Detection Of Hepatic Metastases Research Articles

Detection of Hepatic Metastases from Carcinoid Tumor: Prospective Evaluation of Contrast-Enhanced Ultrasonography

The purpose of our study was to prospectively compare unenhanced ultrasonography (US) to contrast-enhanced US (CEUS) in the detection of hepatic metastases from carcinoid tumor. Thirty patients with carcinoid tumor prospectively underwent US, CEUS, and magnetic resonance imaging (MRI). Differences in sensitivity at US and CEUS were compared using a combination of the results of MR imaging, fine-needle biopsy, and follow-up imaging. Lesion conspicuity was assessed subjectively for US and CEUS. Seventeen patients had a total of 69 hepatic metastases. The addition of CEUS improved the detection of individual metastases from 47 (Se 68%; 95% CI: 57.0, 79.0) to 68 (Se 99%; 99% CI: 96.7, 100.0). Contrast enhancement improved the subjective conspicuity of metastases in 85% of patients. CEUS showed one more metastasis than did MRI in one patient, and MRI showed one more than did CEUS in one patient. CEUS is more sensitive than US in the detection of carcinoid liver metastases.

Sonografische Leberdiagnostik bei Tumorpatienten ohne und mit Kontrastmittel

In patients with known malignancy, correct detection and characterization of liver lesions has important therapeutic consequences. Conventional sonography is the most commonly used modality for liver imaging in tumor patients. However, it has a lower sensitivity for the detection of liver metastases compared to contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI). The majority of liver metastases are hypoechoic and well defined in baseline ultrasound (US), while detection of isoechoic or small liver metastases <1 cm is difficult and the differentiation of liver metastases from benign liver lesions and other malignant liver tumors can be impossible with baseline US. The use of microbubble-based ultrasound contrast agents and contrast-specific imaging techniques advanced the accuracy of ultrasound in liver imaging. Levovist and SonoVue are the US contrast agents approved for liver imaging in Europe. Compared to Levovist, SonoVue allows continuous imaging of the liver in real-time over a period of up to 5 minutes. As a result, SonoVue became the preferred contrast agent for liver imaging in the recent years, while Levovist became less important. Important for the detection of liver metastases are the portal venous and late phases in which metastases show a wash-out and can be detected as hypoechoic lesions in homogeneous enhanced liver parenchyma. The detection of hepatic metastases is substantially improved by CEUS compared to conventional B-mode sonography. Several studies showed sensitivity in detecting liver metastases comparable to that of contrast-enhanced CT and MRI. Furthermore, the typical enhancement patterns of the different benign and malignant liver lesions allow reliable characterization and differentiation from liver metastases in the majority of cases. This paper provides information about the advantages and expedient application of contrast-enhanced ultrasound (CEUS) in tumor patients.

Detection of Hepatic Metastases from Colorectal Cancer: A Comparative Study between the SPIO-enhanced MR and Intraoperative Ultrasound

Purpose: To investigate the efficacy of SPIO (superparamagnetic iron oxide) enhanced MR imaging for the detection of colorectal liver metastasis, compared to the intraoperative ultrasound (IOUS). Materials and Methods: Thirteen patients who underwent IOUS during surgery for colorectal liver metastasis as well as a liver MR before and after administration of SPIO. The mean patient age was 57 years (age range: 43-77). Two observers reviewed the SPIO-enhanced MR via a double blind test. We evaluated the efficacy of the SPIO-enhanced MR compared to the results of IOUS. Results: Following IOUS, 55 lesions were found, including 32 metastases, 20 cysts, 2 calcifications, and 1 coagulation necrosis. The interobserver correlation of the SPIO-enhanced MR is significant, with a kappa index of 0.839. Radiologist 1 and 2 missed three lesions in three patients. Two of the patients had multiple liver lesions (six and eight, respectively), whereas the other patient had tumor recurrence following hepatic surgery for liver metastasis. In the other nine patients, MR detected all lesions. The sensitivity and positive predictive value of the SPIO-enhanced MR was 94.5%, and 100%, respectively. Conclusion: The SPIO-enhanced liver MR shows a good correlation to IOUS, especially in the case of patients who had fewer than three lesions. Therefore, the SPIO-enhanced MR may help to plan a surgical resection of colorectal liver metastasis.

