Three-layered Appearance Research Articles

O-126 Impact of letrozole cO-treatment during ovarian stimulation on the oocyte yield, embryo development, and live birth rate – a randomised controlled trial (RIOT)

Abstract Study question Does letrozole co-treatment during ovarian stimulation for in vitro fertilization (IVF) impact oocyte yield, embryo development, and live birth rate (LBR) in expected normal responders? Summary answer Letrozole co-treatment leads to similar oocyte yield, embryo- development and utilisation rate, and live birth rate after transfer in the fresh cycle. What is known already Letrozole reduces oestradiol levels by inhibiting the aromatization of androgens, this diminishes pituitary suppression and increases endogenous gonadotrophin release. These effects are utilized in ovulation induction in PCOS patients and may benefit certain patients during IVF treatment. In addition, we have recently reported in an RCT that co-treatment with letrozole increases luteal phase progesterone levels and, consistent with previous studies, no significant effect on pregnancy rates was observed. However, the impact of the changes in the endocrine milieu caused by letrozole co-treatment on the developing oocytes and embryos remains unclear as most published studies are retrospective and lack appropriate control-groups. Study design, size, duration A multicentre double-blinded randomised placebo-controlled trial was conducted in four fertility clinics at University Hospitals in Denmark from August 2016 to November 2018. 159 women were randomised, 129 women received single embryo (cleavage stage or blastocyst) transfer in the fresh cycle, and the surplus 257 embryos were vitrified. The study was conducted following the Helsinki Declaration and the ICH-Good-Clinical-Practice. Data collection and reporting followed the guidelines of CONSORT to achieve transparent reporting of trials. Participants/materials, setting, methods Women with expected normal ovarian response received an antagonist protocol with fixed-dose FSH. Co-treatment consisted of 5mg letrozole or placebo from the start of stimulation until the day of triggering final oocyte maturation with hCG. Standardized morphological evaluation was performed at all centres (applying the Istanbul consensus and Gardner-score). A sub-cohort of the embryos were cultured in an EmbryoScope incubator and further assessed by morphokinetic annotation and reported with.KIDScoreD3. Ongoing pregnancies were followed until birth. Main results and the role of chance A total of 1268 oocytes were retrieved from 154 women, leading to development of 386 usable embryos that were either transferred or vitrified. Utilisation rate (the proportion of usable embryos to oocytes) was similar in the letrozole group and placebo group with 0.31 vs. 0.36 (mean difference (MD): -0.05, 95% CI[-0.03;0.12], P = 0.25). Morphologically grading the embryos as “good”, “fair”, and “poor” quality showed similar results, the odds of having a higher quality were 0.78 times higher in the letrozole- vs. placebo group (CI[0.5;1.1], P = 0.2). Morphokinetic annotations (n = 302 embryos) showed similar results with the odds of having a high KIDScore3 1.3 times higher in the letrozole – vs. placebo group (CI[0.9;2.1], P = 0.2). The endometrial thickness at transfer was thinner in the letrozole compared to the placebo group with 8.5 vs. 9.5 mm (MD 1.0, 95% CI[0.4;1.6], P = 0.001) but with the same ultrasonic echogenicity and a preovulatory three-layer appearance. After embryo transfer in the fresh cycle (n = 129), no differences were seen in the pregnancy outcomes: positive serum hCG, ongoing pregnancy rate, early miscarriage rate, foetal miscarriage rate, or LBR. LBR per initiated cycle were similar as well (n = 159): 23.8% vs. 29.1% (MD of -5,3%, CI[-20.3%;9.6%], P = 0.48) in letrozole vs. placebo group, respectively. Limitations, reasons for caution Four clinics participating could lead to interobserver variability. However, bias was reduced by block-randomised design. All data are derived from an RCT, the primary endpoint of which, preovulatory progesterone, was the basis of the sample size calculation. The study may have been underpowered to show a significant impact on LBR. Wider implications of the findings Letrozole co-treatment during ovarian stimulation with gonadotrophins did not have an impact on the oocyte yield and embryo development. These data suggest that letrozole co-treatment is unlikely to compromise outcomes in its growing indications: ovulation induction, IVF in poor responders, and fertility preservation in breast cancer patients. Trial registration number NCT02946684

CT features of confirmed and presumed gastric wall edema in dogs.

