of proper management of scan protocols and bolus administration. Providing this complex population an accurate, non-invasive imaging technique represents a major step-forward in cardiovascular imaging.

Multislice CT coronary angiography for the detection of burden, morphology and distribution of atherosclerotic plaques in the left main bifurcation.

The aim of the study was to explore the differences in plaque burden at different segments of the left main bifurcation and its relationship with the bifurcation angle using high-resolution multislice CT coronary angiography (MSCT). Patients were evaluated using a 40-row MSCT scanner. One observer assessed the localization, severity and distribution of plaques within the left main (LMCA) bifurcation, whereas another observer defined the angle. Fifty patients were included. The mean heart rate was 59.8 +/- 7.1. Seventeen (34%) patients presented at least wall irregularities in the LMCA and in the ostial LCx, whereas the ostial LAD was affected in 32 (64%) patients. More than 90% of plaques were located opposite to the flow divider. The median bifurcation angle was 88.5 degrees (IQR 68.8 degrees, 101.4 degrees). Of the 18 patients with a normal ostial LAD, 13 (72%) had a bifurcation angle < 88.5 degrees , whereas the 63% of the patients with any LAD disease had an angle >or= 88.5 degrees (P = 0.018). In conclusion, at the left main bifurcation, atherosclerotic plaques are commonly located at the ostial LAD and opposite to the flow divider. The angle of the left main bifurcation and the presence of plaques within the bifurcation are closely related.

Acceleration of the Increase of Endogenous Thyrotropin Hormone for Follow up Studies or Radioiodine Treatment in Patients with Differentiated Thyroid Carcinoma / Incremento rápido de tirotrofina endógena en pacientes con carcinoma diferenciado de tiroides para seguimiento o tratamiento con radioyodo

In follow up (F-U), ablation (A), or treatment (T) with radioiodine of patients with differentiated thyroid carcinoma (DTC), it is necessary to obtain elevated figures of serum TSH to assess hTg serum values or carry out 131I scanning. During the past few decades, the method employed was the withdrawal of hormonal treatment (WTH) for several weeks and its variants with the inconvenient symptoms of hypothyroidism, often restraining the use of this method. We aimed to obtain a rapid rice of serum TSH after a very short withdrawal of thyroid hormonal treatment (eight to nine days ) with the use of three or four intravenous application of TRH (200 mcg) during the first 6 days of withdrawal (TRH-St). One hundred determinations were carried out in 66 patients with DTC (ages19-80 y.o ), 20 males and 46 females. Sixty seven TRH-St were carried out for F-U, 20 for FU/T and 13 for A. In all cases the TSH values after the 3rd or 4th TRH application (samples 1 and 2) were over the value of 25 mIU/L and in the case of the second sample 99/100 determination were over the value of 30 mU/L. The values obtained were for the first sample 70.9 mIU/L ± 54.5 (range 25-310) and for the second sample 85.2 ± 61.3 (range 26-360), p<0.001. Patients considered that the symptoms and discomfort observed were mild when compared to those observed in patients submitted previously to the WTH method for 4/5 weeks. The results observed with TRH-St, allow us to consider the method as an alternative to the classic withdrawal method or the use of rhTSH with an adequate relation cost benefit.

