[Postoperative imaging of the peritoneum and abdominal wall]. / Imagerie post-opératoire du péritoine et de la paroi abdominale.

CT scan is the gold standard for follow-up after abdominal surgery and diagnosis of postoperative complications. During the immediate postoperative period, asymptomatic and rapidly regressing peritoneal collections of fluid and gas are often present. Transient ileus is classically present as well. The diagnosis of postoperative peritonitis is difficult on imaging; fluid collections are frequent and easily detected. The main postoperative peritoneal complication is small bowel obstruction, either early and due to inflammatory changes, or delayed and due to adhesions or less frequently to other causes, including transmesenteric hernia. Other rare complications include desmoid tumors and gossypiboma. Wall complications, after laparotomy as well as laparoscopic surgery, are mainly hematoma, infections and wound hernia.

Right portal vein ligation is as efficient as portal vein embolization to induce hypertrophy of the left liver remnant.

BACKGROUND: Aim of this retrospective study was to compare induction of left liver hypertrophy after right portal vein ligation (PVL) and right portal vein embolization (PVE) before right hepatectomy for liver metastases. MATERIALS AND METHODS: Between 1998 and 2005, 18 patients underwent a PVE, whereas 17 patients underwent a PVL during a first stage laparotomy. RESULTS: There was no complication related to PVE or PVL. After a similar interval time (7 +/- 3 vs 8 +/- 3 weeks), the increase of the left liver volume was similar between the two groups (35 +/- 38 vs 38 +/- 26%). After PVE and PVL, right hepatectomy was performed in 12 and 14 patients, respectively. Technical difficulties during the right hepatectomy were similar according to duration of procedure (6.4 +/- 1 vs 6.7 +/- 1 h, p = 0.7) and transfusion rates (33 vs 28%, p = 0.7). Mortality was nil in both groups, and morbidity rates were respectively 58% for the PVE group and 36% for the PVL group (p = 0.6). CONCLUSION: Right PVL and PVE result in a comparable hypertrophy of the left liver. During the first laparotomy of a two-step liver resection, PVL can be efficiently and safely performed.

The effect of maternal care on child survival: a demographic, genetic, and evolutionary perspective.

Models of population dynamics generally assume that child survival is independent of maternal survival. However, in humans, the death of a mother compromises her immature children's survival because children require postnatal care. A child's survival therefore depends on her mother's survival in years following her birth. Here, we provide a model incorporating this relationship and providing the number of children surviving until maturity achieved by females at each age. Using estimates of the effect that a mother's death has on her child's survival until maturity, we explore the effect of the model on population dynamics. Compared to a model that includes a uniform child survival probability, our model slightly raises the finite rate of increase lambda and modifies generation time and the stable age structure. We also provide estimates of selection on alleles that change the survival of females. Selection is higher at all adult ages in our model and remains significant after menopause (at ages for which the usual models predict neutrality of such alleles). Finally, the effect of secondary caregivers who compensate maternal care after the death of a mother is also emphasized. We show that allocare (as an alternative to maternal care) can have a major effect on population dynamics and is likely to have played an important role during human evolution.

[Liver imaging: pitfalls, pseudolesions and pseudotumors]. / Imagerie hépatique: pièges, pseudolésions et pseudotumeurs.

Recognition of pseudolesions of the liver at imaging is important because of their close resemblance to primary liver cancer or metastases. There are several types of pseudolesions: pseudolesions, with mostly straight borders, corresponding to perfusion abnormalities, fatty liver, confluent fibrosis and radiation hepatitis; morphologic changes of the liver; true pseudotumors. The use of multidetector CT and MR imaging increases the likelihood of detecting such lesions in routine practice. Radiologists must recognize these lesions and understand the underlying etiology.

Utility of staging laparoscopy in subsets of biliary cancers : laparoscopy is a powerful diagnostic tool in patients with intrahepatic and gallbladder carcinoma.

