Pancreatoduodenal junction: review of anatomy and pathologic conditions.

INTRODUCTION: The pancreatoduodenal junction is a small anatomic area where pathologic processes involving the distal bile duct, duodenum, pancreatic head, ampulla de Vater, and retroperitoneum converge. Differential diagnosis includes a spectrum of entities that ranges from anatomical variants to malignancies. PURPOSE: The aim of this paper was to review the anatomy and different pathologic conditions, whether tumoral, inflammatory, or congenital in origin, in this specific area that involves the pancreatic head, duodenum, duodenal ampulla, distal pancreatobiliary tract junction, and retroperitoneum. METHODS: Computed tomography (CT) and magnetic resonance (MR) help us to identify specific radiologic signs that allow to divide the pancreatic-duodenal junction abnormalities into three cathegories: (1) normal variants and congenital anomalies (pancreas divisum, santorinicele, annular pancreas,duodenal duplication cyst, choledocal cyst,...); (2) acquired non-tumoral: traumatic, iatrogenic, inflammatory (duodenal hematoma, duodenal iatrogenic perforation, groove pancreatitis, gastroduodenal artery pseudoaneurysm,...); (3) tumoral (pancreatic head adenocarcinoma, periampullary tumors, neuroendocrine pancreatic tumors, duodenal adenocarcinoma,...). The images illustrate morphologic aspects of these entities. RESULTS AND CONCLUSIONS: CT and MR are the most appropiate imaging modalities to evaluate pancreatoduodenal junction. Knowing the imaging features is crucial to reach the right diagnosis and treatment of the different entities that involve this anatomic area.

Thymidylate synthase germline polymorphisms in rectal cancer patients treated with neoadjuvant chemoradiotherapy based on 5-fluorouracil.

PURPOSE: Chemoradiotherapy using 5-fluorouracil has shown to be effective treatment for rectal cancer. Thymidylate synthase (TS) is an important target enzyme for the fluoropyrimidines. However, the predictive role of TS levels in early stage rectal cancer is not yet well understood. We analyzed the value of TS gene polymorphisms as a predictive marker in patients with stage II and III rectal cancer treated with preoperative concomitant radiotherapy and fluoropyrimidine-based chemotherapy. METHODS AND MATERIALS: Between 1998 and 2007, blood samples were obtained from 51 patients with stage II/III rectal cancer. Forty patients were T2-3 (78%), 11 were T4 (22%), and 59% were N+. DNA was extracted from peripheral blood, and the genotypes were analyzed using PCR-restriction fragment length polymorphism and automated sequencing techniques. RESULTS: The *3/*3 thymidylate synthase genotype was associated with a higher response rate (pathological complete remission and microfoci residual tumor; 61 vs. 22% in *2/*2 and *2/*3; P = 0.013). In the multivariate analysis, the *3/*3 thymidylate synthase genotype was also an independent prognostic factor for better survival (P < 0.05). CONCLUSIONS: The thymidylate synthase genotype might help to identify patients with stage II/III rectal cancer who could benefit from pre- and postoperative fluorouracil-based chemotherapy.

In search of the ideal method in perforator mapping: noncontrast magnetic resonance imaging.

A reliable method for precise identification of the dominant perforator would be extremely valuable in perforator flap surgery. During the past 5 years, multidetector-row computed tomography has demonstrated excellent results in preoperative planning of abdominal free flap breast reconstruction, significantly reducing operative time and complications. The main drawbacks of computed tomography are unnecessary radiation to the patient and possible allergic reactions to intravenous contrast material. To circumvent these limitations, we performed noncontrast magnetic resonance imaging for abdominal perforator mapping. The aim of our study was to assess the accuracy and reliability of this technique in preoperative planning of breast reconstruction with deep inferior epigastric artery perforator flaps. From October 2007 to February 2009, noncontrast magnetic resonance preoperative mapping was performed in 56 female patients who underwent breast reconstruction after mastectomy with deep inferior epigastric artery perforator flaps. Imaging results were compared with the intraoperative clinical findings in all patients. Preoperative magnetic resonance imaging without the contrast showed no false-positive or false-negative results. In all cases, the perforator chosen as dominant according to magnetic resonance images corresponded with the perforator chosen intraoperatively (100% predictive value). Preoperative imaging techniques make perforator flap surgery safer for the patient. Noncontrast magnetic resonance imaging provides reliable information on the vascular anatomy of the abdominal wall, facilitating selection of the most appropriate deep inferior epigastric artery dominant perforator. It avoids radiation to the patient and also the need for intravenous contrast medium as required for the multidetector-row computed tomography. In our opinion, noncontrast magnetic resonance imaging is an ideal method for preoperative planning of breast reconstruction with deep inferior epigastric artery perforator flaps.

MDCT in the preoperative planning of abdominal perforator surgery for postmastectomy breast reconstruction.

