Quantitative spleen and liver volume changes predict survival of patients with primary sclerosing cholangitis.

AIM: To assess the value of quantitative spleen and liver volume changes in predicting the survival of patients with primary sclerosing cholangitis (PSC). MATERIALS AND METHODS: This institutional review board-approved single-centre study included 89 PSC patients with baseline and follow-up liver imaging studies and laboratory data between 2000 and 2018. Change in spleen, total and lobar liver volumes, and lobar-to-total liver volume ratio was compared between patients with and without adverse outcome (liver transplantation, transplant waiting list, and death). Receiver operating characteristic (ROC) and Kaplan-Meier analysis were performed to identify the volumetric threshold for prediction of outcome and show how these thresholds predict survival, respectively. A p-value of <0.05 was considered statistically significant. RESULTS: The present cohort included 53 men (60%), with mean age of 42 years at baseline. The only volumetric parameters with significant differences in change between patients with and without adverse outcome were spleen volume (p<0.001) and left-to-total liver volume ratio (L/T; p=0.025). The probability of transplant-free survival at 36 months was 59.1% versus 11.9% for patients with spleen volume change <50 ml versus ≥50 ml, respectively (AUC=0.731); and 61.3% versus 13.8% for patients with L/T change <0.04 versus ≥0.04, respectively (AUC=0.638). The patients with changes below the cut-off in both spleen volume and L/T, had a higher probability of transplant-free survival at 36 months (76.8%), compared to those with change at or below the cut-offs in one or both of these two parameters (36.7%, 15%, respectively; p=0.001). CONCLUSION: Spleen volume change and L/T change might be useful biomarkers for prediction of transplant-free survival in patients with PSC.

Long-term follow-up of hepatic adenoma and adenomatosis: analysis of size change on imaging with histopathological correlation.

AIM: To analyse the change in size on follow-up of hepatic adenomas (HAs) and adenomatosis, and to investigate the relationship of imaging features with size change. MATERIALS AND METHODS: The study included 44 patients (142 lesions) who underwent magnetic resonance imaging (MRI) or computed tomography (CT) for diagnosis and follow-up of HA. The imaging features and percentage change in maximum tumour dimension were observed over a follow-up duration of up to 139 months. RESULTS: With an average follow-up of 43 months, 37% lesions decreased in size, 58% were stable, 4% increased; one lesion regressed completely. Adenomas were stratified into size groups (<3, 3-5, and ≥5 cm). Size change among the three groups was similar (p>0.05). Percent size change was different for lesions followed for ≤12 months (-7.2%) compared with lesions followed for 13-60 months (-20.5%), and those followed for ≥60 months (-23.5%; p<0.05); there was no difference between lesions followed for 13-60 months and ≥60 months (p=0.523). Baseline size and percent size change was similar between the hepatocyte nuclear factor 1α-inactivated HA (HA-H) and inflammatory HA (HA-I) subtype (p>0.05). CONCLUSION: Most adenomas were either stable or regressed on follow-up. Size change was independent of baseline size. After an initial size decrease within 5 years, no further size reduction was noted on extended follow-up. The percent size change in the HA-H and HA-I subtype was similar.

Impact of early postoperative platelet count on volumetric liver gain and perioperative outcomes after major liver resection.

BACKGROUND: Although perioperative platelet count has been associated with postoperative morbidity and mortality, its impact on liver regeneration has not been examined directly. This study sought to determine the impact of platelet count on liver regeneration after major liver resection using cross-sectional imaging volumetric assessment. METHODS: Patients who underwent major liver resection between 2004 and 2015 and had available data on immediate postoperative platelet count, as well as preoperative and postoperative CT images, were identified retrospectively. Resected liver volume was subtracted from total liver volume (TLV) to define postoperative remnant liver volume (RLVp ). The liver regeneration index was defined as the relative increase in liver volume within 2 months ((RLV2m - RLVp )/RLVp , where RLV2m is the remnant liver volume around 2 months after surgery). The association between platelet count, liver regeneration and outcomes was assessed. RESULTS: A total of 99 patients met the inclusion criteria. Overall, 25 patients (25 per cent) had a low platelet count (less than 150 × 10(9) /l), whereas 74 had a normal-high platelet count (at least 150 × 10(9) /l). Despite having comparable clinicopathological characteristics and RLVp /TLV at surgery (P = 0·903), the relative increase in liver volume within 2 months was considerably lower in the low-platelet group (3·9 versus 16·5 per cent; P = 0·043). Patients with a low platelet count had an increased risk of postoperative complications (72 versus 38 per cent; P = 0·003), longer hospital stay (8 versus 6 days; P = 0·004) and worse median overall survival (24·5 versus 67·3 months; P = 0·005) than those with a normal or high platelet count. CONCLUSION: After major liver resection, a low postoperative platelet count was associated with inhibited liver regeneration, as well as worse short- and long-term outcomes. Immediate postoperative platelet count may be an early indicator to identify patients at increased risk of worse outcomes.

