Acta Radiologica

Background: The contrast medium (CM) dose-to-eGFR (estimated glomerular filtration rate) ratio has recently been advocated to express systemic exposure to CM in assessing the risk of contrast medium-induced nephropathy (CIN).

Purpose: To evaluate how CIN risk might vary with decreasing eGFR at fixed CM-dose/eGFR ratios and other CIN risk factors, and to find a relatively safe CM-dose/eGFR ratio.

Material and Methods: 391 patients underwent primary coronary angioplasty for ST-segment elevation acute myocardial infarction. CM dose (grams iodine; g I), eGFR (ml/min), and preprocedural CIN risk factors were entered into a multiple logistic regression model. From the established statistical model, the probability of CIN (≥44.2 µmol/l serum creatinine rise or oliguria/anuria) was calculated at various eGFR levels based on g-I/eGFR ratios of 1:2, 1:1, 2:1, and 3:1.

Results: At a g-I/eGFR ratio <1 the risk of CIN was 3%, while it was 25% at a g-I/eGFR ratio ≥1. Independent predictors of CIN were CM dose, eGFR, left ventricular ejection fraction (LVEF) and cardiogenic shock (ROC area =0.87). An estimated CIN risk of 10% would for example occur at a g-I/eGFR ratio of 1.5:1 in patients with 50% LVEF without shock. At a 1:2, 1:1, 2:1, and 3:1 g-I/eGFR ratio with 50% LVEF without shock, the CIN risk was about 2, 6, 18, and 30%, respectively, over a wide range of eGFR values (30–90 ml/min). At a 1:1 g-I/eGFR ratio with 50% LVEF+shock, 25% LVEF without shock, or 25% LVEF+shock, the CIN risk was 20, 55, and 80%, respectively.

Conclusion: Relating CM dose to eGFR appears to be an attractive pharmacotoxic model to assess CIN risk. At fixed CM-dose/eGFR ratios, CIN risk increased marginally with decreasing eGFR. Limiting the CM dose in g I numerically to the eGFR value in ml/min or less may be relatively safe with regard to CIN, unless multiple risk factors are present.

Purpose: To suggest a more precise tool when assessing the risk of contrast-medium-induced nephropathy (CIN), i.e. the ratio between contrast medium (CM) dose expressed in grams of iodine (g-I) and estimated glomerular filtration rate in ml/min (eGFR; based on equations using serum-creatinine (s-Cr), weight, height, age, and/or sex), here named I-dose/GFR ratio.

Material and Methods: A Medline search of published CIN investigations reporting mean eGFR and mean dose of low-osmolality CM (LOCM) identified 10 randomized controlled prophylactic and 2 cohort coronary investigations, and 3 randomized and 1 cohort computed tomographic (CT) investigation. From the randomized trials, data were collected only from the placebo or control arms, unless there was no significant difference between the control and test groups. The mean I-dose/GFR ratio of each study was correlated with the mean frequency of CIN-1 (s-Cr rise⩾44.2 µmol/l or ⩾20–25%) and CIN-2 (oliguria or requiring dialysis). A maximum dose according to an I-dose/GFR ratio = 1 in patients with s-Cr ranging from 100 to 300 µmol/l was compared with that of Cigarroa's formula and with a “European consensus” threshold published by the European Society of Urogenital Radiology, both using s-Cr alone to predict renal function. McCullough's formula was used to assess the risk of CIN requiring dialysis at an I-dose/GFR ratio = 1 with LOCM.

