Utility of sonography for small hepatic lesions found on computed tomography in patients with cancer

Surveillance for Metastasis in High-Risk Uveal Melanoma Patients: Standard versus Enhanced Protocols

PURPOSE

to evaluate the effectiveness of enhanced surveillance protocols (EP) utilizing high frequency (HF) or enhanced modality (EM) compared to the standard protocol (SP) in detecting metastasis and determining their impact on overall survival (OS) in high-risk uveal melanoma (UM) patients.

METHODS

A total of 87 consecutive patients with Class 2 (high risk) primary UM were enrolled, with negative baseline systemic staging. The patients underwent systemic surveillance with either SP (hepatic ultrasonography [US] every 6 months) or EP (either HF [US every 3 months] or EM [incorporation hepatic computed tomography/magnetic resonance imaging]) following informed discussion. The main outcome measures were largest diameter of largest hepatic metastasis (LDLM), number of hepatic metastatic lesions, time to detection of metastasis (TDM), and OS.

RESULTS

This study revealed significant differences in LDLM between surveillance protocols, with the use of EP detecting smaller metastatic lesions (HF, EM, and SP were 1.5 cm, 1.6 cm, and 6.1 cm, respectively). Patients on the EM protocol had a lower 24-month cumulative incidence of >3 cm metastasis (3.5% EM vs. 39% SP; p = 0.021), while those on the HF protocol had a higher 24-month cumulative incidence of ≤3 cm metastasis compared to SP (31% HF vs. 10% SP; p = 0.017). Hazard of death following metastasis was significantly reduced in the EP (HR: 0.25; 95% CI: 0.07, 0.84), HF (HR: 0.23; 95% CI: 0.06, 0.84), and EM (HR: 0.11; 95% CI: 0.02, 0.5) groups compared to SP. However, TDM and OS did not significantly differ between protocols.

CONCLUSIONS

Enhanced surveillance protocols improved early detection of hepatic metastasis in UM patients but did not translate into a survival advantage in our study cohort. However, early detection of metastasis in patients receiving liver-directed therapies may lead to improved overall survival.

Metastatic uveal melanoma: The final frontier

Treatment of primary intraocular uveal melanoma has developed considerably, its driver genes are largely unraveled, and the ways to assess its risk for metastases are very precise, being based on an international staging system and genetic data. Unfortunately, the risk of distant metastases, which emerge in approximately one half of all patients, is unaltered. Metastases are the leading single cause of death after uveal melanoma is diagnosed, yet no consensus exists regarding surveillance, staging, and treatment of disseminated disease, and survival has not improved until recently. The final frontier in conquering uveal melanoma lies in solving these issues to cure metastatic disease. Most studies on metastatic uveal melanoma are small, uncontrolled, retrospective, and do not report staging. Meta-analyses confirm a median overall survival of 10-13 months, and a cure rate that approaches nil, although survival exceeding 5 years is possible, estimated 2% either with first-line treatment or with best supportive care. Hepatic ultrasonography and magnetic resonance imaging as surveillance methods have a sensitivity of 95-100% and 83-100%, respectively, to detect metastases without radiation hazard according to prevailing evidence, but computed tomography is necessary for staging. No blood-based tests additional to liver function tests are generally accepted. Three validated staging systems predict, each in defined situations, overall survival after metastasis. Their essential components include measures of tumor burden, liver function, and performance status or metastasis free interval. Age and gender may additionally influence survival. Exceptional mutational events in metastases may make them susceptible to checkpoint inhibitors. In a large meta-analysis, surgical treatment was associated with 6 months longer median overall survival as compared to conventional chemotherapy and, recently, tebentafusp as first-line treatment at the first interim analysis of a randomized phase III trial likewise provided a 6 months longer median overall survival compared to investigator's choice, mostly pembrolizumab; these treatments currently apply to selected patients. Promoting dormancy of micrometastases, harmonizing surveillance protocols, promoting staging, identifying predictive factors, initiating controlled clinical trials, and standardizing reporting will be critical steppingstones in reaching the final frontier of curing metastatic uveal melanoma.

Intraoperative (Contrast-Enhanced) Ultrasound Has the Highest Diagnostic Accuracy of Any Imaging Modality in Resection of Colorectal Liver Metastases

AIM

Defining sensitivity, specificity, diagnostic accuracy for detection of colorectal liver metastases in imaging compared to intraoperative assessment. Defining a cutoff, where accuracy of detection is impaired.

