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Diego Jaramillo

Publications and source records attributed to Diego Jaramillo.

34 records · Page 2Linked to original sources
PubMed2004

Analysis of 51 tibial triplane fractures using CT with multiplanar reconstruction.

OBJECTIVE: We determined the most common patterns of triplane fractures and assessed the risk of epiphyseal separation in each pattern. MATERIALS AND METHODS: Fifty-one children with tibial triplane fractures underwent CT, and the resultant scans underwent multiplanar reconstruction. We categorized epiphyseal and physeal involvement, the number of fragments, the appearance of the Salter-Harris fracture in each plane, and the degree of separation of the epiphyseal fragments. RESULTS: The classic two-fragment type of fracture with medial epiphyseal extension occurred most frequently (33/51). All three-fragment types (8/51) of fractures resulted in a separate anterolateral fragment. Extension to the medial malleolus was common (12/51). None of the four reported fractures types involving anteromedial physeal separation was seen. Children with epiphyseal separation requiring surgery were older (odds ratio [OR] = 1.7) and had plafond involvement (OR = 5), CONCLUSION: CT and multiplanar reconstruction of triplane fractures improve the understanding of patterns of injury and their relative prevalence.

Adolescent↗
PubMed2003

Scoliosis: evidence-based diagnostic evaluation.

This article summarizes the evidence behind the imaging evaluation of scoliosis, which is primarily performed with plain radiographs and MR imaging. Issues related to the radiographic evaluation of spinal curvature include interobserver variability of scoliosis measurements and the radiologist's detection of unexpected findings. The effects of radiation exposure during scoliosis evaluation and strategies to minimize radiation dose are summarized. The use of MR imaging in idiopathic scoliosis is discussed, with special attention to imaging groups at higher risk for underlying pathology of the neural axis.

Evidence-Based Medicine↗
PubMed2003

Sports injuries in the young athlete.

Children and adolescents increasingly are participating in competitive sports, and there has been a corresponding rise in the incidence of sports-related injuries in this group. Many sports injuries follow the same patterns as are seen in adults, but the developing musculoskeletal system is uniquely susceptible to other types of injury. This review describes anatomic and developmental aspects that result in increased susceptibility to injury and the magnetic resonance imaging characteristics of immature cartilage, marrow, and menisci. Injuries that are usually or exclusively encountered in children and adolescents are emphasized.

Adolescent↗
PubMed2003

Normal and ischemic epiphysis of the femur: diffusion MR imaging study in piglets.

PURPOSE: To evaluate normal diffusion characteristics in the femur in piglets and changes in diffusion with increasing duration of femoral head ischemia. MATERIALS AND METHODS: Normal epiphyses, physes, and metaphyses of piglets were evaluated with line-scan diffusion imaging (n = 12) and diffusion-tensor imaging (n = 4). Apparent diffusion coefficient (ADC) differences between normal proximal and distal femoral structures, epiphyseal and physeal cartilage, and epiphyseal and metaphyseal marrow were compared (Mann-Whitney test). Short-term femoral ischemia was investigated after maximal abduction of the hips for 3 hours (n = 6); ADCs before and after abduction were compared (Wilcoxon signed rank test). Prolonged ischemia was investigated with placement of a ligature around the neck of a femur (n = 7); the ADC of the femur in this condition was compared (Wilcoxon signed rank test) with that of the normal contralateral femur. Changes in ADC ratios at three durations of ischemia (Kruskal-Wallis test) were compared. RESULTS: ADC was greater in epiphyseal cartilage (mean +/- 1 SD, 1.62 x 10(-3) mm2/sec +/- 0.38) than it was in physeal cartilage (1.28 x 10(-3) mm2/sec +/- 0.31) (P <.007) and greater in epiphyseal marrow (1.26 x 10(-3) mm2/sec +/- 0.38) than it was in metaphyseal marrow (0.91 x 10(-3) mm2/sec +/- 0.35) (P <.001). There was columnar arrangement of tensors in the physis. ADC decreased 26% after 3 hours of maximal abduction. After femoral neck ligature, ADC increased a mean of 27% after 6 hours and a mean of 75% after 96 hours. CONCLUSION: Normal line-scan diffusion imaging findings indicate relative restriction of diffusion in the metaphysis and parallel orientation of tensors in the physis. Diffusion is initially restricted with decreased blood flow but increases if ischemia lasts longer.