Adrenocortical cancer: Improved detection of hepatic metastases with contrast-enhanced ultrasound as compared to contrast-enhanced CT

Adrenocortical cancer: Improved detection of hepatic metastases with contrast-enhanced ultrasound as compared to contrast-enhanced CT

Using the Direct-Injection Model of Early Uveal Melanoma Hepatic Metastasis to Identify TPS as a Potentially Useful Serum Biomarker

To develop a method to screen for serum biomarkers of early hepatic metastasis from uveal melanoma. Cytokeratin 18 (TPS) was identified from gene expression profiles as protein generated by highly invasive uveal melanoma cells. Sera were collected from two groups of 15 SCID mice 2 weeks after injection of either tissue culture medium or MUM2B human metastatic uveal melanoma cells into the mouse liver. Serum TPS levels were assayed in 53 healthy human controls, 64 uveal melanoma patients who were disease free for at least 10 years, and 37 patients with metastatic uveal melanoma. After 2 weeks, small hepatic nodules (0.1-2.8 mm; mean, 0.80 mm) developed in 11 of 15 mice injected with MUM2B cells. Serum TPS levels in media-injected mice (84.7 U/L) were substantially lower than levels in MUM2B-injected mice (601 mug/L). TPS levels were significantly higher (P < 0.0001) in patients with metastatic uveal melanoma (139.63 +/- 22.20) than in healthy controls (54.23 +/- 0.01) or in patients free of disease (69.29 +/- 9.76). Significant differences were found between TPS levels before and after the development of hepatic metastases (P < 0.01), and serum TPS levels became elevated in four patients at least 6 months before the detection of hepatic metastases by abdominal ultrasonography. The direct-injection model of uveal melanoma in the mouse liver may be used to screen for potential serum biomarkers of metastatic uveal melanoma.

Detection of Hepatic Metastases From Colorectal Carcinoma

The specificity and sensitivity of intravenous-enhanced multidetector row computed tomography (MDCT), superparamagnetic iron oxide-enhanced magnetic resonance imaging (SPIO-MRI), multidetector row computed tomography with arterioportography combined with multidetector row computed tomography with hepatic arteriography (CTAP/CTHA), and intraoperative ultrasonography (IOUS) for detecting hepatic metastases from colorectal carcinoma were evaluated based on histopathologic examination of resected livers. MDCT, SPIO-MRI, CTAP/CTHA, and IOUS were performed routinely to determine surgical indications and methods in patients with hepatic metastases from colorectal carcinoma. The resected liver specimens were then cut serially into sections 3 to 5 mm thick for routine histologic examination. Fifty metastatic lesions were detected by histopathologic study of a large amount of anatomically resected liver from 8 patients with colorectal liver metastasis. The tumors ranged in size from 3 to 53 mm (mean 13.8 mm) and 26 lesions (52%) were less than 10 mm in diameter. Histopathologic examination of the resected liver specimens showed that CTAP/CTHA was the most sensitive imaging modality, followed in order by IOUS, SPIO-MRI, and MDCT. Among all the tumors detected by CTAP/CTHA, SPIO-MRI overlooked 5, but all of the tumors detected by SPIO-MRI were also detected by CTAP/CTHA. The number of metastatic liver tumors detected differed significantly among MDCT, SPIO-MRI, and histopathologic examination. One false-positive lesion was detected by IOUS. CTAP/CTHA is a useful preoperative imaging modality for detecting small hepatic metastases from colorectal carcinoma.

