MR imaging of acute pancreatitis: Correlation of abdominal wall edema with severity scores

Objective

To study MRI findings of abdominal wall edema (AWE) in acute pancreatitis as well as correlations between AWE and the severity of acute pancreatitis according to the MR severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation III (APACHE III) scoring system.

Materials and methods

A total of 160 patients with AP admitted to our institution between December 2009 and March 2011 were included in this study. MRI was performed within 48 h after admission. MRI findings of acute pancreatitis were noted, including AWE on the MRI. The abdominal wall area was divided into quarters, and each area involved was recorded as 1 point to score the severity of AWE. The severity of acute pancreatitis was studied using both the MRSI and the APACHE III scoring system. Spearman correlation of AWE with the MRSI and the APACHE III scoring system was analyzed.

Results

In 160 patients with acute pancreatitis, 53.8% had AWE on MRI. The average AWE score was 1.2 ± 1.4 points. The prevalence of AWE was 30.5%, 64.5% and 100% in mild, moderate and severe AP, respectively, according to MRSI. AWE on MRI was correlated with MRSI scores (r = 0.441, p = 0.000). According to APACHE III scores, the averages were 2.0 ± 1.1 and 2.6 ± 1.1 points in mild AP and severe AP, respectively (P = 0.016). AWE was slightly correlated with the APACHE III scores (r = 0.222, p = 0.005).

Conclusion

AWE on MRI in acute pancreatitis is common, which may be a supplementary indicator in determining the severity of AP.     

Age-related changes in normal adult pancreas: MR imaging evaluation

Objective

To investigate age-related changes in normal adult pancreas as identified by magnetic resonance imaging (MRI).

Materials and methods

We examined 115 patients without pancreatic diseases (21–90 years) who underwent upper abdominal MRI to evaluate the normal pancreatic MRI findings related to aging. The parameters examined were the pancreatic anteroposterior (AP) diameter, pancreatic lobulation, pancreatic signal intensity (SI), depiction of the main pancreatic duct (MPD), grade of the visual SI decrease on the opposed-phase T1-weighted images compared with in-phase images, and enhancement effect of the pancreas in the arterial phase of dynamic imaging.

Results

The pancreatic AP diameter significantly reduced (head, p = 0.0172; body, p = 0.0007; tail, p < 0.0001), and lobulation (p < 0.0001) and parenchymal fatty change (p < 0.0001) became more evident with aging. No significant correlation was observed between aging and pancreatic SI, however the SI on the in-phase T1-weighted images tended to decrease with aging. No significant correlation was observed between aging and the depiction of the MPD as well as aging and contrast enhancement.

Conclusion

MRI findings of pancreatic atrophy, lobulation, and fatty degeneration are characteristic changes related to aging, and it is necessary to recognize these changes in the interpretation of abdominal MRI in patients with and without pancreatic disease.     

The prevalence and clinical predictors of incidental atherosclerotic renal artery stenosis

Objective

To evaluate the prevalence of incidental renal artery stenosis due to atherosclerosis and associated risk factors in patients with peripheral arterial disease (PAD).

Materials and methods

To determine renal artery stenosis, aortofemoropopliteal digital substraction angiographies (DSA) of 629 consecutive patients with PAD were prospectively reviewed. Angiographies were performed as catheter angiography with automated pump injection. Of the patients, 540 were male (86%) and 89 female (14%) (mean age ± S.D.: 61.5 ± 11.1 years). Statistical analysis was performed to determine the association of significant renal artery stenosis (≥60% diameter stenosis) with patient demographics (age, sex, reason for angiography and smoking status), medical history (diabetes mellitus, hypertension and coronary artery disease), laboratory values (blood creatinine, fasting glucose, triglycerides, LDL, HDL and total cholesterol) and distribution of PAD (aortoiliac, femoropopliteal and crural diseases and multisegment involvement).

