Contrast-Enhanced Computed Tomography Evaluation of Hepatic Metastases in Breast Cancer Patients Before and After Cytotoxic Chemotherapy or Targeted Therapy.

PURPOSE: To evaluate change in size vs computed tomography (CT) density of hepatic metastases in breast cancer patients before and after cytotoxic chemotherapy or targeted therapy. METHODS: A database search in a single institution identified 48 breast cancer patients who had hepatic metastases treated with either cytotoxic chemotherapy alone or targeted therapy alone, and who had contrast-enhanced CT (CECT) scans of the abdomen at baseline and within 4 months of initiation of therapy in the past 10 years. Two radiologists retrospectively evaluated CT scans and identified up to 2 index lesions in each patient. The size (centimeters) of each lesion was measured according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria, and CT density (Hounsfield units) was measured by drawing a region of interest around the margin of the entire lesion. The percent change in sum of lesion size and mean CT density on pre- and post-treatment scans was computed for each patient; results were compared within each treatment group. RESULTS: Thirty-nine patients with 68 lesions received cytotoxic chemotherapy only; 9 patients with 15 lesions received targeted therapy only. The mean percent changes in sum of lesion size and mean CT density were statistically significant within the cytotoxic chemotherapy group before and after treatment, but not significant in the targeted therapy group. The patients in the targeted therapy group tend to have better 2-year survival. The patients who survived at 2 years tend to have more decrease in tumour size in the cytotoxic chemotherapy group. CONCLUSION: Cytotoxic chemotherapy produced significant mean percent decrease in tumour size and mean CT density of hepatic metastases from breast cancer before and after treatment, whereas targeted therapy did not. Nonetheless, there is a trend that the patients in the targeted therapy group had better 2-year survival rate. This suggests that RECIST is potentially inadequate in evaluating tumour response in breast cancer liver metastases treated with targeted therapy alone, calling for an alternative marker for response evaluation in this subset of patients.

Effect of pre-enhancement set point on computed tomographic perfusion values in normal liver and metastases to the liver from neuroendocrine tumors.

OBJECTIVE: The objective of this study was to assess the effects of pre-enhancement set point (T1) positioning on computed tomographic perfusion (CTp) parameter values. METHODS: The CTp data from 16 patients with neuroendocrine liver metastases were analyzed with distributed parameter modeling to yield tissue blood flow (BF), blood volume, mean transit time, permeability, and hepatic arterial fraction for tumor and normal liver, with displacements in T1 of ±0.5, ±1.0, ±2.0 seconds, relative to the reference standard. A linear mixed-effects model was used to assess the displacement effects. RESULTS: Effects on the CTp parameter values were variable: BF was not significantly affected, but T1 positions of ≥+1.0 second and -2.0 seconds or longer significantly affected the other CTp parameters (P ≤ 0.004). Mean differences in the CTp parameter values versus the reference standard for BF, blood volume, mean transit time, permeability, and hepatic arterial fraction ranged from -5.0% to 5.2%, -12.7% to 8.9%, -12.5% to 8.1%, -5.3% to 5.7%, and -12.9% to 26.0%, respectively. CONCLUSIONS: CTp parameter values can be significantly affected by T1 positioning.

Current update on medullary thyroid carcinoma.

OBJECTIVE: This article will review the multimodality imaging spectrum of medullary thyroid carcinoma (MTC) with an emphasis on anatomic and functional imaging. Recent advances in the molecular cytogenetics of this tumor and the impact on diagnosis, prognosis, and development of novel targeted therapy will be discussed. CONCLUSION: MTC is a neuroendocrine tumor with unique clinicopathologic and radiologic features compared with other thyroid malignancies. Imaging plays an important role in the optimal management of this malignancy.

Metastases to the liver from neuroendocrine tumors: effect of duration of scan acquisition on CT perfusion values.

