Noninavasive angiography for the diagnosis of carotid artery disease using Doppler ultrasound (carotid artery Doppler)

To detect stenosis in the carotid artery with a bidirectional continuous-wave Doppler ultrasound device, the following noninvasive procedure, applied on 800 patients and compared with 249 angiograms of 186 patients, has proved to be about 90% reliable. Measurements of flow signals were taken over the terminal branches of the ophthalmic artery (supratrochlear and supraorbital arteries) and averaged. Compression of superficial temporal and facial arteries revealed flow direction and common carotid artery compression revealed the supplying blood vessel and the effectiveness of the circle of Willis. Measurements over the common carotid arteries were used to evaluate peripheral resistance. A set of eight criteria was used; the diagnostic value of each criterion was calculated by comparing 138 pathological Doppler findings in 123 patients with the angiograms. If reverse flow direction in supratrochlear or supraorbital artery was used alone, only 43% correct diagnoses would have resulted. A more severe stenosis is not necessarily correlated with a more weighted criterion; a subset of criteria is less efficient than the combination of all criteria. Application during 32 extracranial endarterectomies on 28 patients informed the surgeon immediately about the hemodynamic effect of the surgical intervention. Rethrombosis was diagnosed in two patients by postoperative Doppler examination.     

MRI and MR angiography of vertebral artery dissection

A review of 4,500 angiograms yielded 11 patients with dissection of the vertebral arteries who had MRI and (in 4 patients) MR angiography (MRA) in the acute phase of stroke. One patient with incidental discovery at arteriography of asymptomatic vertebral artery dissection and two patients with acute strokes with MRI and MRA findings consistent with vertebral artery dissection were included. Dissection occurred after neck trauma or chiropractic manipulation in 4 patients and was spontaneous in 10. Dissection involved the extracranial vertebral artery in 9 patients, the extra-intracranial junction in 1, and the intracranial artery in 4. MRI demonstrated infarcts in the brain stem, cerebellum, thalamus or temporo-occipital regions in 7 patients with extra- or extra-intracranial dissections and a solitary lateral medullary infarct in 4 patients (3 with intracranial and 1 with extra-intracranial dissection). In 2 patients no brain abnormality related to vertebral artery dissection was found and in one MRI did not show subarachnoid haemorrhage revealed by CT. Intramural dissecting haematoma appeared as crescentic or rounded high signal on T1-weighted images in 10 patients examined 3-20 days after the onset of symptoms. The abnormal vessel stood out in the low signal cerebrospinal fluid in intracranial dissections, whereas it was more difficult to detect in extracranial dissections because of the intermediate-to-high signal of the normal perivascular structures and slow flow proximal and distal to the dissection. In two patients examined within 36 h of the onset, mural thickening was of intermediate signal intensity on T1-weighted images and high signal on spin-density and T2-weighted images. MRA showed abrupt stenosis in 2 patients and disappearance of flow signal at and distal to the dissection in 5. Follow-up arteriography, MRI or MRA showed findings consistent with occlusion of the dissected vessel in 6 of 8 patients.     

Long-term evaluation of vertebral artery injuries following cervical spine trauma using magnetic resonance angiography

STUDY DESIGN: A prospective study to determine the long-term outcome of traumatically induced vertebral artery injuries. Magnetic resonance angiography was performed at the time of cervical injury and at a follow-up office visit. OBJECTIVE: To determine the long-term outcome in terms of arterial flow competency of traumatically induced vertebral artery injuries. SUMMARY OF BACKGROUND DATA: Vertebral artery injury associated with cervical spine trauma has been well documented; however its healing or nonhealing potential has not been elucidated. METHODS: During the 7-month period from July 1993 to January 1994, all patients admitted to the authors' institution with cervical spine injuries underwent magnetic resonance imaging and magnetic resonance angiography of the cervical spine to determine the patency of their vertebral arteries. Magnetic resonance angiography was performed at the time of injury and at a follow-up office visit. Twelve of 61 patients were found to have a lack of signal flow within one of their vertebral vessels during this study period. RESULTS: Eighty-three percent of the patients (five of six) who were available for follow-up observation in this study did not manifest flow reconstitution of their vertebral arteries after an average 25.8-month follow-up period. CONCLUSIONS: According to these data, most patients with vertebral artery injuries after nonpenetrating cervical spine trauma do not reconstitute flow in the injured vertebral arteries. This lack of flow must be considered if future surgery in this region of the cervical spine is contemplated.     

