Hypoplasia of the internal carotid artery: a noninvasive diagnosis

We present the characteristic imaging findings of hypoplasia of the internal carotid artery (ICA) in two cases, one accompanied by an intracranial aneurysm. Finding of a diffuse luminal narrowing of the ICA on MR angiography or digital subtraction angiography (DSA) could wrongly evoke severe acquired diseases such as dissection or atherosclerosis. Absence of associated wall thickening and flow disturbances on color Doppler sonography (CDS) should suggest carotid hypoplasia. Confirmation of the diagnosis is obtained by CT of the skull showing a small carotid canal. Non-invasive procedures are sufficient to differentiate this rare congenital anomaly from acquired string signs. Received: 25 October 1999; Revised: 27 January 2000; Accepted: 30 March 2000     

Recent experience with Moyamoya disease in Turkey

A series of moyamoya patients is presented. Angiographic findings, outcome of revascularization surgery and a young case with moyamoya disease and hyperphosphatemia are reported. Thirteen patients (6 males and 7 females; age range 2–50 years) were included in the study group. Findings of the patients at presentation were intracranial haemorrhage in two adult cases and sequelae of cerebral ischemia in the rest of the group. One young girl had hyperphosphataemia. Angiography showed distal internal carotid or proximal anterior and middle cerebral artery stenosis, unique collaterals, microaneurysm of the posterior lateral choroidal artery and flow-related changes in the posterior circulation. In 3 patients, encephalo-duro-arterio-synangiosis (EDAS) and burrholes were performed at surgery. Follow-up angiograms of these patients showed revascularization. Moyamoya, a rare but potentially devastating disease, must be addressed as a cause of haemorrhagic and ischaemic cerebral events. Received: 19 January 1999; Revised: 14 April 1999; Accepted: 17 May 1999     

Paradoxical emboli: demonstration using helical computed tomography of the pulmonary artery associated with abdominal computed tomography

We report the case of a 60-year-old woman with a recent history of a cerebrovascular accident. Because of clinical suspicion of pulmonary embolism and negative Doppler ultrasound findings of the lower limbs, spiral computed tomography of the pulmonary artery was performed and demonstrated pulmonary emboli. We emphasize the role of computed tomography of the abdomen, performed 3 min after the thoracic acquisition, which showed an unsuspected thrombus within the abdominal aorta and the left renal artery with infarction of the left kidney. Paradoxical embolism was highly suspected on computed tomography data and confirmed by echocardiography which demonstrated a patent foramen ovale. Received: 23 April 1999; Revised: 17 August 1999; Accepted: 18 August 1999     

Therapeutic effect of transcatheter arterial chemoembolization on hepatocellular carcinoma: evaluation with contrast-enhanced harmonic power Doppler ultrasound

The aim of this study was to investigate the usefulness of contrast-enhanced harmonic power Doppler ultrasound (US) for the detection of residual viable hepatocellular carcinoma (HCC) after treatment with transcatheter arterial chemoembolization (TACE). Forty-seven patients with 68 HCC lesions 1.8–9.5 cm in diameter (mean ± SD 4.3 ± 1.7 cm) underwent contrast-enhanced power Doppler US, in the harmonic mode, before and after treatment with TACE. Unenhanced spiral CT and contrast-enhanced dynamic MR imaging were also performed to help establish the outcome of therapy. Before treatment, intratumoral blood flow signals were detected at contrast-enhanced harmonic power Doppler US in 65 (95 %) of 68 lesions. After TACE, flow signals were no longer detectable in 22 of these 65 lesions, which showed complete response at spiral CT and dynamic MR imaging. In 38 (88 %) of the 43 lesions with partial response, intratumoral flow signals were still identified at contrast-enhanced harmonic power Doppler US. Twenty-eight of these 38 lesions underwent additional treatment with percutaneous ethanol injection (PEI) using contrast-enhanced harmonic power Doppler US guidance. Complete response was seen after PEI in 23 of 28 lesions. Contrast-enhanced harmonic power Doppler US proved useful for assessing the therapeutic effect of TACE on HCC and for guiding additional treatment with PEI in cases of partial response. Received: 25 January 2000; Revised: 21 April 2000; Accepted: 25 April 2000     

