Transcranial Doppler ultrasonography in neurologically asymptomatic children and young adults with sickle cell disease

The purpose of the study was to evaluate transcranial Doppler ultrasonography for identifying cerebrovascular disease in neurologically asymptomatic children and young adults with sickle cell disease. A total of 47 consecutive patients with sickle cell disease (28 females, 19 males; age range 8 months to 29 years, mean age 9 years 6 months) were evaluated by transcranial color and duplex Doppler ultrasonography via transtemporal and occipital (2-MHz probe) as well as by transocular (5-MHz probe) approach. Eleven vessels (middle, posterior, anterior cerebral artery, vertebral artery, ophthalmic artery on each side and basilar artery) were analyzed in each patient. Following nine transcranial Doppler findings predictive for cerebrovascular disease, patients with one or more of those abnormal sonographic findings underwent MR imaging and MR angiography. In 8 patients with abnormal transcranial Doppler the MR angiography was normal. Thirty-one patients demonstrated normal results. In 15 of 16 patients with one or more abnormal Doppler findings (34% of all studied patients) MR imaging and MR angiography were performed. The MR angiography disclosed cerebrovascular stenosis in 7 patients (15% of all patients, 44% of those with pathological transcranial Doppler findings). In one of those patients MR imaging revealed silent peripheral ischemic infarction as well. Our findings indicate the usefulness of transcranial Doppler ultrasonography to reveal occult cerebrovascular lesions in neurologically asymptomatic patients with sickle cell disease. It should regularly be performed in all sickle cell patients in order to detect patients at risk for later stroke. Patients with homozygous disease and a high frequency of preceding sickle cell crises should be followed most closely. Electronic Publication     

Clinical use of urinary tract magnetic resonance imaging

MR imaging should not be used to evaluate the majority of the lesions described herein but should be reserved for specific clinical situations. The detection and differential diagnosis of adrenal masses is a legitimate application of this technique. The staging of renal tumors in patients in whom CT fails to do so may be accomplished by MR imaging. Establishment of patency of the renal veins and of surgical shunts involving these veins may be performed by MR imaging if Doppler ultrasonography proves unsatisfactory. MR imaging may differentiate between stable retroperitoneal fibrosis and malignant disease in patients in whom this differential is a problem. Hematomas may be distinguished from nonhemorrhagic fluid collections anywhere in the abdomen or pelvis. In selected patients, the local extent of certain bladder tumors may be evaluated by MR imaging when CT and biopsy fail to do so. In testicular disease, MR imaging may aid in the differential diagnosis of abnormalities that are not sufficiently characterized by ultrasonography, and MR imaging may detect undescended testes in some patients in whom ultrasonography fails to do so. In the future, wider application of fast scanning with bolus administration of soluble paramagnetic contrast agents may refine the differential diagnosis of adrenal masses and aid in the detection of renal masses. MR angiographic techniques ultimately may constitute a screening procedure for renal arteriostenosis. A subset of patients with prostate carcinoma may prove to benefit from local staging of the disease by MR imaging.     

Evaluation of children for liver transplantation: value of MR imaging and sonography

Diagnostic imaging plays a major role in the diagnosis and treatment of chronic liver disease in children. Decisions regarding the need for sclerotherapy, palliative shunts, and anatomic suitability for hepatic transplantation are based on the upper abdominal anatomy. Thirty-six children with various forms of chronic liver disease were referred for diagnostic imaging, including MR and sonography. Each study was evaluated independently without knowledge of the other examination. The first six patients were evaluated retrospectively and the last 30 patients prospectively. The size of the portal vein and inferior vena cava varied in this population, with excellent agreement between sonography and MR. A 2-mm portal vein was shown only on MR imaging in two patients, but MR missed a 3-mm portal vein. Portosystemic collateral vessels also were evaluated and noted to be detected more readily with MR imaging (64%) than with sonography (22%). In particular, paraumbilical veins were detected more often with MR (28% vs 6% by sonography). Associated or coexisting anomalies were relatively common in children with chronic liver disease (14%). These included polysplenia (two cases), preduodenal portal vein (one), unilateral dysplastic kidneys (two), ureteropelvic junction obstruction (one), and splenic (one) and renal (one) cysts. MR imaging was more sensitive than sonography for detection of abnormal anatomy in this group of patients and should be considered the pretransplantation imaging technique of choice in children with end-stage liver disease.     