Clinical and morphometric parameters of frailty for prediction of mortality following hepatopancreaticobiliary surgery in the elderly.

BACKGROUND: Although frailty is a known determinant of poor postoperative outcomes, it can be difficult to identify in patients before surgery. The authors sought to develop a preoperative frailty risk model to predict mortality among patients aged 65 years or more. METHODS: Clinical and morphometric data including total psoas area (TPA), total psoas volume (TPV) and psoas density (Hounsfield unit average calculation, HUAC) were collected for patients undergoing hepatopancreaticobiliary (HPB) surgery between 2012 and 2014. Multivariable Cox proportional hazards regression was used to identify preoperative risk factors associated with 1-year mortality. RESULTS: The median age of the 518 patients included in the study was 72 (i.q.r. 68-76) years; 55·6 per cent of patients were men, and half of the cohort had multiple co-morbidities (Charlson co-morbidity index (CCI) of 4 or more, 55·6 per cent). TPA cut-offs to define sarcopenia were 552·7 mm(2) /m(2) in women and 702·9 mm(2) /m(2) in men; cut-offs for TPV were 18·2 cm(3) /m(2) in women and 26·2 cm(3) /m(2) in men, whereas HUAC cut-offs were 31·1 HU in women and 33·3 HU in men. The overall 1-year mortality rate was 14·1 per cent. In multivariable analysis, risk factors associated with 1-year mortality included CCI of 4 or above (hazard ratio (HR) 2·91, 95 per cent c.i. 1·47 to 5·77; P = 0·002), malignant disease (HR 3·94, 1·17 to 13·30; P = 0·027) and sarcopenia by HUAC (HR 1·85, 1·10 to 3·10; P = 0·021). A weighted 25-point composite score was developed to stratify patients at risk of 1-year postoperative mortality. The 1-year mortality rate was noted to be 2·5 per cent among patients scoring 0-10 (low risk), 17·3 per cent among patients scoring 11-20 (intermediate risk) and 29·2 per cent among those scoring between 21 and 25 (high risk) (P < 0·001). CONCLUSION: Clinical and morphometric measures of frailty accurately predict the risk of 1-year mortality following HPB surgery in elderly patients, and can be used to risk-stratify patients appropriately.

Functional hepatic imaging as a biomarker of primary and secondary tumor response to loco-regional therapies.

Objective criteria to measure tumor response are a key tenet for assessment of treatment efficacy when evaluating a therapeutic modality. Several response criteria have been proposed including the Response Evaluation Criteria in Solid Tumors (RECIST), modified RECIST (mRECIST), RECIST 1-1, and European Association for the Study of the Liver (EASL) guidelines. Response following loco-regional therapies (LRT) can be particularly difficult to assess as post-treatment changes may not always relate to changes in lesion size. As imaging modalities and solid tumor therapies continue to advance, there has been growing recognition that measurement of actual tumoricidal activity may not always be related to tumor size, and accurate assessment of treatment response may vary by therapeutic modality. As such, the objective change in the physical size characteristics of a tumor may not accurately reflect biological response to treatment. Functional imaging encompasses methods that are capable of detecting or measuring changes in tissue metabolism, blood flow, or composition. Conventional imaging modalities such as magnetic resonance imaging (MRI) and computed topography (CT) now include techniques such as diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) maps, dynamic contrast enhancement (DCE-MRI), and perfusion CT (pCT). Use of functional cross-sectional imaging is particularly relevant to assess primary and secondary hepatic malignancies treated with LRT, such as trans-arterial chemoembolization (TACE), radiofrequency ablation (RFA), yttrium-90 (Y-90), and hepatic arterial infusion (HAI) chemotherapy. We herein review the imaging techniques, as well as the methodologies for measuring tumor response and survival, among patients treated with LRT for primary and secondary hepatic malignancies.