METHODS

Prospective single-institution clinical trial (clinicaltrials.gov: NCT01522209). Patients underwent CEUS, MDCT, and 3 Tesla EOB-MRI within 2 weeks preoperatively. Intraoperative palpation, IOUS, and CEIOUS were performed. A patient and lesion-based database was analyzed for accuracy of detection of CEUS, CT, MRI, and Palp/IOUS/CEIOUS combined read. Histology was standard of reference.

RESULTS

Forty-seven high tumor load (mean 5, 4 lesions) patients were analyzed. Histopathology confirmed 264 lesions (245 malignant: 19 benign). Accuracy for detection of all lesions: CEUS 63%, CT 71%, MRI 92%, and PALP/IOUS/CEIOUS 98%. ROC analysis for lesion size showed severe impairment of accuracy in lesion detection smaller than 5mm. Intraoperative imaging was not impaired by lesion size. Patient-based analysis revealed a change of resection plan after IOUS/CEIOUS in 35% of patients.

CONCLUSION

At 5-mm lesion size, preoperative imaging shows a drop in accuracy of detection. In patients with multiple lesions, addition of MRI to MDCT seems useful. Accuracy of intraoperative ultrasound is not impacted by lesion size and should be mandatory. CEIOUS can improve intraoperative decision-making.

TRIAL REGISTRATION

Study registered with clinicaltrials.gov : NCT01522209.

Hepatic Ultrasonography Compared With Computed Tomography and Magnetic Resonance Imaging at Diagnosis of Metastatic Uveal Melanoma

PURPOSE

To evaluate the consistency of hepatic ultrasonography (US) with staging computed tomography (CT) and magnetic resonance imaging (MRI), to analyze why US was inconsistent with CT/MRI, and to compare CT/MRI.

DESIGN

Reliability analysis.

METHODS

Two hundred fifteen patients whose primary uveal melanoma was managed in the Helsinki University Hospital and who were diagnosed with hepatic metastases by US within 60 days of staging CT/MRI from January 1999 to December 2016 were included. Patients attended a real-life follow-up schedule including hepatic US, liver function tests (LFT), and a confirmatory CT/MRI. We evaluated the consistency of US with staging CT/MRI regarding the presence and number of metastases.

RESULTS

The enrolled patients underwent 215 US, 167 CT, and 69 MRI examinations, and 67% of them had biopsy-confirmed metastases. Screening was regular for 98% of the patients, and 66% were asymptomatic. US was fully consistent with CT/MRI in detecting metastases in 113 (53%) patients, in 63 (29%) CT/MRI showed more metastases, and in 16 (7%) CT/MRI showed fewer metastases than US. CT/MRI was inconsistent with US in 23 (11%) patients. The sensitivity of US in detecting metastases was 96% (95% confidence interval, 92-98). US failed to suggest metastases in 10 patients. LFT were abnormal in 6 of them, and a newly detected hepatic lesion was present by US in 4.

CONCLUSIONS

Hepatic US is a sensitive screening modality in detecting metastases in patients with primary uveal melanoma, if combined with LFT and, in case of any newly detected lesion, a confirmatory MRI.

Indeterminate liver lesions - a virtual epidemic: a cohort study over 8 years

BACKGROUND

Within the last decade, advances and availability in radiological imaging have led to an increase in the detection of incidental liver lesions (ILLs) in the asymptomatic patient population. This poses a diagnostic conundrum. This study was undertaken to review the outcome of liver lesions labelled as 'indeterminate' in asymptomatic patients without a biopsy-proven concomitant primary tumour. The secondary aim was to assess the impact on healthcare resources and cost-effectiveness with regards to the frequency and modality of radiological scans, multidisciplinary team discussions and clinic reviews.

METHODS

The study consisted of a retrospective analysis of prospectively collected data from the University Hospitals of Leicester multidisciplinary team database. The study period ranged from 2010 to 2015. All patients were followed-up for 3 years to ensure no late re-occurrences with malignancy.

RESULTS

A total of 92 patients with ILL were identified. The median age was 72 years. The median size of these ILLs was 10 mm. Eighty-seven patients required supplementary imaging and 42 required a third imaging. Ninety-one patients had benign lesions. Only one case was biopsy proven to be malignant.

CONCLUSION

Small (<15 mm) hepatic lesions discovered incidentally in patients with no known primary malignancy and risk factors are virtually always benign, with a 1% risk of malignancy. There is a need for a classification system, which stratifies ILLs by malignant potential based on a standardized and evidence-based approach. This is important to prevent unnecessary investigations. A multidisciplinary approach in an experienced hepatobiliary and pancreatic centre is recommended until such a classification exists.

