Abstract Introduction Early hepatic artery thrombosis remains one of the major causes of graft failure and mortality in liver transplant recipients. It is the most frequent severe vascular ...complication after orthotopic liver transplantation (OLT) accounting for >50% of all arterial complications. Most patients need to be considered for urgent liver retransplantation. Materials and Methods Among 911 OLTs in 862 from 1989 to 2011, we observed 23 cases (2.6%) of acute early hepatic artery thrombosis. Seventeen patients were qualified immediately for liver retransplantation, and 6 underwent endovascular therapies, including intra-arterial heparin infusion or percutaneous transluminal angioplasty with stent placement. Results Among patients who were assigned to early liver retransplantation, 11/17 survived with 3 succumbling due to postoperative complications, including 1 portal vein thrombosis, and 3 succumbling on the waiting list. All patients who underwent endovascular therapy survived with an excellent result obtained in 1 who underwent treatment <24 hours after arterial thrombosis. In 2 patients we achieved a satisfactory result not requiring retransplantation, but 3 patients assigned to endovascular treatment >24 hours after arterial thrombosis needed to be reassigned to liver retransplantation because of poor results of endovascular treatment. Conclusions Endovascular treatment efforts should be made to rescue liver grafts through urgent revascularization depending on the patient's condition and the interventional expertise at the transplant center, reserving the option of retransplantation for graft failure or severe dysfunction.
Published data regarding lymphangiomatous cysts of the adrenal glands (also known as adrenal cystic lymphangiomas) are limited to case reports and a few small case series. We analyzed the ...clinicopathologic features and histomorphologic spectrum of 37 cases of adrenal cystic lymphangiomatous lesions. There were 26 females and 11 males ranging from 12 to 67 years old (median, 34 years). Twenty two lesions (59.5%) were diagnosed incidentally on imaging studies for unrelated causes, while 15 cases (40.5%) were symptomatic: 8 patients presented with abdominal or flank pain and 7 patients presented with arterial hypertension. Clinically, 4 lesions (10.8%) were reported to have concurrent hormonal hypersecretion. Follow-up data were available for 23 patients (62.2%), ranging from 6 to 156 months (median, 52 mo). One of the 22 patients showed local recurrence at 12 months after partial adrenalectomy. The median size of the adrenal lymphangiomatous cysts was 4.5 cm (range, 1.5 to 10 cm). Based on the histopathologic findings these lesions were grouped into three, morphologically distinct types: typical multicystic lymphatic malformation (n = 16), typical unilocular lymphangiomatous cyst (n = 14) and lymphangiomatous cyst with papillary endothelial proliferation (n = 7). The median patient age of the first group was significantly higher than that of the other groups and calcifications in these cysts were more common than in the other two groups. The unilocular lymphangiomatous cysts were more frequently associated with a history of previous intra-abdominal surgical procedures and/or inflammatory processes than the other two groups. Cysts with papillary endothelial proliferation were significantly larger than other cysts and shared some microscopic features with a vascular neoplasm known as papillary intralymphatic angioendothelioma (PILA). In conclusion, adrenal lymphangiomatous cysts are usually asymptomatic, incidentally diagnosed lesions with a female predominance. They may imitate other adrenal tumors, both radiologically and clinically. Despite being non-functioning lesions, they should be considered as a possible cause of pseudopheochromocytoma. Although most adrenal lymphangiomatous cysts seem to be non-neoplastic, vascular abnormalities (malformations or lymphangiectasias), those with papillary endothelial proliferations may represent true neoplastic lesions.
Objectives
To compare the efficacy of two quantitative methods for discrimination between benign and malignant focal liver lesions (FLLs): apparent diffusion coefficient (ADC) values and T2 ...relaxation times.
Methods
Seventy-three patients with 215 confirmed FLLs (115 benign, 100 malignant) underwent 1.5-T MRI with respiratory-triggered single-shot SE DWI (
b
= 50, 400, 800) and dual-echo T2TSE (TR = 3,000 ms; TE1 = 84 ms; TE2 = 228 ms). ADC values and T2 relaxation times of FLLs were calculated. Sensitivity, specificity and accuracy of both techniques in diagnosing malignancy were assessed.