An evaluation of overlying tissues to determine fetal exposure to ultrasound during the third trimester.

Measurements of minimum and average total tissue thicknesses overlying the fetus during the third trimester were taken on 52 patients between 24 and 40 weeks gestation. Minimum total thickness of tissues constantly along the ultrasound path had a mean value of 1.75 cm, ranging from 0.40 to 3.70 cm. This corresponded to a mean attenuation of 0.87 dB MHz-1, ranging from 0.30 to 1.68 dB MHz-1. Average total thickness of tissues constantly along the ultrasound path had a mean value of 2.16 cm, ranging from 1.00 to 4.10 cm. This corresponded to a mean attenuation of 1.16 dB MHz-1, ranging from 0.64 to 2.03 dB MHz-1. Average attenuation was also calculated for all soft tissues along the ultrasound path, including the placenta. The resulting average attenuation was 0.47 dB cm-1 MHz-1. Maternal weight at the time of ultrasound examination had significant correlation with minimum and average ultrasound attenuation by tissues constantly along the ultrasound path. The R2 value was 46.7% for minimum attenuation (p-value < 0.0001) and 53.3% for average attenuation (p-value < 0.0001). Multiple regression analyses showed that the model that included maternal weight, pregnancy weight and fetal gestational age was a better predictor of the amount of attenuation during the third trimester than the model that included maternal weight only. The R2 value of the model that included all three variables was 57.2% (p-value < 0.0001) for minimum attenuation, and 62.4% (p-value < 0.0001) for average attenuation.

Verification of aquatic dilution factors for liquid effluents released from a nuclear power plant.

Dilution factors for liquid effluents released from the Fermi 2 Power Plant into Lake Erie were verified using updated liquid effluent release data, and currently available aquatic dispersion models. A near-field dilution factor of 5 currently used by Fermi 2 appears to be a reasonable assumption as supported by two models and site-specific data. Previously assumed dilution factors for shoreline points outside the near field are of the same order of magnitude as those calculated by this study. The dilution factor of 77, currently used by Fermi 2, at the Monroe water intake point is very conservative when compared with values calculated by this study. More accurate values could be generated by tracer studies as recommended by Regulatory Guide 1.113. Such studies can predict plume behavior and are more accurate than aquatic models. These new values would probably be less conservative than those currently in use, and their use would make it less likely that Fermi 2 will reach technical specification limits for liquid effluent dose.

Assessment of the cortical rim sign in posttraumatic renal infarction.

PURPOSE: The cortical rim sign has frequently been described as a sign of renal infarction. It is reported to be present in approximately 50% of focal or global infarcts and is thought to be due to an intact renal collateral circulation. This study evaluates the incidence and temporal development of the cortical rim sign in posttraumatic renal vascular compromise. METHOD: This retrospective study included 20 patients who were diagnosed by contrast-enhanced CT to have posttraumatic focal or global infarcts. The CT scans were reviewed to evaluate the size of infarcts and the presence and appearance of the rim sign. Medical records were reviewed to identify the timing of trauma in relation to the CT examination. RESULTS: Eight patients had multiple CT examinations and 12 had a single CT study. For all cases that demonstrated a rim sign (n = 14, 8 of which had more than one CT), the earliest appearance of the rim sing was 8 h (median time to appearance was 7 days). All cases with no rim sign (n = 6) were evaluated within 10 h of trauma, with a median time of 4 h. CONCLUSION: This study suggests that in spite of the presence of renal collateral circulation, it takes a minimum period of 8 h after trauma for this circulation to expand and become apparent on CT. CT demonstrated a rim sign in all cases performed after 1 week.

Variations in anatomy of the middle hepatic vein and their impact on formal right hepatectomy.

