Comparison of transcranial color Doppler imaging (TCDI) and transcranial Doppler (TCD) in children with sickle-cell anemia.

BACKGROUND: Transcranial Doppler (TCD) has been demonstrated to identify those at highest risk of stroke among children with sickle-cell disease. Based on a randomized clinical trial [Stroke Prevention in Sickle-Cell Anemia Trial (STOP)], which ended in 1997, the National Heart Lung and Blood Division of NIH has recommended TCD screening and chronic blood transfusion based on Nicolet TC 2000 dedicated Doppler (TCD). Studies performed using TCD imaging modalities need to be correlated to that used in the clinical trial to provide information for treatment decisions when screening with TCDI. OBJECTIVE: To correlate transcranial arterial time-averaged mean velocities obtained from an Acuson Transcranial Doppler Imaging to those obtained using the TCD as the gold standard for treatment decisions based on STOP. MATERIALS AND METHODS: A total of 29 children with sickle-cell disease, age 3-16 years, were studied at one of two scanning sessions using both techniques and a scanning protocol based on that used in STOP performed and read independently. The average difference in the measured velocities for each arterial segment was tested to determine difference from zero. Differences were compared before and after modifications to the TCDI technique were made to mimic the STOP protocol more closely. RESULTS: TCDI velocities were generally lower than TCD velocities for the same segment, but the difference was reduced (from 15 % to 10% for the middle cerebral artery) by modifications to the TCDI protocol. CONCLUSIONS: Measurements using the Acuson system are modestly lower than those obtained with dedicated Doppler using the Nicolet TCD.

Intracranial resistive index (RI) values in normal term infants during the first day of life.

PURPOSE: The purpose of this study was to determine normal resistive index (RI) values for term neonates during the first day of life as part of an ongoing prospective study of RI values in term infants with perinatal asphyxia. MATERIALS AND METHODS: Forty normal term neonates underwent cranial sonography and Doppler during the first 24 h after birth. Transfontanelle Doppler was performed of the internal carotid, anterior cerebral, and middle cerebral arteries bilaterally. In addition, transtemporal Doppler was performed of the middle cerebral arteries bilaterally. Mean and median RI values were calculated in all vessels interrogated. The transfontanelle and transtemporal middle cerebral artery measurements were compared using paired t-tests. RESULTS: The overall mean RI of all interrogated vessels was 0.726 with a standard deviation of 0.057. The mean RI value in the middle cerebral arteries was not significantly different with the two different measurement techniques. CONCLUSION: Normal intracranial RI values for a term infant in the first day of life were calculated for comparison with RI values in term infants with perinatal asphyxia.

Dual-energy x-ray absorptiometry in osteopetrosis.

We have used dual-energy x-ray absorptiometry (DXA) in evaluation and follow-up of a patient with osteopetrosis, before and after cord blood transplantation. Other methods of follow-up in such cases have been described, but the use of DXA has not previously been reported. We have shown that DXA offers a safe means of assessing disease progression, the timing of treatment, and response after therapy for osteopetrosis.

Transcranial Doppler, MRA, and MRI as a screening examination for cerebrovascular disease in patients with sickle cell anemia: an 8-year study.

OBJECTIVE: The authors previously reported five transcranial Doppler ultrasonography (TCD) findings as significant in detecting clinical cerebrovascular disease in a 4-year study in patients with sickle cell disease. This is a follow-up to evaluate the validity of the original findings over another 4-year period during which the study population doubled. A clinical follow-up of the original asymptomatic sickle cell patients with positive TCD, MRA, and MRI was also made. MATERIALS AND METHODS: Over an 8-year period TCD, MRI, and MRA were prospectively performed in 90 sickle cell patients who were clinically asymptomatic for stroke and in 27 sickle cell patients with clinical stroke. RESULTS: Of the 4 out of original 46 control patients in 1992 who had positive MRA and TCD, 3 have subsequently had clinical stroke. None of the 9 original patients with positive TCD and positive MRI but negative MRA have developed stroke. All five original TCD indicators of disease were still significant (P < 0.05) for detecting clinical disease: maximum velocity in ophthalmic artery (OA) > 35 cm/s, mean velocity in middle cerebral artery (MCA) > 170 cm/s, resistive index (RI) in OA < 50, velocity in OA greater than in MCA, and velocity in posterior cerebral (PCA), vertebral, or basilar arteries greater than in MCA. An RI of < 60 in the DA was also now found to be significant [corrected]. Four additional factors were also significant: turbulence, PCA or ACA without MCA, RI < 30, and maximum velocity in MCA > 200 cm/s. CONCLUSION: Positive MRA with a positive TCD in an asymptomatic patient in long-term follow-up suggests a trend for developing clinical stroke. A 4- to 8-year follow-up of nine patients with positive TCD, positive MRI, but not positive MRA did not show development of clinical stroke. Nine Doppler findings are significant in screening for clinically symptomatic vascular disease in sickle cell patients. It is recommended that children with sickle cell disease be screened for cerebrovascular disease with TCD. If one or two indicators of abnormality are present, MRA is recommended. If the MRA is positive, the patient may be considered for transfusion therapy or other treatment for prevention of stroke.

Cerebrovascular disease in symptomatic and asymptomatic patients with sickle cell anemia: screening with duplex transcranial Doppler US--correlation with MR imaging and MR angiography.

PURPOSE: The authors evaluated the role of transcranial Doppler ultrasonography (US) in patients with sickle cell disease (SCD) and cerebrovascular disease. MATERIALS AND METHODS: Twenty-one patients with SCD and stroke (aged 3-22 years; mean age at stroke, 9 years) were evaluated with magnetic resonance (MR) imaging and duplex transcranial Doppler US with a 2-MHz transducer. Nineteen patients also underwent MR angiography. Forty-six asymptomatic patients with SCD were also evaluated with Doppler US, MR imaging, and MR angiography. RESULTS: The following transcranial Doppler US findings were correlated with cerebrovascular disease in patients with SCD: (a) maximum velocity in the ophthalmic artery (OA) of more than 35 cm/sec; (b) mean velocity in the middle cerebral artery (MCA) of more than 170 cm/sec; (c) resistive index in the OA of less than 50; (d) velocity in the OA greater than that of the ipsilateral MCA; and (e) maximum velocity in the posterior cerebral, vertebral, or basilar arteries greater than the maximum velocity in the MCA. CONCLUSION: Transcranial Doppler US scanning has great potential as an inexpensive, easily performed screening procedure for cerebrovascular disease in patients with SCD.

Use of ultrasound in the detection of occult bowel perforation in neonates.

Intestinal perforation is a common and serious complication of NEC in neonates. Plain film evidence often is absent in patients with surgically proved perforation. Some patients with NEC develop a distended, gasless abdomen suitable for sonographic evaluation. Five neonates with gasless abdominal distention and clinical decline were studied with ultrasonography. Four patients demonstrated intraperitoneal fluid-debris levels and ascites; all had surgical proof of perforation. The fifth patient did not demonstrate these findings and subsequently recovered. The sonographic findings of ascites and intraperitoneal fluid-debris levels in patients with NEC are suggestive of perforation.