Para efectuar ablación (A) , tratamiento con radioyodo (T) o seguimiento (S) en pacientes portadores de carcinoma diferenciado de tiroides (CDT) se hace necesario incrementar los valores de tirotrofina sérica (TSH) para elevar la sensibilidad del centellograma y la especificidad de la determinación de tiroglobulina sérica (hTg). Por años el método clásico fue la suspensión del tratamiento opoterápico (WTH) o sus variantes y ocasionalmente el uso de TSH de origen animal o , raramente, humana. Hace una década, la introducción de la TRH recombinante (rhTSH) significó evitar la desagradable sintomatología del hipotiroidismo que conllevaba el uso del método (WTH) y que en ocasiones impedía su utilización. Nuestro objetivo: el rápido ascenso de la TSH sérica después de muy breve WTH (ocho a nueve días) utilizando tres o cuatro aplicaciones intravenosas de la hormona liberadora de tirotrofina (TRH) durante los primeros seis días de WTH, método que denominamos TRH-St. Se efectuaron cien TRH-St en 66 pacientes: 20 masculinos, 46 femeninos, edades 19-80 años; 61 carcinomas papilares de diversas variantes anatomopatológicas, 4 foliculares y una variantes Hürthle. En todos los estudios después de la 3ra y cuarta aplicación de TRH (muestras 1 y 2 respectivamente) los valores de TSH fueron superiores a 25 mUI/L y con respecto a la cuarta TRH, 99/100 estudios ofrecieron valores de TSH superiores a 30 mUI/L. Los promedios obtenidos fueron: muestra 1 : 70.9 ± 54,5 mUI/L de TSH (rango 25-310); muestra 2: 85.2 ± 61.3 (rango 26-360): p < 0,001. Los pacientes consideraron que la sintomatología adversa del hipotiroidismo y el "disconformismo" fueron leves y sin comparación con los observados por aquellos pacientes sometidos anteriormente al método de supresión hormonal por 4/5 semanas.. Estas observaciones nos llevan a considerar que el método TRH-St , es una alternativa válida del método clásico de suspensión hormonal o del uso de rhTSH con una relación adecuada costo / beneficio.

Estimulación iterativa (EI) de TSH endógena (TSH-En) mediante el uso de la hormona liberadora de tirotrofina (TRH) en pacientes portadores de carcinoma diferenciado de tiroides / Rapid iterative stimulation (IS) of endogenous tsh (En-TSH) utilizing thyrotropin releasing hormone (TRH) in patients with differentiated thyroid carcinoma (DTC)

En el CDT es indispensable elevar los valores de TSH para efectuar Tg y barrido (RCT) con 131I, debiéndose suspender la opoterapia (HT) durante 4/5 sem. con el consecuente hipotiroidismo (H) y los trastornos que conlleva. Nuestro objetivo fue incrementar en forma rápida TSH-E acortando el tiempo de abstinencia. Se efectuaron 43 estudios en 37 pacientes con CDT (G-1); de entre 19 y 78 años, 34 con forma papilar y 3 folicular de CDT, 12 de sexo masculino y 25 femenino Se consideraron 2 subgrupos, G-1A, 7 p. para ablación (A); G-1B, 36 p. para seguimiento (S) y/o tratamiento (T) entre 6 meses y 5 años poscirugía; 6 p. efectuaron dos estudios, 4 para A y S y 2 para 2 veces S. Como comparación se revisaron 41 estudios en 35 p (G-2) que efectuaron suspensión de opoterapia por 4/5 semanas, entre 18 y 81 años; 28 de sexo femenino y 7 masculino; 32 papilares y 3 foliculares; 18 para A (G-2 A) y 21 para S, primer control (G-2B); 4 p. efectuaron 2 estudios, A y S. G-1A: entre 8/10 días poscirugía se les administra TRH 200 mcg i.v los días 1, 3, 5 y 6. A los 30 min de la 3ra aplicación, determinación de TSH y RCT con 370 MBq de 99mT; a igual lapso en la 4ta aplicación determinación de TSH, Tg y antiTg y 5,55 o 7,4 GBq de 131I, para A; a los 8 días RCT con 131I. G-1B: se suspende T4 y reemplaza por T3 por 3 semanas. Se suspende T3; a las 24 horas se inicia el esquema indicado para G-1A . A la 4ta aplicación de TRH, se administra el 131I, 14,8 MBq y RCT a las 48 horas en S o la actividad terapéutica indicada para T. En ambos grupos se indicó dieta hipoyódica. Resultados: En G-1, los valores de TSH ascendieron a 26-360 UI/L; promedio 83 UI/L ± 54; G-1A : 137 ±109; G-1B 7, 62 ± 52 . Los RCT no mostraron diferencias con ambos trazadores. En G-1A todos los p presentaron remanentes tiroideos y Tg positivas. En G-1B, 21 p. mostraron RCT y Tg negativas; 7 áreas activas y Tg positivas y 8 p RCT negativos con valores elevados de Tg . En G-2, TSH, 23-170 UI/L ( 63 ± 3 UI/L) ; G-2 A: 71 ± 41 ; G-2B, 63 ± 42. Conclusiones: Estos hallazgos indican que a) la metodología propuesta es adecuada para acortar sensible-mente el tiempo de abstinencia de opoterapia y reducir la sintomatología del H que pasa desapercibida en la mayoría de los casos; b) los valores de TSH-En obtenidos son similares y aun superiores a los alcanzados por suspensión de opoterapia por lapsos prolongados; c) el empleo del RCT con 99mTc como indicador de tejido captante disminuye el uso terapéutico a ciegas de 131I al señalar casos de ausencia de concentración y permite, cuando sea necesario, obtener anticipadamente 131I para su empleo terapéutico.

