Development of non-invasive method for assessment of hepatic steatosis.

Steatosis is a critical feature of liver disease and is considered to play a pivotal role in the progression of nonalcoholic fatty liver disease, as well as being a surrogate marker of metabolic syndrome. The purpose of this study was to develop a non-invasive diagnostic method for assessment of liver steatosis. It is well known that ultrasonic velocity depends on materials and temperature. For example, the ultrasonic velocity in water is 1530m/s at 37°C and 1534m/s at 39°C, while that in fat is 1412m/s at 37°C and 1402m/s at 39°C. On this basis, we thought that the percentage of fat in hepatic steatosis could be assessed by detecting changes of ultrasonic in the liver, caused by warming. In order to confirm the effectiveness of this method, we obtained the ultrasonic velocity changes of tissue phantom including lard oil and the liver of living rabbit by ultrasonic warming, and then succeeded in 2-D imaging of ultrasonic velocity changes of the phantom and the liver of living rabbit. We named this the ultrasonic velocity-change method. The experimental results show the possibility that hepatic steatosis could be characterized using our novel, non-invasive method.

Diabetes mellitus, deafness, muscle weakness and hypocalcemia in a patient with an A3243G mutation of the mitochondrial DNA.

In a 54-year-old woman with diabetes mellitus, hearing loss, muscle weakness and hypocalcemia, caused by idiopathic hypoparathyroidism, an A to G transition at the nucleotide position of 3243 (A3243G mutation) was found in the mitochondrial DNA from her leukocytes. Clinical features of diabetes mellitus and hearing loss in association with the A3243G mutation are compatible with a diagnosis of maternally inherited diabetes and deafness (MIDD). Although hypoparathyroidism is rarely seen in MIDD, we consider that hypoparathyroidism in this patient is a possible phenotype caused by the A3243G mutation of mitochondrial DNA.

Pulmonary sequestration receiving arterial supply from the right coronary artery. A case report.

Pulmonary sequestration is a relatively rare anomaly. The arterial supply usually is derived from the aorta or its major branches. We present a 65-year-old female patient with pulmonary sequestration receiving arterial supply from the right coronary artery, complicated with sick sinus syndrome.

Measurement of portal venous flow velocity with an implantable miniature Doppler probe in pig liver transplantation.

Portal venous flow (PVF) was serially monitored after pig liver transplantation (LTX) with the use of an implantable, miniature Doppler probe developed in our laboratory. Throughout the study period, the mean PVF in pigs that underwent LTX was significantly greater than that in pigs that were sham operated. For three animals with early graft failure secondary to primary nonfunction and for six that survived longer than 7 days, the mean PVF on postoperative day (POD) 1 was 18.7 +/- 3.8 cm/s and 41.7 +/- 11.2 cm/s, respectively (P < 0.05). For animals with acute cellular rejection (ACR), the mean PVF was 61.3 +/- 9.9 cm/s on POD 7 and 54.3 +/- 6.38 cm/s on POD 14. These values were significantly higher than those for animals without ACR (P < 0.05). Moreover, the increase in PVF correlated well with the degree of ACR. The actual PVF volume was measured by ex vivo perfusion, which showed a clear correlation with the PVF velocity obtained with the implanted, miniature Doppler probe. We feel that the liver graft requires increased PVF volume after transplantation to facilitate functional recovery from damage to hepatocytes due to preservation-reperfusion injury, and that ACR is also associated with an increased PVF. We conclude that monitoring the PVF in the early postoperative period after LTX is useful in the evaluation of graft function, particularly for predicting primary nonfunction and severity of ACR.

[Effective low-dose amiodarone therapy for ventricular tachycardia complicated with ischemic heart disease and poor left ventricular function in an elderly patient].

A 71-year-old man who had ischemic heart disease with poor left ventricular function and ventricular tachycardia was admitted to hospital for evaluation. Cardiac catheterization was performed on August 19, 1996, and right coronary arteriography revealed total occlusion at segment 3. Left coronary arteriography revealed total occlusion at segment 6, and a lesion at segment 13 was 75% occluded. Partial collateral flow from the right ventricular branch to the left anterior descending artery was demonstrated, and the left ventricular ejection fraction was 24%. Recurrent ventricular tachycardia followed by pre-syncope occurred from August 23, 1996, and the patient underwent emergency coronary artery bypass surgery to the left anterior descending artery and circumflex artery using saphenous vein grafts. Ventricular tachycardia followed by pre-syncope occurred frequently after the bypass surgery, and antiarrhythmic agents (Vaughan Williams classification Ia and Ib groups) were ineffective. He received amiodarone (100 mg/day after a loading dose of 200 mg/day for 2 weeks) from September 6, 1996. His symptoms of arrhythmia decreased, and side effects have not been observed. Low-dose amiodarone was effective in this case of ischemic heart disease with left ventricular dysfunction and sustained ventricular tachycardia.

