Ultrashort echo time MRI of the lung in children and adolescents: comparison with non-enhanced computed tomography and standard post-contrast T1w MRI sequences.

OBJECTIVES: To compare the diagnostic value of ultrashort echo time (UTE) magnetic resonance imaging (MRI) for the lung versus the gold standard computed tomography (CT) and two T1-weighted MRI sequences in children. METHODS: Twenty-three patients with proven oncologic disease (14 male, 9 female; mean age 9.0 + / - 5.4 years) received 35 low-dose CT and MRI examinations of the lung. The MRI protocol (1.5-T) included the following post-contrast sequences: two-dimensional (2D) incoherent gradient echo (GRE; acquisition with breath-hold), 3D volume interpolated GRE (breath-hold), and 3D high-resolution radial UTE sequences (performed during free-breathing). Images were evaluated by considering image quality as well as distinct diagnosis of pulmonary nodules and parenchymal areal opacities with consideration of sizes and characterisations. RESULTS: The UTE technique showed significantly higher overall image quality, better sharpness, and fewer artefacts than both other sequences. On CT, 110 pulmonary nodules with a mean diameter of 4.9 + / - 2.9 mm were detected. UTE imaging resulted in a significantly higher detection rate compared to both other sequences (p < 0.01): 76.4% (84 of 110 nodules) for UTE versus 60.9% (67 of 110) for incoherent GRE and 62.7% (69 of 110) for volume interpolated GRE sequences. The detection of parenchymal areal opacities by the UTE technique was also significantly higher with a rate of 93.3% (42 of 45 opacities) versus 77.8% (35 of 45) for 2D GRE and 80.0% (36 of 45) for 3D GRE sequences (p < 0.05). CONCLUSION: The UTE technique for lung MRI is favourable in children with generally high diagnostic performance compared to standard T1-weighted sequences as well as CT. Key Points • Due to the possible acquisition during free-breathing of the patients, the UTE MRI sequence for the lung is favourable in children. • The UTE technique reaches higher overall image quality, better sharpness, and lower artefacts, but not higher contrast compared to standard post-contrast T1-weighted sequences. • In comparison to the gold standard chest CT, the detection rate of small pulmonary nodules small nodules ≤ 4 mm and subtle parenchymal areal opacities is higher with the UTE imaging than standard T1-weighted sequences.

Magnetic resonance imaging scans in patients with dorsal root ganglion stimulation.

OBJECTIVE: Patients fitted with a neurostimulator face a greater need to undergo magnetic resonance imaging (MRI) scans. Given the lack of literature in this regard, this study aims to review our experience with MRI examinations on patients implanted with a dorsal root ganglion stimulation (DRG-S) system and their potential adverse events. MATERIALS AND METHODS: We conducted a retrospective analysis of the prospective treatment documentation gathered from November 2011 to October 2020. We identified 259 MRI registrations for patients with an implanted neurostimulation system; the MRI examinations were performed using a 1.5 Tesla MRI system in accordance with a structured scheme. RESULTS: Among the 259 MRI registrations identified in this study, 28 corresponded to patients with an implanted DRG-S system. In 2 cases, no MRI scan was performed, and thus, only 26 MRI examinations were evaluated in detail. The DRG-S device was approved for the requested MRI scans in only 2 of these 26 cases (7.7%). In addition, 2 minor adverse events (syncopal episode and connection problem) were identified, and only the second problem (3.8%) was related to neurostimulator operation. CONCLUSIONS: Necessary MRI examinations in patients with DRG-S systems are rarely covered by the European CE/US Food and Drug Administration (CE/FDA) approval. Although the manufacturer recommendations are against the use of MRI in patients with implanted DRG-S in certain conditions, we performed these scans without causing injury to the patient or damaging the device. Given that data on safety are limited, MRIs should be conducted study related. We provide recommendations for the procedure that should be followed when an MRI is needed urgently.

The association between endothelial microparticles and inflammation in patients with systemic sclerosis and Raynaud's phenomenon as detected by functional imaging.

