Philipp Wiggermann

Apparent diffusion coefficient measurements of the pancreas, pancreas carcinoma, and mass-forming focal pancreatitis

Background Mass-forming focal pancreatitis (FP) may mimic pancreatic cancer (PC) on magnetic resonance (MR) imaging, and the preoperative differential diagnosis is often difficult. Recently, the usefulness of diffusion-weighted imaging (DWI) in the diagnosis of pancreatic cancer has been reported in several studies. Purpose To investigate if apparent diffusion coefficient (ADC) measurements based on diffusion-weighted echo-planar imaging (DW-EPI) may distinguish between normal pancreas parenchyma, mass-forming focal pancreatitis, and pancreas carcinoma. Material and Methods MRI was performed on 64 patients: 24 with pancreas carcinoma (PC), 20 with mass-forming focal pancreatitis (FP), three patients with other focal pancreatic disease as well as 17 controls without any known pancreatic disease. Diffusion-weighted sequence with ADC maps and T2-weighted sequence for anatomical information was performed. Apparent diffusion coefficient (ADC) maps were automatically created and analyzed using a dedicated user interface. In the group with pancreas disease the abnormal parenchyma was detected by using T1- and T2-weighted images and the region of interest (ROI) was transferred exactly to the ADC map and the coefficients were registered. In the control group the ROI was set to the head of the pancreas followed by a similar registration of the ADCs. Results ADC values for mass-forming FP and PC differed significantly from ADC values for normal pancreas parenchyma (P = 0.001/P = 0.002). Mean ADC values for mass-forming FP were 0.69 ± 0.18 × 10−3 mm2/s. ADC values for PC were 0.78 ± 0.11 × 10−3 mm2/s, compared to ADC values of 0.17 ± 0.06 × 10−3 mm2/s in the control group. However there was no significant difference in ADCs between PC and mass-forming FP (P = 0.15). Conclusion ADC measurements clearly differentiated between normal pancreatic tissue and abnormal pancreas parenchyma (PC and mass-forming FP). However there is an overlap in values of PC and mass-forming FP, with the consequent problem of their correct identification.

Transarterial Chemoembolization of Child-A hepatocellular carcinoma: Drug-eluting bead TACE (DEB TACE) vs. TACE with Cisplatin/Lipiodol (cTACE)

BACKGROUND This study is an outcome evaluation of the Drug-Eluting-Bead-Chemoembolization (DEB TACE) compared to conventional TACE (cTACE) with Cisplation and Lipiodol in patients with hepatocellular carcinoma (HCC) and Child-Pugh A Cirrhosis. MATERIAL/METHODS A comparison of interventional therapy with either cTACE or DEB-TACE of 22 patients each with unresectable HCC and Child-Pugh A Cirrhosis was carried out. A comparison of therapy-associated complications, tumour response rates and mean survival was performed. Tumour response was evaluated in accordance with the European Association for the Study of the Liver (EASL) response criteria by two radiologists in consensus reading. RESULTS The choice of TACE procedure (DEB TACE/cTACE) had no significant impact on therapy-associated complications. Objective Response (OR, complete response + partial response) for DEB-TACE was 22.7%; a further 68.2% was stable disease (SD). The respective response rates for the cTACE were OR 22.7 and SD 31.8%. Thus disease control was not significantly increased for DEB TACE (p=0.066). After DEB-TACE mean survival was significantly prolonged with 651 ± 76 days vs. 414 ± 43 days for cTACE (p=0.01). CONCLUSIONS Associated with a similar safety profile and an at least comparable tumour response, the DEB-TACE is a method of treatment for HCC that has the potential to improve mean survival compared to cTACE with Cisplatin/Lipiodol.

