The association of aorto-iliac aneurysms with ureteral obstruction

Aorto-iliac aneurysms may entrap the ureters in perianeurysmal fibrosis, causing medical ureteral deviation and/or obstruction. The latter has been described only in male patients; a further 5 cases due to iliac and 3 to aortic aneurysm are reported. The radiologic picture resembles retroperitoneal fibrosis; the correct diagnosis may be suggested when ureteral tethering or narrowing lies near arterial calcification. Sonography is usually the most appropriate investigation to confirm the diagnosis. When sonography shows an aortic aneurysm, the kidneys should be scanned to rule out hydronephrosis. Similarly, films of the kidneys should be obtained when an abdominal aneurysm is demonstrated by aortography.     

Blood flow to the kidney via the gonadal-renal capsular artery

The gonadal artery is an important collateral pathway of blood flow to the kidney. Collateral routes may be from the gonadal artery to the inferior capsular artery (gonadal-renal capsular artery) or to the periureteric arteries. These pathways develop in cases of renal artery stenosis, or when a vascular renal tumor increases the kidneys need for blood. We present five cases in which the gonadal artery served as a source of blood supply to the kidney.     

18F-FDG PET-CT uptake is a feature of both normal diameter and aneurysmal aortic wall and is not related to aneurysm size

Purpose

Aortic metabolic activity is suggested to correlate with presence and progression of aneurysmal disease, but has been inadequately studied. This study investigates the 2-[¹⁸F] fluoro-2-deoxy-D-glucose (¹⁸F-FDG) uptake in a population of infra-renal abdominal aortic aneurysms (AAA), compared to a matched non-aneurysmal control group.

Methods

The Positron Emission Tomography – Computed Tomography (PET/CT) database was searched for infra-renal AAA. Exclusion criteria were prior repair, vasculitis, and saccular/mycotic thoracic or thoraco-abdominal aneurysms. Matching of 159 non-aneurysmal (<3 cm diameter) controls from the same population was assessed. Infra-renal aortic wall FDG uptake was assessed using visual analysis; maximum standardized uptake value (SUV_max) and target to background mediastinal blood pool ratio (TBR) were documented. Predictors of FDG uptake (age, sex, aortic diameter, hypertension, statin use, and diabetes) were assessed using univariate analysis. Follow-up questionnaires were sent to referring clinicians.

Results

Aneurysms (n?=?151) and controls (n?=?159) were matched (p?>?0.05) for age, sex, diabetes, hypertension, smoking status, statin use, and indication for PET/CT. Median aneurysm diameter was 5.0 cm (range 3.2–10.4). On visual analysis there was no significant difference in the overall numbers with increased visual uptake 24 % (36/151) in the aneurysm group vs. 19 % (30/159) in the controls, p?=?ns. SUV_max was slightly lower in the aneurysm group vs. controls (mean (2 SD) 1.75(0.79) vs. 1.84(0.58), p?=?0.02). However there was no difference in TBR between the AAA group and controls (mean (2 SD) 1.03 (0.46) vs. 1.05(0.31), p?=?0.36). During a median 18 (interquartile range 8–35) months’ follow-up 20 were repaired and four were confirmed ruptured.

Conclusions

The level of metabolic activity as assessed by ¹⁸F-FDG PET/CT in infra-renal AAA does not correlate with aortic size and does not differ between aneurysms and matched controls.     

Vascular neurocutaneous disorders: neurospinal and craniofacial imaging findings

We review the neurospinal and craniofacial imaging findings in vascular neurocutaneous disorders. The patients presented with cutaneous and cerebral lesions associated with craniofacial abnormalities or spinal lesions. Vascular neurocutaneous disorders may involve segmental or localized lesions associated with either low- or high-flow vascular malformations. Other neuroimaging findings include vascular occlusive changes with ischemic stroke, ectatic arteries, aneurysm, cortical migrational disorders such as hemimegalencephaly and congenital anomalies of the posterior fossa. Craniofacial vascular malformations, eye abnormalities, facial deformity and spinal lesions have been reported in some cases. Hamartomatous formation and malignancy have also been reported in some cases. Correlation of clinical findings with neurospinal and craniofacial abnormalities is important to reach a specific diagnosis of some vascular neurocutaneous disorders.     