Animals↗
PubMed2003

Assessment of early osteoarthritis in hip dysplasia with delayed gadolinium-enhanced magnetic resonance imaging of cartilage.

BACKGROUND: The efficacy of surgical and medical treatment of osteoarthritis is difficult to assess because of the lack of a noninvasive, sensitive measure of cartilage integrity. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) was designed to specifically examine glycosaminoglycan changes in articular cartilage that occur during the development of osteoarthritis. Our primary goal was to compare this technique with measurement of the joint space width on conventional radiographs in patients with hip dysplasia. We performed this comparison by assessing the correlation between the findings of each technique and clinically important factors such as pain, severity of dysplasia, and age. METHODS: Sixty-eight hips in forty-three patients were included in the study. Clinical symptoms were assessed with use of the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) questionnaire. The width of the joint space as well as the lateral center-edge angle of Wiberg (as a measure of the severity of the dysplasia) was measured on standard standing radiographs. Magnetic resonance imaging maps of glycosaminoglycan distribution were made with T1-calculated images after administration of gadopentetate (2-) (Gd-DTPA (2-) ). The dGEMRIC index was calculated as the average of the T1 values for the acetabular and femoral head cartilages. RESULTS: The dGEMRIC index correlated with both pain (rs = -0.50, p < 0.0001) and the lateral center-edge angle (rs = 0.52, p < 0.0001), whereas the joint space width did not correlate with either, with the numbers available. There was a correlation between the dGEMRIC index and pain whether or not a labral tear was present. The dGEMRIC index was significantly different (p < 0.0001) among three groups of hips classified according to whether they had mild, moderate, or severe dysplasia, whereas the joint space width did not differ significantly among these three groups. There was no significant correlation between age and any of the other parameters. CONCLUSIONS: We demonstrated that, in patients with hip dysplasia, the dGEMRIC index-a measure of the biochemical integrity of cartilage-correlates with pain and the severity of the dysplasia and is significantly different among groups of hips with mild, moderate, and severe dysplasia, suggesting that it may be a sensitive measure of early osteoarthritis. Additional studies are needed to determine whether dGEMRIC can be used to predict disease progression in different situations and/or demonstrate responses to therapeutic interventions.

Adolescent↗
PubMed2003

Correlation of contrast-enhanced power Doppler sonography and conventional angiography of abduction-induced hip ischemia in piglets.

OBJECTIVE: The purpose of this study was to determine if enhanced power Doppler sonography can detect early ischemia of the capital femoral epiphysis induced by hip hyperabduction in piglets and to correlate these findings with angiography. MATERIALS AND METHODS: Proximal femoral perfusion was evaluated in 18 studies of 10 piglet hips with unenhanced power Doppler sonography, enhanced power Doppler sonography with IV contrast agent, and digital angiography, in neutral position, hyperabduction, and after release to neutral position. Enhancement ratios between pixel intensities of power Doppler sonography and enhanced power Doppler images in each position were calculated. Angiograms were analyzed for differences in flow with changes in hip position. RESULTS: With the piglet in neutral position, power Doppler sonography revealed few vessels in the femoral head. Contrast administration resulted in a temporary marked increase in the visualization of vessels in the femoral head. Quantitative enhanced power Doppler sonography revealed a marked decrease in pixel intensity with abduction (p < 0.001) that was not apparent on unenhanced studies (p = 0.28). The enhancement ratio decreased from 0.45 (mean +/- SD, +/- 0.26) in neutral position to 0.10 (+/- 0.21) after abduction; it returned to 0.41 (+/- 0.14) after release of abduction (p < 0.001 for each comparison). Angiographic studies in hyperabduction revealed a variable level of ischemia. CONCLUSION: Enhanced power Doppler sonography can be used to visualize the vascular supply to the cartilaginous femoral head in piglets and can detect reversible ischemia induced by hip hyperabduction. These differences correlate with digital angiographic evidence of ischemia.

Angiography↗
PubMed2002

Intramuscular juvenile xanthogranuloma: sonographic and MR findings.

