Utility of Sonography for Small Hepatic Lesions Found on Computed Tomography in Patients With Cancer

Abstract

Objective. To assess the performance of sonography in evaluating small indeterminate liver lesions detected on computed tomography in patients with cancer. Methods. Radiology database review from January 1, 1998, to August 4, 2000, identified 76 patients with 124 indeterminate hepatic lesions smaller than 1.5 cm on computed tomography who had abdominal sonography within 3 months. Sonographic reports and images were reviewed to assess whether lesions were referenced or specifically sought and to verify lesion correspondence, detection, and characterization. The validity of sonographic characterization was determined by histopathologic examination or follow-up imaging (mean time to follow up, 17 months; range, 6.5-38.8 months). Results. Sixty (48%) of 124 indeterminate lesions were evident on sonography. Detection improved when lesions were specifically sought and lesion size was greater than 0.5 cm. Forty (66%) of 61 lesions were detected when the radiologist referenced the preceding computed tomography versus 20 (32%) of 63 lesions when the computed tomographic findings were not referenced (P = .0004). Fifty-one (67%) of 76 lesions measuring 0.6 to 1.5 cm were detected on sonography versus 9 (19%) of 48 lesions measuring 0.1 to 0.5 cm. Lesion size (P < .0001) and body habitus (P = .02) were significant factors influencing lesion detection. Sonography characterized 56 (93%) of 60 detected lesions (33 cysts, 18 solid lesions/metastases, and 5 hemangiomas). Sonographic diagnoses were supported in 42 (93%) of 45 lesions by follow-up imaging (37 of 40) or histopathologic examination (5 of 5). Conclusions. Sonography may be useful in cancer patients with average body habitus to characterize small (0.6-to 1.5-cm) indeterminate liver lesions detected on computed tomography. Key words: cancer; liver lesions; metastases.Received November 19, 2002, Abbreviations CT, computed tomography; MRI, magnetic resonance imaging mall liver lesions (<1.5 cm) detected during routine computed tomography (CT) of the abdomen are frequent, estimated as present on abdominal CT in up to 17% of outpatients.1 Schwartz et al 2 evaluated indeterminate and small hepatic lesions (<1.0 cm) found in CT examinations of 378 patients with cancer and found that, despite a nonspecific imaging appearance, 12% of such lesions represented metastases on the basis of interval growth on follow-up. Computed tomography has become the principal examination for initial staging and follow-up of malignancies; however, difficulty in characterizing small hepatic lesions by CT has long been understood.3 Some authors have advocated sonography to characterize such small hepatic lesions.

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

“…The diagnostic accuracy of US-guided interventions of the liver is 93-98% for lesions smaller than 1.5 cm and short access routes [17,18]. However, less than half of all focal liver lesions smaller than 1.5 cm (48%) are detected by US [19]. Tissue sampling under CT guidance also plays an established role and is used in situations where ultrasound techniques failed.…”

Perkutaner Ultraschall in Diagnose und Staging des Bronchialkarzinoms

“…In addition, 13 % -18 % of patients have small ( < 1.5 cm) hypodense lesions that cannot be further specified in CT due to their small size [41]. A supplementary US examination makes it possible to diagnose a large majority of these liver lesions, thus avoiding a more extensive and more expensive diagnosis via MRI [42]. More liver metastases can be detected with signalamplified sonography than with CT [43].…”

“…Darüber hinaus finden sich bei 13 % -18 % der Patienten kleine ( < 1,5 cm) hypodense Läsionen, die aufgrund ihrer geringen Größe in der CT nicht weiter spezifiziert werden können [41]. Durch eine ergänzende US-Untersuchung kann ein großer Teil dieser Leberläsionen geklärt und so eine weiterführende kostenintensivere Abklärung durch eine MRT vermieden werden [42]. Mittels signalverstärkter Sonografie lassen sich mehr Lebermetastasen detektieren als in der CT [43].…”

Evaluating and Staging the Patient with Breast Cancer

“…28 In a study at Memorial SloanKettering Cancer Center of 76 cancer patients in whom 124 indeterminate liver lesions were found on CT, hepatic ultrasound was a useful adjunct for patients with average body habitus in order to characterize small (0.6-to 1.5-cm) lesions. 33 CT and MRI are superior to ultrasound and technetium scanning for the identification of small metastatic foci in the liver; however, neither is more useful for screening asymptomatic patients. 34 Finally, when FDG-PET was retrospectively compared with chest radiography, bone scintigraphy, and ultrasonography of the abdomen for detection of metastatic disease, it was found to be superior in the identification of pulmonary and lymph node metastases in comparison with chest radiography, but its sensitivity in the detection of bone and liver metastases was comparable to that of bone scintigraphy and liver ultrasonography.…”