Ultrasound Densitometric Analysis: Comparison Between an Online Digital Acquisition Acoustic Program and an Offline Analog Program

Videodensitometric analysis of myocardial contrast echocardiography is traditionally performed off line. Recently, an online contrast ultrasound analysis system, Acoustic Densitometry (Hewlett-Packard), was introduced. We compared pixel intensities acquired with Acoustic Densitometry to pixel intensities derived from videodensitometry. A tissue phantom was imaged in phase I using three transducer frequencies (2.5, 3.5, and 5.0 MHz). In phase II, an in vitro flowing tube model with various concentrations of Albunex® was imaged at two flow rates, 0.6 and 1.2 m/sec, and at two transducer frequencies, 2.5 and 3.5 MHz. The relationship between pixel intensities yielded by the two systems for identical ultrasound signals was determined with linear regression. Intensities derived with Acoustic Densitometry strongly correlated with those derived from the offline videodensitometry system. The intensities were related by a predictive multiplicative factor based on display characteristics of the two systems. These results suggest that semiquantitative, online perfusion analysis with Acoustic Densitometry is as sensitive as analysis offline with videodensitometry.     

Breast cancer vascularity: Color Doppler sonography and histopathology study

Summary In this prospective study, the authors examined 50 patients with breast tumors (malignant, n = 32; benign, n = 18) to investigate the correlation between color Doppler flow mapping and histopathological findings and to evaluate the clinical significance of color Doppler mapping. Among the 32 patients with breast cancer, color Doppler signals were detected in 24 patients (75%). The maximum flow velocities varied from 5 to 34 cm/sec, with 16 (67%) of them above 15 cm/sec. Among the 18 patients with benign tumors, color Doppler signals could be detected in 7 (39%). The maximum flow velocity varied from 3 to 30 cm/sec but was over 15 cm/sec in only two patients (28%). Histological studies revealed that color Doppler signals detected by Doppler sonography correlated with disordered neovascularization penetrating the lesion from its periphery, consisting of thin-walled blood vessels and large arteriovenous shunts. Although large tumors tend to have high Doppler flow, there is no significant correlation between the maximum flow velocity and tumor size. There is also no significant correlation between the detection of high flow color Doppler signals and the age, receptor status, tumor size, lymph node metastases, or clinical stage of patients with breast cancer. However, there is a positive association (p < 0.05) between nodal metastases and higher tumor flow velocity in T1 ( 2 cm) breast tumors, but not in larger tumors. It is concluded that color Doppler is useful in the assessment of tumor vascularity but is of limited value in the differentiation of benign from malignant lesions. However, the presence of color Doppler signals in Tl breast cancer suggesting early dissemination of the cancer might be of important clinical significance in detecting those small, apparently early, but aggressive tumors with poor prognosis.     

The stereoisomers of 17α-[123I]iodovinyloestradiol and its 11α-methoxy derivative evaluated for their oestrogen receptor binding in human MCF-7 cells and rat uterus,and their distribution in immature rats