BACKGROUND: Juvenile xanthogranuloma is a rare benign lesion, most often cutaneous or subcutaneous, and found in infants. OBJECTIVE: To review the imaging approach to an intramuscular mass in an infant. METHODS: A case is reported of a 2-month-old boy who presented with a solitary left arm mass which was evaluated with ultrasound and MRI and then biopsied. RESULTS: Imaging demonstrated a well-defined homogeneous solid mass located in the triceps muscle. The mass was resected and pathology revealed intramuscular juvenile xanthogranuloma. CONCLUSION: Intramuscular juvenile xanthogranuloma, although extremely rare, has imaging features similar to those of more common malignant tumors of infancy. The imaging findings are nonspecific, but this diagnosis should be considered in the differential of a solid intramuscular mass in an infant.

Biopsy, Needle↗
PubMed2002

Vitiligo: complex segregation and linkage disequilibrium analyses with respect to microsatellite loci spanning the HLA.

Familial clustering and linkage disequilibrium studies suggest that genetic factors predispose to vitiligo, although a clear transmission pattern and cosegregation of vitiligo with specific mutations have not been demonstrated. We collected pedigree data on vitiligo from a set of 56 multigeneration families belonging to the Paisa community from Antioquia, Colombia, with the goal of applying the unified model of complex segregation and linkage disequilibrium analyses to test the hypotheses of the existence of a major gene predisposing to vitiligo and that allelic or haplotype polymorphisms of microsatellite loci at 6p21.3-21.4 spanning HLA (D6S276, D6S265, D6S273, and D6S291) are associated with this predisposition. Minimum sibship sample size to discriminate dominant and recessive inheritance models was largely accomplished. Between the 15 models of complex segregation used, the one that best fitted the data was that of a major dominant gene and the existence of strong environmental effects acting on the recessive genotype. The penetrance and risk estimations discriminated two sets of vitiligo patients: those with early onset of vitiligo cosegregating with a dominant mode of inheritance without environmental effects, and those with late onset of vitiligo cosegregating with the recessive genotype and being influenced by environmental effects. After establishing the normal distribution of allelic frequencies and performing multiple comparisons correction, the linkage disequilibrium analysis suggested that a major genetic factor could be located at 6p21.3-21.4, because we detected significant case-control differences for allele 122 at D6S265 ( Pc=0.0264) and significant linkage disequilibrium between loci D6S276 and D6S273 in the cases but not in the controls. We cannot explain these results as a consequence of evolutionary forces or as genetic stratification acting differentially on cases and controls, because there was neither deviation from the Hardy-Weinberg expectations nor genetic subdivision between cases and controls, as theta; (non-biased F(ST)) was not significantly different from 0.

Female↗
PubMed2002

Pediatric magnetic resonance imaging techniques.

Optimization of the MR image requires an understanding of technical parameters, pulse sequences, artifacts, and the use of contrast agents. More technical information and in-depth details about the practical concepts for performing MRI in children can be found in the references accompanying this article.

Artifacts↗
PubMed2002

Staging of neuroblastoma at imaging: report of the radiology diagnostic oncology group.

PURPOSE: To compare the accuracies of computed tomography (CT), magnetic resonance (MR) imaging, and bone scintigraphy in staging disease in patients with neuroblastoma. MATERIALS AND METHODS: Ninety-six children with newly diagnosed neuroblastoma were enrolled in a multicenter prospective cohort study. CT, MR, and bone scintigraphy were used to evaluate tumor stage. Sensitivity and specificity values and receiver operating characteristic (ROC) curve analyses were used to compare the accuracy of CT, MR, and scintigraphy for tumor staging. RESULTS: Eighty-eight patients were eligible for staging analysis, and 45 patients who underwent surgery at initial diagnosis were eligible for analysis of local tumor extent. CT and MR had sensitivities of 43% and 83%, respectively (P <.01), and specificities of 97% and 88%, respectively (P >.05), for detection of stage 4 disease. Areas under the ROC curves for CT and MR were 0.81 and 0.85, respectively (P =.06); that for scintigraphy was 0.83. Addition of scintigraphy to both CT and MR increased the areas under the ROC curves to 0.90 and 0.88, respectively. Accuracy of CT and MR for staging disease confined to the chest or abdomen (stages 1, 2, and 3) was poor. CONCLUSION: MR alone and CT and MR combined with bone scintigraphy enable the accurate detection of stage 4 disease. Both CT and MR perform poorly for local tumor staging.

