Resonancia magnética de la osteonecrosis espontánea de la rodilla: ¿existe un proceso agudo o crónico predisponente? / Can MRI determine whether acute or chronic processes predisposing conditions are present in spontaneous osteonecrosis of the knee?

Objetivo. Analizar la posible etiología subyacente de la osteonecrosis (ON) espontánea de la rodilla en adultos, según su comportamiento en la resonancia magnética (RM): lesión aguda (fracturas por insuficiencia) o crónica (degeneraciones artrósicas). Material y método. Se realizó un estudio retrospectivo en el que se evaluaron las RM de rodillas de 48 pacientes que cumplían criterios de ON espontánea. En total, se incluyeron 51 lesiones subcondrales, que se dividieron en 2 grupos según la presencia de imágenes lineales (grupo A) o no (grupo B). Recogimos la localización y el tamaño de las lesiones, su intensidad de señal, su relación con el edema óseo, la rotura meniscal ipsolateral y las anomalías del cartílago adyacente, así como la existencia de artrosis. Resultados. Estudiamos a 28 hombres y a 20 mujeres con una edad media de 55,1±18,0 años. La morfología más frecuente fue la lineal (grupo A) frente a la no lineal (grupo B) (el 58,8 y el 41,2%, respectivamente). En ambos grupos, la localización más frecuente fue el cóndilo femoral interno (el 56,7% en el grupo A y el 52,4% en el grupo B), y la intensidad de señal predominante (88,2%) fue hipointensa en T1 y DP con supresión grasa. El tamaño medio en milímetros de las lesiones en los diámetros anteroposterior y transversal fue en el grupo A de 11,9±3,6×9,4±3,9 y en el grupo B de 10,9±5,1 x 10,5±4,5. El edema óseo predominante fue grave (grado ii–iii) en el grupo A y leve (grado 0–i) en el grupo B (p=0,033). Los defectos del cartílago ipsolateral a la lesión subcondral fueron superiores en el grupo B que en el grupo A (el 76,2 y el 56,7%, respectivamente; p=0,33), mientras que la incidencia de rotura meniscal ipsolateral fue similar en ambos grupos (el 56,7% en el grupo A y el 57,1% en el grupo B; p=0,97). Conclusión: Al conocer los hallazgos de la ON espontánea de la rodilla en la RM y valorar otros datos (tipo de lesión, edema óseo, rotura meniscal y defectos del cartílago ipsolateral), podemos intentar determinar un proceso primario predisponente. Las lesiones lineales podrían relacionarse con un proceso agudo (fracturas por insuficiencia) y las no lineales con un proceso crónico (artrosis) (AU)

Objective. To analyze possible underlying causes of spontaneous osteonecrosis of the knee in adults in function of the lesion's behavior on magnetic resonance imaging (MRI): acute lesion (insufficiency fractures) or chronic lesion (osteoarthritic degeneration). Material and methods. We retrospectively evaluated knee MRI studies in 48 patients who fulfilled criteria for spontaneous osteonecrosis. A total of 51 subchondral lesions were included and classified in two groups: those in which linear images were present (Group A) and those in which linear images were not present (Group B). We recorded the location and size of the lesions, their signal intensity, their relation with bone edema, ipsilateral meniscal tear and abnormalities in the adjacent cartilage, as well as the presence of osteoarthritis. Results. We studied 28 men and 20 women (mean age, 55.1±18.0 years). Linear images were present in 58.5% of lesions (group A) and absent in 41.2% (group B). The most common location in both groups was the internal femoral condyle (56.7% in group A and 52.4% in group B), and 88.2% of lesions were hypointense on T1-weighted and fat suppressed proton density sequences. The mean size of the anteroposterior and transversal diameters was 11.9±3.6×9.4±3.9mm in group A and 10.9±5.1×10.5±4.5mm in group B. The predominant bone edema was severe (grade 2–3) in group A and mild (grade 0–1) in group B (p=0.033). Defects in the cartilage ipsilateral to the subchondral lesion were more common in group B than in group A, although this difference was not significant (76.2% and 56.7%, respectively; p=0.33). The frequency of ipsilateral meniscal tear was similar in the two groups (56.7% in group A and 57.1% in group B; p=0.97). Knowing the MRI findings for spontaneous osteonecrosis and evaluating other data (type of lesion, bone edema, meniscal tear, and ipsilateral cartilage defects) can help determine the primary predisposing process. Linear lesions might be related to an acute process (insufficiency fractures) and non-linear lesions might be related to a chronic process (osteoarthritis) (AU)