UNLABELLED: Systemic sclerosis (SSc) is a systemic, autoimmune connective tissue disease characterized by vasculopathy and microvascular changes. Fluorescence Optical Imaging (FOI) is a technique used to assess inflammation in patients with arthritis; in this study FOI is used to quantify inflammation in the hand. Endothelial Microparticle (EMP) can reflect damage or activation of the endothelium but also actively modulate processes of inflammation, coagulation and vascular function. The aim of the present study was to quantify EMP and FOI, to determine an association between these microparticles and inflammation and to endothelial function. METHODS: EMP were quantified in plasma samples of 25 patients (24 female, 1 male, age: 41 ± 9 years) with SSc using flow cytometry. EMP was defined as CD31+/CD42- MP, and CD62+ MP. Perivascular inflammation was assessed using fluorescence optical imaging (FOI) of the hand. Macrovascular endothelial function was non-invasively estimated using the Endopat system. RESULTS: Plasma levels of CD31+/CD42- EMP and CD62+ EMP were lower in patients with SSc compared to controls (both p <  0.05). An impaired endothelial function with an increased hyperemia index was observed. A strong association could be demonstrated between CD62+ EMP and perivascular soft tissue inflammation as assessed by the FOI global score (Spearman, p = 0.002, r = 0.61). CONCLUSIONS: EMP indicate molecular vascular damage in SSc; in this study a strong association between EMP and perivascular inflammation as quantified by FOI is demonstrated. Consequently EMP, using FOI, may be a potential marker benefitting the diagnosis and therapy monitoring of patients with SSc with associated Raynaud's phenomenon.

Nephrogenic systemic fibrosis risk after liver magnetic resonance imaging with gadoxetate disodium in patients with moderate to severe renal impairment: results of a prospective, open-label, multicenter study.

OBJECTIVE: The objective of this study was to assess the risk of gadoxetate disodium in liver imaging for the development of nephrogenic systemic fibrosis (NSF) in patients with moderate to severe renal impairment. MATERIALS AND METHODS: We performed a prospective, multicenter, nonrandomized, open-label phase 4 study in 35 centers from May 2009 to July 2013. The study population consisted of patients with moderate to severe renal impairment scheduled for liver imaging with gadoxetate disodium. All patients received a single intravenous bolus injection of 0.025-mmol/kg body weight of liver-specific gadoxetate disodium. The primary target variable was the number of patients who develop NSF within a 2-year follow-up period. RESULTS: A total of 357 patients were included, with 85 patients with severe and 193 patients with moderate renal impairment, which were the clinically most relevant groups. The mean time period from diagnosis of renal disease to liver magnetic resonance imaging (MRI) was 1.53 and 5.46 years in the moderate and severe renal impairment cohort, respectively. Overall, 101 patients (28%) underwent additional contrast-enhanced MRI with other gadolinium-based MRI contrast agents within 12 months before the start of the study or in the follow-up. No patient developed symptoms conclusive of NSF within the 2-year follow-up. CONCLUSIONS: Gadoxetate disodium in patients with moderate to severe renal impairment did not raise any clinically significant safety concern. No NSF cases were observed.

Magnetic resonance venography of the upper venous system with blood pool contrast agent: comparison of two different T1-weighted sequences.

OBJECTIVE: Image quality of gadofosveset trisodium-enhanced magnetic resonance venography (MRV) of the upper extremities was evaluated. MATERIAL AND METHODS: Imaging was performed using a 3D Fast Low Angle Shot gradient recalled echo sequence (3D FLASH) and 3D gradient echo Volumetric Interpolated Breath-hold Examination with fat suppression (3D VIBE FS). Image quality was evaluated by two raters. RESULTS: 3D FLASH sequences demonstrated good image quality for depiction of the central venous system; 3D VIBE FS sequences showed good image quality for peripheral veins. CONCLUSION: MRV using Gadofosveset trisodium enables good quality depiction of the venous system of the upper extremities.

Quantitative evaluation of MR perfusion imaging using blood pool contrast agent in subjects without pulmonary diseases and in patients with pulmonary embolism.

OBJECTIVE: To assess the feasibility of time-resolved parallel three-dimensional magnetic resonance imaging (MRI) for quantitative analysis of pulmonary perfusion using a blood pool contrast agent. METHODS: Quantitative perfusion analysis was performed using novel software to assess pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) in a quantitative manner. RESULTS: The evaluation of lung perfusion in the normal subjects showed an increase of PBF, PBV ventrally to dorsally (gravitational direction), and the highest values at the upper lobe, with a decrease to the middle and lower lobe (isogravitational direction). MTT showed no relevant changes in either the gravitational or isogravitational directions. In comparison with normally perfused lung areas (in diseased patients), the pulmonary embolism (PE) regions showed a significantly lower mean PBF (20 ± 0.6 ml/100 ml/min, normal region 94 ± 1 ml/100 ml/min; P < 0.001), mean PBV (2 ± 0.1 ml/100 ml, normal region 9.8 ± 0.1 ml/100 ml; P < 0.001) and mean MTT (3.8 ± 0.1 s; normal region 6.3 ± 0.1; P < 0.001). CONCLUSION: Our results demonstrate the feasibility of using time-resolved dynamic contrast-enhanced MRI to determine normal range and regional variation of pulmonary perfusion and perfusion deficits in patients with PE. KEY POINTS: • Recently introduced blood pool contrast agents improve MR evaluation of lung perfusion • Regional differences in lung perfusion indicating a gravitational and isogravitational dependency. • Focal areas of significantly decreased perfusion are detectable in pulmonary embolism.