Dynamic magnetic resonance defecography in 10 asymptomatic volunteers

AIM Evaluation of the wide range of normal findings in asymptomatic women undergoing dynamic magnetic resonance (MR) defecography. METHODS MR defecography of 10 healthy female volunteers (median age: 31 years) without previous pregnancies or history of surgery were evaluated. The rectum was filled with 180 mL gadolinium ultrasound gel mixture. MR defecography was performed in the supine position. The pelvic floor was visualized with a dynamic T2-weighted sagittal plane where all relevant pelvic floor organs were acquired during defecation. The volunteers were instructed to relax and then to perform straining maneuvers to empty the rectum. The pubococcygeal line (PCGL) was used as the line of reference. The movement of pelvic floor organs was measured as the vertical distance to this reference line. Data were recorded in the resting position as well as during the defecation process with maximal straining. Examinations were performed and evaluated by two experienced abdominal radiologists without knowledge of patient history. RESULTS Average position of the anorectal junction was located at -5.3 mm at rest and -29.9 mm during straining. The anorectal angle widened significantly from 93° at rest to 109° during defecation. A rectocele was diagnosed in eight out of 10 volunteers showing an average diameter of 25.9 mm. The bladder base was located at a position of +23 mm at rest and descended to -8.1 mm during defecation in relation to the PCGL. The bladder base moved below the PCGL in six out of 10 volunteers, which was formally defined as a cystocele. The uterocervical junction was located at an average level of +43.1 mm at rest and at +7.9 mm during straining. The uterocervical junction of three volunteers fell below the PCGL; described formally as uterocervical prolapse. CONCLUSION Based on the range of standard values in asymptomatic volunteers, MR defecography values for pathological changes have to be re-evaluated.

Percutaneous Ablation of Hepatic Tumors Using Irreversible Electroporation: A Prospective Safety and Midterm Efficacy Study in 34 Patients.

PURPOSE To evaluate the safety and efficacy of percutaneous irreversible electroporation (IRE) of primary and secondary liver cancer unsuitable for resection or thermal ablation. MATERIALS AND METHODS In this prospective, single-center study, 65 malignant liver tumors (hepatocellular carcinoma, n = 33; cholangiocellular carcinoma, n = 5; colorectal cancer metastasis, n = 22; neuroendocrine cancer metastasis, n = 3; testicular cancer metastasis, n = 2) in 34 patients (27 men, 7 women; mean age, 59.4 y ± 11.2) were treated. Local recurrence-free survival (LRFS) according to the Kaplan-Meier method was evaluated after a median follow-up of 13.9 months. RESULTS Median tumor diameter was 2.4 cm ± 1.4 (range, 0.2-7.1 cm). Of 65 tumors, 12 (18.5%) required retreatment because of incomplete ablation (n = 3) or early local recurrence (n = 9). LRFS at 3, 6, and 12 months was 87.4%, 79.8%, and 74.8%. The median time to progressive disease according to modified Response Evaluation Criteria In Solid Tumors was 15.6 months. Overall complication rate was 27.5% with six major complications and eight minor complications. Major complications included diffuse intraperitonal bleeding (n = 1), partial thrombosis of the portal vein (n = 1), and liver abscesses (n = 4). Minor complications were liver hematomas (n = 6) and clinically inapparent pneumothoraces (n = 2). CONCLUSIONS IRE showed promising results regarding therapeutic efficacy for the percutaneous treatment of liver tumors; however, significant concerns remain regarding its safety.

Factors associated with short-term local recurrence of liver cancer after percutaneous ablation using irreversible electroporation: a prospective single-center study.

PURPOSE To evaluate the risk factors associated with short-term local recurrence of malignant liver lesions after irreversible electroporation (IRE). MATERIALS AND METHODS Thirty-nine consecutive patients (79 malignant liver lesions) were treated with IRE, of whom 14 were excluded from the analysis (including 12 without 6 mo of follow-up and two with incomplete ablation). The remaining 25 patients (aged 59.4 y ± 11.2) had 48 malignant liver lesions, including 22 hepatocellular carcinomas (HCCs), six cholangiocellular carcinomas, and 20 metastatic liver cancers. Multivariate analyses were used to evaluate the associations of risk factors with early recurrence. The characteristics of patients, lesions, and IRE procedures were assessed by logistic regression. RESULTS Fourteen of the 48 treated lesions (29.2%) showed early local recurrence after 6 months. Tumor volume (< 5 cm(3) vs ≥ 5 cm(3); P = .022) and underlying disease type (HCC, cholangiocellular carcinoma, or metastatic disease; P = .023) were independently associated with early local recurrence. However, distances to the surrounding portal veins (< 0.5 cm vs ≥ 0.5 cm; P = .810), hepatic veins (P = .170), hepatic arteries (P = .761), and bile ducts (P = .226) were not significantly associated with local recurrence. CONCLUSIONS Because short distances to the surrounding vessels were not associated with early local recurrence, percutaneous IRE might provide an alternative treatment option for perivascular tumors. However, patients with larger tumor volumes appeared to be poor candidates for percutaneous IRE. Regarding the different types of treated lesions, patients with HCC had significantly better outcomes.

