Giant hemorrhagic myelolipoma in a patient with sickle cell disease

Adrenal myelolipoma is a rare, benign tumor consisting of adipose tissue and hematopoetic elements. It is generally diagnosed as an incidental finding due to its nonfunctioning, asymptomatic nature (Meaglia and Schmidt J Urol 147:1089, 1992). With increasing size, however, as seen in this case, myelolipomas can cause flank pain and abdominal distention. This lesion was diagnosed in a young male with sickle cell disease during a vaso-occlusive crisis.     

MRI of sickle cell cerebral infarction

Summary Eleven patients with sickle cell disease and neurological symptoms underwent MRI examination. Cerebral infarcts of two types were found, those in the vascular distribution of the middle cerebral artery and those in the deep white matter. In the patient whose hydration and whose oxygenation of erythrocytes has been treated, MRI offers diagnostic advantages over arteriography and CT.     

Cranial involvement in sickle cell disease

Purpose

To evaluate cranial findings in patients with neurologically symptomatic sickle cell disease (SCD).

Materials and methods

We studied 50 consecutive patients with SCD and neurologic symptoms. All patients underwent brain MR examinations: all 50 underwent classic MR imaging; 42, diffusion-weighted MR imaging; 10, MR angiography; four, MR venography; and three patients, digital subtraction angiography.

Results

Of the 50 SCD patients, 19 (38%) had normal MR findings, and 31 (62%) showed abnormalities on brain MR images. Of the 50 patients, 16 (32%) had ischemic lesions; two (4%), subarachnoid hemorrhage; one (2%), moya-moya pattern; one (2%), posterior reversible encephalopathy; one (2%), dural venous sinus thrombosis; 12 (24%), low marrow signal intensity and thickness of the diploic space; 12 (24%), cerebral atrophy; and two (4%), osteomyelitis. Twenty-seven patients (54%) presented with headache, which was the most common clinical finding.

Conclusions

The cranial involvement is one of the most devastating complications of SCD. Early and accurate diagnosis is important in the management of cranial complications of SCD.     

Actinomycetes as the causative organism of osteomyelitis in sickle cell disease

The case of a 17-year-old girl with sickle cell anaemia who presented with extensive osteomyelitis due to actinomycetes is reported. Osteomyelitis in the long bones due to actinomycosis is extremely rare. A review of the literature reveals only six cases in which actinomycetes have been isolated from lesions affecting a long bone. The occurrence of this condition in sickle cell haemoglobinopathy has not been previously reported.     

Quantitative MRI of the brain in children with sickle cell disease reveals abnormalities unseen by conventional MRI

Conventional MRI (cMRI) has shown that brain abnormalities without clinical stroke can manifest in patients with sickle cell disease (SCD). We used quantitative MRI (qMRI) and psychometric testing to determine whether brain abnormalities can also be present in patients with SCD who appear normal on cMRI. Patients 4 years of age and older with no clinical evidence of stroke were stratified by cMRI as normal (n = 17) or abnormal (n = 13). Spin-lattice relaxation time (T1) of gray and white matter structures was measured by the precise and accurate inversion recovery (PAIR) qMRI method. Patient cognitive ability was assessed with a standard psychometric instrument (WISC-III or WISC-R). In all 30 patients with SCD, qMRI T1 was lower than in 24 age- and race-matched controls, in cortical gray matter (P < .0006) and caudate (P < .0009), as well as in the ratio of gray-to-white matter T1 (P < .008). In the 17 patients who were shown to be normal by cMRI, qMRI T1 was still lower than in controls, in both cortical gray matter (P < .02) and caudate (P < .004). Histograms of voxel T1 show that the proportion of voxels with T1 values intermediate between gray and white matter (ie, consistent with encephalomalacia) was 9% higher than controls in patients shown to be normal by cMRI (P < .05) and 15% higher than controls in patients shown to be abnormal by cMRI (P < .0005). The full scale intelligence quotient (FSIQ) of all patients with SCD was 75, compared to the FSIQ of 88 in a historical control group of patient siblings (P < .001). The FSIQ of patients shown to be normal by cMRI was 79, significantly lower than the FSIQ of patient siblings (P < .04). The FSIQ of 71 in patients shown to be abnormal by cMRI was significantly lower than both the patient siblings (P < .005) and the patients shown to be normal by cMRI (P < .04). Patients shown to be abnormal by cMRI scored lower than patients shown to be normal by cMRI, specifically on the subtests of vocabulary (P = .003) and information (P = .03). Cognitive impairment is thus significant, even in patients with SCD who were shown to be normal by cMRI, suggesting that cMRI may be insensitive to subtle neurologic damage that can be detected by qMRI. Because cognitive impairment can occur in children normal by cMRI, our findings imply that prophylactic therapy may be needed earlier in the course of SCD to mitigate neurologic damage.     