Factor VII R353Q polymorphism and lacunar stroke in Japanese hypertensive patients and normotensive controls.

Elevated plasma factor VII (FVII) levels are reported to be associated with cardiovascular disease in both Caucasians and Japanese. Recent reports indicate that individuals with the FVII 353Q allele have decreased plasma FVII levels. Thus, we investigated the association between lacunar stroke and the FVII R353Q polymorphism in 137 hypertensive patients with silent or overt lacunar stroke (stroke group), 83 non-stroke hypertensives without any lacunae detected by magnetic resonance imaging (non-stroke group), and 97 normotensive control subjects matched for age, sex, and smoking status recruited at an annual health examination (normotensive control group). The frequency of the FVII 353Q allele was 0.057 in the normotensive control group, 0.051 in the non-stroke group and 0.061 in the stroke group. These frequencies, as well as genotype distribution, were not significantly different from each other, even when we subclassified the ischemic group into silent (n = 54) and clinically overt (n = 64) lacunar stroke subgroups. These results suggest that the FVII 353Q allele is not an important genetic determinant for cerebrovascular disease in Japanese individuals.

[A 66-year-old woman with a patent ductus arteriosus and no significant progression of pulmonary arterial pressure over 17 years].

We report the case of a 66-year-old woman with a patent ductus arteriosus and no significant progression of pulmonary arterial pressure over 17 years. She was admitted to our hospital in 1978 because of palpitations on exertion and chest discomfort. Cardiac catheterization was done, and she was given a diagnosis of patent ductus arteriosus. Because the left-to-right shunt was small (15%) and because there was no evidence of pulmonary hypertension (38/18 mmHg), she was treated medically. In 1995 she was admitted again, to determine the cause of a cerebral infarction. The cerebral infarction was believed to have been caused by an embolism due to atrial fibrillation. She underwent cardiac catheterization again. The left-to-right shunt had increased to 41%, but the pulmonary artery pressure had not changed (27/14 mmHg). Intravascular ultrasound imaging was used to evaluate the ductus arteriosus. The diameter of the ductus was 4.4 mm and calcification was not observed. During the 17 years of follow-up, heart size increased slightly, but pulmonary artery pressure did not change. In addition, intravascular ultrasound was very useful for evaluating the condition of the ductus arteriosus.

[Aortic inner surface morphology in aortic disease by three-dimensional transesophageal echocardiography].

Aortic inner surface morphology in various pathologies was investigated using three-dimensional (3D) transesophageal echocardiography to clarify the feasibility and limitations for clinical application. Transesophageal echocardiography was performed in 16 patients with aortic disease (12 aortic dissection, 4 aortic sclerosis) and 5 with normal aorta. The transesophageal transverse view of the descending aorta was taken every 2 mm by manually withdrawing the probe. Each image was recorded using VTR during one heart beat, then stored in the memory of a personal computer as a data base for the subsequent 3D reconstruction. The aortic inner surface was displayed using distance and gradient shading. Three-dimensional reconstruction images were obtained in all patients. The aortic inner surface was reconstructed as a wall with ringed protrusion in patients with normal aorta and a rugged wall with various sized protrusions in patients with atherosclerotic plaques by 3D transesophageal echocardiography. However, it was impossible to differentiate calcified lesions from non-calcified areas of plaques. In aortic dissection, 3D reconstruction provided information regarding the spatial anatomy of the dissection in 10 of 12 patients, accurate shape and location of the intimal tears in 3 of 5 patients, and movement of the intimal flap in 9 of 12 patients. However, reconstruction of the false lumen failed in two patients who had false lumens filled with spontaneous contrast echo. Three-dimensional transesophageal echocardiography is potentially useful for estimating the inner surface morphology and spatial extent and actual location of the aortic abnormalities, but there are limitations in evaluating tissue characterization and reconstructing the lumen with spontaneous contrast echo.

New transducers for intraoperative spinal sonography. Technical note.

Although ultrasonography during spinal cord surgery has been widely accepted, it still has limitations in clinical application because of the size of the transducers needed and the immersion method. The authors report on newly designed microprobe transducers used to evaluate intramedullary spinal cord lesions and to monitor surgical procedures. This microprobe system permitted the microscopic use of intraoperative ultrasonography without requiring saline immersion.