BACKGROUND: The aim of this study was to evaluate the utility of staging laparoscopy in patients with biliary cancers in the era of modern diagnostic imaging. METHODS: From September 2002 through August 2004, 39 consecutive patients with potentially resectable cholangiocarcinoma underwent preoperative staging laparoscopy before laparotomy. Preoperative imaging included ultrasonography and triphasic computed tomography for all patients and magnetic resonance cholangiography in 35 patients (90%). Final pathological diagnosis included 20 hilar cholangiocarcinomas (HC), 11 intrahepatic cholangiocarcinomas (IHC), and eight gallbladder carcinomas (GBC). RESULTS: During laparoscopy, unresectable disease was found in 14/39 patients (36%). The main causes of unresectability were peritoneal carcinomatosis (11/14) and liver metastases (5/14). At laparotomy, nine patients (37%) were found to have advanced disease precluding resection. Vascular invasion and nodal metastases were the main causes of unresectability during laparotomy (eight out of nine). In detecting peritoneal metastases and liver metastases, laparoscopy had an accuracy of 92 and 71%, respectively. All patients with vascular or nodal involvement were missed by laparoscopy. For prediction of unresectability disease, the yield and accuracy of laparoscopy were highest for GBC (62% yield and 83% accuracy), followed by IHC (36% yield and 67% accuracy) and HC (25% yield and 45% accuracy) CONCLUSION: Staging laparoscopy ensured that unnecessary laparotomy was not performed in 36% of patients with potentially resectable biliary carcinoma after extensive preoperative imaging. In patients with biliary carcinoma that appears resectable, staging laparoscopy allows detection of peritoneal and liver metastasis in one third of patients. Both vascular and lymph nodes invasions were not diagnosed by this procedure. Due to these limitations, laparoscopy is more useful in ruling out dissemination in GBC and IHC than in HC.

Hepatic abscess: Diagnosis and management.

Microbial contamination of the liver parenchyma leading to hepatic abscess (HA) can occur via the bile ducts or vessels (arterial or portal) or directly, by contiguity. Infection is usually bacterial, sometimes parasitic, or very rarely fungal. In the Western world, bacterial (pyogenic) HA is most prevalent; the mortality is high approaching 15%, due mostly to patient debilitation and persistence of the underlying cause. In South-East Asia and Africa, amebic infection is the most frequent cause. The etiologies of HA are multiple including lithiasic biliary disease (cholecystitis, cholangitis), intra-abdominal collections (appendicitis, sigmoid diverticulitis, Crohn's disease), and bile duct ischemia secondary to pancreatoduodenectomy, liver transplantation, interventional techniques (radio-frequency ablation, intra-arterial chemo-embolization), and/or liver trauma. More rarely, HA occurs in the wake of septicemia either on healthy or preexisting liver diseases (biliary cysts, hydatid cyst, cystic or necrotic metastases). The incidence of HA secondary to Klebsiella pneumoniae is increasing and can give rise to other distant septic metastases. The diagnosis of HA depends mainly on imaging (sonography and/or CT scan), with confirmation by needle aspiration for bacteriology studies. The therapeutic strategy consists of bactericidal antibiotics, adapted to the germs, sometimes in combination with percutaneous or surgical drainage, and control of the primary source. The presence of bile in the aspirate or drainage fluid attests to communication with the biliary tree and calls for biliary MRI looking for obstruction. When faced with HA, the attending physician should seek advice from a multi-specialty team including an interventional radiologist, a hepatobiliary surgeon and an infectious disease specialist. This should help to determine the origin and mechanisms responsible for the abscess, and to then propose the best appropriate treatment. The presence of chronic enteric biliary contamination (i.e., sphincterotomy, bilio-enterostomy) should be determined before performing radio-frequency ablation and/or chemo-embolization; substantial stenosis of the celiac trunk should be detected before performing pancreatoduodenectomy to help avoid iatrogenic HA.

Persistent enhancement after treatment for cerebral toxoplasmosis in patients with AIDS: predictive value for subsequent recurrence.

