[The heterogeneity of blood flow on magnetic resonance imaging: a biomarker for grading cerebral astrocytomas]. / La heterogeneidad del flujo sanguíneo en resonancia magnética, biomarcador para clasificar por grados los astrocitomas cerebrales.

OBJECTIVES: To study whether the histograms of quantitative parameters of perfusion in MRI obtained from tumor volume and peritumor volume make it possible to grade astrocytomas in vivo. MATERIAL AND METHODS: We included 61 patients with histological diagnoses of grade II, III, or IV astrocytomas who underwent T2*-weighted perfusion MRI after intravenous contrast agent injection. We manually selected the tumor volume and peritumor volume and quantified the following perfusion parameters on a voxel-by-voxel basis: blood volume (BV), blood flow (BF), mean transit time (TTM), transfer constant (K(trans)), washout coefficient, interstitial volume, and vascular volume. For each volume, we obtained the corresponding histogram with its mean, standard deviation, and kurtosis (using the standard deviation and kurtosis as measures of heterogeneity) and we compared the differences in each parameter between different grades of tumor. We also calculated the mean and standard deviation of the highest 10% of values. Finally, we performed a multiparametric discriminant analysis to improve the classification. RESULTS: For tumor volume, we found statistically significant differences among the three grades of tumor for the means and standard deviations of BV, BF, and K(trans), both for the entire distribution and for the highest 10% of values. For the peritumor volume, we found no significant differences for any parameters. The discriminant analysis improved the classification slightly. CONCLUSIONS: The quantification of the volume parameters of the entire region of the tumor with BV, BF, and K(trans) is useful for grading astrocytomas. The heterogeneity represented by the standard deviation of BF is the most reliable diagnostic parameter for distinguishing between low grade and high grade lesions.

[Magnetic resonance enterography: technique and indications. Findings in Crohn's disease]. / Enterografía por resonancia magnética: técnica e indicaciones. Hallazgos en la enfermedad de Crohn.

Radiology with oral contrast, or enteroclysis, have traditionally been the techniques of choice in the examination of the small intestine, due to the excellent visualisation of the mucosal pattern. However, the absence of extra-luminal information and the use of ionising radiation have replaced these examinations with sectional techniques which enable the abdominal cavity to be viewed with good resolution. Magnetic resonance enterography is a simple technique, with no ionising radiation, provided quality images, distends the intestinal lumen well by the administration of non-reabsorbable oral substances, minimises peristalsis, and establishes a protocol which includes sequences with intravenous contrast. These properties can be used in patients with Crohn's disease, achieving good diagnostic precision in the assessment of activity and monitoring of treatment, in intestinal obstruction, in the suspicion of small intestine tumours, and in paediatric patients due to it being harmless.

Similar effect of family history of psychosis on Sylvian fissure size and auditory P200 amplitude in schizophrenic and bipolar subjects.

Several cerebral studies point to the non-specificity of structural and functional changes described in schizophrenia and bipolar disorders. Furthermore, the origin of these changes is still unclear. The present study investigated the effect of a family history (FH) of psychotic disorders in first-degree relatives on computed tomographic (CT) measures (ventricular, cerebral and Sylvian fissure size) and auditory event-related potentials (amplitudes and latencies of peak components in oddball paradigms) in 30 schizophrenic patients and 24 bipolar type I patients. We found a significant correlation between FH and the size of the right Sylvian fissure, and between FH and auditory P200 amplitude. More specifically, the schizophrenic and bipolar patients with negative FH (n=36) had larger right Sylvian fissures and smaller P200 amplitude than patients with positive FH (n=18). These findings were independent of the specific diagnosis, gender, and age of subjects. Our results suggest some underlying process common to schizophrenia and bipolar I disorder, and they provide support for the continuum view of the nosologic structure of psychotic illness.

Radiologic diagnosis of pseudoaneurysms complicating pancreatitis.