We studied the potential of both stereoisomers of 17-[¹²³I]iodovinyloestradiol (E- andZ-[¹²³I]IVE) and of 11-methoxy-17-[¹²³I]iodovinyloestradiol (E-andZ-[¹²³I]MIVE) as suitable radioligands for the imaging of oestrogen receptor(ER)-positive human breast tumours. The 17-[¹²³I]iodovinyloestradiols were prepared stereospecifically by oxidative radio-iododestannylation of the corresponding 17-tri-n-butylstannylvi-nyloestradiol precursors. Competitive binding studies were performed in order to determine the relative binding affinity (RBA) of the unlabelled 17-iodovinyloes-tradiols for the ER in both human MCF-7 breast tumour cells and rat uterine tissue, compared with that of diethylstilboestrol (DES). Target tissue uptake, retention and uptake selectivity of their¹²³I-labelled analogues were studied in immature female rats. All four 17-iodovi-nyloestradiols showed high affinity for the ER in human MCF-7 cells, as well as rat uterus. Their RBA for the ER showed the following order of decreasing potency: RBA of DES >Z-IVE >Z-MIVE >E-MIVE E-IVE. Neither of these 17-iodovinyloestradiols showed any significant binding to the sex hormone binding globulin in human plasma. The biodistribution studies showed ER-mediated uptake in the uterus, ovaries and pituitary, that ofE- andZ-[¹²³I]MIVE being higher than that ofE- andZ-[¹²³I]IVE. High target-to-non-target tissue uptake ratios, especially at longer periods after injection (up to 24 h), were exhibited by both isomers of [¹²³I]MIVE. The uterus-to-blood uptake ratio was higher for^E-[¹²³I]MIVE. However, the uterus-to-fat uptake ratio appeared to be higher for theZ-isomer of [¹²³I]MIVE, especially at 24 h after injection. Metabolic properties and temperature effects, which play a more important role in vivo, probably cause the discrepancies seen between in vitro and in vivo binding results. On the basis of their in vitro binding properties and in vivo distribution characteristics we conclude thatE- andZ-[¹²³I]MIVE could be suitable radioligands for the diagnostic imaging of ER in human breast cancer. Therefore, further studies with these radioligands in mature normal and tumour-bearing rats are warranted.     

Delayed image of iodine-123 iomazenil as a relative map of benzodiazepine receptor binding: The optimal scan time

Delayed single-photon emission tomograpic (SPET) images after an intravenous bolus injection of iodine-123 iomazenil have been used as a relative map of benzodiazepine receptor binding. We determined the optimal scan time for obtaining such a map and assessed the errors of the map. SPET and blood data from six healthy volunteers and five patients were used. A three-compartment kinetic model was employed in simulation studies and analyses of actual data. The simulation studies suggested that, in the normal brain, the scan time at which a single SPET image best represented the relative receptor binding was 3.0–3.5 h post-injection. This finding was supported by actual data from the volunteers. The simulation studies also suggested that the optimal scan time was not greatly changed by the variability of the input functions, and that the error in the SPET image contrast in the vicinity of the optimal scan time was not increased by changes in the tracer kinetics in the entire brain. The SPET image contrast in the patients at 3.0 h post-injection agreed well with the reference receptor binding estimated by kinetic analysis, with a mean error of 3.6%. These findings support the use of a single SPET image after bolus injection of [¹²³I]iomazenil as a relative map of benzodiazepine receptor binding. For this purpose, a SPET scan time of 3.0-3.5 h post-injection is recommended.     

Regional myocardial motion and thickening assessed at rest by ECG-gated99mTc-MIBI emission tomography and by magnetic resonance imaging

We have validated ECG-gated emission tomography using technetium-99m methoxyisobutylisonitrile for the assessment of regional ventricular function by comparing it with cine magnetic resonance imaging (MRI). Gated tomography was performed at rest in 24 patients referred for myocardial perfusion imaging [17 males and seven females with a mean age of 58 years, nine of whom had had a previous myocardial infarction (MI)]. Scores were assigned to each of nine myocardial segments for wall motion and for thickening. Cine MRI was analysed in an identical fashion. Four out of 216 (2%) segments were uninterpretable by gated tomography because of inadequate tracer uptake. In eight patients without coronary artery disease (CAD), wall motion and thickening were normal by both methods. Gated tomography showed abnormal wall motion or thickening in all patients with previous MI and in five of seven patients with CAD but no prior MI. Association between wall motion and thickening was good (r _s=0.86). Overall, there was good agreement between gated tomography and MRI for both wall motion (178/212 segments, =0.66) and wall thickening (184/212 segments, =0.69). In segments with severely reduced perfusion, however, there was poorer agreement (=0.31). Interobserver and intraobserver agreement was high ( from 0.61 to 0.78). Thus, in patients investigated for CAD, there is good overall agreement between gated tomography and MRI but the agreement is lower in segments with severe perfusion defects.     