Computed chest tomography in an animal model for decompression sickness: radiologic, physiologic, and pathologic findings

This study was conducted to investigate the early pulmonary effects of acute decompression in an animal model for human decompression sickness by CT and light microscopy. Ten test pigs were exposed to severe decompression stress in a chamber dive. Three pigs were kept at ambient pressure to serve as controls. Decompression stress was monitored by measurement of pulmonary artery pressure and arterial and venous Doppler recording of bubbles of inert gas. Chest CT was performed pre- and postdive and in addition the inflated lungs were examined after resection. Each lung was investigated by light microscopy. Hemodynamic data and bubble recordings reflected severe decompression stress in the ten test pigs. Computed tomography revealed large quantities of ectopic gas, predominantly intravascular, in three of ten pigs. These findings corresponded to maximum bubble counts in the Doppler study. The remaining test pigs showed lower bubble grades and no ectopic gas by CT. Sporadic interstitial edema was demonstrated in all animals – both test and control pigs – by CT of resected lungs and on histologic examination. A severe compression–decompression schedule can liberate large volumes of inert gas which are detectable by CT. Despite this severe decompression stress, which led to venous microembolism, CT and light microscopy did not demonstrate changes in lung structure related to the experimental dive. Increased extravascular lung water found in all animals may be due to infusion therapy. Received: 7 December 1998; Revision received: 2 June 1999; Accepted: 9 June 1999     

Clinical use of Levovist, an ultrasound contrast agent, in the imaging of liver transplantation: assessment of the pre- and post-transplant patient

Colour Doppler US is well established for imaging of hepatic vessels in the assessment of pre- and post-liver transplant patients. Unfortunately, a full colour Doppler US examination of the portal or hepatic venous and hepatic arterial systems is frequently precluded by technical factors. Ultrasound contrast agents are useful in enhancing vascular Doppler signal and play an important role in liver transplantation assessment. A series of patients with vascular problems illustrates the role of US contrast in the pre-transplant candidate, where portal vein patency and direction of flow is assessed, presence of portal vein thrombus is confirmed and cavernous transformation demonstrated. Occlusion of hepatic veins in Budd-Chiari syndrome is confidently confirmed. Following liver transplantation, US contrast allows a comprehensive assessment of hepatic artery thrombosis, hepatic artery stenosis and pseudoaneurysm formation. The need for further imaging is reduced or confidently deferred in many instances. Ultrasound contrast agents play an important role in the liver transplant candidate. Received: 15 April 1999; Revised: 21 June 1999; Accepted: 22 June 1999     

Kontrastverst?rkte Ultraschallbildgebung der A.?carotis

A conventional grey scale, Doppler sonography and color-coded Doppler ultrasound examination should be the first step in the diagnosis of the vessels supplying the brain and have a major impact in diagnostic imaging. This ultrasound examination allows the simultaneous acquisition of morphologic and hemodynamic information with high spatial and temporal resolution. Most of the pathological changes of the extracranial arteries can thus be reliably detected. Contrast-enhanced ultrasound (CEUS) is a promising new non-invasive method for the diagnosis and follow-up of complex carotid abnormalities. In addition to improving current carotid structural scans, CEUS has the potential to improve or provide additional information on carotid arterial diseases, such as the reliable differentiation between internal carotid artery (ICA) occlusion and pseudo-occlusion, improved visualization of in-stent stenosis, extracranial ICA aneurysms and carotid dissection.In this article the contribution of color-coded duplex ultrasound and CEUS in assessing various pathologies of the carotid artery will be addressed.     

