CT Staging to Triage Selection of Patients With Poor-Prognosis Rectal Cancer for Neoadjuvant Treatment.

OBJECTIVE. The purpose of this study was to evaluate CT as a screening tool for determining high risk of local recurrence of rectal tumors in a scenario of limited MRI availability. MATERIALS AND METHODS. Data were retrospectively analyzed for 180 consecutively registered patients with rectal adenocarcinoma and no previous treatment who underwent baseline CT and MRI staging within 30 days of each other. Two radiologists independently reviewed CT and MR images. CT scans were interpreted in multiplanar reformation. High risk of local recurrence was based on the MRI reference standard: T3cd (more than 5 mm of mesorectal fat infiltration) or T4 disease, N2 nodal status, mesorectal fascia involvement, extramural venous invasion, or positive pelvic sidewall nodes. The performance of CT for determination of high risk of local tumor recurrence was evaluated. RESULTS. Among the 180 patients 128 (71%) met MRI criteria for high risk of local recurrence. CT sensitivity was 84.4% (108/128) and specificity was 78.8% (41/52). The positive predictive value (PPV) of any high-risk CT feature was 90.7% (108/119). When T status was considered, the sensitivity of CT was 75.2% (79/105), specificity was 90.7% (68/75), and PPV was 91.9% (79/86). When tumors within 5.0 cm of the anal verge were excluded, sensitivity was 89.5% (51/57), specificity was 85.7% (24/28), and PPV was 92.7% (51/55). Using CT for disease staging could reduce MRI use by 66%. CONCLUSION. Tumors at high risk of local recurrence can be identified with CT without baseline MRI. Use of CT rather than MRI could markedly reduce costs of baseline staging and shorten time to initiation of neoadjuvant treatment.

PREOPERATIVE COMPUTED TOMOGRAPHY VOLUMETRY AND GRAFT WEIGHT ESTIMATION IN ADULT LIVING DONOR LIVER TRANSPLANTATION.

Background: Computed tomography volumetry (CTV) is a useful tool for predicting graft weights (GW) for living donor liver transplantation (LDLT). Few studies have examined the correlation between CTV and GW in normal liver parenchyma. Aim: To analyze the correlation between CTV and GW in an adult LDLT population and provide a systematic review of the existing mathematical models to calculate partial liver graft weight. Methods: Between January 2009 and January 2013, 28 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. All grafts were perfused with HTK solution. Estimated graft volume was estimated by CTV and these values were compared to the actual graft weight, which was measured after liver harvesting and perfusion. Results: Median actual GW was 782.5 g, averaged 791.43±136 g and ranged from 520-1185 g. Median estimated graft volume was 927.5 ml, averaged 944.86±200.74 ml and ranged from 600-1477 ml. Linear regression of estimated graft volume and actual GW was significantly linear (GW=0.82 estimated graft volume, r2=0.98, slope=0.47, standard deviation of 0.024 and p<0.0001). Spearman Linear correlation was 0.65 with 95% CI of 0.45 - 0.99 (p<0.0001). Conclusion: The one-to-one rule did not applied in patients with normal liver parenchyma. A better estimation of graft weight could be reached by multiplying estimated graft volume by 0.82.

Racional: A volumetria por tomografia computadorizada (VTC) é uma ferramenta útil para a previsão do peso do enxerto (PE) para o transplante hepático com doador vivo (TFDV). Poucos estudos examinaram a correlação entre o VTC e PE no parênquima hepático normal. Objetivo: Analisar a correlação entre VTC e PE em uma população adulta de doadores para o TFDV e realização de revisão sistemática dos modelos matemáticos existentes para calcular o peso de enxertos hepáticos parciais. Métodos: Foram revisados retrospectivamente 28 doadores consecutivos submetidos à hepatectomia direita para o TFDV entre janeiro de 2009 a janeiro de 2013. Todos os doadores eram adultos saudáveis ​​com VTC pré-operatório. Os enxertos foram perfundidos com solução de preservação HTK. O volume estimado foi obtido por VTC e estes valores foram comparados com o peso real do enxerto, o qual foi aferido depois da hepatectomia e perfusão do enxerto. Resultados: A mediana do PE real foi de 782,5 g, média de 791,43±136 g, variando de 520-1185 g. A mediana do volume estimado do enxerto foi de 927,5 ml, média de 944,86±200,74 ml e variou de 600-1477 ml. A regressão linear volume estimado do enxerto e PE real foi significativamente linear (PE=0.82 do volume estimado do enxerto, r2=0,98, declive=0,47, desvio-padrão de 0,024 e p<0,0001). Correlação linear de Spearman foi de 0,65, com IC de 95% do 0,45-0,99 (p<0,0001). Conclusão: A regra de "um-para-um" não deve ser empregada em pacientes com parênquima hepático normal. A melhor estimativa do peso do enxerto hepático de doador vivo pode ser alcançado através da multiplicação do VTC por 0,82.