Magnetic Resonance Screening Trial for Hepatic Metastasis in Patients with Locally Controlled Choroidal Melanoma

The aim of the present study was to evaluate the value of magnetic resonance (MR) screening for detection of hepatic metastasis in patients with locally controlled choroidal melanoma. MR examinations were performed after an initial diagnosis of choroidal melanoma in 159 patients (mean age 56 years: range, 10-86 years). The MR follow-up interval was 5.2 +/- 1.7 years (range, 1.2-6.6 years). A total of 363 MR studies were reviewed by two radiologists for predominant signal intensity characteristics. Hepatic metastasis was verified by histological examination: tumor resection and CT-guided needle biopsy specimens and/or on the basis of an obvious progression in number and/or size of the lesions on the follow-up MR examination. The majority of patients underwent MR examinations from one to three times (n = 126, 79%). During a mean follow-up period of 5.7 years, a focal abnormality in the liver was found in 20 patients (13%). Of these, 15 patients (9%) were diagnosed as having hepatic metastasis. The number of the metastatic lesions with a short T1 and short T2 pattern were one (n = 1, 9%), two (n = 2, 18%), three (n = 1, 9%) and multiple (n = 7, 63%). The focal abnormalities of MR examinations in five other patients consisted of vascular artifacts (n = 3, 15%) and cysts with hemorrhage (n = 2, 10%). The screening of MR examinations detected hepatic metastasis in 15 of 159 patients (9%) with locally controlled choroidal melanoma.

Better detection of hepatic metastasis of adrenocortical carcinoma by echo-enhanced ultrasound than by high-resolution computerized tomography

Background: Adrenocortical carcinoma (ACC) is a rare and heterogeneous malignancy with incompletely understood pathogenesis and poor prognosis. Computerized tomography (CT) and magnetic resonance imaging (MRI) are routinely performed for imaging of the adrenal mass and for standard staging of chest and abdomen as lung and liver are the primary organs for metastatic spread in ACC. Contrast ultrasound is a non-invasive procedure which has been shown to have a high sensitivity and specifity for differentiation of hepatic and neuroendocrine tumours.

Detection of hepatic metastases using ferucarbotran‐enhanced MR imaging: Feasibility and diagnostic accuracy of three‐dimensional sensitivity‐encoding water‐excitation multishot echo‐planar sequence (3D‐SWEEP)

To evaluate the diagnostic accuracy of a ferucarbotran-enhanced three-dimensional sensitivity-encoding water-excitation multishot echo-planar sequence (3D-SWEEP) for detecting hepatic metastases compared to a T2*-weighted fast field-echo (FFE) sequence. Twenty-five consecutive patients with hepatic metastases underwent ferucarbotran-enhanced MRI on a 1.5-T unit before hepatic resections. Eighty-two foci of metastases were confirmed by histopathology or intraoperative ultrasonography (US). Signal-intensity decay (SID), tumor-to-liver contrast (TLC), and image quality were compared between T2*-weighted FFE and 3D-SWEEP. Three independent observers reviewed three imaging sets: set 1, without 3D-SWEEP or T2*-weighted FFE; set 2, with T2*-weighted FFE; and set 3, with 3D-SWEEP. The mean values of areas under alternative free response receiver operating characteristic curves (Az) and sensitivities were compared among the three sets. SID and TLC were significantly greater for 3D-SWEEP than T2*-weighted FFE, although 3D-SWEEP had poorer image quality. The mean Az and sensitivity were significantly greater for set 3 compared to set 1 for detecting overall lesions, and compared to sets 1 and 2 for detecting lesions of 1-2 cm in diameter. Despite relatively prominent artifacts, ferucarbotran-enhanced 3D-SWEEP was more sensitive and accurate than T2*-weighted FFE for detecting hepatic metastases.

Hepatic Metastases: Diffusion-weighted Sensitivity-encoding versus SPIO-enhanced MR Imaging