Postcontrast computed tomographic (CT) characteristics of gastrointestinal (GI) wall edema in humans have been described as GI wall thickening with a thickened submucosal layer and thin enhanced inner and outer layers. Published studies describing CT features of gastric wall edema in dogs are currently lacking. The aim of this retrospective, case series was to describe CT features of gastric wall edema in a group of dogs. Medical records were searched for dogs with postcontrast abdominal CT scans and a diagnosis of gastric wall edema based on histopathology (group I) or CT characteristics consistent with those reported in humans (group II). Clinical diagnosis, mean serum albumin concentration, and histopathological diagnosis were recorded. The following CT characteristics were recorded: numbers of wall layers, attenuation and contrast enhancement, presence of blood vessels, locations, distribution, and thickness. Twelve dogs (3 in group I and 9 in group II) were included. The most common clinical finding was hypoalbuminemia. In group I, a well-defined three-layer appearance with a non-enhancing fluid-attenuating middle layer was observed in three dogs and thin blood vessels in the middle layer in two dogs. In group II, nine dogs had a three-layer appearance with a non-enhancing fluid-attenuating middle layer. Locations of gastric wall thickening were diffuse in two, focal concentric in six, and focal asymmetric in four dogs. Findings supported including gastric wall edema as a differential diagnosis for dogs with hypoalbuminemia and CT characteristics of a three-layer appearance in the gastric wall, with a non-enhancing fluid-attenuating middle layer and thin blood vessels.

Clinical Significance of Low Signal Intensity Area Surrounding Stent Struts Identified by Optical Coherence Tomography

Previous intravascular ultrasound studies have shown that echolucent neointimal hyperplasia occasionally appears after bare-metal stent (BMS) or sirolimus-eluting stent (SES) implantation. Optical coherence tomography (OCT) studies have also demonstrated that paclitaxel-eluting stent (PES) restenosis exhibited similar images showing low signal intensity areas (LSIA) surrounding stent struts and three-layer appearance (TLA). The aim of the present study was to investigate the clinical significance of LSIA on OCT images in various types of stents. Fifty nine consecutive patients who underwent scheduled follow-up coronary angiography and OCT were enrolled. There was no significant difference in the prevalence of LSIA among the 3 stent groups (BMS 30%, SES 19%, PES 28%, P = 0.70). LSIA thickness was larger in the PES group than in the other stent groups (BMS 0.51 ± 0.21 mm, SES 0.35 ± 0.06 mm, PES 0.87 ± 0.19 mm, P < 0.01). The ratio of LSIA thickness to the neointimal thickness was also larger in PES compared with other stents (BMS 53 ± 9 %, SES 57 ± 8 %, PES 77 ± 5 %, P < 0.01). Also, LSIA thickness in patients with in-stent restenosis (ISR) was significantly larger than in those without ISR (0.37 ± 0.37 mm versus 0.12 ± 0.26 mm, P = 0.048). Our results suggest that LSIA might be involved in excessive neointimal formation, and that the healing response after PES implantation might be different from BMS or SES.

Demonstration of intrahepatic accumulated microbubble on ultrasound represents the grade of hepatic fibrosis