Results

Renal artery disease was found in 33% (207 of 629) of all patients with peripheral arterial disease, and 9.6% of patients (n = 60) had significant (≥60%) renal artery stenosis. Only age and hypertension (blood pressure systolic >140 mmHg or diastolic >90 mmHg) were independent risk factors for significant renal artery stenosis on multivariate analysis. Mean age of patients with RAS was 66.5 ± 8.9 years compared with 61 ± 11.2 years for patients without RAS (p < 0.001). Hypertension was found in 41% of the patients in control group and in 63% of the patients in RAS group (p = 0.01).

Conclusion

Incidental renal artery stenosis which can be mild or significant is a relatively common finding among patients with peripheral arterial disease. Advance age and hypertension are closely associated with significant renal artery stenosis.     

Magnesium sulfate as an oral contrast medium in magnetic resonance imaging of the small intestine

Background

To explore the use of magnesium sulfate (MgSO₄) as an oral contrast medium (CM) in MRI of the small intestine.

Methods

By comparing MgSO₄ SNRs at different concentrations, we determined that 2.5% MgSO₄ is the ideal concentration for small bowel MRI. Twenty volunteers underwent MRI after drinking 2.5% MgSO₄. Thirty-one patients with clinical suspicion of small intestinal pathology underwent both MRI and the air-barium contrast examination. The patient's tolerance, side effects and complications were noted.

Results

2.5% MgSO₄ can decrease the absorption of water and fully fill the enteric cavity, thereby increasing the contrast between the intestinal wall and lumen and facilitating radiographic examination of the small bowel. The mean diameter of the small intestine was 19.8 ± 1.21 mm in the 20 volunteers consuming 2.5% MgSO₄ and 12.7 ± 0.84 mm in the 20 volunteers given water. There was a significant difference (P < 0.05) between the diameters of the small intestine of the two groups. But there were no significant differences (P > 0.05) in side effects between MgSO₄ and water groups. Small intestinal MRI was successfully performed in all 31 patients, who were also examined by the double contrast barium, which gave almost identical diagnoses to MRI in all cases except for 1 patient with small intestinal hemorrhage.

Conclusions

MRI with 2.5% MgSO₄ can demonstrate intestinal abnormalities. Therefore, 2.5% MgSO₄ solution is an ideal oral CM for small bowel MRI.     

Use of magnetic resonance imaging to detect neoplastic meningitis: limited use in leukemia and lymphoma but convincing results in solid tumors

Background

An early diagnosis of meningitis is important to improve patients’ survival. Data about a direct comparison of cerebrospinal fluid cytology (CSF-cytology) and MRI are very limited. Therefore, the aim of this study was to compare these two diagnostic modalities in diagnosing meningitis in patients with hematopoietic and solid malignancies.

Methods

In 68 patients suspicious for neoplastic meningitis, cytology and MRI (1.5 T) was performed. The meningeal, pial or intraparenchymal hyperintense signal or contrast enhancement was correlated to the final CNS diagnosis and to cytology.

Results

44 patients (64.7%) had neoplastic meningitis, 21 patients (30.9%) had non-neoplastic meningitis. The sensitivity to diagnose meningeal disease was 49.2% for MRI and 95.4% for cytology (p < 0.001). In patients with neoplastic meningitis, sensitivity was 45.5% for MRI and 93.2% for cytology (p < 0.001). In patients with infectious meningitis, sensitivity was 57.1% for MRI and 100% for cytology (p = 0.0013). In patients with solid tumors, the sensitivity was 84.6% for both diagnostic methods. The sensitivity for MRI was low in patients with leukemia (20.0%) and lymphoma (37.5%). The positive predictive value (PPV) for MRI to differentiate infectious from neoplastic meningitis was high in patients with infectious meningitis (75.0%), in patients with lymphoma (83.3%), and in patients with solid tumors (72.7%). Ppv was low in patients with leukemia (33.3%).