PURPOSE: To assess the effects of acquisition duration on computed tomographic (CT) perfusion parameter values in neuroendocrine liver metastases and normal liver tissue. MATERIALS AND METHODS: This retrospective study was institutional review board approved, with waiver of informed consent. CT perfusion studies in 16 patients (median age, 57.5 years; range, 42.0-69.7 years), including six men (median, 54.1 years; range, 42.0-69.7), and 10 women (median, 59.3 years; range 43.6-66.3), with neuroendocrine liver metastases were analyzed by means of distributed parametric modeling to determine tissue blood flow, blood volume, mean transit time, permeability, and hepatic arterial fraction for tumors and normal liver tissue. Analyses were undertaken with acquisition time of 12-590 seconds. Nonparameteric regression analyses were used to evaluate the functional relationships between CT perfusion parameters and acquisition duration. Evidence for time invariance was evaluated for each parameter at multiple time points by inferring the fitted derivative to assess its proximity to zero as a function of acquisition time by using equivalence tests with three levels of confidence (20%, 70%, and 90%). RESULTS: CT perfusion parameter values varied, approaching stable values with increasing acquisition duration. Acquisition duration greater than 160 seconds was required to obtain at least low confidence stability in any of the CT perfusion parameters. At 160 seconds of acquisition, all five CT perfusion parameters stabilized with low confidence in tumor and normal tissues, with the exception of hepatic arterial fraction in tumors. After 220 seconds of acquisition, there was stabilization with moderate confidence for blood flow, blood volume, and hepatic arterial fraction in tumors and normal tissue, and for mean transit time in tumors; however, permeability values did not satisfy the moderate stabilization criteria in both tumors and normal tissue until 360 seconds of acquisition. Blood flow, mean transit time, permeability, and hepatic arterial fraction were significantly different between tumor and normal tissue at 360 seconds (P < .001). CONCLUSION: CT perfusion parameter values are affected by acquisition duration and approach progressively stable values with increasing acquisition times. Online supplemental material is available for this article.

Effect of duration of scan acquisition on CT perfusion parameter values in primary and metastatic tumors in the lung.

OBJECTIVES: To assess the effect of acquisition duration (T(acq)) and pre-enhancement set points (T1) on computer tomography perfusion (CT(p)) parameter values in primary and metastatic tumors in the lung. MATERIALS AND METHODS: 24 lung CT(p) datasets (10 primary; 14 metastatic), acquired using a two phase protocol spanning 125 s, in 12 patients with lung tumors, were analyzed by deconvolution modeling to yield tumor blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability (PS) values. CT(p) analyses were undertaken for the reference dataset (i.e., T1=t0) with varying T(acq) from 12 to 125 s. This was repeated for shifts in T1 (±0.5 s, ±1.0 s, ±2.0 s relative to the reference at t0). Resultant CTp values were plotted against T(acq); values at 30 s, 50 s, 65 s and 125 s were compared using linear mixed model. RESULTS: All CT(p) parameter values were noticeably influenced by T(acq), with generally less marked changes beyond 50 s, and with no difference in behavior between primary and secondary tumors. Apart from BV, which attained a plateau at approximately 50s, the other three CT(p) parameters did not reach steady-state values within the available 125 s of data, with values at 30 s, 50 s and 65 s significantly different from 125 s (p<0.004). Shifts in T1 also affected the CT(p) parameters values, with positive shifts having greater impact on CT(p) values than negative shifts. CONCLUSION: CT(p) parameter values derived from deconvolution modeling can be markedly affected by T(acq), and pre-enhancement set-points. 50 s acquisition may be adequate for BV, but longer than 125 s is probably required for reliable characterization of the other three CT(p) parameters.

Resection of at-risk mesenteric lymph nodes is associated with improved survival in patients with small bowel neuroendocrine tumors.

BACKGROUND: Neuroendocrine tumors of the small intestine commonly metastasize to regional lymph nodes (LNs). Single-institution reports suggest that removal of LNs improves outcome, but comprehensive data are lacking. We hypothesized that the extent of lymphadenectomy reported in a large administrative database would be associated with overall survival for jejunal and ileal neuroendocrine tumors. METHODS: A search of the Surveillance Epidemiology and End Results database was performed for patients with jejunal and ileal neuroendocrine tumors from 1977 to 2004. Descriptive patient characteristics were collected to include age at diagnosis, sex, race, grade, primary tumor size, LN status, number of LNs resected, presence of distant metastasis, and the type of operation. Statistical analyses were limited to patients with only one primary tumor to exclude patients with other malignancies. Univariate and multivariate analyses were performed to analyze the number of LNs resected and the LN ratio (number of positive LNs/total number of LNs removed) to determine the effect on cancer-specific survival. RESULTS: Altogether, 1,364 patients were included in this analysis. Removal of any LNs was associated with improved cancer-specific survival when compared to patients with no LN removal reported (p = 0.0027) on univariate analysis. Among those who had any LNs removed, a median of eight LNs were identified in resection specimens with a median LN ratio of 0.29 (range 0-1). On multivariate analysis (adjusting for age and tumor size), patients with >7 LNs removed experienced better cancer-specific survival than those with ≤ 7 LNs removed (median survival not reached vs. 140 months): hazard ratio and 95 % confidence interval were 0.573 (0.402, 0.817) (p = 0.002). CONCLUSIONS: This review of a large number of surgical patients demonstrates that regional mesenteric lymphadenectomy in conjunction with resection of the primary tumor is associated with improved survival of patients with small bowel neuroendocrine tumors.