Magnetic resonance imaging in the assessment of urologic disease: an all-in-one approach

The aim of this study was to evaluate an “all-in-one” MR procedure to examine the kidneys, the renal vascular supply and renal perfusion, and the urinary tract. In 64 patients (58 with urologic disease and 6 healthy volunteers), MR was performed including: (a) T1- and T2-weighted imaging; (b) 3D contrast-enhanced MR angiography (MRA), including the renal arteries, renal veins, as well as renal perfusion; and (c) 3D contrast-enhanced MR urography (MRU) in the coronal and sagittal plane. For the latter, low- and high-resolution images were compared. Prior to gadolinium injection, 0.1 mg/kg body weight of furosemide was administered intravenously. The results were compared with correlative imaging modalities (ultrasonography, intravenous urography, CT), ureterorenoscopy and/or surgical–pathologic findings. Visualization of the renal parenchyma, the vascular supply, and the collecting system was adequate in all cases, both in nondilated and in dilated systems and irrespective of the renal function. One infiltrating urothelial cancer was missed; there was one false-positive urothelial malignancy. Different MR techniques can be combined to establish an all-in-one imaging modality in the assessment of diseases which affect the kidneys and urinary tracts. Continuous refinement of the applied MR techniques and further improvements in spatial resolution is needed to expand the actual imaging possibilities and to create new tracts and challenges in the MR evaluation of urologic disease. Received: 27 September 1999; Revised: 20 January 2000; Accepted: 22 May 2000     

Imaging of the small bowel: Crohn’s disease in paediatric patients

In more than 20% of all patients, the Crohn’s disease presents before the age of 18years. The diagnosis and management of Crohn’s disease in children has changed dramatically over the last decade, mainly due to increased awareness, availability of newer diagnostic modalities such as magnetic resonance imaging (MRI) and newer, more powerful treatments such as biologics. Imaging of the small bowel is needed for diagnosis, management, follow-up and also evaluation of the disease in terms of location, extent, activity and complications. We review all the methods (barium examinations, ultrasonography, computed tomography, MR, and computed tomography- positron emission tomography) commonly used for imaging the small bowel in paediatric patients with Crohn’s disease analyzing the advantages and disadvantages of each modality, with particular emphasis on MR imaging.     

Rapid MR imaging detection of renal cysts: age-based standards.

PURPOSE: To establish age-based standards for renal cysts depicted at magnetic resonance (MR) imaging and to compare these standards with existing standards for ultrasonography (US). MATERIALS AND METHODS: Three radiologists reviewed subsecond T2-weighted single-shot fast spin-echo kidney MR imaging findings in 528 patients (248 men, 280 women) selected from consecutive abdominal MR studies without regard to clinical indication. Age, sex, and number and diameter of cysts were noted. Results were analyzed with nonparametric tests and were compared with published US results. RESULTS: Men (mean, 2.0; 95% CI: 1.5, 2.5) had more renal cysts than women (mean, 1.2; 95% CI: 0.9, 1.5) (P < .001). Number and diameter of cysts increased with age (P < .001). Of 528 patients, 330 (62.5%) had at least one renal cyst, and 315 (59.7%) had cysts of 10 mm or less. MR imaging findings were comparable to published US criteria for type 1 autosomal dominant polycystic kidney disease (ADPKD) if only cysts larger than 1 cm were considered: Only one subject in the group of 18-29-year-old subjects had at least two renal cysts, and five of 493 subjects aged 30-59 years had at least two cysts in each kidney. CONCLUSION: Compared with reported US results, MR imaging depicted an increased number of simple renal cysts in healthy individuals because of its increased sensitivity for cysts smaller than 1 cm. If only simple renal cysts larger than 1 cm are considered, US criteria for type 1 ADPKD can be applied to MR imaging.     