Bone Neoplasms↗
PubMed2002

Patterns of premature physeal arrest: MR imaging of 111 children.

OBJECTIVE: The purpose of this study was to use MR imaging, especially fat-suppressed three-dimensional (3D) spoiled gradient-recalled echo sequences, to identify patterns of growth arrest after physeal insult in children. MATERIALS AND METHODS: We evaluated 111 children with physeal bone bridges (median age, 11.4 years) using MR imaging to analyze bridge size, location in physis, signal intensity, growth recovery lines, avascular necrosis, and metaphyseal cartilage tongues. Fifty-eight patients underwent fat-suppressed 3D spoiled gradient-recalled echo imaging with physeal mapping. The cause, bone involved, radiographic appearance, and surgical interventions (60/111) were also correlated. Data were analyzed with the two-tailed Fisher's exact test. RESULTS: Posttraumatic bridges, accounting for 70% (78/111) of patients, were most often distal, especially of the tibia (n = 43) and femur (n = 14), whereas those due to the other miscellaneous causes were more frequently proximal (p < 0.0001). The position of the bridge in the physis was related to the bone involved (p < 0.0001). Sixty-five percent of distal tibial bridges involved the anteromedial physis, whereas 60% of the distal femoral arrests were central. Larger bridges had higher T1 signal intensity (p < 0.008). Oblique growth recovery lines were seen exclusively with bridges involving the peripheral physis (p = 0.002) and smaller, more potentially resectable bridges. Metaphyseal cartilaginous tongues were seen with all causes, but avascular necrosis was exclusively posttraumatic (p = 0.03). Signal characteristics and bridge size did not vary with the cause. CONCLUSION: Premature physeal bony bridging in children is most often posttraumatic and disproportionately involves the distal tibia and femur where bridges tend to develop at the sites of earliest physiologic closure, namely anteromedially and centrally, respectively. MR imaging, especially with the use of fat-suppressed 3D spoiled gradient-recalled echo imaging, exquisitely shows the growth disturbance and associated abnormalities that may follow physeal injury and guides surgical management.

Adolescent↗
PubMed2002

Acute hematogenous osteomyelitis of children: assessment of skeletal scintigraphy-based diagnosis in the era of MRI.

UNLABELLED: The emergence of MRI has challenged the long-standing primacy of skeletal scintigraphy in pediatric cases of suspected acute hematogenous osteomyelitis (AHO) with nondiagnostic radiographs. This study evaluated a strategy in which skeletal scintigraphy is the primary and MRI a supplemental test. METHODS: We reviewed the records of 213 children (age range, 8 mo-18 y; mean age, 67 mo) with musculoskeletal symptoms and nondiagnostic radiographs who were referred for skeletal scintigraphy because of the possibility of AHO. MRI was performed when diagnostic uncertainty persisted after skeletal scintigraphy or when abscess was suspected. RESULTS: Diagnosis was made using skeletal scintigraphy without referral for MRI in 179 (84%) of the children, including 79 (92%) of 86 with a final diagnosis of AHO. In no instance was the diagnosis of AHO indicated only by MRI. Treatment and diagnosis were accomplished without referral for MRI in 146 (69%) of all cases and 46 (53%) of the AHO cases. Abscesses that required drainage were found in 3 (6%) of 48 cases of major-long-bone AHO. Each of these 3 had exhibited a slow therapeutic response before MRI. Drainable abscesses were found in 5 (20%) of 25 cases affecting the pelvis, which was the other preponderant location of AHO. These were found with pelvic foci both when MRI was performed at diagnosis and when MRI was performed during treatment. CONCLUSION: An imaging strategy in which skeletal scintigraphy is the first test used when AHO is suspected but radiographs are negative remains highly effective. This approach can be most strongly advocated when symptoms are poorly localized or are localized to major long bones. MRI should be performed after skeletal scintigraphy shows major-long-bone AHO if treatment response is slow. Skeletal scintigraphy is also an appropriate first test for suspected radiographically occult pelvic AHO. Because of the association of abscesses with pelvic AHO, however, the use of MRI should be strongly considered after pelvic AHO is detected, and MRI might be substituted diagnostically for skeletal scintigraphy when symptoms are well localized to the pelvis.