Magnetic resonance VIBE venography using the blood pool contrast agent gadofosveset trisodium--an interrater reliability study.

PURPOSE: In this study, image quality of leg veins and vena cava inferior was scored by independent raters using the new intravascular magnetic resonance imaging (MRI) contrast agent gadofosveset trisodium using fat-suppressed 3D gradient echo Volume Interpolated Breath-hold Examination. MATERIAL AND METHODS: The leg venous system without clinical signs of deep venous thrombosis (DVT) and sonography-ruled out DVT were imaged using a fat-suppressed 3D gradient echo Volume Interpolated Breath-hold Examination (VIBE FS). Image interpretation was done independently by two experienced radiologists (raters) using a 5-point scoring system. RESULTS: High diagnostic image quality with an overall mean visibility score of 4.8±0.1 was acquired in patients enrolled in the study using gadofosveset trisodium-enhanced MRI for the venous system of the leg. There were no cases with moderate, poor or nondiagnostic image quality. Additionally, an excellent interrater reliability was observed. CONCLUSIONS: This study shows the feasibility of acquiring high resolution images with excellent image quality of the venous system of the leg using gadofosveset trisodium.

Combined magnetic resonance imaging of deep venous thrombosis and pulmonary arteries after a single injection of a blood pool contrast agent.

OBJECTIVE: Agreement rate between magnetic resonance imaging (MRI) and Doppler ultrasound (DUS) for the detection of deep vein thrombosis (DVT) in the lower extremities was attempted by using the intravascular MRI contrast agent gadofosveset trisodium. The potential of this method to detect pulmonary embolism (PE) was also evaluated. MATERIAL AND METHODS: Forty-three consecutive inpatients with ultrasound-confirmed DVT but no clinical signs of PE were prospectively enrolled in this feasibility study. MRI was performed after a single injection of gadofosveset trisodium. The pulmonary arteries were imaged using a 3D Fast Low Angle Shot (FLASH) gradient recalled echo sequence. Additionally, pulmonary arteries, abdominal veins, pelvic and leg veins were imaged using a fat-suppressed 3D gradient echo Volume Interpolated Breath-hold Examination (VIBE FS). RESULTS: Gadofosveset trisodium-enhanced MRI detected more thrombi in the pelvic region, upper leg and lower leg than the initial DUS. In addition, PE was detected in 16 of the 43 DVT patients (37%). CONCLUSION: This study shows the feasibility of a combined protocol for the MRI diagnosis of DVT and PE using gadofosveset trisodium. This procedure is not only more sensitive in detecting DVT compared to standard DUS, but is also able to detect PE in asymptomatic patients.

Incomplete paresis of the sciatic nerve due to massive atypical lipoma of the pelvis: a case report.

BACKGROUND: Liposarcomas are classified into four subtypes, with different malignancy potential and characteristic imaging appearances. Well-differentiated liposarcomas have imaging characteristics similar to those of benign lipomas, however they can be usually distinguished from lipomas because of the larger size and broader fibrous septa, with a more nodular appearance. CASE PRESENTATION: This paper presents a case of atypical lipoma (well-differentiated liposarcoma) of the pelvis, leading to partial involvement of the sciatic nerve. In our case, computed tomography (CT) showed a low-density lesion. In magnetic resonance imaging (MRI), T1 and T2-weighted sequences revealed a fatty appearance with signal loss on fat saturation pulse sequences. CONCLUSION: The lesion was successfully resected and no other similar lesions have been found within one year of follow-up.

Brain activation upon selective stimulation of cutaneous C- and Adelta-fibers.