Effect of sampling frequency on perfusion values in perfusion CT of lung tumors.

OBJECTIVE: The purpose of this study was to assess as a potential means of limiting radiation exposure the effect on perfusion CT values of increasing sampling intervals in lung perfusion CT acquisition. SUBJECTS AND METHODS: Lung perfusion CT datasets in patients with lung tumors (> 2.5 cm diameter) were analyzed by distributed parameter modeling to yield tumor blood flow, blood volume, mean transit time, and permeability values. Scans were obtained 2-7 days apart with a 16-MDCT scanner without intervening therapy. Linear mixed-model analyses were used to compare perfusion CT values for the reference standard sampling interval of 0.5 second with those of datasets obtained at sampling intervals of 1, 2, and 3 seconds, which included relative shifts to account for uncertainty in preenhancement set points. Scan-rescan reproducibility was assessed by between-visit coefficient of variation. RESULTS: Twenty-four lung perfusion CT datasets in 12 patients were analyzed. With increasing sampling interval, mean and 95% CI blood flow and blood volume values were increasingly overestimated by up to 14% (95% CI, 11-18%) and 8% (95% CI, 5-11%) at the 3-second sampling interval, and mean transit time and permeability values were underestimated by up to 11% (95% CI, 9-13%) and 3% (95% CI, 1-6%) compared with the results in the standard sampling interval of 0.5 second. The differences were significant for blood flow, blood volume, and mean transit time for sampling intervals of 2 and 3 seconds (p ≤ 0.0002) but not for the 1-second sampling interval. The between-visit coefficient of variation increased with subsampling for blood flow (32.9-34.2%), blood volume (27.1-33.5%), and permeability (39.0-42.4%) compared with the values in the 0.5-second sampling interval (21.3%, 23.6%, and 32.2%). CONCLUSION: Increasing sampling intervals beyond 1 second yields significantly different perfusion CT parameter values compared with the reference standard (up to 18% for 3 seconds of sampling). Scan-rescan reproducibility is also adversely affected.

Vascular pancreatic lesions: spectrum of imaging findings of malignant masses and mimics with pathologic correlation.

The differential diagnosis of hypervascular pancreatic lesions is complex, and includes endocrine and exocrine tumors of the pancreas, metastases to the pancreas, and masses, or mass-like lesions, arising from the neurovascular networks traversing the pancreas. In this manuscript, we will discuss salient imaging findings of these masses, pertinent differential diagnoses, as well as review clinical symptomatology that may aid in the diagnosis of some of these lesions.

Optimal morphologic response to preoperative chemotherapy: an alternate outcome end point before resection of hepatic colorectal metastases.

PURPOSE: The purposes of this study were to confirm the prognostic value of an optimal morphologic response to preoperative chemotherapy in patients undergoing chemotherapy with or without bevacizumab before resection of colorectal liver metastases (CLM) and to identify predictors of the optimal morphologic response. PATIENTS AND METHODS: The study included 209 patients who underwent resection of CLM after preoperative chemotherapy with oxaliplatin- or irinotecan-based regimens with or without bevacizumab. Radiologic responses were classified as optimal or suboptimal according to the morphologic response criteria. Overall survival (OS) was determined, and prognostic factors associated with an optimal response were identified in multivariate analysis. RESULTS: An optimal morphologic response was observed in 47% of patients treated with bevacizumab and 12% of patients treated without bevacizumab (P < .001). The 3- and 5-year OS rates were higher in the optimal response group (82% and 74%, respectively) compared with the suboptimal response group (60% and 45%, respectively; P < .001). On multivariate analysis, suboptimal morphologic response was an independent predictor of worse OS (hazard ratio, 2.09; P = .007). Receipt of bevacizumab (odds ratio, 6.71; P < .001) and largest metastasis before chemotherapy of ≤ 3 cm (odds ratio, 2.12; P = .025) were significantly associated with optimal morphologic response. The morphologic response showed no specific correlation with conventional size-based RECIST criteria, and it was superior to RECIST in predicting major pathologic response. CONCLUSION: Independent of preoperative chemotherapy regimen, optimal morphologic response is sufficiently correlated with OS to be considered a surrogate therapeutic end point for patients with CLM.