Abscess↗
PubMedDate not supplied

Multidetector computed tomography of fracture-separation of the distal humeral epiphysis.

A case of fracture-separation of the distal humeral epiphysis that was diagnosed using unenhanced multidetector computed tomography is reported. Fracture-separation of the distal humeral epiphysis is a rare injury of young children that is difficult to identify on routine radiographs and is frequently misdiagnosed at the time of initial evaluation.

Female↗
PubMedDate not supplied

Multidetector computed tomography of pediatric lateral condylar fractures.

OBJECTIVE: The objective of this study was to compare lateral condylar fracture characterization using radiographs and multidetector computed tomography (MDCT) of the elbow and to evaluate outcomes in a group of children managed based on MDCT findings. METHODS: Unenhanced MDCT of the elbow with sagittal and coronal reformations was prospectively performed without sedation in 10 children between 1 and 16 years of age with lateral condylar fractures identified on frontal and lateral radiographs of the elbow. Two blinded readers reviewed all radiographs and MDCT images independently and in consensus. For the radiographs and MDCT images, readers graded the displacement of the lateral condyle fracture fragment and classified the fractures according to the Milch classification. Articular and epiphyseal cartilage integrity was assessed on MDCT. Patients were managed based on the consensus interpretation of the MDCT study. The frequency of interobserver agreement, discordant grading of fracture displacement and fracture classification between radiographs and MDCT images, and altered management based on the MDCT findings were determined. RESULTS: Individual readers agreed on fracture displacement in 9 patients (90%) on radiographs and in all 10 patients (100%) on MDCT. Individual readers agreed on fracture classification in 4 patients (40%) on radiographs and in 9 patients (90%) on MDCT. In 4 patients (40%), grading of fracture displacement differed between the consensus interpretation of the radiographs and MDCT images. In 6 patients (60%), fracture classification differed between the consensus interpretation of the radiographs and MDCT images. All 3 patients with fracture displacement greater than 5 mm and 1 patient with fracture displacement between 2 and 5 mm demonstrated disruption of the articular and epiphyseal cartilage on MDCT. Two patients (20%) with fracture displacement near the surgical threshold of 2 mm had altered management based on the MDCT findings. All patients progressed to complete fracture healing, with no delayed displacement or other complications. CONCLUSIONS: Multidetector computed tomography is a highly reproducible means of characterizing pediatric lateral condylar fractures and frequently demonstrates disruption of the epiphyseal and articular cartilage in patients with fracture displacement greater than 2 mm. The findings of MDCT may lead to altered treatment in patients with fracture displacement near the surgical threshold of 2 mm.

Adolescent↗
PubMedDate not supplied

Image Interpretation Session: Sunday, November 27, 2005.

The Sunday afternoon Image Interpretation Session has been a high point of the annual meeting of the Radiological Society of North America for over 65 years. A panel of five experts has been selected, representing the very best from the fields of neurologic, abdominal, thoracic, pediatric, and musculoskeletal radiology. Each panelist will dazzle us with an insightful analysis of two difficult cases in their area of expertise. The panelists are to be lauded for their bravery in subjecting their diagnostic acumen to the scrutiny of the thousands of radiologists in the audience. The cases, representing a diverse spectrum of diseases and disease manifestations, were selected from recent clinical imaging studies performed at the Stanford University Medical Center or the Lucille Salter Packard Children's Hospital. This session celebrates the skills of diagnostic radiologists worldwide, who are called on daily to amalgamate disparate clinical information with complex imaging data into focused differential diagnoses and effective treatment planning. We hope that these cases will serve to illustrate the central role that expert image interpretation plays in the care of patients. We welcome our audience of RSNA attendees, readers of RadioGraphics, and cyberspace denizens to join with our experts in solving these medical puzzles and to enjoy the excitement of unraveling the unknown.

Adolescent↗