Preoperative computed tomography volumetry and graft weight estimation in adult living donor liver transplantation / Estimativa do peso do enxerto hepático no transplante intervivos através da volumetria realizada por tomografia computadorizada pré-operatória

ABSTRACT Background: Computed tomography volumetry (CTV) is a useful tool for predicting graft weights (GW) for living donor liver transplantation (LDLT). Few studies have examined the correlation between CTV and GW in normal liver parenchyma. Aim: To analyze the correlation between CTV and GW in an adult LDLT population and provide a systematic review of the existing mathematical models to calculate partial liver graft weight. Methods: Between January 2009 and January 2013, 28 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. All grafts were perfused with HTK solution. Estimated graft volume was estimated by CTV and these values were compared to the actual graft weight, which was measured after liver harvesting and perfusion. Results: Median actual GW was 782.5 g, averaged 791.43±136 g and ranged from 520-1185 g. Median estimated graft volume was 927.5 ml, averaged 944.86±200.74 ml and ranged from 600-1477 ml. Linear regression of estimated graft volume and actual GW was significantly linear (GW=0.82 estimated graft volume, r2=0.98, slope=0.47, standard deviation of 0.024 and p<0.0001). Spearman Linear correlation was 0.65 with 95% CI of 0.45 - 0.99 (p<0.0001). Conclusion: The one-to-one rule did not applied in patients with normal liver parenchyma. A better estimation of graft weight could be reached by multiplying estimated graft volume by 0.82.

RESUMO Racional: A volumetria por tomografia computadorizada (VTC) é uma ferramenta útil para a previsão do peso do enxerto (PE) para o transplante hepático com doador vivo (TFDV). Poucos estudos examinaram a correlação entre o VTC e PE no parênquima hepático normal. Objetivo: Analisar a correlação entre VTC e PE em uma população adulta de doadores para o TFDV e realização de revisão sistemática dos modelos matemáticos existentes para calcular o peso de enxertos hepáticos parciais. Métodos: Foram revisados retrospectivamente 28 doadores consecutivos submetidos à hepatectomia direita para o TFDV entre janeiro de 2009 a janeiro de 2013. Todos os doadores eram adultos saudáveis ​​com VTC pré-operatório. Os enxertos foram perfundidos com solução de preservação HTK. O volume estimado foi obtido por VTC e estes valores foram comparados com o peso real do enxerto, o qual foi aferido depois da hepatectomia e perfusão do enxerto. Resultados: A mediana do PE real foi de 782,5 g, média de 791,43±136 g, variando de 520-1185 g. A mediana do volume estimado do enxerto foi de 927,5 ml, média de 944,86±200,74 ml e variou de 600-1477 ml. A regressão linear volume estimado do enxerto e PE real foi significativamente linear (PE=0.82 do volume estimado do enxerto, r2=0,98, declive=0,47, desvio-padrão de 0,024 e p<0,0001). Correlação linear de Spearman foi de 0,65, com IC de 95% do 0,45-0,99 (p<0,0001). Conclusão: A regra de "um-para-um" não deve ser empregada em pacientes com parênquima hepático normal. A melhor estimativa do peso do enxerto hepático de doador vivo pode ser alcançado através da multiplicação do VTC por 0,82.

Significance of CT scan and color Doppler duplex ultrasound in the assessment of Abernethy malformation.