Spontaneous dissection of both extracranial internal carotid arteries

Summary Neurological examination and Doppler sonography of a 50-year-old patient were suggestive of a spontaneous dissection of the left internal carotid artery (left-sided headaches, amaurosis fugax, Horner's syndrome and hemispheric stroke). Four-vessel angiogram performed several days after the onset of the symptoms showed dissection of both extracranial carotid arteries, more pronounced on right side where the dissection was clinically asymptomatic. Angiogram follow-up demonstrated a recanalization of both carotid arteries. A review of 15 other documented reports indicates that bilateral internal carotid dissection is usually associated with fibromuscular dysplasia. A large majority of cases does not clinically differ from unilateral carotid artery dissection.     

Intra-arterial Doppler flowmetry in the superficial femoral artery following angioplasty

The aim of the study was to assess the diagnostic value of an intravascular Doppler guidewire in patients with peripheral percutaneous angioplasty (PTA). The prognostic value was also evaluated. Measurements were done prior and following angioplasty in 22 patients with peripheral arterial occlusive disease. As additional therapy, stent insertion and peripheral (Aa. poplitea Ill/tibial) angioplasty was performed (4 patients per group). For stress testing, adenosinetriphosphate (ATP) was given intra-arterially. Follow-up was performed by angiography, colour-coded duplex ultrasound or judged by unequivocal clinical stage at follow-up to 13 months. Average (APV) and maximal peak velocity (MPV) increased following PTA, after additional treatment (peripheral PTA or stent), and after intra-arterial application of a vasodilator. Patients with peripheral lesions had markedly lower velocities prior treatment and following PTA after vasodilatation. Following peripheral PTA, the values were similar to the patients with PTA alone. Velocities after stenting were markedly increased in the stress condition. Of the 22 patients, 7 had a recurrent disease. The latter patients had higher velocities at rest prior to and following PTA. In stented lesions higher velocities seem to be linked with a worse outcome. The ratio between velocity prior to and after the application of the vasodilator seems to be of diagnostic importance. A ratio of 1.9 or more was of positive prognostic value. The Doppler guidewire is a practical and valuable tool in assessing technical success after angioplasty of peripheral lesions, critical or morphologically worse lesions. In our study the decision for stent application was made on the morphological image; however, increased velocity and changes in phasicity substantiated our decisions. Increased ratios prior to and after vasodilation (flow reserve) are of prognostic value and therefore suitable as indication for stent placement or tibial angioplasty. Received: 6 April 1998; Revised: 9 December 1998; Accepted: 24 June 1999     

The local spread of lower bile duct cancer: evaluation by thin-section helical CT

This study illustrates the local spread of lower bile duct cancer with thin-section helical CT in correlation with the surgical and pathological findings. Pathologically, 16 patients had pancreatic invasion, 4 had small bowel mesentery invasion, 7 had extrapancreatic nerve plexus invasion, and 3 patients had vascular invasion. On thin-section helical CT, pancreatic invasion was correlated to the clarity or non-clarity of the bile duct mass-pancreas border and the presence of an intrapancreatic mass. Cases with small bowel mesentery and extrapancreatic nerve plexus invasion showed mass or stranding around the superior mesenteric artery and/or inferior pancreatoduodenal artery. Vascular invasion was seen as tumor contiguity to these vessels. Received: 28 September 1998; Revised: 30 December 1998; Accepted: 2 April 1999     

Ruptured adrenal artery aneurysm: a case report

A case of ruptured adrenal artery aneurysm is presented. The ultrasound, computed tomography and selective renal angiography findings are described in detail. Aneurysms of adrenal arteries are particularly rare. Early diagnosis is important because of their tendency towards rupture and subsequent high mortality rate. Received: 12 November 1998; Revised: 10 March 1999; Accepted: 13 April 1999     

Acute mesenteric ischemia caused by spontaneous isolated dissection of the superior mesenteric artery: treatment by percutaneous stent placement

Spontaneous and isolated dissection of the superior mesenteric artery is a rare and often fatal event which has been successfully treated by surgery in several reported cases. We present a patient with acute mesenteric ischemia due to superior mesenteric artery dissection who was successfully treated by percutaneous endovascular placement of a Wallstent. Received: 8 November 1999; Revised: 5 May 2000; Accepted: 9 May 2000     