The value of preoperative computed tomography combined with ultrasound in the investigation of small indeterminate liver lesions in patients with colorectal cancer

Background Computed tomography (CT) is used routinely for the preoperative detection of colorectal cancer (CRC) metastases. When small indeterminate focal liver lesions are detected that are too small to characterize (TSTC) on CT, additional imaging is usually needed, resulting in a potential delay in obtaining a complete diagnostic work-up. Purpose To determine the diagnostic accuracy of ultrasound (US) of the liver performed in direct conjunction to CT in the preoperative investigation among patients with newly diagnosed CRC when indeterminate liver lesions were found on CT. Material and Methods Preoperative investigations with CT and consecutive US where CT had shown at least one focal liver lesion in 74 patients diagnosed with CRC between June 2009 and February 2012 were retrospectively reviewed. Either histopathological findings or a combination of imaging and clinical follow-up one to three years after surgery was used as the reference. Results Liver metastases were diagnosed with CT/US in 13 out of 74 patients (17.6%). In one patient, a liver cyst was preoperatively regarded as liver metastasis by a combined CT/US. The sensitivity and specificity for the CT with consecutive US procedure was 100% (13/13) and 98.4% (60/61). Conclusion US performed in conjunction with CT in patients with indeterminate focal liver lesions on CT is an accurate work-up for detection of liver metastases in patients with newly diagnosed CRC. Although our results are promising, they cannot be considered safely generalizable to all hospitals.

Imaging of Hepatic Metastases

BACKGROUND

Imaging plays an important role not only in screening, evaluating, staging, and monitoring disease, but also in surveillance following tumor ablation. Advances in imaging techniques have increased our ability to detect and characterize focal liver lesions, resulting in improvements in diagnostic capability and improved monitoring of liver metastases. This has led to increased interest in both hepatic imaging and image-guided hepatic interventions.

METHODS

Several imaging options are reviewed according to their effective application, notably computed tomography (CT), CT during arterial portography, ultrasound, magnetic resonance imaging, positron emission tomography, and integrated PET/CT imaging.

RESULTS

Although there are exceptions regarding imaging options based on patient selection and on institution preference and expertise, multidetector helical CT scanning remains the dominant modality in the evaluation of suspected hepatic metastases, and for preoperative planning, treatment monitoring, and posttreatment follow-up.

CONCLUSIONS

Ultimately, the choice of imaging modality must be based not only on the patient and the clinical situation, but also on the imaging expertise within each institution.

That liver lesion on MDCT in the oncology patient: is it important?

Multidetector-row computed tomography (MDCT) has become the primary imaging test for the staging and follow-up of most malignancies that originate outside of the central nervous system. Technical advances in this imaging technique have led to significant improvement in the detection of metastatic disease to the liver. An unintended by-product of this improving diagnostic acumen is the discovery of incidental hepatic lesions in oncology patients that in the past remained undetected. These ubiquitous, incidentally identified hepatic lesions have created a management dilemma for both clinicians and radiologists: are these lesions benign or do they represent metastases? Naturally, the answer to this question has profound prognostic and therapeutic implications. In this review, guidelines concerning the diagnosis and management of some of the more common hepatic incidental lesions detected in patients with extrahepatic malignancies are presented.

Analysis of clinical and ultrasonographic data by use of logistic regression models for prediction of malignant versus benign causes of ultrasonographically detected focal liver lesions in dogs

OBJECTIVE

To investigate the value of clinical, laboratory, and imaging data for use in predicting malignant or benign histologic results for ultrasonographically detected focal liver lesions in dogs.

SAMPLE

Records and archived images of 247 dogs evaluated at the University of Minnesota Veterinary Medical Center from 2005 to 2008 that underwent abdominal ultrasonography and histologic evaluation of the liver.

PROCEDURES

Data were analyzed with multivariable logistic regression models. All dogs were classified as having benign or malignant liver disease on the basis of histologic reports. Three multivariable logistic regression models were fit to a development subset of the data by use of combinations of signalment, historical, physical examination, laboratory, and diagnostic imaging (survey radiography and abdominal ultrasonography) data as predictor variables. The resulting models were validated by evaluating predictive performance against a holdout validation subset of the data.

RESULTS

Models that included ultrasonographic variables had the highest overall predictive value. In these models, greater lesion size and the presence of peritoneal fluid were the only variables that had a positive association with malignant liver disease.