Conclusion

Diagnostic value of MRI for diagnosing meningitis is especially limited in patients with hematopoietic malignancies. MRI better detected leptomeningeal involvement caused by solid tumors than by leukemia or lymphoma. The ppv to specify neoplastic meningitis depends on tumor subtype.     

Meta-analysis: serum creatinine changes following contrast enhanced CT imaging

Purpose

Contrast induced nephropathy (CIN) is defined as a decrease in renal function following administration of contrast media. The aim of this meta-analysis was to asses the overall risk of CIN, chronic loss of kidney function and the need for renal replacement therapy (RRT) after intravenous contrast enhanced CT-scan. Secondly, we aimed to identify subgroups at increased risk for CIN.

Materials and methods

A literature search in Pubmed, Medline, Embase and Cochrane databases was performed. Data extraction was carried out independently by two reviewers. Meta-analysis and meta-regression were performed using an exact likelihood approach.

Results

Forty studies evaluating the incidence of CIN after CT were included. The pooled incidence of CIN was 6.4% (95% CI 5.0–8.1). The risk of RRT after CIN was low, 0.06% (95% CI 0.01–0.4). The decline in renal function persisted in 1.1% of patients (95% CI 0.6–2.1%). Patients with chronic kidney disease (odds ratio 2.26, p < 0.001) or diabetes mellitus (odds ratio 3.10, p < 0.001) were at increased risk for the development of CIN.

Conclusion

CIN occurred in 6% of patients after contrast enhanced CT. In 1% of all patients undergoing contrast enhanced CT the decline in renal function persisted.     

Unenhanced urinary CT: value of parenchymal attenuation measurements in differentiating acute vs. chronic renal obstruction

Objective

We aimed to search if the renal parenchymal attenuation measurements on unenhanced CT scans could be useful in differentiating acutely obstructed kidneys from chronic cases or unobstructed kidneys.

Material and methods

Unenhanced CT scans of 101 patients were retrospectively reviewed. Thirty-two patients with unilateral acute renal obstruction, 34 patients with unilateral chronic renal obstruction due to various reasons and 35 control subjects were included in the study. The parenchymal densities of both kidneys were measured, from the upper poles, middle portions, and lower poles of each kidney. The mean parenchymal densities of both kidneys were calculated in all three groups of subjects. Secondary signs of renal obstruction such as perinephric stranding, size of ureteral stone, degree of hydronephrosis were also noted for each kidney.

Results

The mean parenchymal attenuation value on the acutely obstructed side was lower than the unobstructed side, 24.21 ± 3.68 and 30.68 ± 4.75 respectively (p < 0.001). The mean parenchymal attenuation value on the acutely obstructed side (24.21 ± 3.68) was lower than both the chronically obstructed side (30.85 ± 4.53), and the control subjects (29.62 ± 3.03 on corresponding side). There was no statistically significant attenuation difference between right and left kidneys in the control group and chronic obstruction group.

Conclusion

Renal parenchymal attenuation measurements and attenuation differences of both kidney of same patient could be useful in differentiating acute unilateral obstruction from chronic cases.     

Role of magnetic resonance imaging in evaluation of the activity of perianal Crohn's disease

Aim

To evaluate the diagnostic ability of contrast-enhanced Magnetic Resonance Imaging (MRI) in assessment of the activity of perianal fistulas in Crohn's disease (CD) patients, compared to clinical data.

Materials and methods

Fifty CD patients (25 men; mean[SD] age: 40.4[12.6] years) with known or suspected perianal fistulas underwent perianal space MRI.Radiological activity of disease was measured as the percentage increase (PI) of ROI values of fistulas in relation to ROI values of healthy local fat, after contrast administration. Clinical activity of disease was defined according to Perianal Disease Activity Index (PDAI) and Fistula Drainage Assessment (FDA).