Angiographic and computed tomographic (CT) examinations in five patients with arterial pseudoaneurysms complicating pancreatitis were evaluated retrospectively. Selective arteriography was superior to CT imaging in demonstrating pseudoaneurysm formation. However, angiography was performed in four patients after a CT study considered suspicious for a pseudoaneurysm; none of these four patients had clinical evidence of bleeding. Correlation with surgical findings was established in four patients, indicating that pseudoaneurysms complicating pancreatitis were not located within a pancreatic pseudocyst. Some thrombus-containing pseudoaneurysms may present with a pseudocyst appearance on CT images.

Interobserver agreement in the diagnosis of pulmonary embolism with helical CT.

PURPOSE: Our objective was to asses the interobserver agreement in the detection of pulmonary embolism (PE) with contrast-enhanced helical CT at the main pulmonary, lobar and segmental arteries. A prospective study was carried out in 51 patients with suspected PE. Finally, 29 patients were diagnosed of PE. SUBJECTS AND METHODS: All patients were studied with helical CT. Images (5 mm collimation, 1.5 pitch factor, 3 mm reconstruction interval) were obtained after bolus contrast injection (120 ml, 4 ml/s, 15 s delay time). All cases were blinded and independently interpreted in three ways: two radiologists with different level of expertise and two expert radiologists reading by consensus. Agreement was evaluated by means of the kappa test. RESULTS: Kappa values for thrombi detection expressed an excellent agreement at the main (between 0.802 and 0. 946), lobar (between 0.915 and 0.958) and segmental (between 0.879 and 0.718) levels. For all vessels, mean kappa values were similar and excellent for all three combinations of readers. Arteries with more discrepancies were located mainly at the anterior and posterior areas of the upper lobes. CONCLUSIONS: The high degree of agreement shown in this study indicates that helical CT is a reproducible test in the diagnosis of PE to the segmental level. Isolated readings and levels of expertise do not influence agreement.

Hodgkin's disease: internal mammary lymph nodes relapse diagnosed by gallium-67 scintigraphy.

This article presents the case of a 62-year-old man with treated Hodgkin's disease who had internal mammary lymph nodes relapse after a complete initial response. These masses were gallium avid. These findings were explained by histologically documented Hodgkin's relapse, the first such case reported in that localization without chest wall involvement. The literature on mediastinal Hodgkin's disease and diagnostic procedures are reviewed.

[Psoas abscess secondary to lumbar spondylodiscitis caused by gram negative bacilli]. / Absceso de psoas secundario a espondilodiscitis lumbar por gram negativos.

The association between psoas abscess and lumbar spondylodiscitis by Gram negative bacilli represents a rare clinical entity. Sometimes the absence of demonstrative symptoms complicates the diagnostic schema. We report about a 72 year-old woman, without previous known diabetes mellitus, who was admitted because of fever of one week duration and a non-ketotic hyperosmolar coma. A left psoas abscess was identified by abdominal computed tomography (CT). The abscess was in communication with the L1-L2 intervertebral space. Although Escherichia coli was identified as the causing agent and appropriate antibiotic therapy was administered, the resolution of the abscess occurred only after the implantation of a percutaneous catheter guided by CT without additional surgery. Percutaneous drainage as a diagnostic-therapeutic technique has rendered the surgery as the last resort in the treatment of psoas abscess.

[Transthoracic needle aspiration biopsy. The diagnostic accuracy of pulmonary lesions]. / Punción diagnóstica transtorácica. Precisión diagnóstica de la lesión pulmonar.