ObjectivesTo examine the feasibility of perflubutane-based ultrasound for grading hepatic fibrosis.MethodsThis prospective study included 202 subjects; main study (controls:33, F0–1:35, F2:26, F3:23, cirrhosis:29) and subsequent study (controls:16, F0–1:7, F2:20, F3:7, cirrhosis:6). Diagnostic abilities for assessing fibrosis grade were compared between contrast findings and FIB4 (age × AST/[platelet count × ALT0.5]).ResultsHigh-power emission produced an intrahepatic band-like structure, and the three-layer appearance was less frequent and monolayer appearance was more frequent in cirrhosis than controls/chronic hepatitis (P < 0.0001). Intensity difference at 15-min phase showed most significant correlation with fibrosis grade (ρ = 0.79, P < 0.0001), and the best areas under the receiver operating characteristic curves are 0.88 for marked fibrosis, 0.95 for advanced fibrosis and 0.97 for cirrhosis, which were significantly higher than those of FIB4, 0.85 for marked fibrosis, 0.89 for advanced fibrosis and 0.90 for cirrhosis. Sensitivity, specificity and efficiency of the intensity difference were 88%, 72% and 81% for marked fibrosis, 85%, 91% and 89% for advanced fibrosis and 97%, 90% and 91% for cirrhosis, respectively. The subsequent study validated the main study results; significant correlation between the intensity difference and the fibrosis grade (ρ = 0.73–0.77, P < 0.0001).ConclusionsPerflubutane-based ultrasound accurately predicts the grade of hepatic fibrosis.Key Points• The behaviour of intrahepatic microbubbles depends on the severity of hepatic fibrosis.• Layer enhancement pattern simply represents the degree of chronic liver disease.• Parenchymal intensity change due to high-power emission predicts the hepatic fibrosis grade.

Layer-Dependent Variation in the Anisotropy of Apparent Integrated Backscatter from Human Coronary Arteries

Clinical imaging of the coronary arteries in the cardiac catheterization laboratory using intravascular ultrasound (IVUS) is known to display a three-layered appearance, corresponding to the intima/plaque, media and adventitia. It is not known whether ultrasonic anisotropy arising from these tissues may alter this pattern in future IVUS systems that insonify in the forward direction or obliquely. In anticipation of such devices, the current study was carried out by imaging fresh human coronary arteries in two orthogonal directions in vitro. Twenty-six sites from 12 arteries were imaged with a side-looking IVUS system, and with an acoustic microscope both radially and axially. Side-looking IVUS and radial acoustic microscopy scans demonstrated the typical “bright-dark-bright” pattern of the backscatter, with the media being significantly darker than the other two layers. Images obtained in the axial orientation exhibited a markedly different pattern, with the relative brightness of the media significantly larger than that of the intima/plaque. (E-mail: james.g.miller@wustl.edu)

Gray scale and color Doppler US findings of amniotic sheets

To identify the gray-scale and color Doppler ultrasonography (US) findings of amniotic sheets. Among 1201 pregnant patients who underwent detailed second trimester US, nine had amniotic sheets. An amniotic sheet was defined as a shelf-like structure in the uterine cavity with a free edge not attached to the fetus or umbilical cord. There was no major fetal anomaly observed in any patient. Eight patients had solitary amniotic sheets, and one patient had double sheets. All gray-scale and Doppler US features of amniotic sheets were noted. The incidence of an amniotic sheet was determined to be 0.75% (ten amniotic sheets were observed in nine patients). On gray-scale US images, amniotic sheets were observed as bands of tissue that originated from the uterine wall with a triangular-shaped base that tapered toward the free edge. A three-layered appearance was identified in seven amniotic sheets. Using Doppler US images, four of ten sheets showed a low-resistance arterial flow, and five of ten sheets showed non-pulsatile venous flows. No vascularization was observed in one patient with a thin, membranous sheet. Gray-scale US is sufficient for the diagnosis of amniotic sheets because of the typical US characteristics; however, Doppler US findings of amniotic sheets are highly variable. Thus, Doppler US may not be beneficial in the diagnosis of amniotic sheets.

Cardiac magnetic resonance imaging of eosinophilic endomyocardial disease

Idiopathic hypereosinophilic syndrome (HES) is rare and frequently involves the heart with development of endomyocardial fibrosis, a characteristic restrictive cardiomyopathy. Non-invasive diagnosis is frequently challenging. Recent developments in cardiac magnetic resonance (CMR) imaging techniques offer potential for improved detection and characterization of this entity. We describe the use of contrast-enhanced CMR to demonstrate thrombus, endomyocardial fibrosis and inflammation in eosinophilic endomyocardial disease. A three-layered appearance consisting of normal myocardium, thickened fibrotic endocardium with inflammatory exudate, and overlying thrombus was seen on cine-images. Post-contrast perfusion and delayed enhancement images confirmed the presence and location of endomyocardial fibrosis and thrombus. CMR is an important and powerful addition to current non-invasive diagnostic tools for the clinical diagnosis of eosinophilic endomyocardial disease, and may potentially obviate the need for cardiac biopsy in the future.