Results

Forty-two patients presented perianal disease at MRI (55 fistulas identified). An association between both fistula's PI and PDAI (Pearson's coefficient 0.512, p < 0.0001) and between PI and FDA (p = 0.003) was demonstrated.Areas under ROC curves of PI values in relation to PDAI and FDA were respectively 0.876 [95%CI = (0.743–1.00), p < 0.001] and 0.784 [95%CI = (0.588–0.980), p = 0.003].A cut-off value of PI, calculated on these preliminary data, correctly classified more than 90% of fistulas.

Conclusions

Contrast-enhanced MRI with PI calculation offered practical information about activity of perianal fistulas and might be helpful in providing a comprehensive evaluation of CD perianal disease.     

Imaging findings in phyllodes tumors of the breast

Purpose

To study the radiological appearance and pathological features of breast phyllodes tumors (PTs), and to enhance the recognition of the tumor.

Materials and methods

Clinical and imaging findings were retrospectively reviewed in 24 women with PTs confirmed by surgical pathology. All of the 24 patients had preoperative MRI and sonography, and 10 had preoperative mammography.

Results

The histologic findings were benign, borderline and malignant PTs in 16.7% (4/24), 45.8% (11/24) and 37.5% (9/24) of cases, respectively. The tumor size (p = 0.001), irregular shape on sonographic imaging (p = 0.039), internal non-enhanced septations (p = 0.009), silt-like changes in enhanced images (p = 0.006) and signal changes from T2-weighted to enhanced images on MRI (p = 0.001) correlated significantly with the histologic grade; the BI-RADS category of the MRI could reflect the PT's histologic grade with a correlation coefficient of 0.440 (p = 0.031). If the category BI-RADS ≥4a was considered to be a suspicious malignant lesion, the diagnostic accuracy of mammography, US and MRI would be 70% (7/10), 62.5% (15/24) and 95.8% (23/24), respectively.

Conclusion

The tumor size and several US and MRI findings can be used to help preoperatively determine the histologic grade of breast PTs. When a patient presents with a progressively enlarging, painless breast mass, MRI should be recommended first.     

IVIM-DWI of transplanted kidneys: Reduced diffusion and perfusion dependent on cold ischemia time

Purpose

To evaluate the effect of cold ischemia time (CIT) of renal allografts on diffusion and perfusion using intravoxel incoherent motion (IVIM) derived parameters.

Material and methods

A total of 37 patients with renal allografts (CIT: 27 <15 h, 10 ≥15 h) and 30 individuals with healthy kidneys were examined at 1.5 T using a single-shot echo-planar diffusion-weighted pulse sequence with nine b-values ranging from 0 to 800 s/mm². ADC, perfusion fraction f, and the diffusion coefficient D were calculated using the IVIM model. Parameters of allografts stratified by CIT were compared with healthy kidney groups using the Mann–Whitney U test for unpaired data. We computed the Spearman correlation coefficient for correlation with creatinine values.

Results

ADC, D, and f of transplanted kidneys were significantly lower than in the healthy controls. The long-CIT group showed significantly lower diffusion parameters compared with the short-CIT group [mean ± SD]: ADC: 1.63 ± 0.14 μm²/ms, f: 11.90 ± 5.22%, D: 1.55 ± 0.25 μm²/ms versus ADC: 1.79 ± 0.13 μm²/ms, f: 16.12  ± 3.43%, D: 1.73 ± 0.14 μm²/ms, P_ADC, _f, _D < 0.05.

Conclusion

Our results suggest that diffusion parameters, especially the ADC, depend on the CIT of the kidney allograft. Potentially, this stands for functional changes in renal allografts. Diffusion-weighted imaging could be used for follow-up examinations. Thus, diffusion parameters may help guide therapy in patients with delayed graft function.     

Investigation of renal lesions by diffusion-weighted magnetic resonance imaging applying intravoxel incoherent motion-derived parameters--initial experience

Purpose

Usefulness of biexponentially fitted signal attenuation at different b-values for differentiating the histological characteristics of renal tumors.