Noninvasive differential diagnosis between chronic pulmonary thromboembolism and primary pulmonary hypertension by means of Doppler ultrasound measurement

We examined the development of tolerance to the antiallodynic effect of chronic intrathecal (IT) administration of the adenosine analog R-phenylisopropyladenosine (R-PIA) in a rat model of central pain after ischemic spinal cord injury. After 10 days of IT R-PIA treatment, the effect of IT morphine was also assessed to examine whether cross-tolerance between R-PIA and morphine was present. IT R-PIA completely alleviated allodynia-like behaviors to mechanical and cold stimuli in spinally injured rats. The anti-allodynic effect of R-PIA was maintained for 6-7 days with twice-daily administration and was reduced thereafter, particularly with respect to cold allodynia. IT morphine alleviated mechanical and cold allodynia in rats rendered tolerant to R-PIA to a degree comparable to that in R-PIA-naive (control) rats, which indicates that the anti-allodynic property of R-PIA is independent of the mechanisms by which morphine acts. The possibility of using agonists of adenosine receptors in treating refractory pain in patients with spinal cord injury is discussed. IMPLICATIONS: There is often no satisfactory treatment for chronic pain after spinal cord injury. Our study suggests such pain can be treated with a spinal injection of R-phenylisopropyladenosine in rats. Reduced effect to R-phenylisopropyladenosine was noted with repeated administrations. However, there was no cross-tolerance to morphine.     

Noninvasive detection of iliac artery disease and prediction of its severity from Doppler spectral analysis in common femoral artery

The direct interrogation of iliac artery disease (IAD) with color-coded duplex scanning is limited by the presence of intestinal gas or obesity. The purposes of this study were to examine the diagnostic accuracy of duplex ultrasound (DUS) analysis of spectral waves in common femoral artery (CFA) for detection of IAD and to predict its severity. DUS and arteriography were performed in 107 lower extremities in this study. The following were calculated from the CFA spectral waves obtained by DUS: peak systolic velocity (PSV), acceleration (PSV/pulse rise time), and deceleration (PSV/pulse decay time). In patients with isolated IAD, the treadmill exercise test was also performed to evaluate the ischemic severity expressed as recovery rate of ankle pressure index five minutes after exercise (RR-API). Forty-six lower extremities with IAD and 61 without IAD were diagnosed by arteriography. PSV was significantly reduced in lower extremities with IAD (109.5 +/- 32.7 vs 59.8 +/- 32.9 cm/s, P < 0.05). The deceleration detected IAD with a greater specificity and sensitivity vs acceleration (100.0 vs 82.0% and 97.8 vs 82.6%, respectively). Moreover, the acceleration and deceleration significantly correlated with the RR-API (r = 0.589, P < 0.05 and r = 0.779, P < 0.01, n = 14, respectively). The present evaluation is a simple and accurate technique to augment other examinations for detection of IAD and to assess its ischemic severity.     

Noninvasive vascular imaging in the diagnosis and treatment of adventitial cystic disease of the popliteal artery

Depressed geriatric patients show substantial intersubject variability in cognitive performance, which complicates attempts to evaluate the cognitive effects of depression and of antidepressant therapy. This variability may reflect the multiple medications older patients take, many of which have anticholinergic effects. This study examined whether serum anticholinergicity (SA) explained some of the variability in depressed geriatric patients' memory performance. Before starting antidepressant treatment, 36 elderly depressed subjects were given a verbal learning test. At the same time, a blood sample was taken and analyzed by radioreceptor binding assay to determine their SA level. Nineteen of the subjects had detectable levels (mean = 0.28 pmole atropine equivalent). Subjects with an SA of zero showed significantly better delayed recall than did those with a positive SA level. Thus, even very low SA may produce subtle decrements in memory performance, an area of cognition known to be highly sensitive to anticholinergic effects.     

Early diagnosis of conjoined twins using two-dimensional color Doppler and three-dimensional ultrasound

Transvaginal three-dimensional (3-D) and color Doppler ultrasound were used to establish a first-trimester definitive diagnosis and classification of thoracoomphalopagus conjoined twins following two-dimensional (2-D) transabdominal and transvaginal scans that indicated twin gestation of uncertain classification. Color Doppler in combination with 3-D ultrasound can be a useful complement to 2-D ultrasound to confirm early diagnosis and determine the extent of organ sharing and definitive classification of conjoined twins.     