Results: The coronary investigations revealed a linear correlation with a correlation coefficient between the I-dose/GFR ratio and the frequency of CIN-1 and CIN-2 of 0.91 ( P<0.001) and 0.84 ( P = 0.001), respectively. At a mean I-dose/GFR ratio = 1, the regression line indicated a 10% risk of CIN-1 and a 1% risk of CIN-2. At a mean I-dose/GFR ratio = 3, the risk of CIN-1 and CIN-2 increased to about 50% and 15%, respectively. Pooled weighted data from the CT investigations revealed a 12% risk of CIN-1 at a mean I-dose/GFR ratio = 1.1 and no cases of CIN-2. The maximum CM dose according to an I-dose/GFR ratio = 1 was about 30–50% of that of both Cigarroa's formula and the “European consensus” in elderly low-weight individuals, while it was similar for middle-aged individuals weighing about 90 kg. McCullough's formula suggests that there will be an exponentially increasing risk of CIN requiring dialysis, but at an I-dose/GFR ratio = 1 and using LOCM it will not exceed 1% until GFR decreases below 30 ml/min in diabetics and below 20 ml/min in non-diabetics.

Conclusion: Using the I-dose/GFR ratio may be a more expedient way of improving risk assessment of CIN than today's common practice of estimating CM dose from volume alone and renal function from s-Cr alone. Prospective studies based on individual patient data are encouraged to define the risk of CIN at various I-dose/GFR ratios and correlated to type of CM, examination, risk factors, etc.

Background: Portal vein embolization (PVE) is now widely accepted as a useful preoperative procedure in selected patients undergoing extended hepatectomy. However, the effect of PVE on the growth of liver tumors has not been fully elucidated.

Purpose: To retrospectively evaluate the effects of PVE on the growth of liver tumors in the embolized lobes.

Material and Methods: Eight patients with a primary liver tumor, six hepatocellular carcinomas (HCC) and two cholangiocellular carcinomas (CCC), were studied. The growth rates of the tumors in the embolized lobes and non-embolized liver parenchyma were calculated using the computed tomography (CT) volume values at the time of tumor identification, and before and after PVE.

Result: The median tumor growth rate was 0.59 cm³/day (range 0.22–6.01 cm³/day) before PVE and 2.37 cm³/day (range 0.29–13.97 cm³/day) after PVE ( P = 0.018). The tumor growth acceleration ratios ranged from 1.50 to 7.46 (median 2.65) in the six HCCs, and were 1.00 and 1.32 in the two CCCs. There was no apparent correlation between the tumor growth rate after PVE and the growth rate of non-embolized liver parenchyma (median 6.00 cm³/day, range 1.24–11.0 cm³/day).

Conclusion: Liver tumor growth in an embolized lobe accelerates after PVE, in patients with HCC.

Purpose: To evaluate the utility and economic costs of the 11‐G vacuum‐assisted biopsy probe under ultrasound (US) guidance as an alternative to surgical excision in patients with probably benign lesions.

Material and Methods: US‐guided 11‐G vacuum‐assisted biopsy was performed in 102 probably benign breast lesions in 97 women who refused radiological follow‐up. Complete removal of the lesion was intended in all cases. Open biopsy was done if questionable pathologic findings were present. Treatment was indicated if the diagnosis was malignant. Economic costs were estimated taking into consideration monetary expenses generated to the public health system, as well as expenses for the patients receiving percutaneous and open surgical biopsy.

Results: Median patient age was 42 years (range 18–77). Median lesion size was 14.7 mm (range 6–30 mm). Complete removal of the lesion seen at imaging was achieved in 72.5% of cases. Adequate tissue samples for histopathological evaluation were obtained in all cases. Surgical biopsy was recommended in nine cases. One patient diagnosed with mucinous carcinoma underwent immediate surgical treatment. The remaining 87 women with 92 lesions were included in a follow‐up program. Economic cost of the 11‐G vacuum‐assisted percutaneous biopsy was 82% lower than the surgical biopsy (total savings in this series: €136,402.84). Time spent for the patient was 71% less in percutaneous biopsy than in surgery.

Conclusion: Ultrasound‐guided 11‐G directional vacuum‐assisted breast biopsy is an accurate and less expensive procedure that can be used as an alternative to open surgical excision in a selected group of patients.