Uptake of iodine-123-α-methyl tyrosine by gliomas and non-neoplastic brain lesions

Using single-photon emission tomography (SPET), the radiopharmaceuticall,-3-iodine-123--methyl tyrosine (IMT) has been applied to the imaging of amino acid transport into brain tumours. It was the aim of this study to investigate whether IMT SPET is capable of differentiating between high-grade gliomas, low-grade gliomas and non-neoplastic brain lesions. To this end, IMT uptake was determined in 53 patients using the triple-headed SPET camera MULTISPECT 3. Twenty-eight of these subjects suffered from high-grade gliomas (WHO grade III or IV), 12 from low-grade gliomas (WHO grade II), and 13 from non-neoplastic brain lesions, including lesions after effective therapy of a glioma (five cases), infarctions (four cases), inflammatory lesions (three cases) and traumatic haematoma (one case). IMT uptake was significantly higher in high-grade gliomas than in low-grade gliomas and non-neoplastic lesions. IMT uptake by low-grade gliomas was not significantly different from that by non-neoplastic lesions. Diagnostic sensitivity and specificity were 71% and 83% for differentiating high-grade from low-grade gliomas, 82% and 100% for distinguishing high-grade gliomas from non-neoplastic lesions, and 50% and 100% for discriminating low-grade gliomas from non-neoplastic lesions. Analogously to positron emission tomography with radioactively labelled amino acids and fluorine-18 deoxyglucose, IMT SPET may aid in differentiating high-grade gliomas from histologically benign brain tumours and non-neoplastic brain lesions; it is of only limited value in differentiating between non-neoplastic lesions and histologically benign brain tumours.     

空蝶鞍综合征20例的临床和MRI分析

分析２０例空蝶鞍综合征（ＥＳＳ）的ＭＲＩ表现和其中１６例的内分泌改变。结果１６例ＥＳＳ均有内分泌功能异常。ＭＲＩ表现有蝶鞍充满长Ｔ＿１和长Ｔ＿２的脑脊液;垂体受压至鞍底,冠状位呈“锚”状,矢状位呈“新月”状;垂体柄延长。结果表明ＥＳＳ常具有内分泌功能紊乱,ＭＲＩ对ＥＳＳ具有特征性诊断意义。     

小儿缩窄性心包炎的临床和病理观察

对３０例小儿缩窄性心包炎进行了临床和病量分析。结果显示：临床症状及体征无显性差异。由金典色葡萄球菌引起的急性心包炎中在较短时间内形成缩窄。病理改变既有炎症反应,肉芽组织增生,又有纤维组织增生。     

Spatio-temporal progression of the AEP P300 component using the cortical imaging technique

Summary The cortical imaging technique (CIT), a mathematical method for simulating the potential fields on the surface of the brain, was used to analyze the spatio-temporal progression of the AEP P300 component (as well as the preceding and subsequent N2a and N3 components) from thirty normal adult subjects recorded in a standard oddball paradigm. Comparisons were made between the progressions of the endogenous event-related cognitive potentials and the exogenous stimulus-dependent potentials (Nl component). Cortical imaging results suggest that different and multiple generator sites are involved in the production of exogenous and endogenous evoked responses. We particularly note the asymmetric development of the P300 component and the apparent anterior generator sites for the N2a component. This last result is interesting because the N2a precedes the P300 component and supports an earlier frontal contribution.     

Early MRI findings in Creutzfeldt-Jakob disease

We describe the MRI changes preceding the onset of myoclonus in two patients whose post-mortem examination confirmed the diagnosis of Creutzfeldt-Jakob disease (CJD). MRI showed changes in the striatum early in the course of CJD (2–6 months after the onset of apathy, interpreted as depression, and 1–2 months before the onset of further clinical symptoms). Only in one patient did electroencephalography record the typical triphasic sharp-waves, 1 month after MRI.