Results
The mean ADC value of malignant tumours (1.07 × 10
−3
mm
2
/s) was significantly lower (
P
< 0.05) than that of benign lesions (1.86 × 10
−3
mm
2
/s ); however, with the use of the optimal cut-off value of 1.25 × 10
−3
mm
2
/s, 20 false positive (FP) and 20 false negative (FN) diagnoses of malignancy were noted, generating 79 % sensitivity, 82.6 % specificity and 80.9 % accuracy. The mean T2 relaxation time of malignant tumours (64.4 ms) was significantly lower (
P
< 0.05) than that of benign lesions (476.1 ms). At the threshold of 107 ms 22 FP and 1 FN diagnoses were noted; the sensitivity was 99 %, specificity 80.9 % and accuracy 89.3 %.
Conclusions
Quantitative analysis of T2 relaxation times yielded significantly higher sensitivity and accuracy in diagnosing malignant liver tumour than ADC values.
Key Points
•
Diffusion-weighted magnetic resonance imaging is increasingly used for liver lesions.
•
But ADC values demonstrated only moderate accuracy for differentiation of liver lesions.
•
T2 relaxation times yielded higher accuracy in diagnosing malignant liver tumours.
•
Both ADC and T2 values overlapped between focal nodular hyperplasia and malignant lesions.
•
Nevertheless T2 liver mapping could be valuable for evaluating focal liver lesions.
•Reduction of number of b-values from 7 to 4 does not affect DKI parameters.•Set of four b-values: 0, 500, 1500 and 2000 s/mm2 may be applied in routine practice.•DKI acquisition time can be ...shortened by up to 36% compared to time for 7 b-values.
The objective was to optimise the number of b-values for diffusion kurtosis imaging (DKI) of the liver and pancreas in MR examinations to ensure reliable results with the shortest possible acquisition time.
Twenty healthy volunteers underwent DKI at 3.0 T Siemens Magnetom Skyra using 7 b-values (b = 0, 200, 500, 750, 1000, 1500, 2000 s/mm2). The regions of interest (ROIs) were placed in the liver (right lobe, left lobe) and pancreas (head, tail). DKI parameters (Dapp, Kapp) for ROIs were calculated for 7 b-values utilising the nonlinear least-squares (NLLS) Marquardt-Levenberg algorithm. All calculations were repeated for ten subsets of data, with the number of b-values reduced to 4. DKI parameters calculated for subsets were compared with parameters calculated for all 7 b-values.
The correlation coefficient between DKI parameters calculated for 7 b-values and subsets ranged from 0.65 to 1.00. The coefficient of variation (CoV) of DKI parameters calculated for a group of volunteers varied from 8% to 42% and was not affected by the reduction of the b-values number. Only one subset of data (b = 0, 500, 1500 and 2000 s/mm2) simultaneously met two criteria: no statistical difference (p < 0.05) from results obtained for 7 b-values and very good correlation with them.
DKI acquisition with 4 b-values (b = 0, 500, 1500 and 2000 s/mm2), compared to DKI acquisition utilising 7 b-values, allowed for the reduction of acquisition time by 36%, without affecting the calculated DKI parameters.
Diaphragmatic injuries occur in 0.8-8% of patients with blunt trauma. The clinical diagnosis of diaphragmatic rupture is difficult and may be overshadowed by associated injuries. Diaphragmatic ...rupture does not resolve spontaneously and may cause life-threatening complications. The aim of this study was to present radiological findings in patients with diaphragmatic injury.
The analysis of computed tomography examinations performed between 2007 and 2012 revealed 200 patients after blunt thoraco-abdominal trauma. Diaphragmatic rupture was diagnosed in 13 patients. Twelve of these patients had suffered traumatic injuries and underwent a surgical procedure that confirmed the rupture of the diaphragm. Most of diaphragmatic ruptures were left-sided (10) while only 2 of them were right-sided. In addition to those 12 patients there, another patient was admitted to the emergency department with left-sided abdominal and chest pain. That patient had undergone a blunt thoracoabdominal trauma 5 years earlier and complained of recurring pain. During surgery there was only partial relaxation of the diaphragm, without rupture. The most important signs of the diaphragmatic rupture in computed tomography include: segmental discontinuity of the diaphragm with herniation through the rupture, dependent viscera sign, collar sign and other signs (sinus cut-off sign, hump sign, band sign).