PURPOSE: To determine the predictive imaging (CT and/or MR) features of brain toxoplasmosis recurrences in acquired immunodeficiency syndrome. METHODS: The imaging studies of patients with brain toxoplasmosis were retrospectively reviewed. Forty-three patients with significant decrease or disappearance of brain lesions under specific treatment on follow-up imaging examinations were included. MR examinations were performed using T2- and T1-weighted sequences, before and after intravenous administration of gadolinium-DOTA. RESULTS: A recurrence occurred in 11 (26%) of 43 cases. Ten (91%) of these 11 patients with recurrence showed focal persistent enhancement after the initial treatment of toxoplasmosis abscess. One of the 11 patients with recurrence showed no persistent enhancement; 3 patients showed persistent enhancement but had no recurrence. CONCLUSIONS: Recurrences of brain toxoplasmosis in our series correlated with persistent contrast enhancement. We hypothesize that demonstration of persistent areas of contrast enhancement after treatment for initial toxoplasmosis may be a valuable sign for identifying patients at risk for recurrence.

Haemobilia causing acute pancreatitis after percutaneous liver biopsy: diagnosis by magnetic resonance cholangiopancreatography.

Magnetic resonance cholangiopancreatography (MRCP) has received much attention as a non-invasive alternative to endoscopic retrograde cholangiopancreatography, primarily for investigation of choledocholithiasis, but also for evaluation of less common biliary anomalies. We present a case of haemobilia causing acute pancreatitis after percutaneous liver biopsy in which the diagnosis could be made clearly by MRCP, thus avoiding endoscopic retrograde cholangiopancreatography and sphincterotomy.

Assessment of vascular involvement with magnetic resonance angiography (MRA) in Pancoast syndrome.

The purpose of this study was to evaluate the diagnostic value of MRA in determining vascular involvement in bronchogenic carcinoma with Pancoast syndrome. Six patients with Pancoast syndrome were investigated preoperatively by means of MRA. Following standard spin-echo MR imaging in the axial and coronal planes, two successive two-dimensional (2D) time-of-flight acquisitions were obtained in the axial plane, the first with venous, the second with arterial presaturation. MRA data were compared to angiographic data in four cases, and to surgical findings in all six cases. MRA demonstrated displacement (n = 2) and encasement (n = 2) of subclavian and/or brachiocephalic arteries, and encasement or occlusion of subclavian and/or right brachiocephalic vein (n = 3). Close correlation between MRA, angiography and surgery was obtained. These preliminary results suggest that MRA is a noninvasive diagnostic method complementary to MR imaging for detecting vascular involvement in bronchogenic carcinoma with Pancoast syndrome.

Dynamic Gd-DOTA-enhanced MR imaging of hepatic metastases from pancreatic neuroendocrine tumors.

The aim of this study was to determine the MR imaging features of hepatic metastases from pancreatic neuroendocrine tumors (HMPNT), and to assess their enhancement characteristics on dynamic gadolinium-chelate-enhanced MR imaging. Twelve consecutive patients with pathologically proven HMPNT underwent spin-echo (SE) and dynamic gradient-recalled echo (GRE) MR imaging before and after intravenous administration of a gadolinium-chelate (gadolinium tetraazacyclododecanetetraacetic acid; Gd-DOTA). MR examinations were performed prospectively and interpreted retrospectively in consensus by two radiologists. Fifty-five HMPNT were identified in matching anatomic sections on the different MR sequences and included in the study. On T1-weighted SE images, 45 HMPNT (82%) were hypointense and 10 HMPNT (18%) were isointense. On T2-weighted SE images 55 HMPNT (100%) were hyperintense. On GRE images obtained 20 s after Gd-DOTA injection, 41 HMPNT (75%) showed slight peripheral enhancement, and 14 HMPNT (25%) showed internal enhancement. Forty-four HMPNT (80%) were heterogeneous. On GRE images obtained 4 min after Gd-DOTA injection, 37 HMPNT (67%) showed peripheral enhancement, and 18 HMPNT (33%) showed a global and almost complete enhancement. Heterogeneity of enhancement was seen in all 55 HMPNT (100%). Although HMPNT exhibit a large spectrum of MR features, early enhancement and heterogeneity on dynamic GRE MR images are suggestive features of HMPNT.

Dynamic gadolinium-DOTA-enhanced MR imaging at 1.0 T. Value in the differentiation of hepatic tumors.