Cerebral blood flow mapping using stable Xenon-enhanced CT in sickle cell cerebrovascular disease

Summary The cerebral blood flow (CBF) of 25 patients with sickle cell cerebrovascular disease (SCCVD) was examined using a Xenon-CT flow mapping method. Brain CT and MR findings were correlated with those of the Xenon-CT flow studies. CBF defects on Xenon-CT correlated reasonably well with the areas of cortical infarctions on the MR images, but in 27% of the cases, flow defects were slightly larger than the areas of infarctions on the MR images. In deep watershed or basal ganglia infarctions, abnormal CBF was noted about the cerebral cortex near infarctions in 72% of the patients, regardless of infarction sizes on the MR images. However, decreased CBF was recognized in 4 of the 9 children whose MR images were virtually normal. Thus, the extent of flow depletion cannot be predicted accurately by MR imaging alone. Xenon-CT flow mapping proved a safe and reliable procedure for evaluation of the CBF of patients with SCCVD. Although this study is preliminary, it may have a potential in selecting patients for hypertransfusion therapy, as a noninvasive test and for following children with SCCVD during their therapy. Careful correlation of results of CBF with those of MR imaging or of CT is important for objective interpretations of flow mapping images.     

Hepatic iron deposition in patients with sickle cell disease: Role of breath-hold multiecho T2-weighted MRI sequence

Introduction

The purpose of this study is to detect the role of breath-hold multiecho T2^∗-weighted MRI, in quantification of hepatic iron deposition in patients with sickle cell disease.

Methods

Thirty-seven patients underwent 1.5-T MRI of the liver that included a multiecho T2^∗-weighted sequence. Hepatic T2^∗ iron grading was done for each patient by placing regions of interest in the hepatic parenchyma. Hepatic T2^∗ values were correlated with histopathological iron grade. Liver biopsy was done for all patients. Written consent was obtained from all patients prior to MRI studies.

Results

Thirty-two patients (86.5 %) had evidence of hepatic iron deposition on histopathological examination, including eight (25%) with grade 3, eleven (34%) with grade 2 and thirteen patients (41%) with grade 1.Patients with negative iron deposition histologically, had T2^∗ values ranging from 28–32 ms. For the patients with positive hepatic iron deposition, hepatic T2^∗ decreased with increasing iron grade.Statistical analysis showed that for differentiation of hepatic iron deposition grade 3 from grades 1 and 2, hepatic T2^∗ less than 13 ms had a sensitivity and specificity of 100 % and 98%, respectively.

Conclusion

Breath-hold multiecho T2^∗-weighted MRI sequence offers an accurate estimation of hepatic iron deposition.     

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     

全身弥散加权成像对非小细胞肺癌诊断的价值

目的:探讨全身弥散加权成像(WB-DWI)对非小细胞肺癌的诊断价值。方法:对病理确诊的31例非小细胞肺癌的患者行全身弥散加权成像检查,将结果按病灶解剖部位不同分为4组,即肺内、纵膈内、远处淋巴结区、远处器官区,分别与病理及CT和(或)MRI的检查结果进行统计、分析。结果:与病理结果对照,四组不同解剖部位病灶检出率分别为90.3%、66.7%、81.8%、100%。与CT和(或)MRI结果对照,四组不同解剖病灶敏感性分别为65.12%,39.76%、98%、97.15%,特异性为100%、96.97%、63.04%、26.47%,差异有统计学意义(P(0.05)。结论:全身弥散加权成像对非小细胞肺癌远处淋巴结及器官转移的诊断优于CT和/或MRI,可以作为非小细胞肺癌诊断一种手段。     