BACKGROUND: We evaluated the incidence of variations of the middle hepatic vein (MHV) branches and their impact on formal right hepatectomy for living-donor liver transplantation. METHODS: Fifty consecutive patients who underwent hepatic multidetector row computed tomography (CT) were evaluated. Three-dimensional volume rendering techniques were used to evaluate the different branching patterns of the MHV. An incision plane was constructed to simulate a formal hepatectomy along Cantlie's line, immediately to the right of the MHV. The number of transected vessels was recorded by consensus of two observers. RESULTS: In 11 patients (22%) the MHV had no major (>5 mm) branches. In 15 patients (30%) a major branch was seen draining the right lobe, and in 10 patients (20%) a major branch was seen draining each lobe. In five patients (10%) two major branches were seen draining the right lobe and a single branch draining the left lobe. The remaining nine patients (18%) had other variations, including one patient (2%) with the right hepatic vein arising from the MHV. A formal hepatectomy along Cantlie's line was truly avascular in 15 patients (30%). CONCLUSION: A formal right hepatectomy can be performed without transecting major branches of the MHV in one-third of patients. In the remaining two-thirds, one or more major branch of the MHV will need be transected. Preoperative knowledge of these variations is critical for surgical planning.

Imaging for right lobe living donor liver transplantation.

The authors describe their experience using multidetector, multiphase computed tomography (CT) for the preoperative evaluation of donors undergoing adult right lobe liver transplantation. The marked improvement in image resolution has been extremely valuable in delineating small hepatic arterial structures, including accessory and replaced vessels. Assessment of liver parenchyma is valuable in determining the presence of steatosis or other unexpected abnormalities. Measurement of total liver volume is highly accurate and reproducible. Virtual hepatectomy can be performed in an avascular plane between the right and left lobes, to the right of the middle hepatic vein. Knowledge of the resultant right and left lobe volumes is critical in patient selection. Multidetector, multiphase CT, as a single imaging modality, provides a minimally invasive comprehensive pre-operative evaluation that can be expected to have a major impact on patient selection and surgical planning.

Imaging of abdominal manifestations of melanoma.

Despite an increasing incidence of melanoma in this country, innovative new therapies are allowing patients to receive aggressive experimental treatments. Diagnostic imaging remains crucial for tumor staging and for follow-up of patients being treated with these protocols. Because metastases occur in the abdomen and pelvis in approximately 60% of patients, it is important to accurately identify all sites of tumor spread. A variety of imaging techniques are used to image these patients, with CT currently being used for staging purposes and to guide diagnostic biopsies. Other imaging techniques, such as MR, ultrasound, and fluoroscopy, are currently reserved for investigating specific complications of melanoma, such as vascular invasion, hemorrhage from a tumor, and small bowel involvement, including intussusception. Recently, whole body positron emission tomography (PET) imaging using 2-deoxy-2-fluoro-D-glucose (FDG) has been shown to be highly accurate in assessing patients with metastatic malignant melanoma. This review illustrates the spectrum of manifestations of metastatic melanoma throughout the abdomen and pelvis, including solid organ, hollow lumen, and retroperitoneal involvement, and demonstrates some of the typical and atypical manifestations that may be identified.

Incremental value of CT in PET/CT of patients with colorectal carcinoma.

BACKGROUND: We assessed the contribution of dedicated computed tomographic (CT) interpretation to the accuracy of positron emission tomography (PET) plus CT in imaging patients with suspected primary or metastatic colorectal carcinoma. METHODS: One hundred PET/CT scans in 90 consecutive patients were evaluated retrospectively. Imaging was performed on a GE Discovery LS PET/CT scanner. PET images were obtained from the skull base through the midthigh after intravenous administration of 15 to 20 mCi of [(18)F] fluorine-18-fluoro-2-deoxyglucose. Noncontrast axial CT images were obtained at the same anatomic locations, with 140 kV, 80 mA, 0.8 s/CT rotation, a pitch of 6, and a table speed of 22.5 mm/s. The CT component of the PET/CT study was reviewed independently by consensus of two blinded readers. Scans were evaluated for the presence of primary disease, local recurrence, and distant metastases. Results were compared with the PET/CT report. The gold standard was clinical and imaging follow-up for at least 6 months, surgery, or biopsy. RESULTS: The study included 40 males and 50 females, with a mean age of 63 years (range, 31-92 years). The indications for the examination were to evaluate for recurrence of colorectal cancer in 83 cases, determine disease spread in 15 cases, and evaluate for possible primary malignancy in two cases with rising carcinoembryonic antigen. Sensitivity, specificity, and accuracy of the PET/CT report and of the combined PET/CT with dedicated CT interpretation were 0.914, 0.633, and 0.830 and 0.986, 1.000, and 0.980, respectively. The difference between PET/CT and the combined PET/CT with dedicated CT interpretation with respect to accuracy was statistically significant (p < 0.05). CONCLUSION: The CT portion of PET/CT provides valuable anatomic and pathologic information to the functional information provided by PET and helps improve the overall accuracy of the combined study.