In our study blunt diaphragmatic rupture occurred in 6% of cases as confirmed intraoperatively. In all patients, coronal and sagittal reformatted images showed herniation through the diaphragmatic rupture. In left-sided ruptures, herniation was accompanied by segmental discontinuity of the diaphragm and collar sign. In right-sided ruptures, predominance of hump sign and band sign was observed. Other signs were less common.
The knowledge of the CT findings suggesting diaphragmatic rupture improves the detection of injuries in thoraco-abdominal trauma patients.
Diffusional Kurtosis Imaging (DKI) is a new, rapidly developing magnetic resonance (MR) diffusion weighted imaging (DWI) technique. DKI requires acquisition with several b-values, including high ...b-values (>1000 s/mm2). DKI takes into account the influence of tissue barriers (cell membranes, organelles) on diffusion, and is presumed to better reflect the actual water diffusion processes than standard DWI. However, several limitations hinder use of DKI in routine practice, including lack of standardization and long acquisition time (due to additional b-values). We aimed to optimize the DKI method to ensure reliable results with the shortest possible acquisition time.
In this prospective study 20 healthy volunteers (10 men, 10 women; age: 25–62 years; mean: 39) underwent DKI at 3.0 T Siemens Magnetom Skyra using 7 b-values (0; 200; 500; 750; 1000; 1500; 2000 s/mm2). Region of interests (ROIs) were placed in liver (right lobe, left lobe) and pancreas (head, tail). DKI parameters (Dapp, Kapp) for ROIs were calculated for 7 b-values using program written in Gnuplot, utilizing the nonlinear least-squares (NLLS) Marquardt–Levenberg algorithm. Dapp and Kapp quantitive maps were created using the in–house software based on ImageJ. All calculations were repeated for five subsets of data, with number of b-values reduced to 4 and 5. DKI parameters calculated for subsets were compared with parameters calculated for all 7 b-values (Wilcoxon signed rank test). Statistical analysis was performed in R; p < 0.05 was considered statistically significant.
Correlation coefficient between DKI parameters calculated for 7 b-values and subsets ranged from 0.69 to 0.99. Coefficient of variance (CoV) of parameters calculated for group of volunteers varied from 11% to 33%, with lowest agreement for head of pancreas (Dapp) and left lobe of liver (Kapp), and was not affected by reduction of b-values number. Significant differences between DKI parameters calculated for 7 b-values and subsets were found for all subsets except one (0; 500; 1500; 2000 s/mm2), for which no differences were observed.
DKI acquisition with only 4 b-values (0, 500, 1500, 2000 s/mm2), compared to DKI acquisition utilizing 7 b-values, allowed for the reduction of acquisition time by 36%, without affecting calculated DKI parameters.
To optimise the intravoxel incoherent motion (IVIM) imaging of the liver on a 3.0T scanner by assessing parameter reproducibility on free-breathing (FB) and respiratory-triggered (RT) sequences ...acquired with different numbers of signal averages (NSA).
In this prospective study 20 subjects (M/F: 10/10; age: 25-62 years, mean: 39 years) underwent IVIM magnetic resonance imaging (MRI) on a 3.0T scanner using an 18-channel phase-arrayed coil and four different echo-planar sequences, each with 10 b values: 0, 10, 30, 50, 75, 100, 150, 200, 500, and 900 s/mm
. Images were acquired with FB and RT with NSA = 1-4 (FBNSA1-4, RTNSA1-4) and with NSA = 3-6 (FBNSA3-6, RTNSA3-6). Subsequently, for the assessment of reproducibility of IVIM-derived parameters (f, D, D*), each subject was scanned again with an identical protocol during the same session. IVIM parameters were calculated. The distribution of IVIM-parameters for each DWI sequence were given as the median value with first and third quartile. Inter-scan reproducibility for each IVIM parameter was evaluated using coefficient of variance and Bland-Altman difference. Differences between FB sequence and RT sequence were tested using non-parametric Wilcoxon signed-rank test.
Mean coefficient of variance (%) for f, D, and D* ranged from 60 to 64, from 58 to 84, and from 82 to 99 for FBNSA1-4 sequence; from 50 to 69, from 41 to 97, and from 80 to 82 for RTNSA1-4 sequence; from 22 to 27, 15, and from 70 to 80 for FBNSA3-6 sequence; and from 21 to 32, from 12 to, and from 50 to 80 for RTNSA3-6 sequence, respectively.