BACKGROUND: Abernethy malformation is a rare congenital vascular abnormality in which the portal vein bypasses the liver and drains directly into the inferior vena cava. Diagnosis is complex and requires good quality imaging methods to identify details in systemic and portal circulation in order to establish diagnostic confirmation and treatment strategy. In this study we highlight the significance of the use of CT scans and Color Doppler Duplex Ultrasound for the diagnosis, treatment and evolution assessment in two adults with Abernethy malformation. CASE PRESENTATION: The diagnosis and the treatment of two patients with Abernethy malformation by CT scan and Color Doppler Duplex Ultrasound is described. One patient was submitted to liver transplantation due to chronic liver disease and multiple nodules diagnosed as adenoma. The other patient had normal liver function and a mild neurological and psychomotor dysfunction, therefore we adopted clinical treatment and close liver parenchyma evaluation and nodule surveillance, using an imaging approach involving intercalating CT scan and Color Doppler Duplex Ultrasound every 6 months. We highlight some important direct and indirect findings of non-invasive imaging methods. CONCLUSION: Abernethy malformation requires meticulous image diagnosis to improve treatment and avoid iatrogenic procedures. CT scans and Color Doppler Duplex Ultrasound are both efficient methods for diagnosis, treatment planning and evolution assessment of patients with Abernethy malformation.

Penetrance of functioning and nonfunctioning pancreatic neuroendocrine tumors in multiple endocrine neoplasia type 1 in the second decade of life.

CONTEXT: Data are scarce on the penetrance of multiple endocrine neoplasia type 1 (MEN1)-related nonfunctioning pancreatic neuroendocrine tumors (NF-PETs) and insulinomas in young MEN1 patients. A potential positive correlation between tumor size and malignancy (2-3 cm, 18%; >3 cm, 43%) has greatly influenced the management of MEN1 adults with NF-PETs. OBJECTIVE: The aim of the study was to estimate the penetrance of NF-PETs, insulinomas, and gastrinomas in young MEN1 carriers. DESIGN: The data were obtained from a screening program (1996-2012) involving 113 MEN1 patients in a tertiary academic reference center. PATIENTS: Nineteen MEN1 patients (aged 12-20 y; 16 patients aged 15-20 y and 3 patients aged 12-14 y) were screened for NF-PETs, insulinomas, and gastrinomas. METHODS: Magnetic resonance imaging/computed tomography and endoscopic ultrasound (EUS) were performed on 10 MEN1 carriers, magnetic resonance imaging/computed tomography was performed on five patients, and four other patients underwent an EUS. RESULTS: The overall penetrance of PETs during the second decade of life was 42% (8 of 19). All eight PET patients had NF-PETs, and half of those tumors were multicentric. One-fifth of the screened patients (21%; 4 of 19) harbored at least one large tumor (>2.0 cm). Insulinoma was detected in two NF-PET patients (11%) at the initial screening; gastrinoma was not present in any cases. Six of the 11 (54%) screened patients aged 15-20 years who underwent an EUS had NF-PETs. Potential false-positive EUS results were excluded based on EUS-guided biopsy results, the reproducibility of the NF-PET findings, or the observation of increased tumor size during follow-up. Distal pancreatectomy and the nodule enucleation of pancreatic head tumors were conducted on three patients with large tumors (>2.0 cm; T2N0M0) that were classified as grade 1 neuroendocrine tumors (Ki-67<2%). CONCLUSIONS: Our data demonstrated high penetrance of NF-PETs in 15- to 20-year-old MEN1 patients. The high percentage of the patients presenting consensus criteria for surgery for NF-PET alone or NF-PET/insulinoma suggests a potential benefit for the periodic surveillance of these tumors in this age group.

Multidetector CT evaluation of the postoperative pancreas.

Several pancreatic diseases may require surgical treatment, with most of these procedures classified as resection or drainage. Resection procedures, which are usually performed to remove pancreatic tumors, include pancreatoduodenectomy, central pancreatectomy, distal pancreatectomy, and total pancreatectomy. Drainage procedures are usually performed to treat chronic pancreatitis after the failure of medical therapy and include the Puestow and Frey procedures. The type of surgery depends not only on the patient's symptoms and the location of the disease, but also on the expertise of the surgeon. Radiologists should become familiar with these surgical procedures to better understand postoperative changes in anatomic findings. Multidetector computed tomography is the modality of choice for identifying normal findings after surgery, postoperative complications, and tumor recurrence in patients who have undergone pancreatic surgery.

Helminthic diseases in the abdomen: an epidemiologic and radiologic overview.

