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Pancreatic ductal adenocarcinoma (PDA) remains among the most challenging malignancies to treat. At diagnosis, the tumor often already extends beyond the confines of the pancreas, spreading to an extent such that primary surgery with curative intent is very rarely feasible. Considerable momentum is now being given to a treatment strategy involving neoadjuvant chemotherapy or chemotherapy and radiation therapy in patients with nonmetastatic PDA. The main advantage of this strategy is better selection of patients likely to benefit from curative-intent surgery through the achievement of negative resection margins. Patients with rapidly progressive disease are identified and are spared ineffective surgery with its attendant morbidity. Neoadjuvant therapy can downstage tumors classified as locally advanced at initial imaging studies to resectable tumors. However, the imaging study evaluation of the response to neoadjuvant therapy is extremely complex. Thus, the diagnostic performance of imaging studies is not sufficient to ensure the accurate selection of patients in whom negative-margin resection is likely to be achieved. More specifically, standard criteria for predicting vascular invasion, based on the amount of tumor-vessel contact, are not valid after neoadjuvant therapy. ©RSNA, 2018.

To prospectively determine whether dynamic contrast material-enhanced (DCE) magnetic resonance (MR) quantitative parameters correlate with fibrosis and microvascular density (MVD) in malignant and benign solid pancreatic focal lesions and nontumoral pancreatic tissue.The institutional review board approved the study; written informed consent was obtained. DCE MR was performed in 28 patients with surgically resectable focal pancreatic lesions. DCE MR quantitative parameters derived from one-compartment (OC) (transfer rate constant [K(trans)] and distribution fraction [ƒ]) and two-compartment (TC) (K(trans), tissue volume fraction occupied by extravascular extracellular space [v(i)], and tissue volume fraction occupied by vascular space [v(p)]) pharmacokinetic models were correlated with fibrosis content and MVD counts in focal lesions and nontumoral tissue (Spearman correlation coefficient [SCC]). Pharmacokinetic parameters were compared (Mann-Whitney test) between tumoral and nontumoral tissue. Diagnostic performance of DCE MR fibrosis detection was assessed (receiver operator characteristic curve analysis).K(trans) OC and K(trans) TC were significantly lower in primary malignant tumors compared with benign lesions (P = .023) and nontumoral pancreatic tissue downstream (P.001) and upstream (P = .006); ƒ and v(i) were significantly higher in primary malignant tumors compared with nontumoral pancreatic tissue downstream (P = .012 and .018, respectively). Fibrosis was correlated negatively with K(trans) OC (SCC, -0.600) and K(trans) TC (SCC, -0.564) and positively with ƒ (SCC, 0.514) and v(i) (SCC, 0.464), with P.001 (all comparisons). MVD was positively correlated with ƒ (SCC, 0.355; P = .019) and v(i) (SCC, 0.297; P = .038) but not with K(trans) OC (SCC, -0.140; P = .33) and K(trans) TC (SCC, -0.194; P = .181). Sensitivity and specificity for fibrosis detection were 65% (24 of 37) and 83% (10 of 12) for K(trans) OC (cutoff value, 0.35 min(-1)) and 76% (28 of 37) and 83% (10 of 12) for K(trans) TC (cutoff value, 0.29 min(-1)), respectively.Quantitative DCE MR parameters, derived from pharmacokinetic models in malignant and benign pancreatic solid lesions and nontumoral pancreatic tissue, were significantly correlated with fibrosis and MVD.http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11103515/-/DC1.

To determine the accuracy of 3.0-T pelvic magnetic resonance (MR) imaging in the preoperative assessment of endometriosis and to evaluate colon wall involvement after intrarectal gel administration.Institutional review board approval for this study was obtained, and each patient gave written informed consent. Forty-one consecutive patients with clinical suspicion of endometriosis underwent pelvic MR imaging at 3.0 T before surgery. Single-shot and high-spatial-resolution axial T2-weighted, sagittal fat-suppressed T2-weighted, and axial fat-suppressed T1-weighted sequences were performed. T2-weighted sequences were repeated after the rectum was filled with ultrasonographic (US) gel. Two blinded readers interpreted images independently. Image quality was scored by using a four-point scale. Detailed mapping of deep endometriosis was performed. Colon wall infiltration was graded (none, serosa, muscularis, submucosa, mucosa). MR imaging results were compared with surgical and pathologic findings. Interobserver agreement was assessed by using kappa statistics. Nonparametric tests were performed to compare colon wall infiltration scores without and those with US gel and between observers.Twenty-seven of 41 patients had deep endometriosis at surgery and histopathologic examination. Sensitivity, specificity, positive and negative predictive values, and accuracy for the diagnosis of deep endometriosis at MR imaging were 96.3% (26 of 27), 100% (14 of 14), 100% (26 of 26), 93.3% (14 of 15), and 97.6% (40 of 41), respectively. kappa Values ranged from 0.65 to 1.0, depending on the location of deep endometriosis. Colon wall infiltration assessment by both readers correlated well with pathologic findings (Spearman coefficient,0.93), although median wall involvement scores were lower at pathologic examination than for both readers both before (P = .042 and P = .011) and after (P = .079 and P = .011) intrarectal gel filling.MR imaging of the pelvis at 3.0 T is accurate in the diagnosis and staging of deep endometriosis for the preoperative assessment of patients clinically suspected of having endometriosis.