In the follow up (F) of p with DTC it is necessary to obtain high figures of serum TSH for determination of serum Tg and 131I scan (WBS). For this object, he method, for a long time, was to withdrawal thyroid hormone therapy (generally l-T4) that produce hypothyroidism with the inconvenient for the p, dramatics in certain cases. Our objective was to increase TSH by IS to shortening time of L-T4 withdrawal for F, ablation (A) or treatment (T) with 131I. In 37 p. with DTC (G-1), aged 19-78 y., 34 with pap. DTC and 3 with foll. form, 25 females, 12 males, 43 studies were carried out; 6 p carried 2 studies. The group was divided in 2 sub-groups: G-1A,7 p derived for A; G-1 B 36 p. for F or T with 131I. Six p carried out 2 studies; 4 of them for A and for F and 2 realizes 2 times F. All p treated with l-T4 replaced this hormone for T3 during 3 weeks ,that was withdrawal the day before IS. In G-1A, between 8/10 days after surgery they begin IS. IS: At days 1, 3, 5 and 6, the p were injected i.v. with 200 mcg of TRH; at 30 minutes of the 3rd injec. blood TSH determination ; immediately 370 MBq of 99mT was administered and at 30 minutes a WBS was carried out. At 30 minutes of the 4th injec. blood figures of TSH, Tg and Tg-ab were determined; immediately the activity of 131I indicated for each group was given to the p; in G-1A, at 8 days and in G1-B, at 48 hours WBS were carried out. As a control group (G-2) 41 studies in 35 DTC p. that withdrawal l-T4 for 4/5 weeks, were studied, aged 18-81 years, 31 females and 4 males; 32 with pap. and 3 folli.c form; 18 for A (G-2A) and 23 for F (G-2B); 6 p carried out 2 studies. One for A and the second as the first control. In G-1, TSH values obtained were 26-360 UI/L ( 83 ± 54. In G-1A : 137 ± 109 and in G-1B 62 ± 52). The 2 tracers 131I and 99mTc-Tc, produce show similar figures. In G-1A all p present thyroid remnants and elevated Tg. In G-1B, 7 p showed positive WBS and Tg; 8 p present Tg positive and WBS negative and 21 WBS and Tg negative. In G-2, the TSH values obtained were 23-179 UI/L (63 ± 39 ); G-2A 71 ± 41 and G-2B 63 ± 42. These findings indicate that the methods is adequate to shortened the time of withdrawal of l-T4 and reduce the signs/symptoms of hypothyroidism to an acceptable status. Also allow us to considered the use of 99mTc as an indicator of existence of remnants, relapses or metastases and avoid blind use of therapeutic activities of 131I.