To retrospectively compare accuracy of diffusion-weighted (DW) single-shot echo-planar imaging with sensitivity encoding (SENSE) with that of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging in the evaluation of hepatic metastases due to extrahepatic malignancies. Patients provided informed consent; ethics committee approval was not required. The data of 24 patients (16 men, eight women; age range, 41-68 years; mean age, 61.9 years) with 40 resected hepatic metastases were retrospectively reviewed. Before SPIO administration, DW SENSE imaging and T2-weighted fast spin-echo (SE) and T1-weighted dual-echo fast field-echo (FFE) MR imaging were performed. After SPIO administration, T2-weighted fast SE, T1-weighted dual-echo, and T2*-weighted FFE MR examinations were performed. Images were divided into two sets: The SPIO-enhanced MR image set consisted of pre- and postcontrast T2-weighted fast SE and dual-echo T1-weighted FFE images and postcontrast T2*-weighted FFE images. The DW SENSE image set included DW SENSE images and precontrast T2-weighted fast SE and dual-echo T1-weighted FFE images. Three radiologists individually interpreted these images and sorted the confidence levels for presence of hepatic metastasis in each section into five grades. Area under the receiver operating characteristic (ROC) curve (A(z)) was calculated for each image set. Hepatic metastases showed higher signal intensity on DW SENSE images than on T2-weighted fast SE images. Conversely, signals from vessels and cysts were suppressed with DW SENSE imaging. ROC analysis showed higher A(z) values when the DW SENSE image set was interpreted (0.90) than when the SPIO-enhanced MR image set was interpreted (0.81). The sensitivity and specificity, respectively, of total cases were 0.66 and 0.90, for the SPIO-enhanced MR image set and 0.82 and 0.94 for the DW SENSE image set. During SPIO-enhanced MR image interpretation, lesions 1 cm in diameter or smaller showed significantly lower sensitivity than lesions larger than 1 cm in diameter. During both interpretation sessions, left lobe lesions showed significantly lower sensitivity than right lobe lesions. Combined reading of DW SENSE images and T2-weighted fast SE and dual-echo T1-weighted FFE MR images showed higher accuracy in the detection of hepatic metastases than did reading of SPIO-enhanced MR images.

Hepatic Metastases: Detection with Multi–Detector Row CT, SPIO-enhanced MR Imaging, and Both Techniques Combined

To retrospectively compare the accuracy in detection of hepatic metastases among contrast material-enhanced multi-detector row computed tomography (CT) alone, superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging alone, and a combination of contrast-enhanced CT and SPIO-enhanced MR imaging. The ethics committee did not require its approval or informed consent for this retrospective study, which was compliant with Declaration of Helsinki principles. Data in 38 patients (22 men, 16 women; mean age, 64.5 years; range, 35-78 years) suspected of having hepatic metastases who underwent both contrast-enhanced CT and SPIO-enhanced MR imaging were retrospectively analyzed. Twenty-one of the 38 patients had 61 metastases. Seventeen of the 61 metastases were confirmed histologically; the remaining 44 metastases were defined with imaging follow-up. At MR imaging, SPIO-enhanced heavily T1-weighted images, T2*-weighted gradient echo images, and T2-weighted fast spin-echo images were evaluated. Contrast-enhanced multi-detector row CT images obtained in the portal phase were evaluated. Four blinded observers independently reviewed CT images, MR images, and the combination of CT and MR images. Diagnostic accuracy was evaluated by using the alternative free-response receiver operating characteristic (AFROC) method. Sensitivities and positive predictive values were also analyzed with the Fisher protected least significant difference test and generalized estimating equations. The mean area under the AFROC curve for the combined approach (0.70) was significantly higher than that for SPIO-enhanced MR imaging alone (0.58, P < .05, Fisher protected least significant difference test), and there was no significant difference between each of them and that for contrast-enhanced CT alone (0.66). For all lesions, the mean sensitivity of combined imaging (0.59) was significantly higher than that of CT (0.48) or MR imaging (0.43) alone (P < .05, Fisher protected least significant difference test and generalized estimating equations). For all lesions, the mean positive predictive values were 0.82, 0.89, and 0.81, for combined MR and CT, CT alone, and MR alone, respectively. The addition of SPIO-enhanced MR imaging to contrast-enhanced multi-detector row CT (ie, combined analysis of SPIO-enhanced MR images and contrast-enhanced CT images) can improve sensitivity in the detection of hepatic metastases, although this improvement in sensitivity was not significant at AFROC analysis.