Intraoperative high resolution linear contrast enhanced ultrasound (IOUS) for detection of microvascularization of malignant liver lesions before surgery or radiofrequeny ablation

OBJECTIVE The aim of this study was to evaluate the value of linear contrast enhanced intraoperative ultrasound (CE-IOUS) to improve detection of malign liver tumors lesions before surgery or radiofrequency ablation (RFA). MATERIALS AND METHODS 50 patients were included for surgery of malignant liver tumors (mean age 61 years (19-80); male n = 35, female n = 15), suffering from HCC (n = 15), colorectal liver-metastasis (n = 28), CCC (n = 2) or other malign liver lesions (n = 5). Preoperative CE-CT (n = 38), CE-MRI (n = 23) or PET-CT (n = 8) confirmed hepatic tumor manifestation. Before undergoing surgery, intraoperative conventional (IOUS) as well as CE-IOUS were performed by one experienced examiner in all cases using multifrequency linear probes (6-9 MHz, 6-15 MHz; LOGIQ E9; GE Healthcare, Milwaukee, WI, USA). CE-IOUS was performed after bolus injection of 5 ml up to 15 ml SonoVue(®) (Bracco Imaging SpA, Milan, Italy). Digitally stored images of CE-IOUS were compared with fundamental B-Scan and preoperative imaging (CE-CT, CE-MRI and PET-CET). RESULTS In 28 of 50 patients (56%), additional lesions were found using CE-IOUS (mean tumor size 8 mm, range 4-12 mm). This resulted in a change of surgical strategy or the intraoperative application of RFA in 27 patients (54%). Modification of therapy due to additionally found liver lesions was statistically significant (p < 0.05). Comparing conventional IOUS and CE-IOUS, 14 additional lesions in 10 patients were seen by CE-IOUS. All lesions seen in B-scan could also be detected with CE-IOUS. SUMMARY This is the first study using contrast-enhanced ultrasound with high resolution linear probes for intraoperative detection of malignant liver lesions. Compared to preoperative imaging and also conventional IOUS more than 50% additional lesions were found leading to therapeutic consequences of patients. A recently started prospective study has to show whether these changes in the surgical or interventional therapy will influence morbidity, mortality and especially the recurrence rate.

First results of endocavity evaluation of the microvascularization of malignant prostate tumors using contrast enhanced ultrasound (CEUS) including perfusion analysis: First results

AIM Detection of prostate cancer lesions using transrectal contrast enhanced ultrasound (CEUS) of the prostate utilizing quantitative perfusion analysis. METHOD 20 patients (mean age 63 years, 47-71) with biopsy proven prostate cancer underwent transrectal ultrasound (TRUS) prior to radical prostatectomy by 2 experienced examiners using a multifrequency endocavitary probe (5-9 MHZ, LOGIQ E9, GE Healthcare, Chalfont St Giles, UK) to detect cancer-suspect lesions. CEUS was performed dynamically up to 3 Min after bolus injections of 2.4 ml SonoVue® (BRACCO, Italy). Digital cine loops were analyzed by an independent blinded examiner using perfusion quantification software with colour-coded parametric images in order to define suspect regions based on the perfusion-related parameters early wash in rate (WIR), mean transit time (MTT) and rise time (RT). The results of CEUS perfusion analysis were compared with the histopathology after surgery, obtained from whole mount sections. RESULTS After prostatectomy and histopathology, 34 prostate cancer foci were found in 20 patients. In 30/34 cases an early enhancement within the tumor was detected by CEUS perfusion analysis without early wash out. By evaluating the MTT and RT tumor detection was possible in 29/34 and 25/34 cases. The highest detection rate of prostate cancers was obtained by analysis of early contrast enhancement (priot to the normal prostate parenchyma), with a sensitivity of 88%, specificity 100%, NPP 60%, PPV 90%, in clinically suspicious cases with good correlation to the postoperative histopathological findings (r = 0.728). CONCLUSION This pilot study demonstrates, that quantitaive analysis of perfusion parameters obtained with transrectal CEUS could be helpful for characterization of neoplastic microcirculation of prostate cancer, for preoperative localization of cancer-suspect areas and for therapy guidance and management.