Posttransplant renal rejection: comparison of quantitative scintigraphy, US, and MR imaging

Accuracy of ultrasonography (US), quantitative scintigraphy, and magnetic resonance (MR) imaging in diagnosis of acute renal allograft rejection was studied in 46 patients who underwent renal biopsy. Thirty-three patients had acute rejection; six, cyclosporine nephrotoxicity, as shown by biopsy, clinical findings, and follow-up study; two, acute tubular necrosis; and five, normal biopsy findings and renal function. Accuracy in demonstrating rejection was 72% for US and 75% for scintigraphy, indicating no significant difference between the two. MR imaging was significantly more accurate, reaching a level of 98%. However, accuracy of MR in demonstrating acute tubular necrosis in a larger number of patients is not known, and its accuracy in indicating recurrent glomerulopathy or infectious disease has not been addressed. The definitive role of MR in evaluating posttransplant renal failure is currently not established, but because of its high sensitivity in detecting renal abnormality, MR can be used for cases when results of US or scintigraphy are equivocal or contradict clinical impressions or when biopsy cannot be performed for medical reasons.     

Hydronephrotic kidney: pediatric three-dimensional US for relative renal size assessment--initial experience

PURPOSE: To prospectively evaluate accuracy of three-dimensional (3D) ultrasonography (US) for assessment of relative renal size in infants and children with hydronephrosis. MATERIALS AND METHODS: Informed consent was obtained from parents and also from children who were older than 8 years. Study was approved by ethics committee. Two-dimensional (2D) US, 3D US, and scintigraphy were performed in 40 patients with hydronephrosis (age range, neonate to 16 years; seven girls, 33 boys) without acute renal disease. Twenty patients also underwent magnetic resonance (MR) urography. US and MR urography were performed by one experienced pediatric radiologist; 3D US and MR urographic volume calculations were performed by specifically trained radiologists. Three-dimensional US was performed with integrated 3D volume probes or external system based on electromagnetic positioning devices. At 2D US, kidney volume was calculated with application of ellipsoid equation. At MR urography and 3D US, real renal parenchymal volume was calculated with subtraction of dilated collecting system. Split renal function was assessed with static renal scintigraphy. Three-dimensional US results were graded with respect to image quality and compared with results of 2D US, scintigraphy, and MR urography by using mean difference percentage and standard deviation of the difference. All investigations were performed with blinding. Inter- and intraobserver variability were calculated with coefficient of variation. RESULTS: In 76 of 80 kidneys, 3D US image of diagnostic quality was obtained. Three-dimensional US volume measurements compared well with MR urographic measurements (mean difference, -2.5% +/- 7.8 [standard deviation] vs 25.8% +/- 32.2 for 2D US) and with scintigraphically assessed split renal function (mean difference, 1.2% +/- 9.2 vs 15.9% +/- 43.8 for 2D US). Intra- and interobserver variability were +/-6.4% and +/-9.9%, respectively. CONCLUSION: Initial experience with renal 3D US indicates that it is an accurate method for assessment of renal parenchymal volume and relative renal size, provided there is no acute renal disease.     

Imaging end-stage kidney disease in adults. Low-field MR imaging with magnetization transfer vs. ultrasonography

Purpose: To 1) assess the potential of magnetization transfer (MT)-weighted MR imaging to improve the often poor visibility of native kidneys in patients with a renal transplant; and 2) compare low-field MR imaging and ultrasonography (US) for imaging these fibrotic kidney remnants.Material and Methods: Seventy-two native kidneys of 36 patients were prospectively evaluated with US and MR. In low-field (0.1 T) MR imaging, T1-, T2- and MT-weighted sequences were used. MT-weighted images were compared with T2-weighted images in their ability to delineate the kidneys from their surroundings whereas US and MR were compared for detection of renal cysts and possible solid tumors.Results: MT-weighted images proved superior to conventional T2-weighted images in producing contrast between the kidney remnants and their fatty surroundings. Although US revealed a few small renal cysts that were not seen at MR images, no statistical difference was found between the two modalities in this respect.Conclusion: MT imaging, due to its unique protein-specific signal depression, offers significantly improved visualization and delineation of end-stage kidneys. US, because its better availability and cost-benefit ratio, remains the method-of-choice compared to low-field MR imaging in detecting cysts in multicystic kidneys. MR investigation is helpful in selected patients and may be used as an alternative.     