Purpose: The aim of this study was to establish diagnostic criteria for meniscal subluxation, and to determine whether there was any connection between meniscal subluxation and other common meniscal and knee-joint abnormalities.

Material and Methods: The normal position of the meniscal body was assessed in 10 asymptomatic volunteers. MR signs of meniscal subluxation were evaluated retrospectively in 60 symptomatic patients with pain in the knee, impaired mobility, and/or joint swelling who had no clear diagnosis after the evaluation of case history, clinical examination, and radiography. The criterion for subluxation of the meniscus was defined as a distance of ≥3 mm between the peripheral border of the meniscus and the edge of the tibial plateau.

Results: In the volunteers, the mean distance from the medial meniscus to the edge of the tibial plateau was 0.07 mm, and that from the lateral meniscus was 0 mm. In 55 symptomatic patients without meniscal subluxation, the mean distance from.the meniscus to the edge of the tibial plateau was 0.27 mm. Five patients (8%) had evidence of meniscal subluxation, 4 in the medial meniscus and one in the lateral meniscus. The most commonly associated knee abnormality was joint effusion in 5 knees and osteoarthritis in 2 knees.

Conclusion: Meniscal subluxation was not a rare finding with MR imaging in patients with painful knees. Meniscal subluxation was associated with other knee abnormalities such as joint effusion or osteoarthritis.

Purpose: To establish reference data and to study age-dependency for cerebral perfusion in various regions of the brain in a healthy population.

Material and Methods: Eighty healthy subjects of both genders from 22 to 85 years of age were studied with spin echo echo-planar dynamic susceptibility contrast MR imaging (DSC MRI) at 1.5 T. Cerebral blood volume (CBV), cerebral blood flow (CBF), and contrast agent mean transit time (MTT) were calculated bilaterally for 20 distinct neuroanatomic structures.

Results: In gray matter, the following values were found (mean ± SD): CBV (4.6 ± 1.0 ml/100 g), CBF (94.2 ± 23.0 ml/100 g/min), and MTT (3.0 ± 0.6 s), and in white matter: CBV (1.3 ± 0.4 ml/100 g), CBF (19.6 ± 5.8 ml/100 g/min), and MTT (4.3 ± 0.7 s). The perfusion parameters did not change with age, except for a tendency to an increase in gray matter MTT and CBV. Males exhibited higher MTT and CBV than females. No hemispheric difference was found in either gender.

Conclusion: Cerebral hemodynamics can be assessed with DSC MRI. Age itself seems to have only a marginal effect on cerebral perfusion in healthy population.

Purpose: To evaluate the diagnostic efficacy of mangafodipir trisodium (MnDPDP, Teslascan) as a new contrast agent for MR imaging of the liver based on an independent evaluation of the MR images from the European phase III studies.

Material and Methods: MR imaging of the liver was done at 0.5–2.0 T in 17 European centres and included T1-weighted spin-echo and gradient-echo sequences before and after administration of MnDPDP to patients at a dose of 5 μmol/kg b.w. T2-weighted images were also obtained in all cases before the i.v. injection of the agent. Images of a total of 592 patients were evaluated by 4 independent experienced radiologists who were not involved in the on-site clinical trials.

Results: Statistically significantly more lesions were detected (p = 0.0014) in MnDP-DP-enhanced T1-weighted MR images than in unenhanced images. T1-weighted gradient-echo sequences were found to be superior to T1-weighted spin-echo sequences after injection of MnDPDP. The post-contrast images were found to be statistically significantly superior to the pre-contrast images in confidence in the presence of a lesion ( p≤ 0.0001), quality of lesion delineation ( p≤ 0.0001), lesion conspicuity ( p ≤ 0.0001) and in the confidence in the diagnosis of a lesion (p = 0.001).

Conclusion: This independent evaluation of the European phase III trials confirmed the superiority of MnDPDP-enhanced MR images over unenhanced images for lesion detection and characterization.