CONCLUSIONS AND CLINICAL RELEVANCE

Large ultrasonographically detected liver lesions and the presence of peritoneal fluid were associated with malignant liver disease in dogs.

Diagnosing small hepatic cysts on multidetector CT: an additional merit of thinner coronal reformations

Objective

We wanted to validate the additional merit of the thinner coronal reformation images from multidetector CT (MDCT) for making the diagnosis of hepatic cysts.

Materials and Methods

For the 90 benign hepatic cysts confirmed on MRI, the transverse (5-mm thickness) and additional coronal (2-mm thickness) reformation images from MDCT were compared with each other in terms of the Hounsfield units (HUs) and the size of each hepatic cyst.

Results

The attenuations (mean: 17.2 HUs, standard deviation: ± 14.4) on the thinner coronal images were significantly lower than those (mean: 40.7 HUs; standard deviation: ± 20.6) on the thicker transverse images for the small hepatic cysts (≤ 10 mm on the transverse image, p < 0.01). Twenty-three (79%) of the 29 cysts between 5 mm and 10 mm and 21 (51%) of 41 lesions up to 5 mm showed a mean HU value of 20 or less on the coronal reformation images.

Conclusion

By reducing the partial volume effect, routine coronal reformation of MDCT with a thinner section thickness can provide another merit for making a confidential diagnosis of many small sub-centimeter hepatic cysts, and these small cysts are not easily characterized on the conventional transverse images.

Hepatic incidentalomas

Recent advances in multidetector-row computed tomography, magnetic resonance imaging, and ultrasonography have led to the detection of incidental hepatic lesions in both the oncology and nononcology patient population that in the past remained undiscovered. These incidental hepatic lesions have created a management dilemma for both clinicians and radiologists. In this review, guidelines concerning the diagnosis and management of some of the more common hepatic incidentalomas are presented.

Real-time ultrasonography-computed tomography fusion imaging for staging of hepatic metastatic involvement in patients with colorectal cancer: initial results from comparison to US seeing separate CT images and to multidetector-row CT alone

OBJECTIVES

To prospectively evaluate the role of real-time ultrasonography (US)-computed tomography (CT) fusion imaging (US-CT) in comparison with US seeing separate CT images (US + CT) and multidetector-row CT (MDCT) for the correct staging of hepatic metastatic involvement in patients with colorectal cancer.

METHODS

Sixty-four patients with newly diagnosed colorectal cancer and who were referred for abdominopelvic staging before primary tumor resection underwent same-day MDCT, US + CT, and US-CT. Examinations were evaluated on-site by 2 investigators in consensus. Investigators recorded the size and location of detected lesions on segmental liver maps, classified them as being benign, malignant, or indeterminate, and finally assessed the M stage of the liver as being M0, M1, or Mx (indeterminate). All patients underwent surgical exploration including intraoperative US. Reference standard diagnosis was based on findings at surgery, intraoperative US, histopathology, and MDCT follow-up imaging. Differences among investigated modalities were analyzed using McNemar's test.

RESULTS

The reference standard verified 109 (45 < or = 1 cm) hepatic lesions in 25 patients, including 65 (25 < or = 1 cm) metastases in 16 patients (M1). Regarding the 45 < or = 1 cm liver lesions, rates for detection were significantly higher (P < 0.05) for MDCT (80%, 36/45) and US-CT (77.8%, 35/45) than for US + CT (64.4%, 29/45); the rate for correct classification by US-CT (71.1%, 32/45) was significantly higher than for US + CT (48.9%, 22/45) and MDCT (31.1%, 14/45) (all P < 0.05). On patient-based analysis, specificity of MDCT (85.4%, 41/48) was significantly lower (P < 0.05) than for US-CT (97.9%, 47/48) and US + CT (93.7%, 45/48); the positive predictive value of MDCT (63.1%, 12/19) was not significantly different (P = 0.27) compared with US + CT (82.3%, 14/17) but significantly lower (P < 0.05) than for US-CT (93.7%, 15/16). In 13 patients (59 lesions) with only benign (stage M0) or coexistent benign and malignant lesions (stage M1), indeterminate lesion ratings and indeterminate liver stagings (Mx) occurred both significantly lower (P < 0.05) with US-CT (3.4%, 2/59; and 0%, 0/13) than with US + CT (11.9%, 7/59; and 23.1%, 3/13) or with MDCT (30.5%, 18/59; and 53.8%, 7/13).