Endovascular optical coherence tomography ex vivo: venous wall anatomy and tissue alterations after endovenous therapy

Endovascular optical coherence tomography (OCT) is a new imaging modality providing histology-like information of the venous wall. Radiofrequency ablation (RFA) and laser therapy (ELT) are accepted alternatives to surgery. This study evaluated OCT for qualitative assessment of venous wall anatomy and tissue alterations after RFA and ELT in bovine venous specimens. One hundred and thirty-four venous segments were obtained from ten ex-vivo bovine hind limbs. OCT signal characteristics for different wall layers were assessed in 180/216 (83%) quadrants from 54 normal venous cross-sections. Kappa statistics (kappa) were used to calculate intra- and inter-observer agreement. Qualitative changes after RFA (VNUS-Closure) and ELT (diode laser 980 nm, energy densities 15 Joules (J)/cm, 25 J/cm, 35 J/cm) were described in 80 venous cross-sections. Normal veins were characterized by a three-layered appearance. After RFA, loss of three-layered appearance and wall thickening at OCT corresponded with circular destruction of tissue structures at histology. Wall defects after ELT ranged from non-transmural punctiform damage to complete perforation, depending on the energy density applied. Intra- and inter-observer agreement for reading OCT images was very high (0.90 and 0.88, respectively). OCT allows for reproducible evaluation of normal venous wall and alterations after endovenous therapy. OCT could prove to be valuable for optimizing endovenous therapy in vivo.

Efecto comparativo del tetróxido de osmio y del tetróxido de rutenio como fijadores sobre la ultraestructura de la pared celular de hongos

The fungal cell wall viewed through the electron microscope appears transparent when fixed by the conventional osmium tetroxide method. However, ruthenium tetroxide post-fixing has revealed new details in the ultrastructure of Penicillium sp. hyphae and Saccharomyces cerevisiae yeast. Most significant was the demonstration of two or three opaque diverse electron dense layers on the cell wall of each species. Two additional features were detected. Penicillium septa presented a three-layered appearance and budding S. cerevisiae yeast cell walls showed inner filiform cell wall protrusions into the cytoplasm. The combined use of osmium tetroxide and ruthenium tetroxide is recommended for post-fixing in electron microscopy studies of fungi.

The dissected aorta: part II. Differentiation of the true from the false lumen with intravascular US.

To determine the intravascular ultrasound (US) features of aortic dissection that can be used to differentiate the true from the false lumen. Intravascular US and aortography were performed in 34 patients with aortic dissection. Aortic necropsy specimens were available in five patients. True and false lumina in each patient were identified on the basis of surgical, necropsy, and radiologic findings. Intravascular US studies were reviewed with attention to several local imaging features, which were evaluated for sensitivity and specificity in the differentiation of true from false lumina. An acute angle between the dissection flap and the outer wall of the false lumen was found in 32 patients (sensitivity, 94%; specificity, 100%). The three-layered appearance of the intact wall of true lumen and single-layered appearance of the outer wall of false lumen were seen in 33 patients (sensitivity, 97%; specificity, 100%). Cobwebs were present in the false lumen in eight patients but were not seen in the true lumen (sensitivity, 24%; specificity, 100%). Aortic thrombus was seen in the false lumen in 10 patients but was not seen in the true lumen (sensitivity, 29%; specificity, 100%). Intravascular US findings can be used to differentiate the true from the false lumen in aortic dissection.

