Resonancia magnética en la planificación de la braquiterapia intracavitaria para el tratamiento del cáncer de cérvix localmente avanzado / Magnetic resonance imaging for planning intracavitary brachytherapy for the treatment of locally advanced cervical cancer

El cáncer de cérvix es el tercer cáncer ginecológico más frecuente. El tratamiento depende de la estadificación del tumor en el momento del diagnóstico, siendo la combinación de quimioterapia y radioterapia el tratamiento de elección para cánceres localmente avanzados. El uso combinado de radioterapia externa y braquiterapia aumenta la supervivencia en estas pacientes. La braquiterapia permite proporcionar mayor dosis de radiación al tumor con menor toxicidad de los tejidos vecinos en comparación con la radioterapia externa exclusiva. La planificación de la braquiterapia se ha realizado durante años exclusivamente con tomografía computarizada (TC). La reciente incorporación de la resonancia magnética (RM) ha demostrado que aporta información esencial del tumor y de las estructuras vecinas, y permite definir mejor los volúmenes blanco. No obstante, la RM presenta limitaciones, algunas de las cuales se pueden compensar con la fusión de imágenes de TC y RM, con lo que se consigue una planificación óptima al combinar las ventajas de cada técnica (AU)

Cervical cancer is the third most common gynecological cancer. Its treatment depends on tumor staging at the time of diagnosis, and a combination of chemotherapy and radiotherapy is the treatment of choice in locally advanced cervical cancers. The combined use of external beam radiotherapy and brachytherapy increases survival in these patients. Brachytherapy enables a larger dose of radiation to be delivered to the tumor with less toxicity for neighboring tissues with less toxicity for neighboring tissues compared to the use of external beam radiotherapy alone. For years, brachytherapy was planned exclusively using computed tomography (CT). The recent incorporation of magnetic resonance imaging (MRI) provides essential information about the tumor and neighboring structures making possible to better define the target volumes. Nevertheless, MRI has limitations, some of which can be compensated for by fusing CT and MRI. Fusing the images from the two techniques ensures optimal planning by combining the advantages of each technique (AU)

Magnetic resonance imaging for planning intracavitary brachytherapy for the treatment of locally advanced cervical cancer.

Cervical cancer is the third most common gynecological cancer. Its treatment depends on tumor staging at the time of diagnosis, and a combination of chemotherapy and radiotherapy is the treatment of choice in locally advanced cervical cancers. The combined use of external beam radiotherapy and brachytherapy increases survival in these patients. Brachytherapy enables a larger dose of radiation to be delivered to the tumor with less toxicity for neighboring tissues with less toxicity for neighboring tissues compared to the use of external beam radiotherapy alone. For years, brachytherapy was planned exclusively using computed tomography (CT). The recent incorporation of magnetic resonance imaging (MRI) provides essential information about the tumor and neighboring structures making possible to better define the target volumes. Nevertheless, MRI has limitations, some of which can be compensated for by fusing CT and MRI. Fusing the images from the two techniques ensures optimal planning by combining the advantages of each technique.

Heterotopic pancreas: typical and atypical imaging findings.

Heterotopic pancreas is a common condition often encountered during laporotomy or autopsy. Prospective radiographic diagnosis is challenging because of the variable imaging appearances. The purpose of this review is to present the typical and atypical appearances of heterotopic pancreas on imaging studies. Familiarity with the spectrum of radiological findings in conjunction with biochemical markers is helpful to improve diagnostic accuracy.

MR urography versus retrograde pyelography/ureteroscopy for the exclusion of upper urinary tract malignancy.

AIM: To evaluate the diagnostic performance of magnetic resonance urography (MRU) versus retrograde pyelography and/or ureteroscopy (RPU) in the detection of upper urinary tract neoplasms. MATERIALS AND METHODS: This retrospective study included 35 patients with suspected upper urinary tract malignancy who underwent MRU and RPU within 6-months in our institution during the study period (February 2002 to January 2007). MRU and RPU reports were reviewed and results recorded. For each patient, the urinary tract was sub-divided into four regions for analysis: left kidney/renal pelvis, left ureter, right kidney/renal pelvis, and right ureter. MRU and RPU results for each patient were compared to a reference standard and the diagnostic performance of both techniques was compared. RESULTS: A total of 113 regions were analysed on MRU and 90 regions on RPU. Nineteen neoplasms were identified. Sensitivity, specificity, positive predictive value, and negative predictive value for the detection of urinary tract neoplasms were 63, 91, 60, and 92% for MRU, respectively, and 53, 97, 83, and 88% for RPU, respectively. These differences were not statistically significant (p>0.05). CONCLUSION: The high negative predictive value of MRU in the present series supports its use as a non-invasive screening examination for excluding the presence of upper urinary tract malignancy.