[Can MRI determine whether acute or chronic processes predisposing conditions are present in spontaneous osteonecrosis of the knee?]. / Resonancia magnética de la osteonecrosis espontánea de la rodilla: ¿existe un proceso agudo o crónico predisponente?

OBJECTIVE: To analyze possible underlying causes of spontaneous osteonecrosis of the knee in adults in function of the lesion's behavior on magnetic resonance imaging (MRI): acute lesion (insufficiency fractures) or chronic lesion (osteoarthritic degeneration). MATERIAL AND METHODS: We retrospectively evaluated knee MRI studies in 48 patients who fulfilled criteria for spontaneous osteonecrosis. A total of 51 subchondral lesions were included and classified in two groups: those in which linear images were present (Group A) and those in which linear images were not present (Group B). We recorded the location and size of the lesions, their signal intensity, their relation with bone edema, ipsilateral meniscal tear and abnormalities in the adjacent cartilage, as well as the presence of osteoarthritis. RESULTS: We studied 28 men and 20 women (mean age, 55.1+/-18.0 years). Linear images were present in 58.5% of lesions (group A) and absent in 41.2% (group B). The most common location in both groups was the internal femoral condyle (56.7% in group A and 52.4% in group B), and 88.2% of lesions were hypointense on T1-weighted and fat suppressed proton density sequences. The mean size of the anteroposterior and transversal diameters was 11.9+/-3.6 x 9.4+/-3.9 mm in group A and 10.9+/-5.1 x 10.5+/-4.5 mm in group B. The predominant bone edema was severe (grade 2-3) in group A and mild (grade 0-1) in group B (p=0.033). Defects in the cartilage ipsilateral to the subchondral lesion were more common in group B than in group A, although this difference was not significant (76.2% and 56.7%, respectively; p=0.33). The frequency of ipsilateral meniscal tear was similar in the two groups (56.7% in group A and 57.1% in group B; p=0.97). CONCLUSION: Knowing the MRI findings for spontaneous osteonecrosis and evaluating other data (type of lesion, bone edema, meniscal tear, and ipsilateral cartilage defects) can help determine the primary predisposing process. Linear lesions might be related to an acute process (insufficiency fractures) and non-linear lesions might be related to a chronic process (osteoarthritis).

Ruptured gastrointestinal stromal tumors: radiologic findings in six cases.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are characterized by the expression of c-KIT (antigen CD 117) and are the most common mesenchymal tumors of the digestive tract. An important complication, although infrequently described in the literature, is the rupture of these tumors with accompanying hemoperitoneum. METHODS: We performed a retrospective evaluation of the clinical history and radiologic records of 23 patients with a diagnosis of GIST and anatomopathologic and immunohistochemical confirmation at our hospital between 1999 and 2004. RESULTS: In five cases there was rupture of the primary tumor (four gastric and one jejunal). In all five cases ultrasonographic and computed tomographic examinations showed a heterogenic tumor of laminated or whirled appearance, associated with echogenic or dense ascites. No relation was found between histologic criteria of malignancy and the rupture. Four patients underwent surgical intervention, three of them urgently. Two of five patients died. There was a sixth case with rupture of a hepatic metastasis, with accompanying hemoperitoneum and subcapsular hematoma. This patient died at 3 months, after recurrence of bleeding. CONCLUSIONS: The finding of a heterogeneous tumor of laminated or whirled appearance associated with ascites with characteristics compatible with hemoperitoneum in an appropriate context must lead to a suspicion of the existence of a ruptured GIST.