Potential impact of pediatric MR urography on the imaging algorithm in patients with a functional single kidney

OBJECTIVE: The purpose of this study was to evaluate the potential of MR urography in the assessment of children with a suspected "functional single kidney." SUBJECTS AND METHODS: Sixty patients (age range, 2.7 weeks to 15.7 years) who had been referred for assessment of a suspected functional single kidney underwent MR urography in addition to detailed sonography of the urinary tract and the currently indicated standard imaging. The results of the conventional imaging ((99m)Tc-dimer captosuccinic acid scintigraphy, voiding cystourethrography, and genitography) were compared with the results of sonography and MR urography; surgical findings served as the gold standard if available. RESULTS: Twenty-six patients had a single kidney. The other diagnoses were six contralateral multicystic dysplastic kidneys, two normal ectopic kidneys, one crossfused double system, and 25 ectopic or dysplastic renal buds. Scintigraphy detected all normal kidneys, two ectopic kidneys, and two dysplastic renal buds. Detailed sonography missed two ectopic kidneys and two orthotopic dysplastic renal buds, but one additional renal bud that could not be confirmed on other imaging techniques (accuracy, 91.7%; sensitivity, 88.2%; specificity, 96.2%) was suspected. MR urography results were correct in all patients and verified in all 13 with surgical correlation. CONCLUSION: MR urography allows a reliable assessment of renal and ureteral anatomy and of dysplastic or ectopic renal buds, even in non- or poorly functioning systems. MR urography therefore has the potential to replace the currently used excretory urography and scintigraphy. In patients with a suspected functional single kidney a detailed sonographic study and MR urography should be considered the diagnostic algorithm of choice.     

Imaging the testis: comparison between MR imaging and US

The potential role of magnetic resonance (MR) imaging in the diagnosis and local staging of testicular tumors was evaluated in 23 patients who subsequently underwent surgery or biopsy. Findings at MR imaging were compared with those at ultrasonography (US) and were correlated with the surgical-histologic findings. At surgery, three patients were found to have extratesticular and 20 patients intratesticular abnormalities. This distinction had been correctly made with both imaging modalities, but US did not demonstrate the intratesticular abnormality in four patients with diffuse infiltrating tumors. Neither modality allowed differentiation of benign from malignant disorders. When local tumor staging was analyzed in 11 patients, the accuracy of both modalities was disappointing (true-positive findings with MR imaging in seven patients and with US in five). At present, US remains the primary imaging modality for testicular disease. MR imaging should be employed when findings at physical examination and US are discrepant and considered when diffuse infiltrative disease is suspected.     

Autosomal dominant polycystic kidney disease: MR imaging evaluation using current techniques

PURPOSE: To determine the MR imaging findings of autosomal dominant polycystic kidney disease using current imaging techniques. MATERIALS AND METHODS: We reviewed our five-year experience with MR imaging of autosomal dominant polycystic kidney disease (ADPKD) to determine the spectrum of appearance of kidney disease, the occurrence of cysts in other abdominal organs, the size and number of cysts in the kidneys and other organs, and the association with other benign or malignant disease. Thirty patients (17 men and 13 women, age range 30 to 88 years old) with ADPKD were included in this study. All patients were examined by MR imaging including T2-weighted single-shot echo-train spin-echo and pre- and post-gadolinium chelate spoiled gradient-echo imaging. RESULTS: All kidneys were involved with multiple, varying sized cysts scattered throughout the parenchyma. Giant renal cysts (>8 cm) were associated with pain in the only two patients who possessed them. Hemorrhage in renal cysts was observed in all kidneys with a heterogeneous pattern of involvement on non-contrast T1- and T2-weighted images, reflecting hemorrhage of varying age. The mean kidney size for the right kidney was 17.4 cm in length, 10.3 cm in transverse, and 9.4 cm in antero-posterior diameter (AP); and for the left kidney, 15.9 cm in the length, 9.3 cm in the transverse, and 9.3 cm in AP diameter. Other organs involved included the liver (22 patients), the pancreas (three patients), with two of the above-mentioned patients having both liver and pancreas cysts, and the spleen (one patient) who had both liver and splenic cysts. Massive liver involvement with large cysts was associated with abdominal pain. Malignant disease was present in five patients, including two patients with renal cell carcinoma, one with bladder cancer, one with lung cancer, and one patient with anal adenocarcinoma. Comparison of pre- and post-contrast T1-weighted images was essential to detect renal cancer. CONCLUSION: All kidneys in patients with ADPKD had extensive, varying-sized cysts and in all cases some cysts showed evidence of hemorrhage. The liver was the second most common organ to be involved with cystic disease, in 73% of patients. Large cysts in the kidneys and liver were associated with abdominal pain.     