Noninvasive assessment of collateral blood flow of the cerebral hemisphere by Doppler ultrasound

Directional flow in the frontal artery, a terminal branch of the ophthalmic artery, was assessed nonivasively by Doppler ultrasound druing brief digital compression of the ipsilateral common carotid artery in 62 patients. Directional frontal artery flow during carotid compression was compared with mean distal internal carotid back pressure measured at subsequent carotid endarterectomy. Mean carotid back pressure in 28 patients with normal frontal artery flow direction during carotid compression, 68 +/- 14 millimeters of mercury, was significantly higher than that observed in 24 patients in whom frontal artery flow was completely obliterated and ten in whom frontal artery flow was reversed. Distal internal carotid back pressure exceeded 48 millimeters of mercury in all patients with normal frontal artery flow direction during carotid compression. Conversely, carotid back pressure was below 41 millimeters of mercury in all but one patient in whom frontal artery flow was obliterated or bliterated or reversed during carotid compression. The results of this study indicate that Doppler ultrasound assessment of frontal artery flow direction during simultaneous carotid compression provides a rapid, sale noninvasive estimate of the adequacy of collateral hemispheric circulation.     

Diagnosis of pulmonary arteriovenous malformations by colour Doppler ultrasound and amplitude ultrasound angiography

STUDY OBJECTIVE: To evaluate the effect of ultra-rapid opioid detoxification on spontaneous respiration. DESIGN: Prospective study. SETTING: University of Illinois, Chicago, Hospital. PATIENTS: 20 ASA physical status I and II patients undergoing ultra-rapid opioid detoxification, and 5 ASA physical status I and II control patients undergoing surgical procedures. INTERVENTIONS: Ultra-rapid opioid detoxification patients were anesthetized with propofol, intubated, and spontaneously ventilating. Opioid detoxification was achieved by giving repeated increasing intragastric doses of naltrexone. Control patients were anesthetized with propofol and 70% nitrous oxide and were time-based controls for opioid detoxification. MEASUREMENTS AND MAIN RESULTS: Respiratory rate and minute ventilation were measured and increased 80% to 100% during opioid detoxification (p < 0.05). Respiratory rate and minute ventilation did not change in controls. Oxygen consumption and carbon dioxide (CO2) production were measured in separate studies and increased during ultra-rapid opioid detoxification with increases in spontaneous ventilation, but not when the patients were paralyzed. CONCLUSIONS: Spontaneous ventilation increases during opioid detoxification without a change in end-tidal CO2. An increase in metabolism is produced in opioid withdrawal that is mediated by elevated muscle activity.     

Colour Doppler energy (power) mode ultrasound

During the study period, 24,492 pregnant women attended the Harris Birthright Research Centre at 10-14 weeks of gestation, at which time, in addition to the measurements of nuchal translucency thickness and crown-rump length (CRL), data on fetal abnormalities were recorded onto a computer database. Cases of megacystis were identified and the records were reviewed. Additionally, the relationship of the longitudinal bladder diameter with the CRL and the bladder diameter/CRL ratio (expressed as a percentage) were examined with the use of data from 300 normal fetuses at 10-14 weeks. Megacystis was present in 15 of the 24,492 pregnancies (1 in 1,633) and in these cases the minimum longitudinal bladder diameter was 8 mm and the minimum bladder diameter/CRL ratio was 13%. In the 300 control fetuses the bladder was visualized in 278 (92.7%) of the cases and the longitudinal bladder diameter increased with the CRL (bladder diameter = 0.065 x CRL - 0.69; r = 0.47, p < 0.001), none of the measurements was more than 6 mm and the median bladder diameter/CRL ratio was 5.4% (range 0-10.4%) which did not change significantly with gestation (r = 0.1, p = 0.09). The bladder was visible in all cases with a minimum CRL of 67 mm. In three of the 15 cases with megacystis, there were chromosomal abnormalities. In the chromosomally normal group, there were seven cases with spontaneous resolution, whereas in four cases there was progression to severe obstructive uropathy. The bladder diameter was 8-12 mm and the bladder diameter/CRL ratio 13-22% in all cases with resolution and in one case with progressive megacystis; in the other three cases with progressive obstruction, the bladder length was more than 16 mm and the bladder diameter/CRL ratio was more than 28%.     