CONCLUSIONS

Based on these initial diagnostic experiences, complementary US-CT fusion imaging of small CT-indeterminate liver lesions may have value in staging patients with colorectal cancer, focusing on patients who were likely to harbor only benign or coexisting benign and malignant liver lesions and in whom change of M staging would change the clinical management.

Management of an incidental liver mass

The increased use of sensitive imaging modalities has led to increased identification of the incidental liver mass (ILM). A combination of careful consideration of patient factors and imaging characteristics of the ILM enables clinicians to recommend a safe and efficient course of action. Using an algorithmic approach, this article includes pertinent clinical factors and the specific radiologic criteria of ILMs and discusses the indications for potential procedures. It is the aim of this article to assist with the development of an individualized strategy for each patient with an ILM.

Magnetic resonance-guided upper abdominal biopsies in a high-field wide-bore 3-T MRI system: feasibility, handling, and needle artefacts

OBJECTIVE

To investigate the feasibility and handling of abdominal MRI-guided biopsies in a 3-T MRI system.

METHODS

Over a 1-year period, 50 biopsies were obtained in 47 patients with tumours of the upper abdominal organs guided by 3-T MRI with a large-bore diameter of 70 cm. Lesions in liver (47), spleen (1) and kidney (2) were biopsied with a coaxial technique using a 16-G biopsy needle guided by a T1-weighted three-dimensional gradient recalled echo volumetric interpolated breath-hold examination (T1w-3D-GRE-VIBE) sequence. Sensitivity, specificity, accuracy, complication rate, interventional complexity, room/intervention time and needle artefacts were determined.

RESULTS

A sensitivity of 0.93, specificity of 1.0 and accuracy of 0.94 were observed. Three patients required a rebiopsy. There was a minor complications rate of 13.6%, and no major complications were observed. Histopathology revealed 38 malignant lesions, and 3-month follow-up confirmed 9 benign lesions. Mean lesion diameter was 3.4 ± 3.1 cm (50% being smaller than 2 cm). Mean needle tract length was 10.8 ± 3.3 cm. Median room time was 42.0 ± 19.8 min and intervention time 9.3 ± 8.1 min. Needle artefact size was about 9-fold greater for perpendicular access versus access parallel to the main magnetic field.

CONCLUSION

Biopsies of the upper abdomen can be performed with great technical success and easy handling because of the large-bore diameter. The MRI-guided biopsy needle had an acceptable susceptibility artefact at 3 T. However future research must aim to reduce the susceptibility effects of the biopsy systems.

Natural history of small, "indeterminate" hepatic lesions in patients with colorectal cancer

PURPOSE

The initial staging CT scan for patients with colorectal cancer may reveal small, "indeterminate" hepatic lesions. The significance of these lesions is often unknown at the time of diagnosis. Surveillance of these lesions is often recommended because they may have an impact on the subsequent management of these patients. This study was designed to determine the prevalence and significance of small (<1 cm on CT scan), indeterminate liver lesions detected preoperatively in patients with colorectal cancer and to determine whether further surveillance imaging of these patients is required.

METHODS

Data were collected retrospectively, from January 1, 2002, to December 31, 2005. All colorectal cancer patients with small, indeterminate liver lesions on their initial staging CT scan were included. These lesions were formally reported as being too small to be characterized. All subsequent surveillance images of the liver were reviewed to assess the natural history of these lesions.

RESULTS

Four hundred nineteen patients with colorectal cancer had staging CT performed. Seventy patients (16.7%) had small liver lesions on their initial CT that could not be definitely characterized. Forty-six (65.7%) underwent subsequent imaging of their liver lesions. Forty-one (89.1%) of these were shown to be stable lesions that were likely benign. Only five patients (10.9%) showed progression on subsequent liver imaging, suggestive of early metastases and consistent with their clinical picture.

CONCLUSION

Small, indeterminate liver lesions may occur in up to 16.7% of patients with colorectal cancer. Although most of these lesions remain quiescent, surveillance imaging is recommended because a small but not insignificant proportion of patients with such lesions actually harbor early metastases.

Endoscopic ultrasound versus CT scan for detection of the metastases to the liver: results of a prospective comparative study

BACKGROUND

Computed tomography (CT) scan is a standard test for the detection of the liver metastases; however, metastases are often missed on the CT scan.

OBJECTIVE

To compare the accuracy of the endoscopic ultrasound (EUS)/endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with CT scan for detection of the liver metastases.

DESIGN

Prospective study.