To compare duodenal filling seen at magnetic resonance (MR) pancreatography after secretin stimulation and biochemical parameters determined with the intraductal secretin test (IDST) for evaluation of pancreatic exocrine function.MR pancreatography after secretin stimulation and IDST were performed in 41 patients with chronic pancreatitis (group 1) and eight patients with other pancreatic disease (group 2). A control group (group 3, n = 28) underwent MR pancreatography after secretin stimulation only. MR pancreatograms were acquired before and every 30 seconds for 10 minutes after secretin injection. Duodenal filling was graded from least amount of filling (grade 1) to normal filling (grade 3) on the last MR pancreatogram. Pancreatic exocrine function was determined at IDST. Main pancreatic ductal diameter was compared between groups 1 and 3.All ductal diameters were significantly larger in group 1 (P.001). The maximal diameter variation after secretin stimulation was significantly higher in the control group (P =.001). Pancreatic exocrine function parameters determined at IDST were significantly lower in patients with grade 1 duodenal filling than in those with grade 2 or 3 (P.05). Maximal bicarbonate concentration alone was independently associated with all grades of duodenal filling (P =.007). The sensitivity and specificity of reduced duodenal filling for assessment of reduced pancreatic exocrine function were 72% and 87%, respectively.Duodenal filling grade determined at MR pancreatography after secretin stimulation allows specific estimation of pancreatic exocrine function.

To compare prospectively the data provided with endoscopic retrograde cholangiopancreatography (ERCP) and magnetic resonance (MR) cholangiopancreatography (MRCP) in eight patients with symptomatic choledochal cysts.Eight patients (three children, five adults) with choledochal cyst and abdominal pain underwent sequential single-shot turbo spin-echo T2-weighted MRCP and ERCP. Seven of the eight patients had relapsing pancreatitis. In three patients, a dynamic MR examination was performed after secretin stimulation of exocrine pancreatic function.A complete correlation was observed between ERCP and MRCP for defining the anatomic characteristics of the cyst (seven type I cysts, one type IV cyst) and the presence of an abnormal pancreaticobiliary junction (PBJ) (six patients) with a long common channel. Of the seven patients with acute pancreatitis, six had an abnormal PBJ and one had common bile duct (CBD) stones with a normal ductal union evidenced with both techniques. In two patients, dynamic MRCP demonstrated preferential filling of the gallbladder and the CBD after secretin injection, whereas normal duodenal filling was observed in another patient without a junctional abnormality.MRCP provides information equivalent to that provided with ERCP, without potential complications, for the preoperative assessment of choledochal cysts. Dynamic secretin-stimulated MRCP studies might help better understand the pathophysiologic characteristics of this entity.

Plain radiographs obtained in 25 patients with acute anterior cruciate ligament (ACL) tears detected with magnetic resonance imaging were retrospectively evaluated to identify associated bone lesions. Fracture of the posterior part of the lateral tibial plateau (LTP) was seen in 11 patients, impacted fracture of the lateral femoral condyle (LFC) in two, lateral tibial rim fracture (Segond fracture) in three, and avulsion fracture of the tibial attachment of the ACL in two. The latter three fractures have been associated with an ACL tear. Conversely, fractures of the posterior part of the LTP have not been associated with ACL tear and are recognizable on plain radiographs. Impaction of the LFC on the LTP and avulsion of the posterior tibial capsular junction may account for the association of the fracture of the LTP with the acute ACL tear. This type of fracture represents the most frequent indirect sign of ACL tear seen on plain radiographs.

Two cases of fetal perirenal uriniferous pseudocyst were diagnosed in utero with ultrasound studies. The perirenal collections resolved spontaneously in utero. Follow-up examination showed growth impairment of the affected kidney. At birth, no renal function was demonstrated in one case and only slight function in the other case. Pathologic examination showed a highly dysplastic kidney with extravasated urine in the case in which surgery was performed. Some hypodysplastic kidneys apparently result from acute in utero obstruction with secondary pyelocalyceal rupture. Renal dysplasia could render the kidney more vulnerable to such phenomena.