A prospective study was performed to determine the value of dynamic gadolinium-tetraazacyclododecane-tetraacetic acid (Gd-DOTA)-enhanced magnetic resonance (MR) imaging at 1.0 T, using a gradient-echo (GRE) technique, in the differentiation of hepatic tumors. Fifty patients with hemangiomas (n = 14), focal nodular hyperplasia (n = 4), and malignant tumors of the liver (n = 32) underwent GRE MR imaging at 1.0 T before and repeatedly for 4 minutes after intravenous bolus administration of Gd-DOTA. The diagnoses were proved by histology or follow-up examination. On unenhanced GRE images, hemangiomas had a significantly lower tumor-to-liver contrast-to-noise (C/N) ratio (-14.74 +/- 4.49) than did the other tumors (-6.96 +/- 5.49) (p < 0.02), and benign tumors had a significantly lower C/N ratio (-12.43 +/- 5.99) than did malignant tumors (-7.29 +/- 5.71) (p < 0.05). On contrast-enhanced images, hemangiomas had a significantly lower C/N ratio (-17.60 +/- 6.90) than did the other tumors (-5.07 +/- 12.12) (p < 0.05) in the early phase. During the delayed phase, hemangiomas had a significantly higher C/N ratio (3.90 +/- 3.81) than did the other tumors (-4.85 +/- 6.51) (p < 0.01), and benign tumors had a significantly higher C/N ratio (3.21 +/- 3.65) than did malignant tumors (-5.56 +/- 6.56) (p < 0.001). Our data suggest that dynamic Gd-DOTA-enhanced MR imaging at 1.0 T provides useful information to differentiate between benign and malignant hepatic tumors, and to distinguish hemangiomas from the other tumors.

[Prognostic value of x-ray computed tomography in acute pancreatitis: contribution of the injection of intravenous contrast media]. / Valeur pronostique de la tomodensitométrie dans les pancréatites aiguës: apport de l'injection de produit de contraste intraveineux.

Thirty seven patients suffering from acute pancreatitis were explored using contrast-enhanced computed tomography (CT). The authors found a good concordance between the extension of the lesions on the initial CT examination, prognostic criteria on admission and the course of the disease. In addition, a new prognostic CT sign was reported in the early phase of parenchymal contrast perfusion, i.e. the lack of contrast-enhancement in a limited portion of the pancreas. This sign was present in 8 patients, all with severe clinical symptoms. These 8 patients showed the highest morbidity rate in the series with abscess-type complications occurring in all, compared with 24 p. 100 among the 29 other patients who did not exhibit this CT sign. Moreover, these 8 patients showed the highest mortality rate (25 p. 100 compared with 3.5 p. 100 among the other patients). An histological analysis of partial pancreatectomy specimens was performed in 7 out of the 8 patients. Devitalized pancreatic tissue, at the site of the parenchymal abnormalities on CT scan, was found in all cases. One false negative case was reported. Contrast-enhanced CT scan seems to be the most reliable method for diagnosing pancreatic necrosis during acute severe pancreatitis. It appears to be an useful prognostic predictor of morbidity. It can improve the outcome of the disease by depicting and guiding needle aspiration of a fluid collection, and/or surgery in case of clinical findings suggesting abscess formation.

[Comparison of scanners and porto-scanners, both in helical mode, for the study of hepatic metastases. Prospective study in 12 patients]. / Comparaison du scanner et du porto-scanner, tous deux en mode hélicoïdal, pour l'étude des métastases hépatiques. Etude prospective chez 12 malades.

PURPOSE: The aim of this study was to compare helical CTAP and helical CT-scan in the preoperative assessment of liver metastases. METHODS: A prospective unicentric study in 12 patients was performed with helical CTAP and helical CT-scan. All patients underwent partial hepatectomy with intraoperative palpation and sonography within 19 days (mean: 9 days). RESULTS: Examination of resected liver specimens found 38 metastases, from colorectal cancer in 36 cases. The sensitivity was 92.1% for helical CTAP and 79% for helical CT-scan. This sensitivity was 85% for helical CTAP and 60% for helical CT-scan for nodules 1 cm or less in diameter (P = 0.08). CONCLUSION: In the preoperative screening of liver metastases, helical CT-scan should be performed as the first choice examination. When hepatic lesions seem to be curable by resection based on helical dynamic CT-scan results, helical CTAP should be performed to increase the sensitivity of detection of lesions 1 cm or less in diameter.