Effect of dual vascular input functions on CT perfusion parameter values and reproducibility in liver tumors and normal liver.

OBJECTIVE: To assess the impact on absolute values and reproducibility of adding portal venous (PV) to arterial input functions in computed tomographic perfusion (CTp) evaluations of liver tumors and normal liver. METHODS: Institutional review board approval and written informed consent were obtained; the study complied with Health Insurance Portability and Accountability Act regulations. Computed tomographic perfusion source data sets, obtained from 7 patients (containing 9 liver tumors) on 2 occasions, 2 to 7 days apart, were analyzed by deconvolution modeling using dual ("Liver" protocol: PV and aorta) and single ("Body" protocol: aorta only) vascular inputs. Identical tumor, normal liver, aortic and, where applicable, PV regions of interest were used in corresponding analyses to generate tissue blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability (PS) values. Test-retest variability was assessed by within-patient coefficients of variation. RESULTS: For liver tumor and normal liver, median BF, BV, and PS were significantly higher for the Liver protocol than for the Body protocol: 171.3 to 177.8 vs 39.4 to 42.0 mL/min per 100 g, 17.2 to 18.7 vs 3.1 to 4.2 mL/100 g, and 65.1 to 78.9 vs 50.4 to 66.1 mL/min per 100 g, respectively (P < 0.01 for all). There were no differences in MTT between protocols. Within-patient coefficients of variation were lower for all parameters with the Liver protocol than with the Body protocol: BF, 7.5% to 11.2% vs 11.7% to 20.8%; BV, 10.1% to 14.4% vs 16.6% to 30.1%; MTT, 4.2% to 5.5% vs 10.4% to 12.9%; and PS, 7.3% to 12.1% vs 12.6% to 20.3%, respectively. CONCLUSION: Utilization of dual vascular input CTp liver analyses has substantial impact on absolute CTp parameter values and test-retest variability. Incorporation of the PV inputs may yield more precise results; however, it imposes substantial practical constraints on acquiring the necessary data.

Response of borderline resectable pancreatic cancer to neoadjuvant therapy is not reflected by radiographic indicators.

BACKGROUND: Experience with preoperative therapy for other cancers has led to an assumption that borderline resectable pancreatic cancers can be converted to resectable cancers with preoperative therapy. In this study, the authors sought to determine the rate at which neoadjuvant therapy is associated with a reduction in the size or stage of borderline resectable tumors. METHODS: Patients who had borderline resectable pancreatic cancer and received neoadjuvant therapy before potentially undergoing surgery at the authors' institution between 2005 and 2010 were identified. The patients' pretreatment and post-treatment pancreatic protocol computed tomography images were rereviewed to determine changes in tumor size or stage using modified Response Evaluation Criteria in Solid Tumors (RECIST) (version 1.1) and standardized anatomic criteria. RESULTS: The authors identified 129 patients who met inclusion criteria. Of the 122 patients who had their disease restaged after receiving preoperative therapy, 84 patients (69%) had stable disease, 15 patients (12%) had a partial response to therapy, and 23 patients (19%) had progressive disease. Although only 1 patient (0.8%) had their disease downstaged to resectable status after receiving neoadjuvant therapy, 85 patients (66%) underwent pancreatectomy. The median overall survival duration for all 129 patients was 22 months (95% confidence interval, 14-30 months). The median overall survival duration for the patients who underwent pancreatectomy was 33 months (95% confidence interval, 25-41 months) and was not associated with RECIST response (P = .78). CONCLUSIONS: Radiographic downstaging was rare after neoadjuvant therapy, and RECIST response was not an effective treatment endpoint for patients with borderline resectable pancreatic cancer. The authors concluded that these patients should undergo pancreatectomy after initial therapy in the absence of metastases.

Effect of neoadjuvant chemoradiation and surgical technique on recurrence of localized pancreatic cancer.