“Tower vertebra”: a new observation in sickle cell disease

Background. Skeletal abnormalities are common in sickle cell anemia. Ischemia, infarction, and growth disturbance of the thoracic and lumbar vertebral bodies are among the most common abnormalities, and can suggest the diagnosis radiographically. Design and patients. We recently encountered two adult patients in whom vertebrae had grown abnormally in height adjacent to infarcted short vertebrae. We then reviewed the thoracic and lumbar spine radiographs of 54 more adult patients with sickle cell anemia. Results and conclusion. A total of eight patients (14%) displayed infarcted vertebrae with compensatory vertical growth of at least one adjacent vertebrae. These resemble the elongated vertebral bodies associated with other conditions. We can find no prior report of this finding in association with sickle cell anemia.     

Regional cerebral blood flow in patients with sickle cell disease: study with single photon emission computed tomography

Objective Neurological complications have been reported in patients with sickle-cell disease (SCD) using positron emission tomography (PET), magnetic resonance imaging (MRI), and computed tomography (CT), but not with single photon emission computed tomography (SPECT). The objective of this study was to investigate brain perfusion in the patients with SCD using SPECT after technetium-99m hexamethylpropylene amine oxime (^99mTc-HMPAO), was administered and compare the findings with those of demography, physical examination, MRI and hematological profile. Methods The study involved 21 patients (12 males, 9 females, age at study 8–45 years) who were known to be having SCD for a duration of at least 5 years. The patients were not in acute crisis and had normal neurological assessments with no known history of stroke or transient ischemic episode or previous abnormal CT or MRI brain scan, and were right-handed. The brain SPECT was performed after intravenous injection of 740 MBq (20 mCi) ^99mTc-HMPAO in adults or an appropriate dose in pediatric patients. The scans were visually interpreted by two nuclear medicine physicians and a decision was reached by consensus. An MRI done 3 months later was interpreted by a radiologist. The demographic data and hematological profile were obtained from the medical records of the patients. Results Of the 21 patients, 7 (age 11–22 years) had brain perfusion deficit mostly in the frontal lobe either alone or in combination with temporal and/or parietal lobe. The MRI was abnormal in 2 patients. The brain perfusion deficit was not associated with the demographic data of the patients or hematological profiles. Conclusions The findings show that SPECT was useful in detecting brain perfusion deficit in SCD patients, and such an early detection may be clinically useful in the subsequent follow-up of such patients, since it is known that cerebral perfusion deficit can lead to silent infarct and/or overt stroke, and affect cognitive skills.     

Comparison of magnetic resonance angiography and conventional angiography in sickle cell disease: clinical significance and reliability

We retrospectively reviewed the medical records and conventional angiograms of 21 patients with known sickle cell disease, who underwent a total of 50 magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) studies. MRA and conventional angiography were assessed separately for evidence of stenosis or occlusion. Follow up MRI/MRA studies were also assessed for evidence of progression, regression or stability of the disease in these patients. In the carotid circulation, MRA made the correct diagnosis in 85% of the vessels evaluated with a sensitivity of 80.5% and a specificity of 94%. MRA was also found to show evidence of disease progression, more often than did MRI or the clinical condition of the patients.     

Perspectives for preventive screening with total body MRI

Radiology has started to increasingly recognise its potential for screening with the advent of “whole-body” imaging techniques. This article briefly reviews prerequisites for successful screening, presents a quick summary of single-organ screening with magnetic resonance (MR) imaging, and introduces how this knowledge can be integrated into whole-body MR (wb-MR) screening. MR colonography has demonstrated its potential for screening. Wb-MR in the form of wb-MR angiography has already entered both clinical and screening settings; also, the search for metastases with wb-MR has been evaluated and has performed well when compared with other imaging modalities. But screening a group of healthy subjects requires more than feasibility and high accuracy of the screening test; thus, technical and ethical considerations are also presented. Wb-MR is only at its beginning and will in the near future certainly inspire many new research activities as well as transform the radiological market.     