Materials and methods

A total of 26 patients with 28 renal masses (histologically proven: 20 clear cell renal cell carcinomas [ccRCC], three transitional cell carcinomas, two oncocytomas, and one papillary RCC) and 30 volunteers with healthy kidneys were examined at 1.5 Tesla using an echo-planar DWI sequence. Using the IVIM model, we calculated the perfusion fraction f and the diffusion coefficient D. Furthermore, the ADC was obtained. These tumor parameters were compared to healthy renal tissue nonparametrically, and a receiver operating characteristic (ROC) analysis was performed.

Results

Healthy renal parenchyma showed higher ADC and D values (p < 0.001) than ccRCC (ADC 1.95 ± 0.10 [SD] μm²/ms, f 18.32 ± 2.52%, and D 1.88 ± 0.11 μm²/ms versus ADC 1.45 ± 0.38 μm²/ms, f 18.59 ± 6.16%, and D 1.34 ± 0.38 μm²/ms). When detecting malignancies the area under the curve for D was higher than for ADC. The f values for ccRCC were higher (p < 0.001) than for non-ccRCC (ADC 1.52 ± 0.47 μm²/ms, f 8.44 ± 1.24%, and D 1.30 ± 0.18 μm²/ms). Both f and D correlated with ccRCC grading.

Conclusion

IVIM imaging is able to provide reliable diffusion values in the human kidney and may enhance the accuracy of tumor diagnosis. The D value was the best parameter to distinguish renal tumors from healthy renal tissue. The f value is promising for determining the histological subgroups.     

Tolerability and diagnostic value of gadoteric acid in the general population and in patients with risk factors: results in more than 84,000 patients

Purpose

To review the tolerability and diagnostic effectiveness of gadoteric acid under daily practice conditions in the general population and at-risk patients.

Materials and methods

A total of 84,621 patients (45.4% men, 54.6% women, mean age 52.0 ± 16.9 years) were studied in 129 German centers. Patients underwent contrast-enhanced magnetic resonance imaging (MRI) using gadoteric acid (Gd-DOTA, Dotarem^®, Guerbet, Roissy CdG, France) as IV contrast medium (mean volume, 16.4 ml). 22.9% of the patients had at least one risk factor (e.g., allergies, previous allergic reaction to a contrast medium, and renal impairment). 554 patients received pretreatment before contrast medium administration (0.7%). Adverse events were documented and image quality was assessed.

Results

A diagnosis was possible in 99.7% of all cases. Image quality was rated good or excellent in 97.1%. Adverse events (e.g., nausea, vomiting, and urticaria) were observed in 0.34% of the examinations and were mostly rated as minor. There were 8 patients with serious adverse events. The adverse event rate was significantly higher in patients with a history of allergies (0.62%; p < 0.001) and in patients with a previous allergic reaction to contrast medium (1.23%; p < 0.001). There was no elevated incidence of adverse events in patients with renal impairment.

Conclusion

Gadoteric acid is a well-tolerated MRI contrast medium in patients with and without risk factors that is associated with a low rate of adverse events and good or excellent image quality in most patients.     

Correlation between tumor size and surveillance of lymph node metastasis for IB and IIA cervical cancer by magnetic resonance images

Purpose

To assess the feasibility of preoperative MRI based measurement of tumor size with regard to lymph node (LN) metastasis in early uterine cervical cancer.

Material and Methods

A retrospective review of patients with FIGO stage IB–IIA cervical cancer who underwent lymphadenectomy was performed. Diagnostic accuracy of MRI in detecting LN metastasis and rate of LN recurrence in terms of tumor size (≤4 cm versus >4 cm) were analyzed. ROC curve analysis was used to determine LN size for differentiating LN metastasis in terms of tumor size. P < 0.05 was considered statistically significant.