The spectrum of brain MR abnormalities in sickle-cell disease: a report from the Cooperative Study of Sickle Cell Disease.

PURPOSETo define the spectrum of abnormalities in sickle-cell disease, including infarction, atrophy, and hemorrhage, that are identified by brain MR imaging.METHODSAll MR studies included T1, T2, and intermediate pulse sequences. Images were interpreted without knowledge of the clinical history or neurologic examination findings. Brain MR imaging was performed in 312 children with sickle-cell disease.RESULTSSeventy patients (22%) had infarction/ischemia and/or atrophy, infarction/ischemia was noted in 39 children (13%) who had no history of a stroke (the "silent" group). The prevalence rates for silent lesions were 17% for sickle-cell anemia and 3% for hemoglobin sickle-cell disease. For patients with sickle-cell anemia and a history of cerebrovascular accident, infarction/ischemia lesions typically involved both cortex and deep white matter, while silent lesions usually were confined to deep white matter. Within the age range studied, the prevalence of infarction/ischemia did not increase significantly with age, although older patients with lesions had more lesions than did younger patients with lesions.CONCLUSIONSBrain MR imaging showed infarction/ischemia in the absence of a recognized cerebrovascular accident in 13% of patients. The prevalence of these lesions did not increase significantly between the ages of 6 and 14 years, suggesting that lesions are present by age 6. However, the increase in the average number of lesions per patient with age may indicate progressive brain injury.     

Value of MR imaging of the brain in children with hypoxic coma

BACKGROUND AND PURPOSE: The contribution of MR imaging to identify hypoxic-ischemic injuries has been studied mostly in neonates or adults. The purpose of this study was to describe the MR imaging findings of toddlers and older children with hypoxic coma and to analyze the prognostic value of an MR imaging scoring system. METHODS: The conditions of 40 children with hypoxic coma (age range, 6 weeks to 18 years) were clinically graded according to the pediatric risk of mortality score, and MR imaging studies were performed. Sixty-four MR imaging studies were distributed in five categories according to their timing relative to the hypoxic event: days 1 through 3, 4-7, 8-15, 16-50, and after day 50. These were evaluated retrospectively by using an eight-point scoring system based on two lesion categories assessing watershed areas and basal ganglia involvement, including signal intensity and morphologic features with respect to maturation-related norms. Two age groups (< or =1 year and >1 year) were considered. The surviving children were grouped according to neurologic outcome. RESULTS: The occurrence of watershed areas or basal ganglia involvement was not significantly different in association with age. Sixteen children died. Twelve children had moderate to severe sequelae resulting from neurodevelopmental disabilities, and 12 had good neurologic outcomes. There was no correlation between pediatric risk of mortality score and neurologic evolution. There was a strong correlation between first MR imaging score (P <.001) and neurologic outcome. The sensitivity of the first MR imaging score was high (96%), even when obtained during the first 3 days, with a specificity of 50% and a positive predictive value of 82%. Six patients with definite abnormal MR imaging findings experienced good neurologic outcomes. CONCLUSION: The MR imaging scoring system proposed in this study can be used to establish an early prognosis in a significant proportion of children with hypoxic coma. It is helpful, even during the first 3 days after the event. However, some patients with definite abnormal MR imaging findings may experience good neurologic evolution.     

Occult lumbosacral dysraphism in children and young adults: diagnostic performance of fast screening and conventional MR imaging.