We performed 91 transthoracic functions, under fluoroscopy, sonographically or by computed tomography control, at Clinic Hospital in Valencia. The procedures was performed with Chiba needle 22 gauges while the cytopathologist was present. Maximum number of needle passes was four. Malignant diagnosis has been obtained in 64.8% of cases, in 12 patients a benign diagnosis was obtained and confirmed, 13 cases were false negative and the specimen was insufficient for diagnosis in 7 (5 of them lesions had a diameter less than 2 cm). The study showed 82% for sensitivity, 100% for specificity and 85% for accuracy. The punction was guided by fluoroscopy in 49 patients, by sonography in 6 and by computed tomography control in 36. The accuracy diagnosis for fluoroscopy guidance was 96%. The complications were 9 (9.9%): Two patients presented minor hemoptysis resolved spontaneously, 6 patients showed minor pneumothorax and one patient was treated a cause of a large pneumothorax. We concluded that transthoracic biopsy is a simple and save technique that can provide a high diagnosis accuracy in patients with pulmonary pathology.

[Treating iatrogenic pneumothorax with small-bore chest tube]. / Drenaje de neumotórax iatrogénico con catéter de calibre pequeño.

OBJECTIVE: To evaluate the feasibility of small-bore chest tube placement to treat pneumothorax caused by percutaneous procedures. MATERIAL AND METHODS: Between November 2004 and July 2006 we performed 151 interventional chest procedures (127 biopsies and 24 radiofrequency ablations) in 131 patients (25 women and 106 men; mean age, 63 years, range, 36-83 years). Fine needles (21-25 G) were used in 70 procedures and large core needles (14-20 G) were used in the remaining 81. Pneumothorax occurred in 16 diagnostic procedures (13 of these were treated with small-bore catheter placement) and in two radiofrequency procedures (both cases were treated with small-bore catheter placement). Chest tubes were placed immediately after pneumothorax occurred in all cases because the pneumothorax was greater than 20% or caused symptoms or occurred in patients with emphysema. RESULTS: Chest tubes were successfully placed without incidents in all cases and a Heimlich valve evacuated the air completely. Mean hospital stay was 43 hours (range, 24-72 hours). It was not necessary to place a larger-bore chest tube in any case. CONCLUSION: Small-bore chest tube placement is the treatment of choice for iatrogenic pneumothorax greater than 20% or less than 20% when symptomatic or occurring in patients with emphysema. The procedure is easy, effective, and well tolerated; furthermore, it shortens the hospital stay. The effectiveness of the procedure makes it possible to safely perform percutaneous procedures on patients with emphysema or difficult lesions and to finish an interventional procedure when pneumothorax occurs.

[The evaluation of lower limb arteriopathy by multidetector computed tomography compared with digital subtraction angiography]. / Evaluación de la arteriopatía de los miembros inferiores por tomografía computarizada multidetector comparada con la angiografía por sustracción digital.

OBJECTIVE: To evaluate the diagnostic efficacy of multidetector computed tomography angiography (MDCTA) in lower limb arteriopathy (LLA) by comparing it with digital subtraction angiography (DSA). MATERIAL AND METHODS: Twenty-four patients with LLA were studied. All patients underwent MDCTA (four detectors) and DSA, with double reading between the two techniques. Vascular territories were divided to facilitate analysis. Sensitivity (S), specificity (Sp), prevalence, positive and negative predictive values (PPV, PNV), and concordance (Kappa test) were evaluated. In third-portion arteries, the diagnostic performance of MDCTA was evaluated using an ROC curve. RESULTS: MDCTA study to evaluate arterial pathology showed: Lower sensitivity in the study of the internal iliac artery (S: 0.65 and 0.71) with Sp 0.94 and 1. In the other vascular territories, S approached 1, with a slight decrease in Sp. Concordance with DSA was very high (kappa between 0.62 and 1) in all of the territories studied. MDCTA showed greater vessel longitude than DSA. In the third portion, the best diagnostic performance (ROC) was obtained in the reading of pathological vessels. CONCLUSION: MDCTA was highly reliable in the study of LLA, with high concordance with DSA. In tortuous vessels, MDCTA depicted the lesions poorly; however, in straight vessels and third-portion vessels, MDCTA showed more vascular segments.