Autoimmune pancreatitis: multidetector-row computed tomography (MDCT) and magnetic resonance (MR) findings in the Italian experience

Multidetector-row computed tomography (MDCT) and magnetic resonance (MR) imaging are currently the most frequently performed imaging modalities for the study of pancreatic disease. In cases of suspected autoimmune pancreatitis (AIP), a dynamic quadriphasic (precontrast, contrast-enhanced pancreatic, venous and late phases) study is recommended in both techniques. In the diffuse form of autoimmune pancreatitis (DAIP), the pancreatic parenchyma shows diffuse enlargement and appears, during the MDCT and MR contrast-enhanced pancreatic phase, diffusely hypodense and hypointense, respectively, compared to the spleen because of lymphoplasmacytic infiltration and pancreatic fibrosis. During the venous phase of MDCT and MR imaging, the parenchyma appears hyperdense and hyperintense, respectively, in comparison to the pancreatic phase. In the delayed phase of both imaging modalities, it shows retention of contrast media. A “capsule-like rim” may be recognised as a peripancreatic MDCT hyperdense and MR hypointense halo in the T2-weighted images, compared to the parenchyma. DAIP must be differentiated from non-necrotizing acute pancreatitis (NNAP) and lymphoma since both diseases show diffuse enlargement of the pancreatic parenchyma. The differential diagnosis is clinically difficult, and dynamic contrast-enhanced MDCT has an important role. In the focal form of autoimmune pancreatitis (FAIP), the parenchyma shows segmental enlargement involving the head, the body-tail or the tail, with the same contrast pattern as the diffuse form on both modalities. FAIP needs to be differentiated from pancreatic adenocarcinoma to avoid unnecessary surgical procedures, since both diseases have similar clinical and imaging presentation. The differential diagnosis is clinically difficult, and dynamic contrast-enhanced MDCT and MR imaging both have an important role. MR cholangiopancreatography helps in the differential diagnosis. Furthermore, MDCT and MR imaging can identify the extrapancreatic manifestations of AIP, most commonly biliary, renal and retroperitoneal. Finally, in all cases of uncertain diagnosis, MDCT and/or MR follow-up after short-term treatment (2–3 weeks) with high-dose steroids can identify a significant reduction in size of the pancreatic parenchyma and, in FAIP, normalisation of the calibre of the upstream main pancreatic duct.     

Postmortem dynamic cerebral angiography for detecting aneurysm and bleeding sites in cases of subarachnoid hemorrhage

One of the advantages of postmortem imaging is its ability to obtain diagnostic findings in a non-destructive manner when autopsy is either difficult or may destroy forensic evidence. In recent years, efforts have been made to incorporate computed tomography (CT) based postmortem angiography into forensic pathology; however, it is not currently clear how well the modality can determine sites of bleeding in cases of subarachnoid hemorrhage. Therefore, in this study, we investigated the utility of postmortem cerebral angiography using multi-detector row CT (MDCT) by injecting a contrast medium through a catheter inserted into the internal carotid and vertebral arteries of 10 subarachnoid hemorrhage cases. While postmortem MDCT angiography (PMCTA) was capable of detecting aneurysms in a non-destructive manner, it was sometimes difficult to identify the aneurysm and bleeding sites because of a large amount of contrast medium leaking into the extravascular space. To overcome this problem, we developed the novel contrast imaging method “dynamic cerebral angiography,” which involves scanning the same area multiple times while injecting contrast medium to enable real-time observation of the contrasted vasculature. Using multiphase contrast images acquired by this method, we successfully captured the moment when contrast medium leaked from the hemorrhage site. This method will be useful for identifying exact bleeding sites on PMCTA.     

