Improving CT-guided transthoracic biopsy of mediastinal lesions by diffusion-weighted magnetic resonance imaging

OBJECTIVES: To evaluate the preliminary results obtained using diffusion-weighted magnetic resonance imaging and the apparent diffusion coefficient for planning computed tomography-guided biopsies of selected mediastinal lesions. METHODS: Eight patients with mediastinal lesions suspicious for malignancy were referred for computed tomography-guided biopsy. Diffusion-weighted magnetic resonance imaging and apparent diffusion coefficient measurement were performed to assist in biopsy planning with diffusion/computed tomography fused images. We selected mediastinal lesions that could provide discordant diagnoses depending on the biopsy site, including large heterogeneous masses, lesions associated with lung atelectasis or consolidation, lesions involving large mediastinal vessels and lesions for which the results of biopsy using other methods and histopathological examination were divergent from the clinical and radiological suspicion. RESULTS: In all cases, the biopsy needle was successfully directed to areas of higher signal intensity on diffusion-weighted sequences and the lowest apparent diffusion coefficient within the lesion (mean, 0.8 [range, 0.6-1.1]×10-3 mm2/s), suggesting high cellularity. All biopsies provided adequate material for specific histopathological diagnoses of four lymphomas, two sarcomas and two thymomas. CONCLUSION: Functional imaging tools, such as diffusion-weighted imaging and the apparent diffusion coefficient, are promising for implementation in noninvasive and imaging-guided procedures. However, additional studies are needed to confirm that mediastinal biopsy can be improved with these techniques. .

Tratamento minimamente invasivo do adenoma hepático em situações especiais / Minimally invasive treatment of hepatic adenoma in special cases

O adenoma hepatocelular é um tumor benigno raro, que apresentou aumento do número de diagnósticos nas décadas de 1980 e 1990, o que foi atribuído à difusão dos contraceptivos hormonais orais, e à melhor disponibilização e ao avanço dos exames radiológicos. Apresentamos aqui o relato de dois pacientes com grandes adenomas hepáticos submetidos ao tratamento minimamente invasivo por meio de embolização arterial. O primeiro caso foi submetido à embolização eletiva, por apresentar múltiplos adenomas, além de hemorragia recente de um desses nódulos. O segundo, caracterizado por vítima de trauma abdominal fechado e rotura de adenoma hepático, foi realizado em caráter de urgência, tendo a paciente sinais clínicos de choque hemodinâmico secundário à hemorragia intra-abdominal. O desenvolvimento de terapias minimamente invasivas locorregionais, como a embolização arterial, trouxe um novo horizonte para pacientes com adenomas hepáticos. Na ressecção emergencial de um adenoma hepático roto, as taxas de mortalidade são de 5 a 10%, enquanto que a ressecção eletiva reduz a 1% esse desfecho. A embolização arterial dos adenomas hepáticos na vigência de hemorragia é tema de debate. Essa constatação aponta para um possível papel da embolização transarterial desses tumores rotos e não rotos, visto que tal conduta poderá limitar a indicação cirúrgica em casos selecionados, resultando na redução da morbimortalidade. O seguimento das pacientes tratadas foi realizado por meio de ressonância magnética e, após 30 dias, já havia diminuição das lesões embolizadas bem como a presença de significativo componente avascular. O controle radiológico, após 12 meses, mostrou ausência de novas lesões e diminuição daquelas embolizadas.

Hepatocellular adenoma is a rare benign tumor that was increasingly diagnosed in the 1980s and 1990s. This increase has been attributed to the widespread use of oral hormonal contraceptives and the broader availability and advances of radiological tests. We report two cases of patients with large hepatic adenomas who were subjected to minimally invasive treatment using arterial embolization. One case underwent elective embolization due to the presence of multiple adenomas and recent bleeding in one of the nodules. The second case was a victim of blunt abdominal trauma with rupture of a hepatic adenoma and clinical signs of hemodynamic shock secondary to intra-abdominal hemorrhage, which required urgent treatment. The development of minimally invasive locoregional treatments, such as arterial embolization, introduced novel approaches for the treatment of individuals with hepatic adenoma. The mortality rate of emergency resection of ruptured hepatic adenomas varies from 5 to 10%, but this rate decreases to 1% when resection is elective. Arterial embolization of hepatic adenomas in the presence of bleeding is a subject of debate. This observation suggests a role for transarterial embolization in the treatment of ruptured and non-ruptured adenomas, which might reduce the indication for surgery in selected cases and decrease morbidity and mortality. Magnetic resonance imaging showed a reduction of the embolized lesions and significant avascular component 30 days after treatment in the two cases in this report. No novel lesions were observed, and a reduction in the embolized lesions was demonstrated upon radiological assessment at a 12-month follow-up examination.