Helminthic diseases have a worldwide distribution. They affect billions of people in endemic areas and can result in serious clinical complications. Some parasites have a human gastrointestinal life cycle with resultant abdominal manifestations. However, the symptoms of helminthic diseases are usually nonspecific. Radiologic imaging, along with the identification of risk factors, may help narrow the differential diagnosis. To avoid diagnostic delays, radiologists should be familiar with the geographic distribution, transmission cycle, and characteristic and atypical manifestations of common helminthic diseases at abdominal imaging with radiography, computed tomography, magnetic resonance imaging, and ultrasonography. Awareness of the clinical, epidemiologic, and pathogenic characteristics of these diseases also may be helpful for narrowing the diagnosis when imaging features are nonspecific.

MR imaging findings of iron overload.

Hemochromatosis can be classified as (a) primary, when it originates from a genetic disturbance that promotes the increase of iron absorption, or (b) secondary, when it relates to chronic diseases or to multiple transfusions. The distribution of iron accumulation differs between these two forms; therefore, they can be distinguished by using imaging methods in the majority of cases. Magnetic resonance (MR) imaging is the most sensitive and specific imaging modality in the diagnosis of hemochromatosis. The susceptibility effect caused by the accumulation of iron leads to signal loss in the affected tissues, particularly with the T2*-weighted sequences, which makes the diagnosis of iron overload possible. By using MR imaging techniques, it is possible to estimate the hepatic iron concentration in a noninvasive way, thereby avoiding repeated biopsies. Hemochromatosis can lead to complications, such as a higher frequency of neoplasia, particularly the development of hepatocellular carcinoma. Other neoplasms, such as colorectal tumors, are also associated. Complications related to the treatment of chronic anemia include the appearance of peliosis hepatis and tumors, which can regress after the suspension of treatment with drugs. Knowledge of the disease and of the patterns of iron deposition in patients with iron overload enables not only diagnosis, but also treatment, follow-up, and the detection of possible complications by using imaging methods.

Renal cell carcinoma: t1 and t2 signal intensity characteristics of papillary and clear cell types correlated with pathology.

OBJECTIVE: The objective of our study was to describe the T1 and T2 signal intensity characteristics of papillary renal cell carcinoma (RCC) and clear cell RCC with pathologic correlation. MATERIALS AND METHODS: Of 539 RCCs, 49 tumors (21 papillary RCCs and 28 clear cell RCCs) in 45 patients were examined with MRI. Two radiologists retrospectively and independently assessed each tumor's T1 and T2 signal intensity qualitatively and quantitatively (i.e., the signal intensity [SI] ratio [tumor SI / renal cortex SI]). Of the 49 tumors, 37 (76%) were assessed for pathology features including tumor architecture and the presence of hemosiderin, ferritin, necrosis, and fibrosis. MRI findings and pathology features were correlated. Statistical methods included summary statistics and Wilcoxon's rank sum test for signal intensity, contingency tables for assessing reader agreement, concordance rate between the two readers with 95% CIs, and Fisher's exact test for independence, all stratified by RCC type. RESULTS: Papillary RCCs and clear cell RCCs had a similar appearance and signal intensity ratio on T1-weighted images. On T2-weighted images, most papillary RCCs were hypointense (reader 1, 13/21; reader 2, 14/21), with an average mean signal intensity ratio for both readers of 0.67 +/- 0.2, and none was hyperintense, whereas most clear cell RCCs were hyperintense (reader 1, 21/28; reader 2, 17/28), with an average mean signal intensity ratio for both readers of 1.41 +/- 0.4 (p < 0.05). A tumor T2 signal intensity ratio of < or = 0.66 had a specificity of 100% and sensitivity of 54% for papillary RCC. Most T2 hypointense tumors exhibited predominant papillary architecture; most T2 hyperintense tumors had a predominant nested architecture (p < 0.05). CONCLUSION: On T2-weighted images, most papillary RCCs are hypointense and clear cell RCCs, hyperintense. The T2 hypointense appearance of papillary RCCs correlated with a predominant papillary architecture at pathology.

Area hipoecogênica ultra-sonográfica periportal: importante pseudolesäo hepática / Hypoechoic area in the porta hepatis: an important hepatic pseudolesion

Os autores apresentam dois casos de achado ultra-sosnográfico de zona hipoecogênica periportal. A correlaçäo com exames de tomografia computadorizada demonstrou que tais zonas tinham coeficientes de atenuaçäo previstos para um fígado normal e que o restante do parênquima hepático corrrespondia a um fígado esteatótico. Säo revisadas as diversas causas de esteatose hepática e comentadas as limitaçöes e dificuldades de seu diagnóstico ultra-sonográfico