Anti-epithelial membrane antigen monoclonal antibodies and radioimmunolocalization of colorectal cancer

The monoclonal antibodies LICR-LON M8 and 77-1, which react with epithelial membrane antigen, showed a strong reaction with colorectal cancer on immunohistochemistry. In a radioimmunolocalization study in patients with colorectal cancer, 111In-labelled M8 detected 13 of 16 tumour sites present in 16 patients. 111In-labelled 77-1 detected 10 of 15 tumour sites present in 14 patients. The high radioactive background in the liver prevented the detection of hepatic metastases in eight patients (five in the M8 and three in the 77-1 group). The mean (s.d.) tumour to normal colon ratio was 2.5(1.2) for M8 and 1.6(0.5) for 77-1 at day 6 after antibody administration. The mean (s.d.) tumour to blood ratio was 4.9(3.7) for M8 and 3.6(1.5) for 77-1. There was no statistical difference between these results. All scan-positive cancers reacted with M8 and 77-1 on immunohistochemistry. The results suggest that these monoclonal antibodies may have a role in the immunolocalization of colorectal cancer.

The value of plasma gamma-glutamyl transpeptidase in the detection of hepatic metastases.

Abstract It has been suggested that measurement of the plasma enzyme gamma-glutamyl transpeptidase (GGTP) may be useful in the detection of hepatic metastases. To assess the value of GGTP as a screening test for hepatic metastases, 40 cases of gastro-intestinal carcinoma were studied prior to surgery. Ten patients had hepatic metastases, and in 5 of these the plasma GGTP was within normal limits. Abnormal GGTP results were always associated with elevation of the plasma alkaline phosphatase, and preoperative clinical examination of the liver proved to be the most accurate method for the detection of hepatic metastases.

European federation of societies for ultrasound in medicine and biology (EFSUMB) guidelines for the use of contrast agents in liver ultrasound: what is the impact in clinical practice?

Ultrasound is the most commonly used liver imaging modality worldwide. Unfortunately, ultrasound has limited sensitivity in the detection of small tumour nodules. Moreover, ultrasound findings are often non-specific, as there is enough variability and overlap in the appearance of benign and malignant liver lesions to make a definite distinction problematic. Recently, the introduction of microbubble contrast agents and the development of contrast-specific techniques have opened new prospects in liver ultrasound. The advent of second-generation agents that have higher harmonic emission capabilities has been instrumental in improving the easiness and the reproducibility of the examination. Over the past few years, several reports have shown that real-time contrast-enhanced ultrasound can substantially improve detection and characterization of focal liver lesions with respect to baseline studies. With the publication of the guidelines for the use of contrast agents in liver ultrasound by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB), contrast-enhanced ultrasound has entered clinical practice. The guidelines define the indications and recommendations for the use of contrast agents in focal liver lesion detection, characterization and posttreatment follow-up. In this paper, we discuss the impact of EFSUMB guidelines on diagnostic protocols currently adopted in liver imaging with regard to four clinical scenarios: (1) characterization of focal liver lesions of incidental detection; (2) diagnosis of HCC in patients with cirrhosis; (3) detection of hepatic metastases in oncology patients; (4) guidance and assessment of the outcome of percutaneous tumour ablation procedures.

Microcirculation and tumor-infiltrating macrophages in choroidal and ciliary body melanoma and corresponding metastases.