Increasing the number of signal averages for IVIM acquisitions allows us to improve the reproducibility of IVIM-derived parameters. The sequence acquired during free-breathing with NSA = 3-6 was optimal in terms of reproducibility and acquisition time.
Abstract We present imaging findings (ultrasound, computed tomography, and magnetic resonance imaging) of eight patients with hepatic angiomyolipoma (HAML). The lesions were solitary in seven ...patients, and one patient had multiple tumors ( n = 11). Angiomyolipoma, even though a rare liver tumor, should be included in the differential diagnosis in cases of highly vascularized lesion containing a significant amount of fat. Suggestion of the diagnosis of HAML might be helpful for the pathologist in the selection of the typical histochemical staining of the tumor, allowing accurate diagnosis, which, in turn, determines the implementation of appropriate therapeutic intervention.
To aim of this study was to assess the diagnostic performance of the state-of-the-art magnetic resonance cholangiography (MRC) comprising several 2D and 3D hydrographic sequences in patients after ...liver transplantation with biliary-enteric and duct-to-duct biliary anastomosis.
Retrospective analysis included MRC examinations of 42 patients (21 men, 21 women) performed from 18 days to 86 months (average, 18.9 months) after liver transplantation. Studies were carried out on 1.5 T units, using 4 hydrographic (turbo spin echo, TSE) sequences. The analysis included accuracy of MRC in detecting biliary complications, as well as frequency of specific complications in patients with biliary-enteric anastomosis (n=15) and duct-to-duct biliary anastomosis (n=27). In 34 patients the results were correlated with endoscopic retrograde cholangiopancreatography ERCP (n=9), ERCP and CT (n=5), ERCP and percutaneous cholangiography (n=2), ERCP and T-tube cholangiography (n=1), ERCP, PTC, and histopathology (n=1), PTC (n=1), PTC and CT (n=1), PTC and histopathology (n=1), T-tube cholangiography (n=4), T-tube cholangiography and CT (n=1), fistulography (n=1), CT (n=4), and histopathology (n=3). In the remaining 8 patients other imaging studies (US, CT, follow-up MRC), laboratory liver function tests, and clinical status were the standard of reference. Results MRC yielded 94.6% sensitivity in detecting biliary complications in patients after liver transplantation. In patients with biliary-enteric anastomosis, disseminated biliary strictures were more frequent than in patients with duct-to-duct biliary anastomosis (20% vs. 7%). Less frequently, the biliary-enteric anastomosis was accompanied by anastomotic strictures (40% vs. 56%) and the presence of stones/sludge (20% vs. 37%), but the differences did not show statistical significance.
MRC allowed accurate diagnosis of biliary complications in patients after liver transplantation and therefore can be used as a safe alternative to invasive diagnostic procedures such as ERCP and PTC, especially in patients with biliary-enteric anastomosis, in which invasive diagnostic procedures are technically challenging. The main limitation of MR hydrography is its low accuracy in distinguishing bilomas from other fluid collections.
The aim of this study was to determine if the appearance of hepatic epithelioid hemangioendothelioma (HEHE) on state-of-the-art MRI including hepatocyte phase after administration of hepatobiliary ...contrast agent can facilitate preoperative diagnosis and identification of potential candidates for liver transplantation.
The study group comprised 6 patients with pathologically confirmed HEHE. Analysis included signal characteristics of 55 tumor nodules (maximum of 10 lesions per patient) on T2-weighted images, dynamic contrast-enhanced, 5-minute delayed, and hepatobiliary phase images.
The most common feature of HEHE, observed in 84% of lesions, was progressive contrast-enhancement, followed by subcapsular location (66%), confluent appearance (60%) and hyper- or isointensity on hepatobiliary phase images (53%). In 5 of 6 patients, capsular retraction was observed.
The appearance of HEHE on hepatobiliary phase images was variable, but examined tumors often demonstrated hyper- or isointensity, most probably due to prolonged retention of contrast material. These features, along with typical morphology (subcapsular, confluent nodules, with progressive enhancement and capsular retraction), may contribute to correct diagnosis and recognition of potential candidates for liver transplantation.
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