Korotkoff sound: the cavitation hypothesis.

Blood pressure is universally measured by the auscultatory method, but the origin of the Korotkoff sounds remains controversial. A reproducible, brief and high amplitude signal, simultaneous to the Korotkoff sound, and instantly followed by the systolic wave, was recorded amongst ten healthy subjects by a pulsed Doppler examination during the deflation of the sphygmomanometer. A device simulating the brachial artery was also built in order to reproduce the high amplitude signal. It is explained by the cavitation phenomenon which takes place when the blood changes to vapor due to the release of the cuff pressure. With the incoming flow, the cavitation bubbles collapse and the energy is released as noise.

Involvement of superior mesenteric vessels and portal vein in pancreatic adenocarcinoma: detection with CT during arterial portography.

A prospective study was designed to determine the utility of computed tomography (CT) during arterial portography (CTAP) in the detection of superior mesenteric vessels and portal vein involvement in patients with pancreatic adenocarcinoma. Eighteen patients with adenocarcinoma of the head of the pancreas and eight patients with benign pancreatic disease were investigated with CTAP, dynamic contrast-enhanced CT, and angiography. Appropriate review was made to determine presence or absence of superior mesenteric vessels and portal vein involvement. Final diagnosis was obtained in all cases by surgical explorations. The overall accuracy rate for detecting or excluding superior mesenteric vessels and portal vein involvement was 96% (25 of 26 patients) with CTAP, 88% (23 of 26 patients) with dynamic contrast-enhanced CT, and 85% (22 of 26 patients) with angiography. No statistically significant difference in accuracy was found among the three techniques. Our results suggest that the use of CTAP is not indicated in the preoperative detection of superior mesenteric vessels and portal vein involvement in patients with pancreatic adenocarcinoma.

CT arterial portography of the abdomen: effect of injecting papaverine into the mesenteric artery on hepatic contrast enhancement.

OBJECTIVE: The purpose of this study was to determine the effect of precontrast injection of papaverine hydrochloride into the superior mesenteric artery on the degree of contrast enhancement of the hepatic parenchyma during CT arterial portography (CTAP, CT with injection of contrast material into the superior mesenteric artery). SUBJECTS AND METHODS: Twenty-two patients were included in this study. All patients had a baseline unenhanced CT scan and then had CTAP performed with transcatheter injection of 150 ml of nonionic iodinated contrast material (30 g iodine/100 ml) at a rate of 2 ml/sec. Eleven patients received a precontrast injection of 40 mg of papaverine hydrochloride via catheter into the superior mesenteric artery, and 11 patients had CTAP without papaverine hydrochloride. Attenuation of the liver was measured before and after contrast administration in both groups of patients. For each CTAP section, the absolute hepatic enhancement (postcontrast attenuation--precontrast attenuation) and the relative hepatic enhancement ([absolute hepatic enhancement/precontrast attenuation] x 100) were calculated. Also, the mean absolute enhancement and the mean relative enhancement for the entire liver were calculated for each patient. RESULTS: The mean relative enhancement (+/- SD) of hepatic parenchyma was 192 +/- 54% with papaverine hydrochloride and 146 +/- 26% without papaverine hydrochloride. Relative enhancement was significantly higher when papaverine hydrochloride was used (p < .02). The mean absolute enhancement (+/- SD) of hepatic parenchyma was 123 +/- 25 H with papaverine hydrochloride and 91 +/- 19 H without papaverine hydrochloride. Absolute enhancement was significantly higher in patients who had papaverine hydrochloride (p < .01). CONCLUSION: The results show that precontrast transcatheter infusion of papaverine hydrochloride increases the degree of contrast enhancement of the liver during CTAP.

[Ultrasound-guided biopsy in focal lesions of the liver. Report on an automated biopsy system]. / Biopsie échoguidée des lésions focales du foie. Apport d'un système de prélèvement biopsique automatisé.