Coronary compliance in patients following orthotopic heart transplantation: An intravascular ultrasound study

The aim of this study was to investigate coronary compliance in patients early and 71.8 weeks after orthotopic heart transplantation. Thirty patients (mean age 51.4 years, women n = 6) underwent coronary angiography early after orthotopic heart transplantation (mean interval 11.6 +/- 5.5 weeks), by which time 12 recipients had already been treated for episodes of rejection. A total of 153 different coronary segments were investigated using a mechanical 30 MHz intravascular ultrasound system. In all segments, the intimal index and the circumferential extension of the vessel wall, which had a three-layered appearance, were assessed. Systolic-diastolic changes in area, and pressure with respect to vessel wall area, were used to study normalized compliance. All measurements were repeated in a subgroup of 13 patients 71.8 +/- 10.7 weeks after transplantation. At the first investigation, the mean intimal index of all estimated cross-sectional areas was 0.07 +/- 0.10. The mean circumferential extension of the 'three-layered' coronary vessel wall was 74 degrees +/- 101 degrees. No correlation could be found between normalized compliance and the intimal index (r = -0.322, P < 0.001) or between normalized compliance and the circumferential extension of the three-layered vessel wall (r = -0.362, P < 0.001). Donor age did not correlate with normalized compliance either (r = -0.515, P = 0.004). In 12 patients with proven rejection periods before the first investigation, normalized compliance was significantly lower (1.76 +/- 0.81 mmHg-1) than in those without rejection (2.95 +/- 1.22 mmHg-1, P = 0.005). Both the intimal index and the circumferential extension of the three-layered architecture of the vessel wall were significantly higher in recipients with rejection periods. A comparison of the subgroup of 13 recipients between first and second investigation showed that the intimal index increased slightly from 0.03 +/- 0.03 to 0.09 +/- 0.13 (ns) 71.8 weeks after transplantation, but that normalized compliance did not differ significantly between the first and the follow-up investigation. Early after orthotopic heart transplantation, normalized compliance does not correlate with donor age or the extent of atherosclerotic vessel alterations identifiable by intravascular ultrasound. Early rejection periods are associated with reduced coronary arterial compliance. Using intravascular ultrasound, this adverse functional effect on arterial compliance can be observed together with an increase in the intimal index.

Can T1-201 myocardial SPECT abnormalities in orthotopic heart recipients be explained by coronary vessel wall alterations assessed by intravascular ultrasound?

The aim of this study was to compare findings on coronary intravascular ultrasound and thallium-201 SPECT in patients following orthotopic heart transplantation. Background: No data are available on whether pathological thallium scintigraphic findings in heart recipients are based on coronary vessel wall alterations identifiable by intravascular ultrasound. Methods: 29 patients (mean age: 50.9 ± 11.5 years; male n = 23) were investigated by means of intravascular ultrasound of selected coronary segments and thallium-201 myocardial SPECT. Patients were investigated 11.6 ± 5.4 weeks post transplantation, a subgroup of 13 patients was re-investigated 70.2 ± 18.4 weeks following transplantation. A total of 214 cross-sectional areas of the left coronary artery were examined using a 3.5 French intravascular ultrasound catheter to measure intimai index and the circumferential extension of a three-layer appearance of the vessel wall. Shortly after catheterisation, an ergometric stress-test was performed to examine all recipients by means of thallium-201 SPECT. In each patient, 20 segments of the left ventricle were evaluated using a score system to differentiate between persistent defects, redistribution, and reverse redistribution. A score was developed that measured the degree of inhomogeneity and severity of perfusion defects, respectively. Findings on scintigraphy were correlated to coronary intravascular ultrasound findings. Results: At first investigation, mean intimai index of all evaluated coronary cross-sectional areas was 0.06 ± 0.1. Sixty-four cross-sectional areas demonstrated a three-layer appearance of the vessel wall, mean circumferential extension was 72 ± 122 degrees. Thallium scintigraphy demonstrated a total of 336 (40%) pathological left ventricular segments; 168 (20%) were regarded as permanent defects, 67 (8%) demonstrated redistribution and 101 (12%) showed reverse redistribution. The score of inhomogeneity was calculated as 5.8%±2.6%. In the subgroup of patients at the follow-up study, the score was 6.4±2.8%. There was no correlation between intimai index and the score, nor could any correlation be confirmed between the score and the circumferential extension of a three-layer appearance of the vessel wall. At second investigation, no significant differences of intimai index (0.05±0.07) or circumferential extension of a three-layer appearance of the vessel wall (74±118 degrees) could be confirmed. The score was slightly, but significantly increased to 8.1 ± 4.5% at the second investigation ( P < 0.05). Conclusion: Early after orthotopic heart transplantation, pathologic thallium distribution patterns of the left ventricle could be observed. These pathological patterns did not correlate with the extent of diffuse coronary vessel wall alterations identifiable by intravascular ultrasound. After more than 1 year, the degree of scintigraphic abnormalities increased significantly, not accompanied by an increase of diffuse coronary vessel wall alterations.