Small renal carcinoma with large retroperitoneal hemorrhage: Diagnostic considerations

Two cases of small peripheral papillary renal carcinoma causing large spontaneous perirenal hemorrhages are presented. The value and limitations of computerized tomography, ultrasonography, arteriography, and percutaneous aspiration biopsy in these cases are discussed. The need for careful explorative surgery and dissection of the specimen is emphasized. Excretory urography should be the first examination in all patients with renal pain and signs of internal bleeding. Arteriography should be done when the diagnosis is not evident.     

Direct aneurysm sac catheterization and embolization of an enlarging internal iliac aneurysm using cone-beam CT

Since cone-beam computed tomography (CT) has been adapted for use with a C-arm system it has brought volumetric CT capabilities in the interventional suite. Although cone-beam CT image resolution is far inferior to that generated by traditional CT scanners, the system offers the ability to place an access needle into position under tomographic guidance and use the access to immediately begin a fluoroscopic procedure without moving the patient. We describe a case of a “jailed” enlarging internal iliac artery aneurysm secondary to abdominal aortic aneurysm repair, in which direct percutaneous puncture of the internal iliac artery aneurysm sac was performed under cone-beam CT guidance.When planning for successful abdominal endovascular aneurysm repair (EVAR), it is important to evaluate if there are associated internal iliac artery (IIA) aneurysms and the potential for type II endoleaks via retrograde IIA flow. In cases of short, ectatic, or aneurysmal common iliac arteries, placement of the distal limb of the stent graft into the external iliac artery may be necessary to ensure safe graft limb positioning and an adequate seal. In situations such as this, where there is not an associated IIA aneurysm, standard therapy is to embolize the origin of the IIA prior to stent graft placement in order to prevent type II endoleaks (1).The situation should be differentiated from the setting in which the IIA is not just a potential source of a type II endoleak, but is also aneurysmal. In this setting, embolization of the affected IIA origin is insufficient to protect the IIA aneurysm from retrograde perfusion and potential rupture (Fig. 1). This retrograde perfusion can lead to persistent aneurysm sac pressurization with subsequent aneurysm enlargement and increased risk of rupture. Furthermore, proximal embolization precludes future antegrade access into the aneurysm if an additional intervention is needed. The standard endovascular treatment of an isolated IIA aneurysm consists of embolic occlusion of all inflow and outflow branches (2). Hence, when an IIA aneurysm is associated with an abdominal aortic aneurysm (AAA), it should be treated in a similar manner prior to endograft placement (3).Open in a separate windowFigure 1.Illustration demonstrates endovascular aneurysm repair of an abdominal aortic aneurysm extending into the common iliac arteries and internal iliac arteries (IIA), with embolization of all inflow and outflow branches of the IIA to prevent enlargement of the IIA aneurysms. (Illustration by D.C. Botos)We present a case of cone-beam computed tomography (CBCT) guided direct puncture of a “jailed” enlarging IIA aneurysm. The IIA aneurysm was not directly accessible through an antegrade endovascular approach secondary to prior IIA origin coil occlusion and stent graft exclusion of the IIA orifice.     

Assessment of aortitis by semiquantitative analysis of 180-min 18F-FDG PET/CT acquisition images

Purpose

The aim of this study was to evaluate the contribution of semiquantitative analysis of 180-min ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT images for the assessment of aortitis in cases of suspected large vessel vasculitis (LVV) and to establish a threshold index for application in the clinical setting.

Methods

This prospective study included 43 patients (mean age 67.5?±?12.9?years) with suspicion of LVV (25 with a final diagnosis of aortitis). ¹⁸F-FDG PET/CT scan was acquired 180 min after injection of 7 MBq/kg of ¹⁸F-FDG. A semiquantitative analysis was performed calculating the aortic wall maximum standardized uptake value (SUV_max) (T), the lumen SUV_max (B) and the target to background ratio (TBR). These results were also compared with those obtained in a control population.