Results

Of the 200 patients, 45 (22.3%) had LN metastasis. There was no statistical difference between patients-based and region-specific analysis. The patients with tumor size with >4 cm revealed higher diagnostic accuracy of MRI in detecting LN metastasis (85.4% versus 50.6%, P = 0.023) and rate of LN recurrence (20.0% versus 6.4%, P = 0.031) in than those with size with ≤4 cm, the differences were statistically significant. Discriminant analysis of LN size for the differentiation of metastasis from non-metastasis resulted in cut-off values (11.8 mm; size with >4 cm versus 8.3 mm; size with ≤4 cm) and diagnostic accuracy (84.0% of size with >4 cm versus 72.0% of size with ≤4 cm).

Conclusion

MRI has limited sensitivity, but high specificity in predicting surveillance of LN metastasis in the preoperative early cervical cancer, especially useful tool for patients with tumor size with >4 cm.     

MR determination of neonatal spinal canal depth

Objectives

Lumbar punctures (LPs) are frequently performed in neonates and often result in traumatic haemorrhagic taps. Knowledge of the distance from the skin to the middle of the spinal canal (mid-spinal canal depth – MSCD) may reduce the incidence of traumatic taps, but there is little data in extremely premature or low birth weight neonates. Here, we determined the spinal canal depth at post-mortem in perinatal deaths using magnetic resonance imaging (MRI).

Patients and methods

Spinal canal depth was measured in 78 post-mortem foetuses and perinatal cases (mean gestation 26 weeks; mean weight 1.04 kg) at the L3/L4 inter-vertebral space at post-mortem MRI. Both anterior (ASCD) and posterior (PSCD) spinal canal depth were measured; MSCD was calculated and modelled against weight and gestational age.

Results

ASCD and PSCD (mm) correlated significantly with weight and gestational age (all r > 0.8). A simple linear model MSCD (mm) = 3 × Weight (kg) + 5 was the best fit, identifying an SCD value within the correct range for 87.2% (68/78) (95% CI (78.0, 92.9%)) cases. Gestational age did not add significantly to the predictive value of the model.

Conclusion

There is a significant correlation between MSCD and body weight at post-mortem MRI in foetuses and perinatal deaths. If this association holds in preterm neonates, use of the formula MSCD (mm) = 3 × Weight (kg) + 5 could result in fewer traumatic LPs in this population.     

Evaluation of right ventricular function by 64-row CT in patients with chronic obstructive pulmonary disease and cor pulmonale

Purpose

The aim of this study was to investigate the clinical application value of right ventricle (RV) function measured by 64 multi-detector row CT (MDCT) in patients with chronic obstructive pulmonary disease (COPD) and cor pulmonale.

Materials and methods

Sixty-three consecutive patients with COPD and cor pulmonale were referred for electrocardiographically gated MDCT for evaluation of suspected or known coronary artery disease. Magnetic resonance imaging (MRI) for cardiac function analysis was performed on the same day. The MDCT and MRI examinations were successfully completed in 58 patients. Forty-six patients with COPD were divided into three groups according to the severity of disease by the pulmonary function test (PFT). Twelve patients diagnosed as cor pulmonale and 32 control subjects were also included. The RV function and myocardial mass (MM) were obtained by 64-MDCT and 1.5 T cardiac MRI in all of the groups. The results were compared among the groups using the Newman–Keuls method. Pearson's correlation was used to evaluate the relationship between the right ventricular ejection fraction (RVEF) and MM with the PFT results in COPD and cor pulmonale patients.

Results

The RVEF was significantly lower in patients with severe COPD and cor pulmonale than it was in those patients with mild or moderate COPD (P < 0.01). There were strong correlations between MDCT and MRI (r = 0.826 for RV MM, r = 0.982 and 0.969 for RV EDV and RV ESV, r = 0.899 for RVEF) and between MDCT results and forced expiratory volume in 1 s (r = 0.787 for RVEF, r = −0.774 for RV MM) in all patients.

Conclusion

MDCT can accurately quantify RV function and MM. The RVEF and RV MM measured by MDCT correlate well with the severity of disease as determined by PFT in patients with COPD and cor pulmonale. The assessment of right ventricular function is clinically important for evaluation of the severity of COPD, which may provide an objective basis for therapeutic strategy.     