PATIENTS

Subjects with newly diagnosed tumors of the lung, pancreas, biliary tree, esophagus, stomach, and colon were enrolled.

INTERVENTIONS

A CT scan and EUS examination of the liver was performed. EUS-FNA was performed on noncystic liver lesions.

RESULTS

One hundred thirty-two cases were enrolled. The presence of liver metastasis was established in 26 cases. The diagnostic accuracy of EUS/EUS-FNA and CT scan was 98% and 92%, respectively (P=0.0578). In comparison to CT scan, EUS detected significantly higher number of metastatic lesions in the liver (40 vs.19; P=0.008). CT scan detected lesions in liver that were too small to be characterized in 8 cases (malignant-3; benign-5). Of these, EUS-FNA correctly characterized the lesion to be malignant in 3/3 cases and benign in 4/5 cases. No complications were observed as a result of EUS-FNA.

LIMITATIONS

Endoscopist was not blinded to the findings of the CT scan.

CONCLUSIONS

In comparison with the CT scan, there was trend in favor of EUS/EUS-FNA for the superior diagnostic accuracy. EUS was distinctly superior to the CT scan in detecting the number of metastatic lesions. EUS-FNA was also useful to identify the nature of lesions that were too small to be characterized on the CT scan.

The role of contrast-enhanced ultrasound for focal liver lesion detection: an overview

The development of new ultrasound (US) contrast agents and sonographic techniques has considerably improved the possibilities of ultrasound in the assessment of liver tumors. An overview is given on diagnostic potential of contrast-enhanced US (CEUS) and real-time low mechanical index technique in the detection of various focal liver lesions compared with computed tomography, magnetic resonance imaging or intraoperative US. In two of our own studies that included 100 patients each we showed an increase of correct findings in CEUS compared with B-mode US from 64% to 87% and from 67% to 84% as confirmed by intraoperative evaluation of the liver. Especially after chemotherapy and in the case of small metastases, significantly more metastases were correctly detected by CEUS compared with B-mode US. These results and clinical study results in the literature show that CEUS allows tumor detection and direct visualization of the tumor vascularity and put contrast-enhanced sonography among recommended noninvasive imaging methods for focal liver lesions with improvements in diagnostic strategy.

Radiological staging of colorectal liver metastases

Rapid advances in imaging technology have improved the detection, characterization and staging of colorectal liver metastases. Multi-modality imaging approach is usually the more useful in staging colorectal liver metastases. Multi-detector computed tomography (MDCT) remains the main imaging modality for preoperative planning, lesion detection and tumour surveillance. Magnetic resonance imaging (MRI) and contrast enhanced ultrasonography (US) are invaluable in problem solving for characterization indeterminate lesions, while contrast enhanced intra-operative ultrasound (CE-IOUS) may be the new gold standard staging tool prior to liver resection. Ultimately, the imaging strategy has to be tailored to the clinical situation to obtain the most relevant information for optimal use of available imaging resources.

Contrast-enhanced ultrasonography to detect liver metastases : a prospective trial to compare transcutaneous unenhanced and contrast-enhanced ultrasonography in patients undergoing laparotomy

BACKGROUND/AIMS

The advent of contrast-enhanced ultrasound (CEUS) has called into question the efficacy of standard ultrasonographic techniques. In this study, we evaluated B-mode and color-duplex imaging and CEUS in the detection of liver metastases, using intraoperative and histological findings as a reference.

MATERIALS AND METHODS

Before laparotomy, 108 patients suspected of having liver metastases were prospectively examined with B-mode and color-duplex imaging, followed by contrast-enhanced ultrasound (2.4 ml SonoVue). Patients with unresectable tumors (n=8) were excluded from the analysis. The sonographic diagnosis in the remaining 100 patients was compared to the intraoperative and histological findings.

RESULTS/FINDINGS

CEUS improved the sensitivity for detecting liver lesions from 56.3% (B-mode) to 83.8% (CEUS) (p=0.004). In particular, the contrast agent led to an improvement in ultrasonographic detection in the following cases: nodular metastases smaller than one centimeter; after adjuvant chemotherapy; for tumors near the surface of the liver; and for lesions situated around the ligamentum teres.

INTERPRETATION/CONCLUSIONS

CEUS provides significant improvement in the detection of liver metastases, and should therefore, be performed routinely in the surveillance of cancer patients.