The diagnosis of obstructions of the vertebral and subclavian arteries by means of directional Doppler sonography (author's transl)

The Doppler examination of the vertebral and subclavian arteries was compared with the angiographic findings in 40 cases. The vertebral flow was recorded at its atlas slope, the subclavian artery at the supraclavicular fossa. Twenty-seven normal Doppler results were confirmed by angiography in 26 cases. In one case there was a 70% stenosis at the origin of the vertebral artery. Occlusions, stenoses, and severe hypoplasia of the vertebral artery can be detected, but not distinguished from each other by the Doppler examination. Diagnostically relevant findings are either nondetectable flow above the vertebral artery or only minor pulsations with amplitudes less than 25% of the normal side. Eleven cases showed a flow reversal in a vertebral artery. Five of them were angiographically controlled and all showed a typical subclavian steal syndrome. Although the precision of the results of the examination of the vertebral artery is not as good as for the carotid arteries, it is a rough, suitable atraumatic screening method particularly for the subclavian steal syndrome.     

Magnetic resonance angiography and magnetic resonance tomography in dissection of the vertebral artery

Vertebral artery dissection (VAD) is an important cause of posterior circulation stroke in young adults. Initial symptoms are often non-specific and diagnostic arteriography is not performed until neurological deficits are obvious. Since magnetic resonance tomography (MRT) is superior in the diagnosis of vertebrobasilar ischemia, we retrospectively analyzed the role of MRT and MR angiography (MRA) in the detection of dissections of the vertebral artery. Between 1989 and 1995 we identified 24 patients with a vertebral artery dissection and 1 patient with a basilar artery dissection (8 females and 17 males, 23-60 years of age, mean 41.2 years). The diagnosis of VAD (14 left VAD, 9 right VAD, 1 bilateral VAD, 1 basilar artery dissection) was established by specific arteriographical findings (DSA) or clinical and neuroradiological course. All patients underwent a combined MRT/MRA examination protocol at 1.5T that consisted of spin-echo imaging and time of flight MRA of the intra- and extracranial arteries using 2D Flash and 3D Fisp sequences. The MRT/MRA findings were correlated to DSA and ultrasound results. During the acute and subacute stage, MRT/MRA revealed abnormal findings in 21 of 22 dissected vessels (95.5%). There was one false-negative MRT/MRA in a patient with a V1 dissection (intimal flap without peripheral flow disturbances). In 7/22 VAD the MRT/MRA findings were rated specific (double lumen n = 1, mural hematoma n = 4, pseudoaneurysm n = 2). DAS was sensitive in 100% and ultrasound in 77.3%. Specific results were obtained by DSA in 8/ 22 VAD (36.4%) and in 7/22 VAD (30.4%) by MRT/MRA. When MRT/MRA and DSA results were combined, the specific findings increased to 43.5%. Follow-up examinations revealed recanalization in 52% of initially stenosed or occluded vertebral arteries; four patients developed a pseudoaneurysm, and two of them underwent ligation of the VAD. With this retrospective approach, we were able to show a high sensitivity of MRT/ MRA for the presence of disturbed flow in the dissected vertebral artery. The MRA projections tended to overestimate stenosis and were inferior to DSA in the appreciation of irregularities of the vessel wall. Identification of high-grade stenosis, especially in the presence of distal occlusion, was improved on the MRA source images. During the acute and subacute stage, the diagnosis of luminal thrombus can be difficult, because signal ambiguities exist between hemoglobin breakdown products and flow effects and adjacent fat tissues. The differentiation between luminal thrombus and mural hematoma requires interpretation of MRA source images, together with flow compensated spin-echo images. Additional fat suppressed images and flow presaturation may be required at the appropriate levels. The identification of mural hematoma is important, because this finding is considered specific and cannot be obtained with DSA. There is a complementary role of MRT/MRA and DSA for an improved overall specificity for vertebral artery dissection. A negative MRT/MRA result in a patient with appropriate symptoms, however, cannot exclude a dissection and should prompt DSA. On the other hand, a suggestive MRT/MRA result in the appropriate clinical context can replace DSA. The advantage of MRT/MRA is that the method offers a simultaneous diagnosis of posterior fossa ischemia and vertebral artery abnormalities. Therefore, MRT/MRA should be recommended in patients with suspected VAD and especially in those who have no definite neurological deficit. These patients will benefit greatly from early diagnosis and therapy. The fact that all our patients were diagnosed after neurological symptoms and that 64% of them have residual deficits gives an ethical and economical rationale for advocating early MRT/MRA in these patients.     