Thermal and nociceptive cutaneous stimuli activate the brain via two types of nerve fibers, slightly myelinated Adelta-fibers with moderate conduction velocity and unmyelinated C-fibers with slow conduction velocity. Differences in central processing upon selective stimulation of these two fiber types in healthy human subjects still remain poorly understood. By means of event-related functional magnetic resonance imaging the present study investigated brain activation in response to stimulation of Adelta- and C-fibers in healthy subjects. We used the stimulation of tiny skin areas to perform a selective stimulation upon cutaneous C-fibers. Besides similar activation in several brain areas in response to both kinds of stimulation, we observed pronounced brain activation to selective C-fiber stimulation as compared to Adelta-fiber stimulation in the right frontal operculum and anterior insula. Based on a putative function of these structures we suggest that the C-fiber system might be engaged in homeostatic and interoceptive functions in a manner other than the Adelta-fiber system, producing a signal of greater emotional salience.

Photodynamic treatment as a novel approach in the therapy of arthritic joints.

BACKGROUND AND OBJECTIVE: Minimal invasive local treatment of joints is a desirable option in the therapy of rheumatoid arthritis (RA). Aim of this study was to evaluate the effects of photodynamic treatment (PDT) with different doses of the photosensitizer meta-tetra(hydroxyphenyl)chlorin (m-THPC; or temoporfin) in a murine model of RA (antigen-induced arthritis, AIA). METHODS IN VIVO DISTRIBUTION: The distribution of native and liposomal m-THPC (including a formulation with polyethylene glycol [PEG] coating) was assessed by fluorescence spectrometry in arthritic joints, normal joints, and skin. TREATMENT: AIA mice received different concentrations of pegylated liposomal m-THPC (0.1, 0.05, 0.01, or 0.005 mg/kg body weight; n = 5 per group) and subjected to PDT with a laser system 12 hours post-injection of the photosensitizer. Treatment effects were evaluated histologically in comparison to untreated AIA (n = 5). RESULTS: Pegylated liposomal m-THPC showed the most favorable accumulation in arthritic joints compared to native m-THPC and to non-peg-liposomal m-THPC, therefore it was selected as photosensitizer for PDT treatment. In comparison to untreated AIA, PDT reduced the arthritic score with all doses of pegylated liposomal m-THPC; statistical significant effects were obtained with doses of 0.05 and 0.01 mg/kg. CONCLUSION: Our study demonstrated that local PDT of arthritic joints is feasible. Application of pegylated liposomal m-THPC for PDT resulted in significant reduction of arthritis scores.

The adjacent vessel on dynamic contrast-enhanced breast MRI.

OBJECTIVE: The purpose of this study was to investigate whether an adjacent vessel leading to an enhancing lesion seen on subtraction images can help differentiate malignant from benign breast lesions and therefore increase the specificity of breast MRI. MATERIALS AND METHODS: The study included 132 histologically verified lesions (71 malignant lesions, 10 pure carcinoma in situ, and 51 benign lesions) enhancing on dynamic breast MRI before biopsy. The lesions were evaluated by three radiologists in a double-blinded manner. The presence of an adjacent vessel was supposed if at least two observers voted positively. RESULTS: Sixty-one (85.9%) of 71 malignant lesions, six (60%) of 10 carcinomas in situ, and 10 (19.6%) of 51 benign lesions were associated with an adjacent vessel, which differed significantly (p < 0.001) between benign and malignant lesions (the latter with and without including pure carcinoma in situ), leading to a positive predictive value of 85.9% (87% including pure carcinomas in situ), a negative predictive value of 80.4% (74.5% including pure carcinomas in situ), an accuracy of 83.2% (81.6% including pure carcinomas in situ), a sensitivity of 85.9% (82.7% including carcinomas in situ), and a specificity of 80.4% for this sign concerning malignancy. CONCLUSION: The presence of an adjacent vessel seen on subtraction images promises to be a good marker for malignancy and can therefore help increase the specificity of breast MRI.

The potential of digital X-ray radiogrammetry (DXR) in the assessment of osteopenia in children with chronic inflammatory bowel disease.