[Congenital cystic dilatation of the common bile duct. Radio-anatomical correlations in 14 patients]. / Dilatation kystique congénitale de la voie biliaire principale. Corrélations radio-anatomiques chez 14 malades.

OBJECTIVES: The aim of this study was to compare imaging and pathological results of congenital cystic enlargement of the biliary tract to determine the best preoperative management strategy. PATIENTS AND METHODS: Radiological findings of 14 cases treated by surgery were reviewed. Radiological examinations were reviewed: ultrasound (n = 20), computed tomography (n = 13), endoscopic ultrasound (n = 8), endoscopic retrograde cholangiopancreatography (n = 10), percutaneous transhepatic cholangiography (n = 3), peroperative cholangiography (n = 11). Imaging and surgical or pathological correlations were obtained with regard to topographical type using Todani's classification, pancreatobiliary junction, and associated diseases, especially biliary malignancies (cystic wall and gallbladder). RESULTS: Cystic enlargement of the biliary tract was type Ia in 2 patients, type Ib in 1, type Ic in 4, type IVa in 5, and type IVb in 2. The radio-pathological correlation was excellent for the topographical type, and quite good for intrahepatic extension. An abnormal pancreatobiliary junction was identified in 5 cases, and visualized before surgery in I case. This junction was not opacified pre- or pre-operatively in 7 cases. Gallbladder stones were present in 2 cases, choledocal stones, in 2 cases, and intrahepatic stones in one cases, always seen on ultrasound. Malignant degeneration was present in the cyst in one case in the pathological specimen, but was not visualized by imaging procedures or peroperatively; one intrahepatic degeneration was visualized on CT and histologically proven in the surgical specimen. CONCLUSION: Ultrasound and CT allow positive diagnosis of cystic enlargement of the biliary tract, and diagnosis of intrahepatic cyst and associated diseases. The bifurcation extension and the study of pancreatobiliary junction require peroperative or retrograde cholangiography.

[Percutaneous drainage of intra-abdominal abscesses guided by real-time ultrasonography]. / Drainage percutané des abcès intra-abdominaux guidé par échographie en temps réel.

From October 1982 to October 1984, a percutaneous drainage under realtime ultrasound guidance was performed in 53 patients with abdominal abscesses. The location of the abscesses was subphrenic (23), retroperitoneal (16), and intrahepatic (14). A safe access route was found by using ultrasound and fluoroscopy in 53 out of 55 patients (96 p. 100). Percutaneous drainage failed in 8 patients and 3 of these patients died. The causes of death were: cerebral abscess (1), renal failure after surgery for correction of a duodenal fistula (1), and pancreatic abscess (1). The other five patients were cured by surgical drainage. Two complications were observed: one case each of pneumothorax and purulent peritonitis. Forty-five patients were healed by percutaneous drainage without operation. The duration of the catheter drainage was 14 days +/- 13 (m +/- 1 SD). Our results suggest that percutaneous drainage under realtime ultrasound guidance is an efficient and safe way to treat abdominal abscesses.

[Sensitivity of fine-needle puncture-biopsy in the histologic diagnosis of hepatic and pancreatic malignant tumors]. / Sensibilité de la ponction-biopsie à l'aiguille fine dans le diagnostic histologique des tumeurs malignes hépatiques et pancréatiques.

Aspiration-biopsies under ultrasound guidance, using a fine needle (external diameter inferior to 1 mm) have been performed in 61 malignant hepatic tumors (group I) and 25 pancreatic carcinomas (group II). Malignancy was diagnosed in 83 p. 100 cases; in group I, the sensitivity is 87 p. 100; the difference between hepatocellular carcinoma and liver metastases could be made in 88 p. 100 cases and in case of metastases, the site of the primitive carcinoma could be suggested in 77 p. 100 cases. In group II, the sensitivity is 72 p. 100. No complications were noted.

[Imaging of atypical cysts of the liver. Study of 26 surgically treated cases]. / Imagerie des kystes atypiques du foie. Etude de 26 lésions opérées.