Right lower quadrant pain and suspected appendicitis: nonfocused appendiceal CT--review of 100 cases.

PURPOSE: To determine the value of standard, nonfocused computed tomography (CT) in examining patients with right lower quadrant (RLQ) pain and suspected appendicitis. MATERIALS AND METHODS: The CT scans and medical records of 100 consecutive patients who presented to the emergency department with RLQ pain and were clinically suspected of having appendicitis were retrospectively reviewed. Helical CT of both the abdomen and pelvis was performed at 7-mm increments after oral and intravenous contrast material administration. CT scans were evaluated for the presence of appendiceal or other disease. Results were correlated with surgical and pathologic findings in 34 patients or with 3-month clinical follow-up in 66 patients. RESULTS: CT depicted abnormalities in 66 patients (66%). In 59 (59%) patients, the abnormality was located in the pelvis; 23 (39%) of these patients had appendicitis. Seven (7%) patients had abnormalities outside of the pelvis, a region not typically scanned during focused appendiceal imaging. Four of these seven patients required surgery. Thus, if only pelvic focused RLQ CT had been performed, overall sensitivity would have decreased from 99% to 88% (P <.05) and sensitivity for cases necessitating surgery would have decreased from 96% to 82% (P <.05). CONCLUSION: Both abdominal and pelvic CT examinations are necessary to increase sensitivity and identify the many possible causes of RLQ pain in patients with clinically suspected appendicitis.

Imaging of neuroendocrine tumors: accuracy of helical CT versus SRS.

BACKGROUND: We retrospectively compared the accuracy of somatostatin receptor scintigraphy (SRS) with that of helical computed tomography (CT) in the detection and localization of primary and metastatic neuroendocrine tumors. METHODS: A medical record search identified 27 patients with known or clinically suspected neuroendocrine tumors who underwent helical CT and SRS within 3 months of one another at our institution. CT images were evaluated retrospectively by two blinded radiologists who used consensus reading. Images were evaluated for the presence or absence of primary tumor and hepatic and extrahepatic metastases. CT results were compared with the SRS report as interpreted by the nuclear medicine physicians. The results of the surgical, clinical follow-up, and pathologic findings were considered as the gold standard. Sensitivity, specificity, and accuracy were calculated for both imaging techniques. In addition, McNemar analysis was performed to determine statistically significant differences between CT and SRS. RESULTS: Helical CT was more sensitive than SRS in the detection of extrahepatic metastases, and the difference between the two imaging modalities was statistically significant (p = 0.0312) as determined by the McNemar chi-square test. However, the difference between CT and SRS in detecting primary neuroendocrine tumors, hepatic metastasis, and combined hepatic and extrahepatic metastasis was not statistically significant (p = 0.625, 1.000, and 1.000, respectively). CONCLUSION: Helical CT and SRS have similar sensitivity, specificity, and accuracy in detecting primary neuroendocrine tumor and hepatic metastasis. However, helical CT appears to be more sensitive in detecting extrahepatic metastasis from primary neuroendocrine tumors.

Accuracy of volumetric measurements after virtual right hepatectomy in potential donors undergoing living adult liver transplantation.