To investigate the relationship between progression to hepatic metastasis and tumor-infiltrating macrophages and microcirculation attributes in uveal melanoma, a cancer that almost invariably disseminates hematogenously to the liver. A cross-sectional histopathologic analysis of 48 hepatic metastases and corresponding primary choroidal and ciliary body melanomas was conducted, by using statistical tests appropriate for paired data. Main outcome measures were the number and type of CD68-immunopositive, tumor-infiltrating macrophages, extravascular matrix loops and networks identified with periodic acid-Schiff stain, and microvascular density (MVD) counted as the number of discrete structures labeled by monoclonal antibody QBEND/10 to the CD34 epitope. Hepatic metastases had a significantly lower grade of pigmentation (P < 0.0001), more frequent epithelioid cells (P = 0.0027), more intermediate and dendritic types of CD68-immunopositive macrophages than round ones (P = 0.0031), and a higher MVD (median difference, 15 counts more/0.313 mm2, P = 0.0003) than the primary uveal melanomas that spawned the metastases. The frequency of tumors with extravascular loops and networks did not increase on metastasizing. The survival of the patient after diagnosis of disseminated disease tended to be shorter if hepatic metastases had a high MVD (P = 0.098), adjusting for the size of the specimen. Of the markers studied, the presence of epithelioid cells and MVD most closely parallel progression of uveal melanoma from primary tumor to metastasis. These two tumor characteristics may be interrelated, and high MVD may help to predict survival after detection of hepatic metastases. The results also suggest that the grade of pigmentation and morphologic type of tumor-infiltrating macrophages are interrelated.

Follow-up Results After Negative Findings on Unenhanced Hepatic MR Imaging for Hepatic Metastasis from Rectal Cancer

ObjectiveTo assess the follow-up results after negative findings on unenhanced hepatic MR imaging in rectal cancer patients who have undergone locally curative surgery.Materials and MethodsFrom all pertinent imaging reports and medical records, we selected 255 patients who had negative results on unenhanced hepatic MR imaging. When selecting patients who had undergone curative resection, the following patients were excluded from the study: 1) patients in whom extrahepatic metastases were detected on preoperative staging work-ups, 2) patients in whom the surgery was judged to be non-curative due to peritoneal seeding or local aggressiveness. Cases with follow-up periods of less than 18 months were also excluded, as these cases were considered insufficient to confirm the negative outcomes. Thus, a total of 149 patients were ultimately enrolled in our study. The follow-up results of unenhanced MR imagings were assessed according to the assumption that the newly developed hepatic metastases had been false-negative lesions on preoperative MR image.ResultsDuring a median follow-up period of 29.3 months, 25 hepatic metastases were detected in 13 patients (8.7%), which indicated a negative predictive value of 91.3%.ConclusionUnenhanced hepatic MR imaging provides a high negative predictive value with regard to the detection of hepatic metastasis in the preoperative evaluation of rectal cancer.

New techniques for imaging colorectal cancer: the use of MRI, PET and radioimmunoscintigraphy for primary staging and follow-up.

Modern imaging techniques such as computed tomography (CT) and ultrasound (US) are in the majority of cases able to detect local and metastatic spread of malignancy. Increasingly, the requirement is for even more accurate pre-operative tumour staging to enable the use of new surgical techniques, neo-adjuvant therapies and, postoperatively, to enable detection of tumour recurrence on follow-up. Recent imaging research has focused on magnetic resonance imaging (MRI) for the detection of local tumour extension particularly for rectal tumours and on positron emission tomography (PET) and radioimmunoscintigraphy (RIS) for the detection of metastatic nodal and soft tissue disease. This article briefly describes these three imaging modalities and their role in primary staging, detection of hepatic metastases and local recurrence.

Multi-detector row helical CT in preoperative assessment of small (< or = 1.5 cm) liver metastases: is thinner collimation better?

To determine the value of collimations less than 5 mm in detecting hepatic metastases 1.5 cm or smaller by using multi-detector row helical computed tomography (CT). Thirty-one patients underwent contrast material-enhanced multi-detector row helical CT before hepatic resection in this prospective study. Images were reconstructed at collimations of 5.00, 3.75, and 2.50 mm with 50% overlap and reviewed independently by three radiologists. Each lesion was characterized as metastatic, benign, or equivocal and graded for conspicuity. Criterion standards were pathologic assessment of the resected liver and follow-up of the nonresected liver. Only lesions 1.5 cm or smaller were analyzed. There were a total of 88 liver lesions 1.5 cm or smaller, and 25 of these were metastases. Pooled sensitivity for all lesions improved with thinner collimation (66% [58 of 88 lesions], 69% [61 of 88], and 82% [72 of 88] at collimations of 5.00, 3.75, and 2.50 mm, respectively), and this was statistically significant (P =.01). However, no significant difference was noted between collimations in the pooled sensitivity for metastatic lesions (80% [20 of 25 lesions] at all collimations) (P >.99). No statistical difference was noted in the conspicuity of lesions at different collimations (P =.18). Image reconstruction with multi-detector row helical CT at collimations less than 5 mm may not improve sensitivity in the detection of hepatic metastases 1.5 cm or smaller.