OBJECTIVES: Differential diagnosis between a benign cystic hepatic lesion, biliary cyst, and a potentially malignant lesion or biliary cystadenoma, is difficult. The aim of this study was to evaluate imaging features of atypical cystic liver lesions and the role of imaging techniques in determining a specific diagnosis. METHODS: Twenty-six patients with atypical cystic hepatic lesions were included in this study. All patients underwent surgery and pathological diagnosis was atypical hepatic cyst (n = 18), biliary cystadenoma (n = 4), hydatic cyst (n = 3), and ciliated hepatic foregut cyst (n = 1). We systematically reviewed US (n = 24), CT (n = 24), and MRI (n = 8) examinations. RESULTS: Septum were seen in both cystadenomas (US: n = 4, CT: n = 1) and hepatic cysts (US: n = 11, CT: n = 6). No mural nodules were seen. A thin wall was noted in both hepatic cysts (n = 2) and cystadenomas (n = 3). The intrahepatic biliary tract was dilated in 3 patients with hepatic cysts, 1 patient with cystadenoma, and 2 patients with hydatic cysts. Calcifications were noted in 1 patient with hepatic cyst, 3 patients with hydatic cysts, and in the case of ciliated hepatic foregut cyst. We found an associated typical hepatic cyst in 77% of cases (14/18) with atypical hepatic cysts; this was never found in other atypical cystic lesions (P < 0.01). CONCLUSION: In this series, no imaging features provided a differential diagnosis of atypical hepatic cysts and cystadenomas. The presence of associated typical hepatic cysts is helpful in suggesting the diagnosis of hepatic cyst.

[Echography of tumors with multiple localizations in the urinary tract. Apropos of 2 cases]. / Echographie des tumeurs à localisations multiples de la voie urinaire excrétrice. A propos de deux observations.

The authors report 2 cases of unilateral non functioning hydronephrotic kidney, associated with homolateral bladder tumoral filling defect. Cystoscopy and histology showed a non infiltrating tumor. In one case, sonography showed a diffuse tumoral proliferation from the renal pelvis to the bladder and in the other case revealed a tumor located in the lower ureter prolapsed into the bladder. Both were non infiltrating ureteral tumors on histologic examination. These sonographic features, suggesting that the level of obstruction was not the bladder, accounted for the contradiction between urographic findings and lack of histological infiltration.

[Real time echographic study of the normal Wirsung duct. Comparison with retrograde catheterization]. / Etude du canal de Wirsung normal en échographie temps réel. Confrontation avec le cathétérisme rétrograde.

An ultrasonogram (US) of the pancreatic duct was performed in 59 patients prior to a retrograde pancreatography (ERCP). In 41 patients with normal ERCP, the pancreatic duct in the body of the pancreas was found to be on US less than 2 mm. The diameter measured on ERCP on the same portion of the pancreas was found to be 2,5 larger. On 18 abnormal ERCP, 3 patients had normal US defined by a pancreatic duct less than 2 mm in internal diameter and a normal pancreatic parenchyma. These 3 patients had mild ductal abnormalities of chronic pancreatitis on ERCP, undetectable by US. These 3 false negative cases give to a normal pancreatic US a negative predictive value of 93%. The injection of 5 normal autopsy pancreas, combined with US of the pancreatic duct, showed that neither the radiological magnification nor the pressure of injection accounted for the discrepancy between US and ERCP in the measurement of the pancreatic duct diameter. It is thought to be due to an underestimation of the internal diameter of the duct which may be related to an apparent thickening of its highly echogenic walls.

[Abdominal echography in the diagnosis and monitoring of retroperitoneal fibrosis. Apropos of 2 cases]. / Echographie abdominale dans le diagnostic et la surveillance des fibroses rétropéritonéales. A propos de 2 observations.

The authors report 2 new cases of unilateral ureteral obstruction due to a retroperitoneal fibrosis diagnosed by ultrasound examination. Retroperitoneal fibrosis presents as a hypo-echogenic, homogeneous mass, anterior to the sacral promontary, extending more or less cranially or caudally around the aorta and the iliac vessels where it gets a circumferential appearance. The complete regression of the mass has been followed by ultrasound on one patient. The authors underline the diagnostic problem posed with the R.P.F. secondary to metastatic neoplasm and discuss the place of ultrasound guided fine needle biopsy performed on one patient for the diagnosis of the affection.