Comparison of Doppler US and CT angiography for evaluation of renal artery stenosis

RATIONALE AND OBJECTIVES: The authors compared Doppler ultrasound (US) with computed tomographic (CT) angiography in the evaluation of stenosis of the main renal artery. MATERIALS AND METHODS: Fifty-six patients who had undergone conventional angiography of the renal arteries participated in a prospective comparison of Doppler US (45 patients) and CT angiography (52 patients). US evaluation included both the main renal artery and segmental renal arteries. RESULTS: There were 27 main renal arteries with at least 50% stenosis in 20 patients. In 36 patients, there was no significant stenosis. All cases of main renal artery stenosis detected with Doppler US of the segmental arteries were also identified with Doppler US of the main renal artery. The by-artery sensitivity (63%) of US of the main renal artery was greater than that (33%) of US of the segmental arteries. CT angiography was more sensitive (96%) than Doppler US (63%) in the detection of stenosis, but the specificity of CT (88%) was similar to that of US (89%). The difference in the area under the receiver operating characteristic curve (AUC) between CT (AUC = 0.94) and US (AUC = 0.82) was statistically significant (P = .038). CONCLUSION: Doppler US of the main renal artery is more sensitive than Doppler US of segmental arteries in the detection of stenosis. CT angiography is more accurate than Doppler US in the evaluation of renal artery stenosis.     

Repeat angiography and magnetic resonance imaging (MRI) of dissecting aneurysms of the intracranial vertebral artery. Report of four cases

We here present 4 cases with dissecting aneurysm (DA) of the intracranial vertebral artery, who were followed up by repeat cerebral angiography and MRI. The patients consisted of 2 males and 2 females, and the mean age was 43 years. Two cases were associated with polyarteritis nodosa (PN) and hypertension, respectively. Three of the cases developed subarachnoid haemorrhage (SAH), while the other one suffered from lateral medullary syndrome. In cerebral angiography, "pearl and string" signs were revealed in all cases, while a "double lumen" indicating a true diagnostic sign of DA was demonstrated in only one case. Repeat angiography showed that a bleb formation with a bulging of the aneurysmal sac was seen in 2 cases, and an irregularity of the wall in one case. On the other hand in one case, the ectatic part shrank, while the stenotic part was restored. In magnetic resonance imaging (MRI), a hyperintensity mass on T 1-weighted image (T 1-WI) adjacent to flow void suggesting either an intramural haematoma or a linear shape hyperintensity on T 1-WI were demonstrated in 3 cases. In the follow up MRI done in 2 cases, a serial change in the intensity from iso-intensity to hyperintensity on T 1-WI was observed in one case suggesting intramural haemorrhage, while an enlargement of the ectasic flow void was seen in the other case. Three of 4 cases were operated on by trapping of the aneurysms. One, who had systemic vascular diseases due to PN, and repeat angiography showed a regression of the aneurysm, was conservatively treated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Magnetic resonance angiography demonstrates vascular healing of carotid and vertebral artery dissections

BACKGROUND AND PURPOSE: Dissection of the carotid and vertebral arteries is most accurately diagnosed with conventional angiography. MR techniques are sensitive for detecting the abnormalities associated with dissection but may lack specificity. We hypothesized that MR may be useful for serial monitoring of dissection and may therefore guide therapy. METHODS: All patients with angiographically proven carotid and/or vertebral artery dissection from July 1994 to June 1996 were followed for a median duration of 10.5 months. Of these 29 patients (44 vessels), 18 were concurrently evaluated with MR, and a target group of 9 patients (17 vessels) was prospectively followed with MR at 3-month intervals. RESULTS: In the 18 patients with both imaging studies at baseline, angiography revealed 30 dissected vessels while MR detected 27 (90%). In the target group of 9 patients, initial MR identified 15 of the 17 dissections diagnosed with angiography. Serial MR revealed complete healing in 5 vessels, improvement in 6 vessels, no change in 4 vessels, and worsening in 2 vessels. The radiographic features most likely to resolve were stenosis and mural hematoma, while occlusion and luminal irregularity tended to persist. Late ischemic events occurred in 2 patients, both with persistent MR evidence of dissection, one while subtherapeutic on warfarin therapy and the other occurring 1 week after warfarin was discontinued. CONCLUSIONS: MR is a reliable noninvasive method for following the vascular response to treatment and may guide the course of a clinical trial comparing medical therapies for carotid and vertebral artery dissection.