Detection of Hepatic Metastases from Cancers of the Gastrointestinal Tract by Using Noninvasive Imaging Methods (US, CT, MR Imaging, PET): A Meta-Analysis

To perform a meta-analysis to compare current noninvasive imaging methods (ultrasonography [US], computed tomography [CT], magnetic resonance [MR] imaging, and (18)F fluorodeoxyglucose [FDG] positron emission tomography [PET]) in the detection of hepatic metastases from colorectal, gastric, and esophageal cancers. A MEDLINE literature search and review of article bibliographies and our institutional charts of patients with colorectal cancer identified data with histopathologic correlation or at least 6 months of patient follow-up. Two authors independently abstracted data sets and excluded data without contingency tables or data published more than once. Summary-weighted estimates of sensitivity were obtained and stratified according to specificity of less than 85% or 85% and higher. A covariate analysis was used to evaluate the influence of patient- or study-related factors on sensitivity. Among 111 data sets, nine US (509 patients), 25 CT (1,747 patients), 11 MR imaging (401 patients), and nine PET (423 patients) data sets met the inclusion criteria. In studies with a specificity higher than 85%, the mean weighted sensitivity was 55% (95% CI: 41, 68) for US, 72% (95% CI: 63, 80) for CT, 76% (95% CI: 57, 91) for MR imaging, and 90% (95% CI: 80, 97) for FDG PET. Results of pairwise comparison between imaging modalities demonstrated a greater sensitivity of FDG PET than US (P =.001), CT (P =.017), and MR imaging (P =.055). At equivalent specificity, FDG PET is the most sensitive noninvasive imaging modality for the diagnosis of hepatic metastases from colorectal, gastric, and esophageal cancers.

Ferumoxide-enhanced MRI in patients with colorectal cancer and rising CEA: surgical correlation in early recurrence

The purpose of this study was to evaluate the value of Ferumoxide-enhanced magnetic resonance (MR) imaging in the detection of hepatic metastases in high-risk patients treated for colorectal cancer that have rising CEA. We used 19 patients treated previously for colorectal cancer with rising CEA levels underwent an unenhanced T 1-weighted (T1W), T 2-weighted (T2W), STIR, and Ferumoxide-enhanced hepatic MRI. Following these studies, a laparotomy was performed and the liver was evaluated by palpation and intraoperative ultrasound. Two observers who were blinded to surgical results evaluated each MR sequence separately. The number of lesions considered highly suspicious for metastatic lesions were determined for each sequence and were compared to the results of surgery. The McNemar test was used to compare the outcomes of the different sequences. MR Imaging was unable to detect small (<5 mm) metastases discovered at surgery. The best non-contrast sequences for detecting metastases were the STIR with 42% sensitivity, 83% specificity and an overall accuracy of 56% and the T1W sequence (sensitivity 38%, specificity 100%, accuracy 57%), which were not significantly different ( p > 0.4). The noncontrast T2W sequence had a sensitivity of 29% and a specificity of 77% with an overall accuracy of 46%. When all pre contrast scans were grouped together the common sensitivity was 42%, specificity was 77% and accuracy was 54%. The post-ferumoxide T 2W scans had a sensitivity of 42%, specificity of 85%, and accuracy of 57%, but did not detect any additional lesions. There was no statistical difference between the pre- and post-contrast studies with regard to identifying patients with metastatic disease ( p > 0.1). In conclusion, we found small hepatic metastases in patients with early signs of recurrent colorectal cancer are difficult to detect on MRI. Ferumoxide-enhanced MRI was unable to detect additional hepatic metastases and performed no better than unenhanced MRI in detecting small hepatic metastasis.