造血干细胞移植中预先全身照射对全身及造血系统的影响及并发症治疗

Objective To explore the effects of total body irradiation (TBI) combined with high-dose chemotherapy as conditioning regimen on the whole body and hematopoietic system of patients undergoing hematopoietic stem cell transplantation,and to sum up the clinical experiences in diagnosis and treatment of acute radiation syndrome.Methods A total of 64 patients underwent TBI and high-dose chemotherapy and then received hematopoietic stem cell transplantation.The hematologic changes and clinical toxicity after TBI were observed and the characteristics of bone marrow reconstitution analyzed.Results The transplantation related mortality was 3.12%.Follow-up was carried out post transplantation for 9-72 months (the median follow-up time was 26 months).1,3,5-year overall survival rates were (95.8 ± 3.3)%,(89.8 ± 4.7)% and (81.7 ± 6.9)%,respectively.All patients suffered fromhematologic toxicity.The white blood cells and platelets were obviously decreased.The minimum total number of white blood cells was (0.18 ± 0.13) × 109/L,and the minimum platelet was (14.48 ±8.85) × 109/ L.In addition,gastrointestinal reactions,infection,liver damage,bleeding and other adverse reactions occurred to some extent.Conclusions TBI combined with high-dose chemotherapy as conditioning regimen followed by hematopoietic stem cell transplantation might be effective for treatment of malignant hematological diseases.The clinic conditions after TBI and high-dose chemotherapy could simulate the clinical course of acute accidental radiation syndrome and provide the clinical experience for acute radiation syndrome.     

Whole-body MRI of neuroblastoma

Whole-body MRI (WBMRI) is an emerging imaging method that has a great potential in pediatric oncologic imaging. It appears useful in staging and monitoring neuroblastoma although its clinical impact has not been thoroughly evaluated. Among various imaging techniques currently available for WBMRI, coronal and sagittal STIR imaging with a quadrature body coil at 1.5T MR system is recommended for a standard protocol. Nevertheless, further technical improvements are anticipated at 3.0T MR system and multi-channel surface coil system. Scan time of WBMRI is reasonably short ranging from 20 min to 60 min. In localized neuroblatoma, WBMRI may help in predicting surgical risks by evaluating image-defined risk factors accurately. In addition, WBMRI is quite useful in detecting distant metastasis, assessing initial treatment responses, and identifying tumor recurrence of neuroblastoma. We should understand limitations of WBMRI in the evaluation of lymph node involvement, in the differentiation between viable tumor and non-viable residual lesion, and in the detection of calcified lesion. Diffusion-weighted imaging may improve diagnostic accuracy of WBMRI. Complementary use of WBMRI and other metabolic imaging method such as MIBG scintigraphy or PET probably increases diagnostic accuracy and, subsequently, improves clinical outcome of children with neuroblastoma.     

Quantitative MR imaging of children with sickle cell disease: Striking T1 elevation in the thalamus

Nineteen patients with sickle cell disease (SCD) were examined with conventional MR imaging (cMRI), including T1- and T2-weighted sequences and MR angiography (MRA). qMRI mapping of T1 was also done using a precise and accurate inversion-recovery (PAIR) technique optimized and validated previously. In addition, 21 healthy African-American control subjects had the qMRI examination. Nonparametric Kruskal-Wallis analysis of variance of control subjects, of SCD patients without stroke, and of SCD patients with stroke showed that T1 increased with disease severity in the thalamus, frontal white matter, genu, and occipital white matter. T1 was significantly longer in SCD patients without stroke (n=13) than in control subjects (n=21) in the thalamus and frontal white matter. In addition, T1 values were significantly longer in SCD patients with stroke than in patients without stroke in the genu and frontal white matter. Abnormality of the thalamus was identified by qMRI in a substantial fraction of patients read as normal by both cMRI and MRA, suggesting that it may be possible to use T1 elevation to identify a subset of patients with SCD who are at elevated risk for stroke.     

