Manganese (II) N,N'-dipyridoxylethylenediamine-N,N'-diacetate-5,5'-bis(phosphate) (DPDP) was evaluated as a contrast agent for magnetic resonance (MR) imaging (1.5 T) of focal liver lesions in 40 patients. Doses of 5 and 10 mumol/kg were administered intravenously. Mn-DPDP-enhanced T1-weighted images were compared quantitatively and subjectively with standard T1- and T2-weighted nonenhanced images. Use of Mn-DPDP resulted in a statistically significant increase in signal intensity of liver parenchyma in T1-weighted images at both doses. No enhancement was seen in metastases, cholangiocarcinomas, or lymphomas, while all hepatocellular carcinomas were enhanced. Enhancement was seen in focal nodular hyperplasia and in regenerative nodules. The lesion-to-liver contrast in Mn-DPDP-enhanced gradient-recalled-echo images was superior to that of all precontrast images (P less than .01). The number of nonenhancing malignant liver lesions detected in spin-echo (SE) images was increased (272 in T2-weighted SE images vs 390 in T1-weighted Mn-DPDP-enhanced SE images). Image interpretation (eg, visualization and demarcation of the lesions) was markedly better in Mn-DPDP-enhanced images than in all precontrast images (P less than .001).

The recently developed paramagnetic hepatobiliary contrast agent manganese dipyridoxyl diphosphate (DPDP) was evaluated in eight patients. Pathologic diagnoses included five hepatocellular carcinomas, two cirrhoses, and one focal nodular hyperplasia. T1-weighted spin-echo and gradient-echo images were obtained after intravenous injection of 5 or 10 mumol/kg Mn-DPDP; these were compared with unenhanced T1-weighted spin-echo and gradient-echo images and T2-weighted spin-echo images. In all patients with lesions of hepatocellular origin, focal areas of increased enhancement were seen in the lesions after administration of Mn-DPDP. In the cirrhotic livers, these areas corresponded to foci of hepatic regeneration. In all patients, the signal-to-noise ratio in normal liver tissue increased significantly after injection of Mn-DPDP. Signal intensity in the six primary liver tumors was further increased, so that they appeared hyperintense relative to surrounding liver tissue on all T1-weighted images. Conspicuity and demarcation of all lesions were improved on Mn-DPDP-enhanced images.

In an open prospective study the tolerance and diagnostic value of the new hepatobiliary contrast agent Mn-DPDP in MR imaging was evaluated in 20 patients suspected of having focal liver lesions. T1- and T2-weighted spin-echo sequences and T1-weighted gradient-echo sequences were obtained before and after intravenous application of Mn-DPDP. In all patients the signal to noise (S/N) values of normal liver tissue increased significantly after application of Mn-DPDP. All focal lesions could be better localized and differentiated due to increased contrast to noise ratios of lesion to liver. Pathological examination revealed in 14 patients malignant and in 5 patients benign liver lesions; one patient had no pathological findings. In metastatic disease of the liver 25-120% more lesions could be detected in MRI after Mn-DPDP-application, compared with the unenhanced images. In 5 patients the lesions showed significant enhancement of Mn-DPDP (2 cirrhotic nodules, 2 hepatocellular carcinomas, 1 focal nodular hyperplasia). Our preliminary results indicate that Mn-DPDP is a well-tolerated contrast agent useful for the detection and differentiation of liver lesions in MR imaging.

Generalised lymphangiomatosis is a rare benign congenital abnormality of the lymphatic vessels with a complex pattern. 3 patients with different types of lymphangiomatosis were studied by MRT and MRA and histopathologically. All patients had multiple organ involvement in the abdomen, the skeleton and the skull. The basis in each case was lymphangiomatosis of capillary-cavernous, cystic or cavernous type. The results of MRT and MRA in diagnosing splenic, vascular and skeletal changes correlated accurately with operative findings and with the histopathological classification. In summary, MRT combined with MRA and using paramagnetic contrast media are the diagnostic methods of choice for the investigation of generalised lymphangiomatosis with multiple organ involvement.

Background Concomitant cholecysto- and choledocholithiasis is common. Standard treatments are ERCP followed by cholecystectomy or laparoendoscopic rendez-vous. ERCP has drawbacks such as post-ERCP-pancreatitis (5%) or -bleeding (5%) and potentially more than one intervention to address common bile duct (CBD) stones. Safety and feasibility of an intraoperative antegrade transcystic single-stage approach during cholecystectomy with papillary balloon dilation and pushing of concrements to the duodenum has not been evaluated prospectively. Aims The aim of the study was to evaluate this procedure regarding safety and stone clearance rate. Methods Prospective single centre intervention study. 80 consecutive patients admitted to our institution between 1/2021 and 4/2022 with suspected or confirmed choledocholithiasis (stones ≤ 6 mm) and known cholecystolithiasis were included. Success of the procedure was defined as lack of filling defects in the intraoperative control cholangiography and absence of symptoms at 6 weeks follow up. Simon's two stage design was used to determine sample size. Aiming for 95% positive outcomes (no pancreatitis) and tolerating at most 15% negative outcomes, power analysis revealed 57 participants (80% power, alpha 0.05). Results 57/80 patients (71%) fulfilled the inclusion criteria. While there was no postoperative pancreatitis, 2 patients (3.5%) had asymptomatic amylasemia 4h postoperatively. Stone clearance was achieved in 54 patients (94%). The main reason for failed stone clearance was the inability to push the guide wire along the concrement into the duodenum. Median number of CBD-stones was 1 (1-6). Median stone diameter was 4 mm (0.1-6 mm). Median intervention time was 28 min (14-129 min). Conclusions Intraoperative bile duct clearance by balloon dilation of the sphincter Oddi appears to be safe and highly feasible. Its overall superiority to the current standards requires evaluation in a randomized controlled trial.