Intravascular ultrasound appearance of normal and mildly diseased coronary arteries: Correlation with histologic specimens

Intravascular ultrasound imaging was performed in vitro on six histologically normal and 104 minimally diseased arteries in patients aged 13 to 83 years. This study tested the hypothesis that normal coronary arteries produce a three-layer image that corresponds to the histologic layers of intima, media, and adventitia. The results showed a very good correlation between area of the echolucent ultrasound layer with the media and the inner echogenic layer with intimal area. In addition, a three-layer appearance was consistently seen when the internal elastic membrane was present with or without intimal hyperplasia. If the internal elastic membrane was absent, a three-layer appearance was still seen if the collagen content of the media was low. However, a two-layer appearance was observed when there was absence of the internal elastic membrane as well as a high collagen content of the media.

Evaluation of pulmonary artery histopathologic findings in congenital heart disease: An in vitro study using intravascular ultrasound imaging

This study aimed to 1) compare in vitro intravascular ultrasound images of human pulmonary arteries with corresponding histologic sections, and 2) correlate the relation between intravascular ultrasound findings and Heath-Edwards pathologic grade of pulmonary vascular changes. The pathologic assessment of the pulmonary vascular bed is essential for diagnosis and management of congenital heart disease with pulmonary hypertension. We evaluated and compared intravascular ultrasound images with histologic findings at identical sites in 40 pulmonary artery segments from 17 autopsy studies: group 1 = 7 patients with pulmonary hypertension (Heath-Edwards grade I to V, 20 segments); group 2 = 10 patients without cardiopulmonary disease (20 segments). In group 2, the pulmonary artery wall echo consisted of a single layer. In group 1, 1) all segments of pulmonary arteries from patients with pulmonary hypertension showed a three-layered appearance; 2) in patients with mild pulmonary hypertension (Heath-Edwards grades I and II), intravascular ultrasound demonstrated increased thickness of the echoluscent zone due to medial hypertrophy with no intimal reaction; 3) patients with severe pulmonary hypertension (Health-Edwards grade III or higher) had intravascular ultrasound findings of increased medial thickness and a bright inner layer from intimal hyperplasia; 4) percent wall thickness derived from intravascular ultrasound showed a significant correlation with that determined by histologic examination (r = 0.89, p = 0.0001, n = 20). Changes observed with intravascular ultrasound imaging correlate well with histopathologic grade. Thus, intravascular ultrasound may have significant utility in the evaluation of pulmonary vascular morphology in patients with pulmonary hypertension.

Wall morphology of the pulmonary artery--intravascular ultrasound imaging and pathological evaluations.