BACKGROUND: Loss of bone mass is a known complication of chronic inflammatory bowel disease (IBD) in children. The gold standard in the evaluation of bone mineral density (BMD) is dual energy X-ray absorptiometry (DXA). OBJECTIVE: In this preliminary study we evaluated digital X-ray radiogrammetry (DXR) which estimates BMD (DXR-BMD) from hand radiographs in children with IBD. MATERIALS AND METHODS: A total of 26 children with IBD (10 girls, 16 boys; age range 10-18 years) underwent DXR for the calculation of DXR-BMD and metacarpal index (DXR-MCI) using the Pronosco X-posure system. The results were compared with a local reference database and correlated with the results of DXA. RESULTS: DXR-BMD was 0.36-0.56 g/cm(2) (median 0.46 g/cm(2)) in Crohn disease patients and 0.38-0.63 g/cm(2) (median 0.48 g/cm(2)) in ulcerative colitis patients. DXR-MCI was 0.29-0.49 in Crohn disease patients and 0.28-0.53 in ulcerative colitis patients. The Z-scores were reduced to <-1 SD in five Crohn disease patients and in six ulcerative colitis patients. The coefficients (r) for the correlations between DXR-BMD and DXA-BMD were 0.78 for the lumbar spine and 0.61 for the proximal femur (P<0.01), and between DXR-MCI and DXA-BMD were 0.78 for the lumbar spine and 0.51 for the proximal femur (P<0.01). CONCLUSIONS: DXR seems to be able to estimate cortical osteopenia in children with chronic IBD. The DXR results showed a positive correlation with DXA results.

Potential MRI interpretation model: differentiation of benign from malignant breast masses.

OBJECTIVE: Our objective was to increase the accuracy of breast MRI using a semiquantitative analysis of typical MRI features and their diagnostic potential. The prevalence of recently reported MRI signs of breast lesions were analyzed and compared with other well-known signs. CONCLUSION: New MRI features, especially from T2-weighted images, are promising for more reliable and accurate interpretation of breast lesions. Prospective studies of these findings are required to define cut-off values and test clinical practicality.

Further signs in the evaluation of magnetic resonance mammography: a retrospective study.

PURPOSE: To increase accuracy and reliability of magnetic resonance breast imaging, a new evaluation method might be helpful. The recently suggested evaluation method (Fischer U, et al) resulted in a relevant number of equivocal cases (3 or 4 points). Additional morphologic and dynamic signs as an extension of this score were evaluated. METHOD AND MATERIALS: One hundred thirty-two histologically verified lesions were evaluated by 3 radiologists double-blinded using 2 evaluation methods: 1) method 1 (according to Fischer, et al): 2pt: initial signal increase >100%, washout, centripetal enhancement, 1pt: initial signal increase 50-100%, plateau phenomenon, centrifugal inhomogeneous enhancement, irregular borders, linear, stellar or dendritic structure; and 2) method 2 (according to Malich, et al): 3pt: hook sign (sign of pectoral invasion), 2pt: unifocal edema, blooming. 1pt: hypointensity in T2, lymph nodes >10 mm, skin thickening, adjacent vessels, a lesion's distorted inner architecture, disruption of the mamillary edge; -1pt: isointensity in T2, no edema, enhancing septations; -3pt: hyperintensity in T2, non enhancing septations. Method 1 judged a lesion to be malignant if 5 or more points were given and benign if 2 or less points were given, respectively. Method 2 (mean value of 3 radiologists) was tested in those cases in which a clear possible decision using method 1 was not sufficiently possible. RESULTS: Method 1 alone resulted in a negative predictive value of 96.8% and a positive predictive value of 90.8% (without carcinoma in situ), a sensitivity of 83.1%, a specificity of 58.8%, and revealed uncertain results (3 and 4 points) in 29 cases (out of 132; 22%). Adding the new scoring system in these 29 equivocal cases and an increase of 2 or more points by using method 2 is supposed to be a sign of malignancy; findings suggest a sensitivity of 90.9% and a specificity of 60% if an increase of maximum 1 is observed in benign lesions. In conclusion, our results show that Göttingen score alone has a sensitivity of 83.1%, a specificity of 58.8%; the second evaluation method reveals a sensitivity of 90.9% and a specificity of 60% in equivocal cases of Göttingen score. Göttingen score then reaches in all cases and second, adding the second evaluation method in equivocal cases, a sensitivity of 97% and a specificity of 76.5%. CONCLUSION: The application of a second evaluation method in those cases remaining unclear in Göttingen score can lead to a decrease of uncertainty and a higher sensitivity and specificity of diagnosis in MR mammography. In this study, Göttingen score reaches a sensitivity of 83.1% and a specificity of 58.8%, increasing to a sensitivity of 97% and a specificity of 76.5% when being extended by a second evaluation method in unclear cases.

Effect of breast density on computer aided detection.