OBJECTIVE: This study aimed to evaluate the utility of MDCT in planning abdominal perforator surgery for breast reconstruction in patients who have undergone mastectomy. SUBJECTS AND METHODS: One hundred twenty-six consecutive patients scheduled for postmastectomy breast reconstruction using deep inferior epigastric perforator flaps underwent MDCT. The images were evaluated to identify, characterize, and map the dominant musculocutaneous perforator vessels of the deep inferior epigastric artery. In the first 36 patients, we compared the intraoperative findings with the preoperative MDCT findings. In the latter 90 patients, the dominant perforator vessels were directly selected on the basis of MDCT findings. RESULTS: We found an exact correlation between the intraoperative and radiologic findings in the first 36 cases. In the following 90 cases, the average operating time saved per patient was 1 hour 40 minutes and there was a significant reduction in postsurgical complications. The preoperative evaluation by MDCT confirmed the wide range of variability in the vascular anatomy of the abdominal wall previously described in anatomic studies. CONCLUSION: MDCT provides valuable information before surgery about the arterial anatomy of the inferior abdominal wall. It enables accurate identification of the most suitable dominant perforator vessel and makes surgical perforator flap procedures for breast reconstruction faster and safer.

Síndrome de Carney / Carney Syndrome

En 1977, Carney describió un síndrome inusual caracterizado por la aparición, concomitante o sucesiva, de tres tumores diferentes: leiomiosarcoma gástrico, condroma pulmonar y paraganglioma extraadrenal funcionante. La presencia de dos de los tumores es suficiente para establecer el diagnóstico, y es excepcional que los pacientes manifiesten la tríada completa. Sus principales características clínicas son la alta incidencia en pacientes jóvenes, especialmente mujeres, la multicentricidad de los tumores y la escasa sintomatología local tumoral, particularmente del sarcoma gástrico. Presentamos el caso de un síndrome de Carney en un varón de 55 años con un tumor del estroma gastrointestinal y condromas pulmonares múltiples aparecidos de forma sucesiva, en un intervalo de 18 años (AU)

Pancreatic duct after pancreatoduodenectomy: morphologic and functional evaluation with secretin-stimulated MR pancreatography.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of secretin-enhanced MR pancreatography in evaluating morphologic changes and pancreatic function after pancreatoduodenectomy. SUBJECTS AND METHODS: Twenty patients who underwent pancreatoduodenectomy were evaluated with secretin MR pancreatography. Single-shot fast spin-echo T2-weighted dynamic MR pancreatograms were obtained before and every minute for 10 min after secretin injection. Image analysis included image quality for the visualization of the pancreatic duct and morphologic features of the pancreatic duct (side branches, ductal narrowing, irregular ductal contour, and patency of the anastomotic site). Pancreatic function was assessed using the Van de Kamer method and the fasting blood glucose and oral glucose tolerance tests. Jejunal filling was graded from the lowest amount of filling (grade 1) to normal filling (grade 3) on the last MR pancreatogram. RESULTS: The visualization of the main pancreatic duct was significantly improved with dynamic MR pancreatography (p < 0.05). The anastomotic site was visualized in 14 patients (70%) on MR pancreatography after secretin administration (p < 0.05). No statistically significant improvement in other morphologic data was seen after secretin administration. The sensitivity, specificity, positive predictive value, and negative predictive value of reduced jejunal filling (grade 1) for assessment of reduced pancreatic exocrine function were 92%, 71%, 85%, and 83%, respectively. The relation between reduced jejunal filling (grade 1) and diabetes was statistically significant (p < 0.05). CONCLUSION: The administration of secretin improves visualization of the pancreatic ducts and helps in the evaluation of remnant pancreatic function after pancreatoduodenectomy.

Extensor mechanism of the fingers: MR imaging-anatomic correlation.

Extension of the fingers is a complex function carried out by simultaneous action of extrinsic and intrinsic muscles, as well as retinacular structures in the dorsum of the wrist, hand, and fingers that support and coordinate the action of the muscles. The extensor mechanism of the fingers is divided into topographic zones, which extend from the forearm to the distal phalanx. Magnetic resonance (MR) imaging shows in detail the musculotendinous and retinacular structures of the extensor apparatus. In the different extensor zones, MR imaging findings are similar to those seen macroscopically in anatomic sections. Understanding of and familiarity with the extensor anatomy of the hand and fingers by the radiologist is crucial for better assessment of pathologic conditions with MR imaging and optimization of this modality as a diagnostic tool. Extensor tendon injuries and tenosynovitis represent clinical situations in which knowledge of this anatomy is useful for the clinical radiologist.

MR imaging of ligament and tendon injuries of the fingers.

Magnetic resonance (MR) imaging can provide important information for diagnosis and evaluation of soft-tissue trauma in the fingers. An optimal imaging technique should include proper positioning, dedicated surface coils, and specific protocols for the suspected abnormalities. Familiarity with the fine anatomy of the normal finger is crucial for identifying pathologic entities. MR imaging is a powerful method for evaluating acute and chronic lesions of the stabilizing articular elements (volar plate and collateral ligaments) of the fingers and thumbs, particularly in the frequently affected proximal interphalangeal and metacarpophalangeal joints. As in other body regions, MR imaging is also useful for depicting traumatic conditions of the extensor and flexor tendons, including injuries to the pulley system. In general, normal ligaments and tendons have low signal intensity on MR images, whereas disruption manifests as increased signal intensity. Radiologists need to understand the full spectrum of finger abnormalities and associated MR imaging findings.