Loading of the knee during 3.0T MRI is associated with significantly increased medial meniscus extrusion in mild and moderate osteoarthritis

Purpose

Standard knee MRI is performed under unloading (ULC) conditions and not much is known about changes of the meniscus, ligaments or cartilage under loading conditions (LC). The aim is to study the influence of loading of different knee structures at 3 Tesla (T) in subjects with osteoarthritis (OA) and normal controls.

Materials and methods

30 subjects, 10 healthy and 20 with radiographic evidence of OA (10 mild and 10 moderate) underwent 3 T MRI under ULC and LC at 50% body weight. All images were analyzed by two musculoskeletal radiologists identifying and grading cartilage, meniscal, ligamentous abnormalities. The changes between ULC and LC were assessed. For meniscus, cartilage and ligaments the changes of lesions, signal and shape were evaluated. In addition, for the meniscus changes in extrusion were examined. A multivariate regression model was used for correlations to correct the data for the impact of age, gender, BMI. A paired T-Test was performed to calculate the differences in meniscus extrusion.

Results

Subjects with degenerative knee abnormalities demonstrated significantly increased meniscus extrusion under LC when compared to normal subjects (p = 0.0008–0.0027). Subjects with knee abnormalities and higher KL scores showed significantly more changes in lesion, signal and shape of the meniscus (80% (16/20) vs. 20% (2/10); p = 0.0025), ligaments and cartilage during LC.

Conclusion

The study demonstrates that axial loading has an effect on articular cartilage, ligament, and meniscus morphology, which is more significant in subjects with degenerative disease and may serve as an additional diagnostic tool for disease diagnosis and assessing progression in subjects with knee OA.     

Assessment of acute cholangitis by MR imaging

Purpose

The purpose of this study is to assess the common MRI findings of acute cholangitis compared with those of non-acute cholangitis.

Materials and methods

During a 31-month period, we performed MRCP and contrast-enhanced MRI on 173 patients with biliary abnormalities including duct dilatation or stricture. The causes of the biliary abnormalities included biliary stone disease (n = 85), cholangiocarcinoma (n = 47), periampullary cancer (n = 20), GB cancer (n = 4), and others (n = 17). Among 173 patients, 66 consecutive patients were confirmed with acute cholangitis diagnosed according to the Tokyo guideline, and 107 patients were confirmed as having non-acute cholangitis. Two radiologists retrospectively and independently accessed the MR findings, including the cause of biliary abnormality, increased periductal signal intensity on T2-weighted images, the transient periductal signal difference, and the presence of abscess, thrombosis, and ragged duct. They also measured the dilated duct and the thickened wall. The Student t-test and the Pearson chi-square were used. The κ statistics were used to determine interobserver agreement. Logistic regression was used to identify the MR findings that predicted acute cholangitis.

Results

MRI correctly accessed the cause of biliary abnormality in 163 patients (94%). The statistically common findings for acute cholangitis were as follows: increased periductal signal intensity on T2-weighted imaging (n = 26, 39%, p < 0.05); transient periductal signal difference (n = 31, 47%, p < 0.05); abscess (n = 18, 27%, p < 0.05); thrombosis (n = 12, 18%, p < 0.05); and ragged duct (n = 11, 17%, p < 0.05). Interobserver agreement was good to excellent for each finding (κ = 0.74–0.97). The wall thickness showed a statistically significant difference between the acute cholangitis and the non-acute cholangitis group (2.65 mm:2.32 mm, p < 0.05), however, there was no significant difference in duct dilatation in the two groups. The periductal transient attenuation difference was an independent predictor of acute cholangitis (Exp (B) = 6.389, p = 0.018).

Conclusion

MRI accurately assesses the cause of biliary abnormality in patients with cholangitis. Using statistically common MR findings for acute cholangitis, MR imaging is very successful in predicting acute cholangitis.     