Power Doppler ultrasound of gallbladder wall vascularization in inflammation: clinical implications

We investigated the role of Power Doppler US in the diagnosis and follow-up of cholecystitis. We reviewed the examinations of 21 surgical patients aged 27–48 years with US findings of cholecystitis. We performed B-mode and then Power Doppler US. Wall thickness and US structure, the presence/absence of stones, and US Murphy's sign were assessed at B-mode US, whereas only the presence/absence of wall vascularization was studied with Power Doppler. B-mode and Power Doppler changes post treatment were also investigated. Ultrasound showed wall thickening in all patients. In addition, positive Murphy's sign and/or gallbladder stones were seen in 6 patients each at B-mode US and wall vascularization in 7 patients with Power Doppler. Acute cholecystitis was diagnosed in these patients. The other 14 patients presenting wall thickening but no vascularization and negative US Murphy's sign were diagnosed as having chronic cholecystitis; 10 of them had gallbladder stones. Two of seven acute cholecystitis patients were operated on in the acute stage for the onset of complications and histologic findings confirmed the US diagnosis. As for the remaining patients, histology diagnosed chronic cholecystitis in 17, whereas wall thickening was not inflammatory in 2 cases. All the cases with early wall vascularization were eventually diagnosed as cholecystitis. Power Doppler US permits confirmation of the diagnosis of acute cholecystitis and distinguishing of chronic disease, which helps in planning of surgery. Received: 30 April 1999; Revised: 26 November 1999; Accepted: 27 January 2000     

Dissection of the internal carotid artery. Personal case reports and a review of the literature

The clinical and angiographic features of 20 patients affected by internal carotid artery dissection are reported. In one patient the neurological signs were related to a traumatic event, in two cases the symptoms presented after hyperextension of the neck during athletic events, while their onset was apparently spontaneous in the remaining 17 patients. Plain CT was normal in 14 cases and positive for ischemic necrosis in 6 patients. Angiography demonstrated extensive/segmental stenosis of the internal carotid lumen in 12 cases (60%), pseudoaneurysmal dilatation in 3 cases (15%), and complete carotid occlusion in 5 patients (25%). The "double lumen" feature was seen in 3 cases at the origin of the dissection. One patient died, surgical ligature of the internal carotid artery was performed in two cases, while the other patients received medical treatment with platelet inhibitors, except for the young patient affected by post-traumatic artery dissection. Complete recovery was observed in 82% of the patients. Follow-up angiograms demonstrated normal recanalization of the internal carotid artery in 4 out of 6 patients; one of them had two false aneurysms which following angiograms demonstrated to be completely resolved. Regression of stenosis was observed in 6 of the remaining patients by Doppler US. On the whole, the recanalization of the internal carotid artery was observed in 59% of cases. Angiographic findings seemed not to play a decisive role in the prognosis of carotid dissections, which largely depends on the overall patient's condition and on the presence/absence of ischemic cerebral damages.     

MRI evaluation of soft tissue hydatid disease

Infestation in soft tissue by Echinococcus granulosus is not a common disease, and its diagnosis is based on clinical, laboratory data and radiological findings. The aim of our retrospective study is to give an overview of the different signs and patterns shown by MRI that can be useful in characterizing soft tissue hydatid disease. The MRI images obtained in seven patients with soft tissue and subcutaneous hydatidosis were reviewed. Typical signs of hydatidosis were multivesicular lesions with or without hypointense peripheral ring (“rim sign”). Related to the presence and absence, respectively, of viable scolices in the microscopic exam, daughter cysts were presented either as high signal intensity or low signal intensity on T2-weighted images. Low-intensity detached layers within the cyst and peripheral enhancement with gadolinium-DTPA were also presented. Atypical signs were presented in an infected muscular cyst, a subcutaneous unilocular cyst and several unilocular cysts. Knowledge of the different patterns in MRI of soft tissue hydatid disease can be useful in diagnosing this entity. We observed that the “rim sign” is not as common as in other locations, and in addition, MRI seems to be of assistance when evaluating the vitality of the cysts. Received: 27 July 1998; Revision received: 11 March 1999; Accepted: 23 April 1999     