Small hepatic lesions found on single-phase helical CT in patients with malignancy: Diagnostic capability of breath-hold, multisection fluid-attenuated inversion-recovery (FLAIR) MR imaging using a half-fourier acquisition single-shot turbo spin-echo (HASTE) sequence

PURPOSE

To evaluate the diagnostic capability of breath-hold, multisection fluid-attenuated inversion-recovery (FLAIR) imaging using a half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence in combination with T2-weighted fast spin-echo (FSE) magnetic resonance (MR) sequences for small hepatic lesions found on CT in patients with malignancy.

MATERIALS AND METHODS

This study included 48 patients with extrahepatic malignancy who underwent both CT and MR examinations. There were a total of 112 small hepatic lesions (73 cysts and 39 liver metastases, <2 cm in diameter) that showed low attenuation on enhanced CT. Three radiologists independently reviewed the CT and MR (FLAIR-HASTE and T2-weighted FSE) images and assigned a confidence level to their evaluation (cyst or metastasis) on a five-point scale.

RESULTS

All three reviewers were significantly better able (P < 0.05) to differentiate small hepatic cyst from liver metastasis with combined FLAIR-HASTE and T2-weighted FSE images (Az values = 0.997-0.999) than with CT (0.917-0.932). The mean values of sensitivity, specificity, and accuracy were significantly higher (P < 0.001) for T2-weighted FSE with FLAIR-HASTE (96.6%, 96.8%, and 96.7%, respectively) than for CT (76.9%, 61.6%, and 67.3%, respectively). A confident diagnosis was rendered in 12 of 112 lesions (10.7%) on the basis of CT, and this rate increased to 83 of 112 (74.1%) on the basis of T2-weighted FSE and FLAIR-HASTE imaging.

CONCLUSION

FLAIR-HASTE is considered to be an effective sequence for differentiating hepatic cysts from liver metastases without the use of a contrast agent. With FLAIR-HASTE one can confidently diagnose small hepatic lesions found on CT in patients with a malignancy.

MRI evaluation of small hepatic lesions in women with breast cancer

OBJECTIVE

The purpose of this study was to assess the utility of MRI in differentiating benign and malignant causes of hepatic lesions deemed too small to characterize on CT in women with breast cancer.

MATERIALS AND METHODS

A list of all women with breast cancer diagnosed between January 2000 and June 2003 was cross-referenced with radiologic and medical records to identify patients who had undergone MRI of the liver and who had had a hepatic lesion too small to characterize reported on previous CT performed after the diagnosis of breast cancer. The cause reported at MRI for each hepatic lesion too small to characterize seen on CT was recorded as benign, malignant, indeterminate, or no lesion seen on MRI. Subsequent relevant imaging examinations and medical records were reviewed.

RESULTS

Seventy-six (1.4%) of 5,440 women underwent MRI that included the liver. In 38 (50%) of the women a hepatic lesion too small to characterize was found on CT performed before MRI. The reported MRI diagnoses of hepatic lesions too small to characterize on CT included benign lesions (n = 22 women), lesions that remained indeterminate (n = 11 women), no lesion seen on MRI corresponding to the site of a lesion too small to characterize on CT (n = 8 women), and metastatic lesions (n = 2 women). Four women had more than one reported type of hepatic lesion. Subsequent findings of imaging, biopsy, or both performed on eight of 11 women with indeterminate lesions supported benign diagnoses in all eight women.

CONCLUSION

In women with newly diagnosed breast cancer and no definite liver metastasis on initial CT, immediate further evaluation of hepatic lesions too small to characterize with MRI offers only marginal benefit. In only approximately 5% of such women will lesions too small to characterize be shown on MRI to represent metastasis.

A practical approach to analyzing focal lesions in the liver

Ultrasound evaluation of patients with hepatic masses should extend beyond basic lesion detection to characterization and clinical management. A systematic approach for hepatic lesion evaluation using ultrasound makes it possible to triage patients and, in many cases, leads to definitive diagnosis that may eliminate the need for additional imaging.

Hepatic lesions deemed too small to characterize at CT: prevalence and importance in women with breast cancer

PURPOSE

To retrospectively evaluate the prevalence and clinical importance of hepatic lesions considered too small to characterize (TSTC) at initial computed tomography (CT) in women with breast cancer.

MATERIALS AND METHODS

Approval for this retrospective study was obtained from the institutional review board, which waived the requirement for informed consent. For each woman who received a diagnosis of breast cancer between 1998 and 2002, the authors reviewed the report of the first contrast material-enhanced CT examination that included assessment of the liver. For women with no definite liver metastasis and at least one hepatic lesion considered TSTC, reports of follow-up imaging examinations were reviewed for a change in lesion size; medical records and images were reviewed if there was a change in lesion size. The 95% confidence intervals (CIs) were calculated for best- and worst-case analyses of cases in which different assumptions were used to classify a lesion as benign.