PURPOSE: This study was conducted to assess the clinical impact of breast density and density of the lesion's background on the performance of a computer-aided detection (CAD) system in the detection of breast masses (MA) and microcalcifications (MC). MATERIALS AND METHODS: A total of 200 screening mammograms interpreted as BI-RADS 1 and suspicious mammograms of 150 patients having a histologically verified malignancy from 1992 to 2000 were selected by using a sampler of tumor cases. Excluding those cases having more than one lesion or a contralateral malignancy attributable to statistical reasons, 127 cases with 127 malignant findings were analyzed with a CAD system (Second Look 5.0, CADx Systems, Inc., Beavercreek, OH). Of the 127 malignant lesions, 56 presented as MC and 101 presented as MA, including 30 cases with both malignant signs. Overall breast density of the mammogram and density of the lesion's background were determined by two observers in congruence (density a: entirely fatty, density b: scattered fibroglandular tissue, density c: heterogeneously dense, density d: extremely dense). RESULTS: Within the unsuspicious group, 100/200 cases did not have any CAD MA marks and were therefore truly negative (specificity 50%), and 151/200 cases did not have any CAD MC marks (specificity 75.5%). For these 200 cases, the numbers of marks per image were 0.41 and 0.37 (density a), 0.38 and 0.97 (density b), 0.44 and 0.91 (density c), and 0.58 and 0.68 (density d) for MC and MA marks, respectively (Fisher's t-test: n.s. for MC, p < 0.05 for MA). Malignant lesions were correctly detected in at least one view by the CAD system for 52/56 (92.8%) MC and 91/101 (90.1%) MA. Detection rate versus breast density was: 4/6 (66.7%) and 18/19 (94.7%) (density a), 32/33 (97.0%) and 49/51 (96.1%) (density b), 14/15 (93.3%) and 23/28 (82.1%) (density c), and 2/2 (100%) and 1/3 (33.3%) (density d) for MC and MA, respectively. Detection rate versus the lesion's background was: 19/21 (90.5%) and 36/38 (94.7%) (density a), 34/36 (94.4%) and 59/62 (95.2%) (density b), 8/9 (88.9%) and 20/24 (83.3%) (density c), and 9/10 (90%) and 4/8 (50%) (density d) for groups 2 and 3, respectively. Detection rates differed significantly for masses in heterogeneously dense and extremely dense tissue (overall or lesion's background) versus all other densities (Fisher's t-test: p < 0.05). A significantly lowered FP rate for masses was found on mammograms of entirely fatty tissue. CONCLUSION: Overall breast density and density at a lesion's background do not appear to have a significant effect on CAD sensitivity or specificity for MC. CAD sensitivity for MA may be lowered in cases with heterogeneously and extremely dense breasts, and CAD specificity for MA is highest in cases with extremely fatty breasts. The effects of overall breast density and density of a lesion's background appear to be similar.

Evaluation of bone-mineral density by digital X-ray radiogrammetry (DXR) in pediatric renal transplant recipients.

BACKGROUND: Loss of bone mass and increased fracture risk are known complications after renal transplantation in adults. Risk factors include donor source, dialysis status prior to transplantation, aetiology of renal disease, transplant rejection and drug therapy, particularly steroids. OBJECTIVE: In this preliminary study of quantification of bone loss in children after renal transplantion, we evaluated the applicability of digital X-ray radiogrammetry (DXR) of hand radiographs to estimate cortical bone mineral density (DXR-BMD). MATERIALS AND METHODS: A total of 23 renal transplant recipients (9 girls, 14 boys; age 6.5-20 years, median 16.3 years) underwent DXR measurements for calculation of DXR-BMD and metacarpal index (DXR-MCI) using radiographs of the non-dominant left hand. The duration between transplantation and the DXR evaluation, the duration of dialysis and medication were considered. The results were compared to a local age-matched and gender-matched reference data base. RESULTS: Our study revealed a significant decrease in bone mineral density compared to an age-matched and sex-matched normal population (P<0.05). In three patients the DXR-BMD was reduced more than -2.5 SD. In 12 patients the DXR-BMD was between -1 and -2.5 SD, and in 7 patients the DXR-BMD was in the normal range. In one patient, evaluation was not possible. Fractures were documented in three patients following transplantation. Reduced DXR-BMD was not significantly associated with immunosuppressive therapy or the duration of dialysis, and there was no significant correlation between DXR-BMD and the time between transplantation and DXR evaluation. CONCLUSIONS: Paediatric renal transplant patients show reduced DXR-BMD. In this preliminary study we demonstrated that DXR-BMD seems to be a reliable technique for quantification of demineralisation following renal transplantation in children.