OBJECTIVES: To determine the influence of neoadjuvant chemoradiation and standardized dissection of the superior mesenteric artery upon the oncologic outcome of patients with localized pancreatic adenocarcinoma. METHODS: One hundred ninety-four patients with pancreatic adenocarcinoma who underwent pancreaticoduodenectomy between 2004 and 2008 were evaluated. The retroperitoneal dissection was performed directly along the superior mesenteric artery in all cases. A standard histopathologic protocol that measured the "superior mesenteric artery (SMA) margin distance" between cancer cells and the superior mesenteric artery was employed. RESULTS: Seventy-six percent of patients received neoadjuvant chemoradiation. The SMA margin was positive in 4% of patients but an additional 22% of patients with a negative margin had a SMA margin distance of ≤1 mm. Preoperative CT images overestimated the SMA margin distance in 73% of cases. Patients who received chemoradiation had longer SMA margin distances than those who did not. Patients who received chemoradiation and had a SMA margin of >1 mm had the lowest recurrence rates. Administration of neoadjuvant chemoradiation and lower estimated blood loss were independently associated with longer progression-free survival on multivariate analysis. CONCLUSIONS: Preoperative chemoradiation and meticulous dissection of the superior mesenteric artery maximize the distance between cancer cells and the SMA margin and may influence locoregional control.

Phase II trials of imatinib mesylate and docetaxel in patients with metastatic non-small cell lung cancer and head and neck squamous cell carcinoma.

PURPOSE: Two phase II clinical trials in the aerodigestive tumors were undertaken to evaluate the efficacy of imatinib mesylate-docetaxel. We hypothesized that imatinib mesylate would inhibit platelet-derived growth factor receptor (PDGFR) on pericytes and increase docetaxel uptake into tumor cells for an additive antitumor effect. Baseline tumor specimens, serum, and perfusion computed tomography (CT) scans were obtained for supportive evaluation. MATERIALS AND METHODS: Eligible patients with metastatic non-small cell lung cancer (NSCLC) treated with 1 prior therapy and chemonaive patients with head and neck squamous cell carcinoma (HNSCC) were enrolled in separate trials, which administered both docetaxel (60 mg/m every 3 weeks) and oral imatinib mesylate (400 mg daily). Both trials used interim analyses for efficacy and safety. RESULTS: Twenty-two patients with NSCLC and seven patients with HNSCC were enrolled. Both trials were closed early due to lack of efficacy, significant toxicity, and a potential antagonistic effect. In the NSCLC study, the response rate was 4.5%, median progression-free survival (PFS) 7.9 weeks, and overall survival 35.6 weeks. The HNSCC trial yielded a response rate 0%, PFS 8.8 weeks, and overall survival 34.7 weeks. Baseline NSCLC tumor immunohistochemical biomarker analyses indicated that lower expression of stromal PDGFRß correlated with a better PFS, whereas stromal PDGFRα and tumor cell PDGFRß were associated with a worse clinical outcome when treated with imatinib mesylate-docetaxel. CONCLUSION: We do not recommend further investigation of this regimen in the aerodigestive tumors. Future investigations in PDGFR tyrosine kinase inhibitors should be used with caution in combination with taxanes and validation of the potential predictive or prognostic biomarkers stromal PDGFRα/ß, and tumor cell PDGFRß are needed.

Reproducibility of CT perfusion parameters in liver tumors and normal liver.

PURPOSE: To assess the reproducibility of computed tomographic (CT) perfusion measurements in liver tumors and normal liver and effects of motion and data acquisition time on parameters. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained for this prospective study. The study complied with HIPAA regulations. Two CT perfusion scans were obtained 2-7 days apart in seven patients with liver tumors with two scanning phases (phase 1: 30-second breath-hold cine; phase 2: six intermittent free-breathing cines) spanning 135 seconds. Blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability-surface area product (PS) for tumors and normal liver were calculated from phase 1 with and without rigid registration and, for combined phases 1 and 2, with manually and rigid-registered phase 2 images, by using deconvolution modeling. Variability was assessed with within-patient coefficients of variation (CVs) and Bland-Altman analyses. RESULTS: For tumors, BF, BV, MTT, and PS values and reproducibility varied by analytical method, the former by up to 11%, 23%, 21%, and 138%, respectively. Median PS values doubled with the addition of phase 2 data to phase 1 data. The best overall reproducibility was obtained with rigidly registered phase 1 and phase 2 images, with within-patient CVs for BF, BV, MTT, and PS of 11.2%, 14.4%, 5.5% and 12.1%, respectively. Normal liver evaluations were similar, except with marginally lower variability. CONCLUSION: Absolute values and reproducibility of CT perfusion parameters were markedly influenced by motion and data acquisition time. PS, in particular, probably requires data acquisition beyond a single breath hold, for which motion-correction techniques are likely necessary.