OBJECTIVE: The purpose of this study was to evaluate accuracy for determining the total and lobar liver volumes using a multidetector CT scanner in potential donors undergoing living adult right lobe liver transplantation. SUBJECTS AND METHODS: Fifty-two adult donors underwent CT using a multidetector scanner after IV injection of 180 mL of contrast material. For volumetric determination, portal venous phase images were acquired at 60 sec. Hand-tracing was used to isolate the entire liver, and a curved hepatectomy plane was then identified in a manner simulating the surgical incision. Two observers performed hand-tracing of the entire liver to calculate total liver volume, and of the right lobe to calculate expected graft volume. RESULTS: The mean volume of the entire liver, right lobe, and left lobe was 1807 mL, 990 mL, and 817 mL, respectively, for observer 1, and 1788 mL, 1007 mL, and 781 mL, respectively, for observer 2. There was significant agreement between the two observers in determining total and lobar liver volumes (r = 0.996, 0.977, and 0.965 for total, right lobe, and left lobe volumes, respectively; p< 0.0001). There was no statistically significant difference between the two observers in measuring total or lobar liver volumes (p< 0.0001). There was significant agreement between right lobe volume measured by each observer and graft weight obtained in 14 donors at surgery (r = 0.898 and 0.879, for observers 1 and 2, respectively; p <0.001). CONCLUSION: Total and lobar volume determinations after virtual right hemihepatectomy provides accurate and reproducible information that is critical in selecting potential living liver donors.

Impact of multidetector CT on donor selection and surgical planning before living adult right lobe liver transplantation.

OBJECTIVE: This study was performed to document the impact of multidetector multiphase CT in facilitating patient selection and surgical planning in potential donors being evaluated for living adult right lobe liver transplantation. SUBJECTS AND METHODS: Forty consecutive potential donors were included in the study. There were 26 men and 14 women, (age range, 18-57 years; mean, 37 years) We performed CT using a multidetector scanner, after IV injection of 180 mL of contrast material at 5 mL/sec. Arterial phase images were acquired at 18 sec (collimation, 1.25 mm; table speed, 7.5) and portal phase images, at 60 sec (collimation, 2.5 mm; table speed, 15). Postprocessing was performed on a commercially available workstation. CT data included dual-energy assessment of liver parenchyma for fatty infiltration; depiction of arterial, portal venous, and hepatic venous anatomy and identification of important vascular variants; and determination of total and lobar liver volume. RESULTS: Of the 40 potential liver donors evaluated, 15 patients (37.5%) were excluded on the basis of CT findings, with most exclusions a result of portal vein anomalies (n = 8). Fatty infiltration resulted in four exclusions (10%), and small liver volume resulted in three exclusions (7.5%). CONCLUSION: Multidetector multiphase CT provided comprehensive parenchymal, vascular, and volumetric preoperative evaluation of potential donors undergoing living adult right lobe liver transplantation. This information had a major impact on patient selection because it was used to stratify patients. It allowed the surgeons to plan their surgical approach, and this planning may reduce postoperative complications.

Radiation dose reduction in CT of the pediatric pelvis.

PURPOSE: To determine whether a lower radiation dose technique can be used for computed tomography (CT) of the pediatric pelvis without significant loss of diagnostic image quality. MATERIALS AND METHODS: Thirty-six pediatric patients underwent CT at 80 mAs (experimental group), and 42 underwent CT at 240 mAs (control group). Anatomic details, image quality, and the degree of confidence in reaching a diagnosis were graded on a scale of 1 (poor) to 4 (excellent). RESULTS: The difference in perceived image quality between the experimental and control groups was not statistically significant. The mean scores for scans evaluated by the first reader were 3.88 for the experimental group and 3.92 for the control group (P = .2804). The mean scores for the second reader were 3.78 and 3.77 for the experimental and control groups, respectively (P = .8131). CONCLUSION: A substantial dose reduction can be achieved if pelvic CT is performed at 80 mAs, without a recognizable deterioration of diagnostic image quality.

Liver regeneration after living adult right lobe transplantation.

BACKGROUND: The purpose of this study was to describe liver regeneration in patients undergoing living-adult liver transplantation. METHODS: This prospective study included 10 donors and eight recipients who had a total of 65 computed tomographic (CT) scans. All patients had preoperative CT ( n = 18), and follow-up CT scans ( n = 47) were obtained for up to 14 months after transplantation. Liver and spleen volumes were measured by hand tracing each organ on the axial portal venous phase images. RESULTS: Both donors and recipients showed immediate increases in liver volume. However, liver regeneration was significantly faster and reached a higher peak in recipients than in donors. Splenic volume in donors demonstrated an initial increase followed by a decline, reaching the preoperative volume after 1 year. Splenic volume in recipients demonstrated immediate decline postoperatively. CONCLUSION: Restoration of liver volume occurred rapidly after transplantation, but followed different patterns in donors and recipients. Deviation from these patterns warrants further investigation.