High-resolution MRI of pancreatic masses with a new circularly polarized body phased-array coil

A total of 18 patients with clinical suspicion of a pancreatic tumor underwent dynamic contrast-enhanced CT and MRI examinations. A fat-suppressed T1-weighted 2D fast-low-angle-shot (FLASH) sequence and a T2-weighted spin-echo (SE) sequence were applied in a transverse orientation using a circularly polarized (CP) body phased-array coil. The FLASH sequence was repeated after Gd-DTPA administration. The highest spatial resolution was 1.37×1.37×3.00 mm³. In two cases a half Fourier single-shot turbo-SE sequence (HASTE) was additionally applied. In a comparison between CT and MRI, pancreatic masses could be demonstrated and characterized with excellent image quality. The fat-saturated 2D FLASH sequence yielded the highest contrast-to-noise ratios after Gd-DTPA administration between pancreas and inflammatory or neoplastic lesion. One non-contour deforming carcinoma could be detected only with MRI and was only retrospectively visible on CT with an element of uncertainty. Magnetic resonance imaging using a CP body phased-array coil and fat-suppressed T1- and T2-weighted FLASH, SE, and turbo-SE sequences offers diagnostic possibilities in improved imaging of the pancreas.     

Standardized assessment of whole body adipose tissue topography by MRI

PURPOSE: To assess standardized whole body adipose tissue topography in a cohort of subjects at an increased risk for type 2 diabetes and to compare fat distribution in subgroups regarding anthropometric (age, body mass index [BMI]) and metabolic parameters (insulin sensitivity). MATERIALS AND METHODS: A total of 80 volunteers (40 females, 40 males) underwent T1-weighted MR imaging of the entire body. Standardized adipose tissue (AT) profiles were calculated considering the different body structure of the participants. The measured data were interpolated to a defined number of sampling points enabling a direct comparison of the profiles independent on body structure. Resulting mean profiles and region-dependent standard deviations of four age groups and three BMI-groups were compared for females and males. Correlations between insulin sensitivity and body fat distribution were analyzed. RESULTS: Reliable adipose tissue profiles could be obtained from all volunteers. In BMI-matched subgroups, females show significant higher AT and subcutaneous abdominal AT (P < 0.05 both), but lower visceral AT (P < 0.01) compared to the males. Furthermore, visceral AT increases with age, as shown in the matched age groups. In both gender groups, insulin-resistant subjects are characterized by higher visceral adipose tissue (VAT) compared to insulin-sensitive subjects. In addition, profiles of insulin-resistant subjects show more AT in the shoulder/neck region but less AT in the upper extremities. CONCLUSION: Standardized assessment of whole body AT profiles based on T1-weighted MRI provides a reliable basis for interindividual comparison of the body fat distribution and allows a fast and reliable quantification of total body adipose tissue and the distribution of different AT components as subcutaneous and visceral fat in different body regions. Differences in standardized profiles might enable an early identification of people at risk of metabolic disorders, as not only the amount but also the distribution of AT is expected to play an essential role in the pathogenesis of metabolic diseases.     

Different findings in Tc-99m MDP bone scintigraphy of patients with sickle cell disease: report of three cases

Objective Sickle cell anemia is an inherited disorder caused by abnormal hemoglobin, the S hemoglobin. Although vaso-occlusive crises can occur virtually in any organ, they are particularly common in the bony skeleton of affected patients. Bone marrow necrosis, bone infarcts, osteomyelitis, and aseptic necrosis are common complications in patients with sickle cell disease. Beside these abnormalities of the skeletal system, diffuse micro or macro calcification resulting from both splenic infarction and repeated vaso-occlusive episodes in the kidneys can be shown by technetium-99m methylenediphosphonate (Tc-99m MDP) bone scintigraphy. We present here the different osseous and extraosseous abnormalities noted on bone scintigraphies of three patients with sickle cell anemia. Methods Whole-body bone scan was performed after injecting 740 MBq of Tc-99m MDP in three patients with sickle cell disease. Results Tc-99m MDP whole-body image of the first patient showed non-uniform uptake in the anterior and posterior aspects of multiple ribs and bilateral femurs and tibias that was attributed to repetitive infarcts. Additionally, increased activity in shoulders, right elbow, and right knee was consistent with arthritis. Tc-99m MDP image of the second patient demonstrated avascular necrosis of the left femoral head and diffuse activity in the enlarged kidneys. Increased activity in the spleen that was attributed to repetitive infarcts was visualized in bone scan of the third patient. Conclusions In light of the findings in these cases, bone scintigraphy is a reliable imaging method in detecting both osseous and extraosseous abnormalities of sickle cell disease and may be used initially.