Congenital absence of the horizontal portion of the left portal vein: ultrasound findings

Congenital absence of the horizontal portion of the left portal vein is very rare and has been very reported sporadically. We present three such cases referred from other hospitals with a diagnosis of intrahepatic vascular anomaly. Color Doppler ultrasound not only confirmed the diagnosis but also allowed a quantitative measurement of blood flow in these cases. Although it is a very rare condition, knowledge of the ultrasound and color Doppler findings helps in establishing the diagnosis of this congenital anomaly. Received: 9 July 1999; Revised: 25 October 1999; Accepted: 25 October 1999     

颈部血管彩超对缺血性脑血管病患者颈部动脉血管病变的诊断价值

目的探讨颈部血管彩超对缺血性脑血管病患者颈部动脉血管病变的诊断价值。方法 51例经头部CT或MRI及临床确诊的缺血性脑血管病患者,均进行了多层螺旋CT血管成像（CTA）和颈部血管超声（CVUS）检查,以CTA为对照,评价颈部血管彩超的诊断价值。结果 CTA和CVUS发现颈动脉狭窄及闭塞分别为20例、17例,椎动脉狭窄或发育异常分别为29例、15例。结论对于颈动脉狭窄的评价,颈部血管彩超和CTA具有很好的一致性,但颈部血管彩超对椎动脉病变的评价不足,联合使用CVUS和CTA可以更全面地评价缺血性脑血管病患者的颈部动脉病变。     

Ultrasound examination of carotid and vertebral arteries

Ultrasound is the most widespread diagnostic procedure in obstructive disease of the arteries supplying the brain. The combined non-invasive information on morphology and function makes duplex ultrasound the procedure of choice in screening and follow-up of carotid artery disease. This review deals with all relevant aspects of color duplex ultrasound of the carotids and the vertebral arteries. After a short introduction into the clinical background, the paper focuses on aspects of examination technique. In the main part of the review the relevant ultrasound findings in carotid artery disease are discussed. The different methods for grading stenoses of the internal carotid artery are explained in detail. Other relevant pathologies, such as vertebral artery disease, dissection and aneurysms, are briefly mentioned. The clinical value of ultrasound in the work-up of carotid and vertebral artery disease is briefly discussed in comparison with other imaging procedures.     

Asymptomatic aneurysm of the proximal right subclavian artery: a rare ultrasound diagnosis

True aneurysms of otherwise normal subclavian arteries are uncommon peripheral vascular anomalies. Most patients with subclavian artery aneurysms are symptomatic by presenting neurologic signs. We report a young woman who had an asymptomatic true aneurysm of the right subclavian artery assumed to be of congenital origin. This case is unique in that the aneurysm was in the extremely rare anatomic location of the right supraclavicular fossa between the origins of the right subclavian artery and the vertebral artery. Aneurysms of the right subclavian artery may represent a potential pitfall in conventional gray-scale ultrasound of the neck particularly the supraclavicular fossa. Differential diagnosis includes cervical cyst, pharyngo-esophageal diverticulum, vascular anomalies, struma, enlarged lymph node, as well benign or malignant neoplasms. Color duplex ultrasound should be performed as the method of choice for further analysis of suspected aneurysms. In this report the role of B-mode ultrasound and color duplex ultrasound is discussed in relation to digital subtraction- and MR angiography in confirmation of the diagnosis. Received: 5 January 1999; Revision received: 26 April 1999; Accepted: 18 June 1999     

Spontaneous dissection of the cervical internal carotid artery. Diagnosis by MRI

A case of spontaneous dissection of the cervical internal carotid artery documented by angiography and MRI is reported. Angiography showed an irregular stenosis of the upper part of the cervical internal carotid artery extending up to the base of the skull, suggestive of spontaneous dissection. The diagnosis was confirmed beyond doubt by MRI which showed a sub-intimal collection of blood with a typical hyperintense appearance.