Results

The mean aortic wall SUV_max was 2.00?±?0.62 for patients with aortitis and 1.45?±?0.31 for patients without aortitis (p?p?max (0.997 vs 0.871). The highest sensitivity and specificity was obtained for a TBR of 1.34 (sensitivity 100 %, specificity 94.4 %).

Conclusion

Semiquantitative analysis of PET/CT images acquired 180 min after ¹⁸F-FDG injection and the TBR index of 1.34 show very high accuracy and, therefore, are strongly recommended for the diagnosis of aortitis in the clinical setting.     

18F-fluorodeoxyglucose positron emission tomography combined with whole-body computed tomographic angiography in critically ill patients with suspected severe sepsis with no definite diagnosis

Purpose

Timely identification of septic foci is critical in patients with severe sepsis or septic shock of unknown origin. This prospective pilot study aimed to assess ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET), combined with whole-body computed tomographic angiography (CTA), in patients with suspected severe sepsis and for whom the prior diagnostic workup had been inconclusive.

Methods

Patients hospitalized in an intensive care unit with a suspected severe sepsis but no definite diagnosis after 48 h of extensive investigations were prospectively included and referred for a whole body FDG-PET/CTA. Results from FDG-PET/CTA were assessed according to the final diagnosis obtained after follow-up and additional diagnostic workup.

Results

Seventeen patients were prospectively included, all on mechanical ventilation and 14 under vasopressor drugs. The FDG-PET/CTA exam 1) was responsible for only one desaturation and one hypotension, both quickly reversible under treatment; 2) led to suspect 16 infectious sites among which 13 (81 %) could be confirmed by further diagnostic procedures; and 3) triggered beneficial changes in the medical management of 12 of the 17 study patients (71 %). The FDG-PET/CTA images showed a single or predominant infectious focus in two cases where CTA was negative and in three cases where CTA exhibited multiple possible foci.

Conclusion

Whole-body FDG-PET/CTA appears to be feasible, relatively safe, and provides reliable and useful information, when prospectively planned in patients with suspected severe sepsis and for whom prior diagnostic workup had been inconclusive. The FDG-PET images are particularly helpful when CTA exhibits no or multiple possible sites.     

Ureteral leak after an abdominal aortic aneurysm repair: case report

Iatrogenic ureteral injuries are an infrequent complication of vascular reconstructive surgery, and if they are not suspected at the time of surgery the diagnosis is usually delayed. Diagnosing these injuries may be challenging, since patients usually show signs and symptoms appropriate to a normal postoperative course and usually do not develop hematuria or renal dysfunction. In the proper clinical setting, a fluid collection adjacent to the ureter on cross-sectional imaging studies should alert the emergency radiologist to the possibility of ureteral injury. A high clinical suspicion would allow earlier diagnosis and treatment, potentially reducing the morbidity and mortality associated with a delay in diagnosis. We present a case of a ureteral leak diagnosed 1 week after an abdominal aortic aneurysm repair. A fluid collection seen adjacent to the ureter on contrast-enhanced CT prompted the radiologist to obtain delayed images that demonstrated urinary extravasation. Electronic Publication     

Observer Variability of an Angiographic Grading Scale Used for the Assessment of Intracranial Aneurysms Treated with Flow-Diverting Stents