Two techniques for focal liver lesion biopsy were retrospectively evaluated to compare relative safety and efficacy. After sonographic localization of the focal liver lesion and biopsy with a hand-held 18-gauge cutting needle, a pathologically adequate specimen was obtained in 49 of 55 cases (89%) requiring 1 to 4 passes (mean, 2.1 per patient). A major complication occurred in one case and minor complication were noted in three cases. Forty one biopsies were performed by using a single use automatic core biopsy system with a 18-gauge cutting needle and real time sonographic guidance. With this automatized technique, specimens adequate for diagnosis were obtained in 40 of 41 cases (97.5%), requiring only 1 pass in all cases. Neither major nor minor complication was noted with this technique. We conclude that using sonographic guidance, the automatic core biopsy system with a 18-gauge cutting needle yields a slightly better rate of adequate specimens with a lower frequency of complications.

False-positive CT portography: correlation with pathologic findings.

OBJECTIVE: A retrospective study was performed to determine the causes of false-positive diagnoses based on CT findings obtained during superior mesenteric arterial portography (CT portography) and to correlate the imaging characteristics of the incorrectly diagnosed lesions with their pathologic findings. MATERIALS AND METHODS: In a series of 52 patients who had CT portography before surgical exploration of the liver, eight had a total of 10 false-positive findings, yielding a false-positive diagnosis rate of 15%. In eight cases, the false-positive findings from CT portography were correlated with the histologic material obtained during partial hepatic resection or intraoperative biopsies at the corresponding sites. RESULTS: Of the 10 false-positive findings on CT portograms, seven led to false-positive diagnoses of hepatic tumors. Conversely, three nontumorous false-positive findings were erroneously considered to be portal perfusion defects. The final diagnoses based on pathologic findings included focal fatty infiltration of the liver (three), cirrhosis (two), and portal perfusion defect (three). Two false-positive findings for which no histologic correlation was possible were considered to be portal perfusion defects on the basis of intraoperative findings. CONCLUSION: Recognition of false-positive findings is crucial in the preoperative evaluation of hepatic tumors because the findings may be interpreted as contraindications for surgery in patients who have operable tumors. The pathologic correlations show that several different entities can cause diagnoses based on CT portographic findings to be false-positive. However, differentiating between those entities remains a diagnostic challenge.

[Digestive hemorrhage caused by congestive gastropathy in a patient with liver cirrhosis: emergency treatment by transjugular intrahepatic portosystemic anastomosis]. / Hémorragie digestive par gastropathie congestive chez un malade atteint de cirrhose: traitement en urgence par anastomose porto-systémique intra-hépatique transjugulaire.

A 34-year-old woman with liver cirrhosis and portal hypertension was admitted for gastric bleeding due to congestive gastropathy. Her past medical history included 4 episodes of variceal rupture within the last 5 months. As medical treatment was a failure, an emergency transjugular intrahepatic portosystemic shunt was successfully performed, resulting in a marked drop in portal pressure (from 32 to 15 mm Hg) and a subsequent arrest of acute hemorrhage. Four months later, no recurrent bleeding has been observed and the shunt has remained patent as documented by duplex Doppler sonography.

MRI of adenomatous hyperplastic nodules of the liver in Budd-Chiari syndrome.

We present two cases of adenomatous hyperplastic nodules (AHN) occurring in patients with chronic Budd-Chiari syndrome who were investigated with MRI. In one case the foci of AHN were isointense to the liver on spin echo (SE) T1-weighted MRI and were hyperintense on both SE proton density and SE T2-weighted MRI. In the other case the nodules were hyper-intense on SE T1-weighted MRI. They were isointense on SE proton density-weighted MRI and became slightly hyperintense on SE T2-weighted MRI. Furthermore, in both cases one nodule displayed hyperintensity with hypointense rims on SE T2-weighted MRI.

High-resolution sonographic guidance for transjugular liver biopsy.

A prospective randomized study was performed to compare conventional right internal jugular vein catheterization technique with high-resolution sonographically guided catheterization for transjugular liver biopsy. Forty-seven patients were assigned to undergo either conventional or high-resolution sonographically guided right internal jugular vein catheterization for transjugular liver biopsy. Sonographic guidance was significantly better than conventional guidance, reducing the number of failed catheterizations, from 22% (5 of 23) to 0% (0 of 24) (p < .05). Sonography also reduced the mean number (+/- SD) of passes required to catheterize the vein from 4.21 +/- 1.53 to 1.54 +/- 0.66 (p < .001) and was successful in 100% (5 of 5) of patients in whom conventional catheterization failed. High-resolution sonographic guidance is strongly recommended for transjugular liver biopsy in patients at high risk for bleeding.