Bronchoscopic ultrasonography in the diagnosis of lung cancer.

An ultrasonic bronchoscope has been newly developed for diagnosis and lymph node staging in the hilum and mediastium. The instrument comprises an Echo-camera, SSD-630 (Aloka), and a transbronchial ultrasonic probe similar to the currently used videobronchoscope. The scope is equipped with an ultrasonic transducer in its tip. The maximum diameter of the probe head is 6.3 mm and that of the transducer, 5.0 mm. The frequency employed is 7.5 Megahertz (MHz) and the direction of scanning is parallel to the bronchoscopic axis. The device can easily be introduced into the lobar bronchus under topical anesthesia in a similar procedure to that used for routine videobronchoscopy. The location of the transducer in the airway is confirmed by monitoring endoscopic images on a TV monitor screen. With the device, 25 patients, who had given their consent for the ultrasonographic study beforehand, were examined during the two-month period, January and February, 1992. Vessels such as the thoracic aorta, pulmonary artery and truncus brachiocephalicus were good landmarks for diagnosis. Lung cancer was detected in five patients by biopsy, three malignant lesions in the hilum were diagnosed by videobronchoscopy while two malignant lesions in the periphery were confirmed by bronchoscopic ultrasonography as anterior mediastinal lymph node swellings.

Variomatrix--a newly developed transesophageal echocardiography probe with a rotating matrix biplane transducer. Technological aspects and initial clinical experience.

The recently developed multiplane transesophageal echocardiography (TEE) probes cannot provide real-time synchronous biplane imaging. We have developed a new "Variomatrix" probe that combines the advantages of the rotating mechanism of the multiplane probe with the capability of providing simultaneous, side-by-side imaging. Its advantages are: (1) easy manipulation to obtain the optimal planes; (2) avoidance of excessive movement of the probe inside the esophagus; (3) assessment of oblique planes that are not viewed with the usual biplane probe; (4) better understanding of the continuity of structures by the simultaneous, side-by-side biplane, rotating images, providing clearer three-dimensional conception; and (5) shorter examination time by providing a 180 degrees imaging range by rotating the transducer just 90 degrees .

Physiological and pharmacological responses of arterial graft flow after coronary artery bypass grafting measured with an implantable ultrasonic Doppler miniprobe.

BACKGROUND: The present study was designed to investigate physiological and pharmacological responses of the arterial graft flow measured by the directly implanted ultrasonic pulsed Doppler miniprobe after coronary artery bypass grafting (CABG). METHODS AND RESULTS: Our original 5-MHz, 5-mm-diameter, Doppler mini-flow probe catheter, which has four silicone brims in front to facilitate its fixation onto the graft without direct suture, was attached onto internal thoracic artery (ITA) and gastroepiploic artery (GEA) grafts during CABG in 10 patients. Approximately 2 weeks postoperatively, when the patient's condition was quite stable without medication, changes of flow velocity in those grafts induced by catecholamine, exercise, taking meals, and coronary vasodilating drugs were measured. Dobutamine significantly increased both ITA and GEA graft flow velocity (p < 0.01), whereas dopamine had no distinct positive effect. Upon the patient taking meals, the GEA graft showed an 83% increase of the flow velocity (p < 0.05), whereas the ITA graft showed no significant change. Walking exercise for 6 minutes increased both grafts' flow velocity up to two times that of control values (p < 0.01). Oral intake of coronary vasodilating drugs showed no significant effect. After the investigation was completed, the probe was removed easily at bedside without difficulty. CONCLUSIONS: Using this implantable Doppler miniprobe, postoperative function in the individual coronary bypass graft under various conditions was effectively investigated.

Doppler miniprobe to measure arterial graft flow in coronary artery bypass grafting.

Using a 5 X 5-mm ultrasonographic Doppler miniprobe, the flow volume of arterial grafts (internal thoracic artery and gastroepiploic artery) was measured four times during the course of coronary artery bypass grafting. Graft flow just before sternal closure was almost equivalent to that in the preoperative phase when the anastomosis was optimal. Use of the Doppler miniprobe facilitated evaluation of the arterial graft flow pattern easily and quickly. We conclude that the Doppler miniprobe can provide helpful information for the evaluation of results of coronary artery bypass grafting in real time without necessitating any additional procedures.

New direction of biplane transesophageal echocardiography with special emphasis on real-time biplane imaging and matrix phased-array biplane transducer.

This article reports on the technical aspects of an online real-time biplane transesophageal echocardiographic imaging system and of a single-matrix, phased-array transducer capable of transverse and longitudinal scanning.