BACKGROUND AND PURPOSE:Novel angiographic grading scales for the assessment of intracranial aneurysms treated with flow-diverting stents have been recently developed because previous angiographic grading scales cannot be applied to these aneurysms. The purpose of this study was to evaluate the inter- and intraobserver variability of the novel O''Kelly Marotta grading scale, which was developed specifically for the angiographic assessment of aneurysms treated with flow-diverting stents.MATERIALS AND METHODS:Multiple raters (n = 31) from the disciplines of neuroradiology and neurosurgery were presented with pre- and posttreatment angiographic images of 14 aneurysms treated with intraluminal flow diverters. Raters were asked to classify pre- and posttreatment angiograms by using the OKM grading scale. Statistical analyses were subsequently performed with calculation of a generalized multirater κ statistic for assessment of inter- and intraobserver variability and by performing a Wilcoxon signed rank sum test for assessment of group differences.RESULTS:Variability analysis of the OKM grading scale yielded substantial (κ = 0.74) and almost perfect (κ = 0.99) inter- and intraobserver agreement, respectively, with no statistically significant differences between raters with a background of neuroradiology versus neurosurgery or attending physician versus trainee.CONCLUSIONS:The OKM grading scale for the assessment of intracranial aneurysms treated with flow-diverting stents is a reliable grading scale that can be used equally well by users of varying backgrounds and levels of training. Comparison with interobserver variability of pre-existing angiographic grading scales shows equal or better performance.

The development of flow-diverting stents has ushered in an era of new paradigms and possibilities for the endovascular treatment of intracranial aneurysms. These devices are garnering momentum for difficult intracranial aneurysms that are wide-neck, have fusiform configuration, are located in perforator territories, or have complex geometry. Their mechanism of action relies on a reduction of filling of the aneurysmal sac with flow diversion toward the parent vessel, leading to stasis and subsequent thrombosis within the aneurysm. This process usually occurs with time, and angiographic evidence of aneurysm protection is usually not seen in immediate posttreatment angiograms. Rather, the process of stasis and thrombosis may not be complete for months after initial flow-diverting stent placement. While residual filling is a suboptimal or unacceptable posttreatment angiographic result for an aneurysm treated with endosacular coiling, this can be optimal and acceptable for an aneurysm treated by using flow-diverting devices. Traditional grading scales, such as the 3-point grading scale of Roy and Raymond used for aneurysms treated with coiling or clipping,¹ do not apply to aneurysms treated with flow-diverting stents. For example, after treatment, filling within the aneurysm body would be classified as residual aneurysm and would not be considered a desirable result according to the Roy and Raymond classification, but in the case of flow-diverting stent placement, this would be an expected immediate posttreatment result.A new grading scale specifically tailored to the angiographic assessment of aneurysms treated with flow-diverting stents was published by O''Kelly et al,² termed the O''Kelly Marotta grading scale. This novel grading scale incorporates 2 dimensions as parameters, which reflect the mechanism by which flow-diverting devices accomplish aneurysm protection: reduction in aneurysm sac filling (filling grade), which reflects an anatomic aspect, and promotion of stasis within the aneurysm sac (stasis grade), which reflects a more dynamic or physiologic parameter (Fig 1).Open in a separate windowFig 1.OKM angiographic grading scale for assessment of aneurysms treated with flow-diverting stents. Aneurysms are assigned grades on the basis of the amount of contrast filling of the aneurysm lumen (filling grades, A, B, C, D) and how long contrast persists in the aneurysm lumen with respect to angiographic phase (stasis grades 1, 2, 3). A grade consisting of a letter and a number is assigned to an aneurysm (eg, an aneurysm that fills its lumen completely with contrast persisting within the lumen into the venous phase of the angiogram is assigned grade A3).² Modified from O''Kelly CJ, Krings T, Fiorella D, et al. A novel grading scale for the angiographic assessment of intracranial aneurysms treated using flow diverting stents. Interv Neuroradiol 2010;16:133–37 and reproduced with permission from Centauro srl Publishing.With any novel grading scale, an evaluation of performance in the hands of the evaluating end user is necessary for an assessment of reliability. We present here an analysis of the inter- and intraobserver variability of the OKM grading scale based on evaluation of conventional angiographic images of aneurysms pre- and posttreatment with flow-diverting stents by 31 evaluators with a background in neurointervention from the disciplines of neuroradiology and neurosurgery.     