Dynamic evaluation and quantification of microvascularization during degradable starch microspheres transarterial Chemoembolisation (DSM-TACE) of HCC lesions using contrast enhanced ultrasound (CEUS): A feasibility study

PURPOSE To evaluate the time dependent changes of microcirculation in hepatocellular carcinoma (HCC) lesions during degradable starch microsphere (DSM)-TACE using contrast enhanced ultrasound (CEUS). MATERIALS AND METHODS A total of 48 CEUS examinations were performed (1-5 MHz, convex probe) in 6 selected patients who underwent DSM-TACE with EmboCept®S for the treatment of HCC lesions. I.v. application of ultrasound contrast media was performed before and 24 hours post embolization. In addition i.a. contrast application was performed via the angiographic catheter right before and after the embolization and during a follow up time of 2 hours every 30 minutes. The capillary circulation of the treated HCC lesions was analyzed and quantitative perfusion analysis was performed using a perfusion software by two experienced radiologists in consensus. RESULTS A significantly reduced microvascularization was seen right after DSM-TACE in all cases using CEUS. The reduction of PEAK, RBV (regional blood volume) and RBF (regional blood flow) compared to preembolization values was highly significant. Mean PEAK was 34.3 ± 13.1 prior to embolization and 9.4 ± 9.1 post embolization (p < 0.001). Mean RBV was 446.5 ± 122.4 prior to embolization and 70.9 ± 23.8 post embolization (p < 0.001). The corresponding figures for RBF were 34.7 ± 13.4 prior- and 4.8 ± 3.4 post embolization (p < 0.001). During follow up a stepwise revascularization of the lesions was documented: 90 minutes post embolization perfusion parameters were not significantly different from prae-embolization values. CONCLUSION In this feasibility study, capillary perfusion quantification of HCC lesions after DSM-TACE could be demonstrated using CEUS. Using quantitative perfusion analysis it was possible to quantify the transient embolizing effect of DSM-TACE.

Evaluation of the microcirculation of hepatocellular carcinomas using contrast-enhanced ultrasound with intraarterial and intravenous contrast application during transarterial chemoembolization with drug-eluting beads (DEB-TACE): preliminary data.

PURPOSE The objective was the evaluation of microcirculation in hepatocellular carcinomas (HCC) in vivo by dynamic contrast-enhanced ultrasound (CEUS) after intravenous (i.v.) and intraarterial (i.a.) application of contrast agent during transarterial chemoembolization (TACE) using drug-eluting beads (DEB). PATIENTS AND METHODS Eleven patients with HCC underwent CEUS directly before and immediately after DEB-TACE. The sonographic contrast agent was injected through the microcatheter intraarterially and intravenously. The grade of hypervascularization was evaluated before Bead application. The percentage of devascularization after Bead application was calculated and quantitative devascularization was carried out using time intensity curves (TIC). These results were compared to postinterventional angiography after Bead application and postprocedural computed tomography. RESULTS The hypervascularization of HCC was marginal improved after i.a. contrast application compared to i.v. application (p = 0.163). The reduction of vascularization after Bead application correlated significant between i.a. and i.v. contrast application (p = 0.007) and decreased significant using TIC analysis (p = 0.003). Postinterventional angiography related with CEUS after i.a. sonographic contrast agent application. Extrahepatic tumor-feeding arteries were detected by a mismatch between i.a. and i.v. CEUS in one case. CONCLUSION Quantification of the reduction of microvascularization using TIC analysis may be a valuable periinterventional tool during DEB-TACE. Intraprocedural CEUS with i.a. and i.v. ultrasound contrast agent injection may help finding extrahepatic tumor-feeding arteries.

Real-time elastography of hepatic thermal lesions in vitro: histopathological correlation.

PURPOSE To evaluate the reliability of elastography, a new ultrasonographic method, for delineating thermal lesion boundaries in porcine liver tissue by comparing lesion dimensions determined by real-time elastography with the findings at gross pathology. MATERIALS AND METHODS A total of 15 thermal lesions with diameters ranging from 17 to 60 mm were created using radiofrequency ablation (RFA). Color-coded elastography was performed by one experienced examiner, using a 6 - 15 MHz high frequency linear transducer (LOGIQ E9, GE). Lesions were examined using B-mode and real-time elastography (RTE). Lesion detection, delineation and size were assessed using B-mode and RTE immediately after each thermal ablation ( < 5 min). Measurements of the sections representing the same image plane used for elastography were taken during pathologic examination and compared to the measurements obtained from the elastograms. RESULTS In our sample a statistically significant correlation in vitro between RTE and pathological measurements with respect to the lesions principal axis and area (r2 = 0.9338 long axis, r2 = 0.8998 short axis and r2 = 0.9676 area) was found. Overall, elastography slightly underestimated the lesion size, as judged by the digitalized pathologic images. CONCLUSION These results support that RTE outperforms conventional B-mode ultrasound and could potentially be used for the routine assessment of thermal therapies.