The pathological assessment of the pulmonary vascular bed is essential for the diagnosis and management of congenital heart disease with pulmonary hypertension. To investigate the relationship between intravascular ultrasound (IVUS) findings and the Heath-Edwards (H.E.) grade of human pulmonary arteries, 40 pulmonary arterial segments from 17 autopsies and 5 patients with pulmonary hypertension were evaluated using a high-frequency IVUS imaging system. Histological observations were carried out at the same sites that were examined with IVUS and at the distal pulmonary arterioles of the same branches. The subjects were subdivided into 3 groups-group I: 7 patients with pulmonary hypertension (20 segments); group II: 10 patients without pulmonary hypertension (20 segments); and group III: 5 patients with pulmonary hypertension who were studied in vivo. All 20 segments from group I had a three-layered appearance, and 3 patients with H.E. grade < 3 had an increased thickness of the echolucent zone due to media hypertrophy without an intimal reaction. In contrast, IVUS findings from patients with severe pulmonary hypertension (H.E. grade > or = 3) showed an increased thickness with a bright inner layer due to intima hyperplasia. Evidence for a plaque-like lesion was defined in one patient with severe pulmonary hypertension. The percentage of wall thickness derived from IVUS was significantly correlated with that determined by histological examination in group I. The pulmonary artery walls in group II had a one-layer appearance. Similar IVUS findings were obtained from the in vivo study regardless of whether pulmonary hypertension was present. These findings indicate that the IVUS may be an unique technique for evaluating the morphology of the pulmonary artery or arteriole in pulmonary hypertension and may provide objective and quantitative evaluation without a lung biopsy.

The appearance of normal and abnormal arterial morphology on intravascular ultrasound

The ultrasonic appearance of in vitro normal and atherosclerotic arterial wall was investigated with an intravascular ultrasound (IVUS) probe. Fresh cadaver specimens were used: two carotid, two aorta, four iliac and eight superficial femoral arteries. The wall of muscular arteries has a three-layered sonographic appearance. The central hypoechoic layer corresponds to the media, which is primarily composed of smooth muscle. Elastic arteries whose media have a high elastin content appear uniformly echogenic. Calcified plaque is strongly echogenic with acoustic shadowing, fibrous plaque is moderately echogenic, and where there is no cellular matrix the plaque is poorly echogenic. IVUS can provide information about internal plaque architecture. Three-dimensional reconstructions can be generated using a transputer-based workstation coupled to the transducer, providing detailed views of surface contour.

Histopathologic correlation of the three-layered intravascular ultrasound appearance of normal adult human muscular arteries

The purpose of this study was to correlate intravascular ultrasound images from normal peripheral muscular arteries with the microscopic arterial components by using surgical microdissection techniques. There has been uncertainty about the precise anatomic constituents that are represented by the intravascular ultrasound three-layer image in human peripheral arteries. Forty of 66 grossly normal human femoropopliteal arterial segments obtained at autopsy were found to have a three-layered appearance and were subjected to selective surgical microdissection of intima, media, or adventitia. After microdissection, arteries were imaged with a 30 MHz intravascular ultrasound system; two observers blindly reviewed video tapes to assess for the presence or absence of a one-, two-, or three-layered arterial appearance. Removal of internal elastic lamina and/or intima results in a weak but evident inner ultrasound acoustic interface as a result of the media, which is normally echolucent. Removal of the adventitia and/or external elastic lamina results in a weak outer ultrasound acoustic interface. Isolated removal of the media does not alter the three-layered ultrasound image. In normal adult human femoropopliteal arteries the inner bright acoustic reflection (layer) is derived from the interface of blood with the intima and internal elastic lamina and the second bright interface (third layer) is from the external elastic lamina and adventitia. The midecholucent zone is the result of the media. However, any portion of the arterial wall, including muscular media, can act as an acoustic interface.

Intracoronary ultrasound assessment of directional coronary atherectomy: Immediate and follow-up findings