RESULTS

Of 7692 women, 1012 (13.2%) underwent contrast-enhanced CT including liver assessment. The mean age of the 1012 women was 54.6 years (range, 20.7-89.1 years). The median time from diagnosis of breast cancer to initial CT examination was 14.1 weeks (range, -3.7 to 296 weeks). The presence of at least one hepatic lesion deemed TSTC was reported in 277 of 941 women (29.4%) in whom no definite hepatic metastasis was reported. Subsequent imaging examinations were performed in 191 of the 277 women (69.0%) (median time from initial CT to last follow-up imaging examination, 54 weeks; range, 0.3-302 weeks). Those examinations revealed the lesions were unchanged in 175 (91.6%) women, no longer visible in eight (4.2%), and larger in six (3.1%). In two women (1.0%), change could not be determined. The enlarging hepatic lesions deemed TSTC represented metastatic breast cancer (three patients), metastatic pancreatic cancer (one patient), or cysts (one patient); in one patient, the etiology was not known. Results of best- and worst-case analyses showed that the lesions were benign in 96.9% (95% CI: 93%, 99%) and 92.7% (95% CI: 88%, 96%) of women, respectively.

CONCLUSION

In 92.7%-96.9% of women with breast cancer and hepatic lesions deemed TSTC but no definite liver metastases at initial CT, the lesions represented a benign finding.

Ultrasound of focal liver masses

Detecting and characterizing focal liver lesions is one of the most difficult challenges in imaging today. All standard noninvasive imaging modalities are less sensitive than generally perceived, and characterization is imperfect. Liver sonography's main strengths are its ability to definitively characterize common benign lesions (eg, cysts and hemangiomas), safety, low cost, and its ability to guide biopsy. Sonography's weaknesses include its inability to image the entire liver in many patients and its inferiority to CT as a means of detecting extrahepatic malignant disease. Sonography is less sensitive than CT or MRI in detecting focal lesions. Ultrasound contrast agents will certainly improve liver lesion detection and characterization, but their impact is not yet clear. Typical findings in common focal liver lesions are discussed, and some hints to improve sonographic diagnosis are presented. Increased color Doppler flow should bring the possibility of hepatocellular carcinoma and focal nodular hyperplasia to mind, but Doppler diagnosis is ultimately not highly specific. Sonography, including Doppler analysis, is useful to assess the resectability of malignant masses. Intraoperative ultrasound is the most sensitive imaging modality in detecting focal liver lesions.

Small Hypoattenuating Hepatic Lesions at Contrast-enhanced CT: Prognostic Importance in Patients with Breast Cancer

PURPOSE

To retrospectively determine the prognostic importance of small hypoattenuating hepatic lesions at contrast material-enhanced computed tomography (CT) in patients with breast cancer.

MATERIALS AND METHODS

This retrospective study was approved by the committee on human research. Written informed consent was not required. The authors retrospectively identified 153 patients with breast cancer who underwent serial abdominal CT and who did not have definite liver metastases present at initial CT. The mean age was 56 years (age range, 27-93 years). Two readers independently recorded the presence, size, and number of small (15 mm or less in diameter) hypoattenuating hepatic lesions at initial CT. Another reader independently recorded the presence or absence of definite hepatic metastases at final CT. The association between the presence, size, and number of small hypoattenuating hepatic lesions at initial CT and the subsequent development of metastases was analyzed by using Kaplan-Meier analysis.

RESULTS

One or more small hypoattenuating hepatic lesions were seen at initial CT in 54 of 153 patients (35%). After a median follow-up of 584 days (range, 16-1827 days), definite hepatic metastases developed in 43 of 153 patients (28%), including 15 of 54 patients (28%) with hypoattenuating lesions at initial CT and 28 of 99 patients (28%) without hypoattenuating lesions at initial CT. Findings from the Kaplan-Meier analysis showed no association between the presence (P = .56), size (P = .55), or number (P = .30) of small hypoattenuating hepatic lesions at initial CT and the subsequent development of hepatic metastases.

CONCLUSION

In patients with breast cancer who do not have definite hepatic metastases at initial examination, there is no evidence that small hypoattenuating hepatic lesions seen at initial CT contribute to an increased risk of subsequently developing hepatic metastases.