MRI evaluation of residual tumor size after neoadjuvant endocrine therapy vs. neoadjuvant chemotherapy

Aim

To investigate if there is any difference in evaluation of residual tumor size after neoadjuvant chemotherapy (NAC) and neoadjuvant endocrine therapy (NAE).

Methods

Seventy-eight tumors in 57 patients were prospectively enrolled. Residual tumor sizes in contrast-enhanced MRI after NAC and NAE were compared with those measured on surgical specimen by using linear regression analyses. The line slope values >1 indicates overestimation by MRI. Differences in types of shrinkage patterns: concentric shrinkage (CS) and dendritic shrinkage (DS) were also investigated.

Results

Fifty lesions were treated with NAC and 28 lesions were treated with NAE. Shrinkage patterns were CS in 33 lesions and in 45 lesions. The slopes values were 0.75 (R = 0.92) and 0.70 (R = 0.90) for NAC and NAE, respectively, and no significant difference was observed (p = 0.46). However, they were 1.02 (R = 0.92) and 0.68 (R = 0.92), respectively for CS and DS with significant difference (p < 0.01). The difference between CS and DS was found only in a subgroup with size by MRI >20 mm.

Conclusion

Contrast enhanced MRI enabled fairly accurate measurement in NAE as well as in NAC.     

Accurate perioperative flow measurement of the portal vein and hepatic and renal artery: A role for preoperative MRI?

Background

Quantification of abdominal blood flow is essential for a variety of gastrointestinal and hepatic topics such as liver transplantation or metabolic flux measurement, but those need to be performed during surgery. It is not clear whether Duplex Doppler Ultrasound during surgery or MRI before surgery is the tool to choose.

Objective

To examine whether preoperative evaluation of abdominal blood flow using MRI could prove to be a useful and reliable alternative for the perioperative sonographic approach.

Methods

In this study portal and renal venous flow and hepatic arterial flow were sequentially quantified by preoperative MRI, preoperative and perioperative Duplex Doppler Ultrasound (DDUS). 55 Patients scheduled for major abdominal surgery were studied and methods and settings were compared. Additionally, average patient population values were compared.

Results

Mean (±SD) plasmaflow measured by perioperative DDUS, preoperative DDUS and MRI, respectively was 433 ± 200/423 ± 162/507 ± 96 ml/min (portal vein); 96 ± 70/74 ± 41/108 ± 91 ml/min (hepatic artery); 248 ± 139/201 ± 118/219 ± 69 ml/min (renal vein). No differences between the different settings of DDUS measurement were detected. Equality of mean was observed for all measurements. Bland Altman Plots showed widespread margins. Hepatic arterial flow measurements correlated with each other, but portal and renal venous flow correlations were absent.

Conclusions

Surgery and method (DDUS vs. MRI) do not affect mean flow values. Individual comparison is restricted due to wide range in measurements.Since MRI proves to be more reliable with respect to inter-observer variability, we recommend using mean MRI results in experimental setups.     

Ossification variants of the femoral condyles are not associated with osteochondritis dissecans

Purpose

To determine if ossification variants of the femoral condyles involving the subchondral bone plate are associated with osteochondritis dissecans (OCD).

Materials and methods

The prevalence of ossification variants of the unaffected femoral condyle in 116 patients (aged 9–14 years) with unicondylar OCD on MRI (magnetic resonance imaging) of the knee was compared to a control group of 579 patients (aged 9–14 years) without OCD. The evolution of the ossification variants in both groups was studied by reviewing follow-up MR imaging side by side with the baseline study.

Results

The prevalence of ossification variants in the unaffected condyle in patients with OCD (12.9%) and in the control group of patients without OCD (12.6%) was similar (p = 0.88).Evolution of ossification variants to OCD was not seen on follow-up MRI examinations. All variants had decreased in size or were no longer visible.

Conclusion

Ossification variants of the femoral condyle that involve the subchondral bone plate are not associated with OCD.

Clinical relevance statement

Ossification variants are not associated with OCD, indicating that routine MRI follow-up in affected children is not mandatory.