Electromagnetic field quantization in time-dependent linear media.

We present a quantization scheme for the electromagnetic field in time-dependent homogeneous nondispersive conducting and nonconducting linear media without sources. Using the Coulomb gauge, we demonstrate this quantization can be mapped into a damped (attenuated) time-dependent quantum harmonic oscillator. Remarkably, we find that the time dependence of the permittivity, for epsilon>0, gives rise to an attenuation of the radiation field. Afterwards, we obtain the exact wave functions for this problem and consider an exponential time accretion of the permittivity as a particular case.

Renal pseudotumors due to fat necrosis in acute pancreatitis.

Retroperitoneal fat necrosis is a well-known complication of acute pancreatitis. We describe an unusual case of fat necrosis presenting as multiple, bilateral renal pseudotumors in a patient with acute pancreatitis. The imaging findings on CT and MR are discussed.

Effect of different bowel preparations on residual fluid at CT colonography.

The effect of different bowel preparations on residual fluid during computed tomographic (CT) colonography was evaluated. Forty-two patients received either a polyethylene glycol electrolyte solution preparation or a phospho-soda preparation the day prior to CT colonography. The amount of residual fluid was calculated for each patient. On average, a phospho-soda preparation provided significantly less residual fluid than a polyethylene glycol electrolyte solution preparation.

Primary malignant rhabdoid tumour of the brain in an adult.

We report a mass in the left cerebral hemisphere of a 20-year-old man. Histological, ultrastructural and immunohistochemical features of the tumour were consistent with primary malignant rhabdoid tumour. The age of presentation, imaging features prior to histological examination, and prognosis in this case were unusual.

Hydatid disease: radiologic and pathologic features and complications.

Hydatid disease primarily affects the liver and typically demonstrates characteristic imaging findings. However, there are many potential local complications (eg, intrahepatic complications, exophytic growth, transdiaphragmatic thoracic involvement, perforation into hollow viscera, peritoneal seeding, biliary communication, portal vein involvement, abdominal wall invasion). Furthermore, secondary involvement due to hematogenous dissemination may be seen in almost any anatomic location (eg, lung, kidney, spleen, bone, brain). Ultrasonography (US) is particularly useful for the detection of cystic membranes, septa, and hydatid sand. Computed tomography (CT) best demonstrates cyst wall calcification and cyst infection. CT and magnetic resonance (MR) imaging may demonstrate cyst wall defects as well as the passage of contents through a defect. Chest radiography, US, CT, and MR imaging are all useful in depicting transdiaphragmatic migration of hydatid disease. CT is the modality of choice in peritoneal seeding. US and CT demonstrate rupture in most cases that involve wide communication. Indirect signs of biliary communication include increased echogenicity at US and fluid levels and signal intensity changes at MR imaging. CT allows precise assessment of osseous lesions, whereas MR imaging is superior in demonstrating neural involvement. Familiarity with atypical manifestations of hydatid disease may be helpful in making a prompt, accurate diagnosis.

["I will never forget it!": the experience of a woman with induced abortion]. / "Não vou esquecer nunca!": a experiência feminina com o abortamento induzido.

Based on the symbolic interactionist approach, we aimed to verify the meanings attributed to induced abortion by women who adopted such behavior as well as to analyze the impact of the experience on their self-image. The results point out the contradiction in women's discourse when they evaluate the experience, and the emotional negative reactions they had developed: remorse/guilty conscience, regret, feeling of grief, and mainly guilt, which, according to their accounts, they will carry for the rest of their lives.

CT evaluation of gastric wall pathology.

The purpose of this study is to show the CT features of common and infrequent pathological lesions of the gastric wall. Although CT features are not often specific, familiarity with the most frequent pathological gastric findings on CT can assist in differential diagnosis.

"Eraseroma" as a cause of rhinolith: CT and MRI in a child.

We report a 5-year old girl with progressive difficulty in breathing through the nose whose clinical diagnosis was nasal tumour. CT showed a calcified nodular mass and MRI a nonspecific nodular lesion in the right nasal cavity. The radiological suspicion was a rhinolith. The operative specimen showed that an eraser from a pencil was the primary source. We underline the rarity of this entity and the important role of radiological studies in preoperative recognition.