PURPOSE: To compare fast screening and conventional magnetic resonance (MR) imaging for the detection of occult dysraphic myelodysplasias in children and young adults. MATERIALS AND METHODS: A retrospective case-control study included 101 patients (mean age, 4.9 years; range, 1 day to 26 years) suspected of having occult lumbosacral dysraphism. Sixty case patients had myelodysplastic lesions (19 filar lipoma, 14 syringomyelia, 10 intradural lipoma, eight dermal sinus, five diastematomyelia, five lipomyelomeningocele, two caudal regression syndrome); 41 control patients had no dysraphic lesions; 17 patients had associated renal anomalies. Two neuroradiologists reviewed MR images from conventional and fast screening protocols. Diagnostic performance parameters included sensitivity, specificity, and area under the receiver operating characteristic curve (Az value). RESULTS: The sensitivity of conventional and fast screening MR studies was 97.1% and 98.5%, respectively, the specificity was 90.9% and 84.8%, respectively. The Az value was 0.973 for the fast screening and 0.976 for the conventional MR studies (P = .83). Interobserver agreement was very good for fast screening images (kappa = 0.68) and excellent for conventional images (kappa = 0.75). For renal anomalies, the Az value was 0.786 and 0.853 for fast screening and conventional MR imaging, respectively (P = .28). CONCLUSION: Conventional three-plane lumbosacral MR imaging in children and young adults suspected of having occult dysraphism provides better diagnostic information than does fast screening two-plane MR imaging because of its higher specificity and interobserver agreement.     

MR imaging of Hippel-Lindau disease: value of gadopentetate dimeglumine.

Hippel-Lindau disease is an autosomal dominant disorder characterized by tumors of the central nervous system and abdominal viscera. Frequent multisystem radiologic evaluation of persons at risk is desirable. Twenty-seven patients with Hippel-Lindau disease or a family history of the disease were examined with both unenhanced and gadopentetate dimeglumine-enhanced magnetic resonance (MR) imaging to study the usefulness of the contrast medium in the evaluation of these patients. The MR studies were correlated with computed tomographic (CT) scans in seven patients and cerebral angiograms in five. Twelve patients had hemangioblastomas in the brain, and eight of these patients also had spinal cord lesions (most were multiple), well demonstrated with gadopentetate dimeglumine. Contrast-enhanced MR imaging enabled detection of more central nervous system lesions and provided better delineation than unenhanced MR imaging, CT, or angiography. In addition, four patients with multiple renal cysts seen on CT scans and unenhanced MR images had enhancing lesions that were later proved to be renal cell carcinoma at angiography and/or surgery. Four patients had cystic lesions in the pancreas that did not enhance and were later proved to be pancreatic cysts. The authors conclude that gadopentetate dimeglumine-enhanced MR imaging appears to be a useful method for evaluating and following up patients with Hippel-Lindau disease.     

Caroli's disease: magnetic resonance imaging features

Our objective was to describe the main aspects of MR imaging in Caroli's disease. Magnetic resonance cholangiography with a dynamic contrast-enhanced study was performed in nine patients with Caroli's disease. Bile duct abnormalities, lithiasis, dot signs, hepatic enhancement, renal abnormalities, and evidence of portal hypertension were evaluated. Three MR imaging patterns of Caroli's disease were found. In all but two patients, MR imaging findings were sufficient to confirm the diagnosis. Moreover, MR imaging provided information about the severity, location, and extent of liver involvement. This information was useful in planning the best therapeutic strategy. Magnetic resonance cholangiography with a dynamic contrast-enhanced study is a good screening tool for Caroli's disease. Direct cholangiography should be reserved for confirming doubtful cases. Electronic Publication     

MR diffusion-weighted imaging of kidney: differentiation between hydronephrosis and pyonephrosis

The objective of the study was to evaluate the capability and reliability of the magnetic resonance (MR) diffusion-weighted imaging (DWI) in differentiation between hydronephrosis and pyonephrosis. Single-shot echoplanar MR diffusion-weighted imaging was performed in 12 patients who had dilatation of the renal pelvis and calyces detected by ultrasonography (US). Microbiological tests confirmed that there were four cases of pyonephrosis and eight cases of hydronephrosis. Signal intensities of the collecting (pelvicalyceal) systems on the diffusion-weighted images and apparent diffusion coefficient (ADC) maps were noted. ADC values of the pelvicalyceal system in all patients were computed and compared using Student's t test. On diffusion-weighted images, the pelvicalyceal system of the hydronephrotic kidney was hypointense while the pelvicalyceal system of the pyonephrotic kidney was markedly hyperintense. The mean ADCs of the hydronephrotic and pyonephrotic renal pelvis were 2.98 +/- 0.65 x 10(-3) and 0.64 +/- 0.35 x 10(-3) mm(2)/s, respectively. The extremely low ADC of the renal pelvis of the pyonephrotic kidney accounted for its signal hyperintensity on diffusion-weighted images as well as signal hypointensity on ADC maps. In conclusion, the MR diffusion-weighted imaging may be a reliable tool to differentiate pyonephrosis from hydronephrosis.     