Objectives. This study was conducted to assess the relations among intracoronary ultrasound, angiographic and histologic data obtained from patients with coronary artery disease successfully treated by directional coronary atherectomy. In addition, it was designed to elucidate whether some aspects of intravascular ultrasound or pathologic findings could predict a propensity to restenosis.Background. Intracoronary ultrasound is a useful technique in guiding and assessing atherectomy. However, there is little information about the characterization of the different types of coronary plaques and the changes observed in them after resection. Furthermore, the follow-up ultrasound appearance of previously treated lesions remains undepicted.Methods. Fifty-two patients (54 ± 10 years old) were studied. All were successfully treated by atherectomy with the aid of intracoronary ultrasound guidance. Qualitative and quantitative ultrasound and angiographic variables were derived before and after resection. Quantitative histologic morphometric information was also obtained from the specimens. In 22 patients, a follow-up echoangiographic reevaluation was performed 6 ± 4 months later.Results. Echogenic plaques had a higher collagen and calcium content, whereas echolucent plaques had an increased level of fibrin, nuclel and lipids. Ultrasound plaque reduction after atherectomy was greater in echolucent (76 ± 21%) than in echogenic plaques (60 ± 18%; p < 0.05). That reduction correlated with the weight of the resected material (r = 0.62; p < 0.01). At follow-up study, 13 of 22 patients had angiographic and ultrasound evidence of restenosis. Most recurrent lesions had a stenotic three-layer appearance. The incidence of restenosis of primary lesions treated with atherectomy was higher in echolucent (100%) than in echogenic (33%) plaques. Similarly, a higher proportion of nuclear content in the resected material was observed in patients who developed restenosis (2.1 ± 0.7%) than in patients who had late success after atherectomy (1.2 ± 0.6%).Conclusions. Our findings suggest that echolucent plaques are easier to resect than are echogenic plaques but frequently develop restenosis. In contrast, the resection of echogenic plaques, although often incomplete, is associated with better long-term results.

Intravascular ultrasound imaging of arterial wall architecture.

Intravascular ultrasound (IVUS) is a promising new technique for assessing vascular morphology and structure. Controversy exists whether the three-layer appearance of the arterial wall correctly reflects the histologic structures of the intima, media, and adventitia. We performed an experimental study to clarify the three-layer appearance. The vessel wall architecture was analyzed by IVUS on eight different kinds of plastic cylinders, 24 normal blood vessels from pigs, and 59 human arterial segments. A distinct three-layer appearance was observed on all the plastic cylinders when the ultrasound beam was perpendicular to the wall. A three-layer appearance was also seen in the arterial wall, in the muscular (iliac, femoral artery) and elastic types (aorta), when the echo beam was perpendicular to the vessel wall. The three-layer pattern was even observed on the arterial wall when the intima was removed. Furthermore, the removed intima itself provided a three-layer image. Histologic examination showed that there was no correspondence between the IVUS three-layer appearance and the intima, media, and adventitia. Moreover, we also performed IVUS on nine patients who suffered from aortic dissection. Intravascular ultrasonic visualization of the dissected intima showed a distinct three-layer pattern. The pattern disappeared when: (1) the echo beam was not perpendicular to the vessel wall; (2) there was connective tissue around the vessel wall; (3) there was arterial wall calcification; or (4) the vessel wall was too thick or the distance between the ultrasound transducer and the vessel wall was too large.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of coronary atherosclerosis in young adult hearts using intravascular ultrasound.

Coronary atherosclerosis has been demonstrated in young adults by postmortem pathology. Angiographic evaluation of coronary disease in young adults is limited by ethical issues and the insensitivity of angiography for detecting early pathology. Catheter-based intracoronary ultrasound has proven useful both in detecting and quantitating coronary disease, but the ultrasound appearance of young, angiographically normal, coronary arteries has not been well defined. Twenty-five subjects were examined with intracoronary ultrasound within 1 month of cardiac transplantation. Mean age of the donor hearts was 28 years (range, 14-43 years). Measurements of an index of intimal thickening were obtained at four left anterior descending coronary artery sites in each patient. All study patients had angiographically normal coronary arteries. Ultrasound in 14 subjects demonstrated a three-layered appearance of the coronary vessel wall with a mean intimal index of 0.16 +/- 0.07. The other 10 subjects, including all donors under the age of 25 years, had coronary vessel wall layers too thin to be imaged separately at the 30-MHz sound frequency. Five subjects had ultrasound evidence of focal intimal thickening greater than 500 microns. The donors of these hearts each had risk factors for coronary artery disease. Two subjects died within 5 weeks of their ultrasound study. Histological measurements of the vessel wall layers were similar to the corresponding ultrasound values. This study provides a reference for the intravascular ultrasound appearance of young adult coronary arteries and confirms pathology findings that young subjects with angiographically normal vessels have a range of coronary intimal thickening, which includes occasional evidence of focal, early atheromatous lesions.