Reproducibility of perfusion parameters obtained from perfusion CT in lung tumors.

OBJECTIVE: The purpose of this article is to assess the variability of perfusion CT measurements in lung tumors and the effects of motion and duration of data acquisition on perfusion CT parameter values. SUBJECTS AND METHODS: Two perfusion CT scans were obtained in 11 patients with lung tumors, 2-7 days apart, using phase 1 scans (30-second breath-hold cine) followed by phase 2 scans (six intermittent helical breath-holds), spanning 125 seconds. Tumor blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability were calculated for phase 1 using all-cine and motion-corrected (rigidly registered) images, both with and without matching phase 2 images (manually or rigidly registered). Variability was assessed by the within-patient coefficient of variation (CV) and Bland-Altman analyses. RESULTS: BF, BV, MTT, and permeability values varied widely by method of analysis (median BF, 45.3-65.1 mL/min/100 g; median BV, 2.6-3.8 mL/100 g; median MTT, 3.6-4.1 seconds, and median permeability, 13.7-39.3 mL/min/100 g), as did within-patient CVs (10.9-114.4%, 25.3-117.6%, 22.3-51.5%, and 29.6-134.9%, respectively). Parameter values and variability were affected by motion and duration of data analyzed: permeability values doubled when phase 2 images were added to phase 1 data. Overall, the best reproducibility was obtained with registered phase 1 and 2 data, with within-patient CVs of 11.6%, 26.5%, 45.4%, and 30.2%, respectively. CONCLUSION: The absolute values and reproducibility of perfusion parameters in lung tumors are markedly influenced by motion and duration of data acquisition. Permeability, in particular, probably requires data acquisition beyond a single breath-hold. The smallest variability in parameter values was obtained with motion correction and extended acquisition durations.

Imaging features of hematogenous metastases to the pancreas: pictorial essay.

This pictorial essay illustrates the imaging appearances of a wide variety of metastases to the pancreas as seen on computed tomography (CT), magnetic resonance imaging and positron emission tomography/CT. Key clinical and radiologic features (lesion distribution, non-contrast imaging appearance, enhancement pattern and pattern of spread) that may aid differentiation of primary from solitary secondary pancreatic malignancies are discussed.

Planning and follow-up after ablation of hepatic tumors: imaging evaluation.

CTs or MRIs are essential for preablative therapy planning of hepatic tumors to identify accurate size, number, and location of tumors. Tumors larger than 5 cm and located near the major branches of the portal vein and hepatic vein have a higher potential for incomplete ablation. Postablative imaging studies are needed to determine if the entire tumors are included in the treatment zone to minimize the risk of local tumor recurrences. Complications of ablative therapy can be identified on post-treatment imaging studies.

Pathways of extrapelvic spread of pelvic disease: imaging findings.

The complex extraperitoneal anatomy of the pelvis includes various outlets for the transit of organs and neurovascular structures to the rest of the body. These outlets include the greater sciatic foramen, lesser sciatic foramen, inguinal canal, femoral triangle, obturator canal, anal and genitourinary hiatuses of the pelvic floor, prevesical space, and iliopsoas compartment. All of these structures serve as conduits for the dissemination of malignant and benign inflammatory diseases from the pelvic cavity and into the soft-tissue structures of the abdominal wall, buttocks, and upper thigh. Knowledge of the pelvic anatomy is crucial to understand these patterns of disease spread. Cross-sectional imaging provides important anatomic information and depicts the extent of disease and its involvement of surrounding extrapelvic structures, information that is important for planning surgery and radiation therapy.

Extramural venous invasion by gastrointestinal malignancies: CT appearances.

The purpose of this article is to describe and demonstrate the appearances of extramural vascular invasion on computed tomography in gastrointestinal malignancies as one of the pathways of disease spread. In this article, we demonstrate the imaging features with pathologically proven examples, along with a brief description of relevant vascular anatomy. We shall also discuss the clinical significance and prognostic implications of extramural vascular invasion in gastrointestinal malignancies.