MR imaging of the brain in Wilson disease of childhood: findings before and after treatment with clinical correlation

BACKGROUND AND PURPOSE: Although brain MR imaging findings in adult Wilson disease have been described in considerable detail, a paucity of information currently exists regarding brain MR imaging findings in pediatric Wilson disease. The purpose of this study was to analyze the brain MR imaging findings in Wilson disease of childhood at the initial stage and during follow-up after treatment and to correlate these observations with clinical response. METHODS: We evaluated 50 patients with pediatric Wilson disease. Fifty initial and 20 follow-up MR images from 15 patients following penicillamine treatment were analyzed retrospectively, and the data were correlated with clinical findings. RESULTS: Patients were categorized into 3 groups on the basis of initial MR imaging findings. Group I (n = 23) showed normal MR imaging findings. Group II (n = 15) was characterized by T1-weighted images with increased signal intensity in the globus pallidus (n = 15, 100%) followed by the putamen, midbrain, and caudate nucleus. Group III (n = 12) demonstrated T2-weighted images with increased signal intensity in the putamen (n = 10, 83%), followed by the caudate nucleus, globus pallidus, thalamus, midbrain, and pons. There was a significant difference in mean age, the presence of neurologic symptoms, and Child-Pugh classification among the 3 groups (P < .001). Following copper chelating therapy, the changes on follow-up MR imaging were strongly correlated with clinical response to treatment (P < .001). CONCLUSION: Brain MR imaging in children with Wilson disease can be categorized into distinct groups and demonstrated a significant correlation with clinical findings. Interval changes on follow-up MR imaging were also closely correlated with clinical findings and helpful in assessing the clinical response.     

Peripheral arterial disease: clinical and cost comparisons between duplex US and contrast-enhanced MR angiography--a multicenter randomized trial

PURPOSE: To prospectively determine the clinical and economic consequences of replacing duplex ultrasonography (US) with contrast material-enhanced magnetic resonance (MR) angiography for the initial imaging work-up of patients with peripheral arterial disease (PAD). MATERIALS AND METHODS: This randomized multicenter study was approved by the institutional review board of each hospital, and all patients signed written informed consent prior to randomization. Patients with PAD who needed to undergo imaging work-up and who had an ankle-brachial pressure index (ABPI) of less than 0.90 were recruited by vascular surgeons between January 2002 and September 2003. Patients were randomly assigned to undergo contrast-enhanced MR angiography or duplex US. The primary outcome measure was cost. Secondary outcome measures included therapeutic confidence, changes in disease severity, and changes in quality of life (QOL) assessed during 6 months of follow-up. Indicators for disease severity were based on the Rutherford classification, treadmill walking distance, ABPI at rest, and ABPI after exercise. QOL was assessed with the Rating Scale, Short Form 36, EuroQol-5D, and VascuQol questionnaires. The cost of (additional) imaging procedures, therapeutic interventions, and outpatient visits were calculated from a hospital perspective (ie, all costs incurred inside the hospital were estimated, including physician costs). Data were evaluated by using the Student t test and a multivariable linear regression analysis. RESULTS: At 6 months, 352 patients (239 [68%] men, 113 [32%] women; mean age, 65 years) were analyzed. The use of contrast-enhanced MR angiography versus duplex US reduced the number of additional vascular imaging procedures by 42%; contrast-enhanced MR angiography was also associated with higher therapeutic confidence. Diagnostic costs for contrast-enhanced MR angiography were 167 euros (186 dollars) higher than those for duplex US (P < .001). No statistically significant differences were found for total cost, changes in disease severity, or changes in QOL between patients examined with duplex US and those examined with contrast-enhanced MR angiography (P > .05). CONCLUSION: Replacing duplex US with contrast-enhanced MR angiography for the initial imaging work-up of patients with PAD reduces the need for additional imaging, although diagnostic costs are higher.