Ultrasound of the neonatal urinary tract

Ultrasound (US) is a safe and accurate imaging method in the evaluation of the urinary tract. It should be the first procedure used in the neonate to confirm prenatal diagnosis, in patients with a malformation in another organ system that is known to be associated with kidney anomalies, in patients presenting with a spontaneous pneumothorax, in cases of an abdominal mass, and, in renal failure, asphyxiated babies, septicemia or urinary tract infection, or, prolonged jaundice. In association with the other uroradiological methods, it will lead to the correct diagnosis in most cases.     

Angiographic findings in homocystinuria

Homocystinuria (HC) is an inborn error of amino acid metabolism characterized by ectopia lentis, mental retardation, and skeletal abnormalities. Vascular disorders may also occur in HC, although they are less common. Arteriographic studies of two sisters with HC are described. The younger woman's renal arteries showed wall irregularities and aneurysms, narrowing of the celiac and superior mesenteric arteries, and some aneurysmatic changes. In the older patient, irregular right carotid and splenic arteries were seen and a splenic aneurysm was present.     

Sonographic evaluation of renal masses: Correlations with angiography

The value of sonography in the diagnosis of renal masses in a series of 119 consecutive histologically confirmed cases is presented. Sonography correctly identified 92% of the cystic and 90% of the solid renal masses. Causes of incorrect diagnoses included lesions smaller than 2 cm, masses in the left upper pole, diffusely infiltrating urothelial tumors, echogenic fatty lesions (early in our experience), and acute abscesses and hematomas. Angiography in the same series of cases correctly diagnosed 80% of the cystic and 88% of the solid renal masses. Avascular lesions were the main cause for equivocal or incorrect angiographic diagnoses. We conclude that sonography is more definitive than angiography in the diagnosis of avascular masses, while angiography excels when the lesion is vascular or small. Combining the sonographic and angiographic findings allowed accurate diagnosis in over 99% of the cases.     

Extracorporeal shock wave lithotripsy (ESWL) for kidney stones. An alternative to surgery?

Four years of experience with extracorporeal shock wave lithotripsy (ESWL) for renal and ureteral calculi is summarized. Ninety-nine percent of treated patients had a satisfactory clinical result; 90% of them were stone-free. No significant complications were encountered. We conclude that 85% of all patients with stones can be cured by nonsurgical means. Surgical and other therapeutic modalities will still have a place in the future, but an experienced urologic surgeon can best decide which of the available therapies is best suited for an individual patient.     

Contrast-enhanced ultrasound of focal nodular hyperplasia: a matter of size

Objectives

To assess the contrast-enhanced ultrasound (CEUS) frequencies of centrifugal enhancement, spoke-wheel sign and central scar in focal nodular hyperplasia (FNH) as a function of lesion size.

Methods

Ninety-four FNHs were retrospectively reviewed to assess their largest diameter and enhancement pattern, including centrifugal enhancement from one central artery, spoke-wheel sign, diffuse or centripetal enhancement, central scar and late-phase washout.

Results

Mean FNH-lesion size was 3.7?±?2.1 cm. Only 43.6 % of FNHs had centrifugal enhancement, with a spoke-wheel pattern (23.4 %) or without (20.2 %), while 56.4 % showed diffuse or centripetal enhancement. Centrifugal enhancement was observed in 73.9 % of FNHs ≤3.1 cm and 14.6 % of FNHs >3.1 cm (P?–4). Size and frequency of centrifugal enhancement were negatively correlated (r?=?–0.57, P?–4). The spoke-wheel pattern was also seen more frequently in smaller (37 %) than in larger FNHs (10.4 %) (P?–3). Late-phase washout was described in 5.3 % of FNHs and was not size-dependent. Lesions with a central scar were larger than those without, respectively, 5.7?±?1.7 and 3.6?±?2.0 cm (P?=?0.012).

Conclusions

Typical centrifugal enhancement yielding a confident FNH diagnosis is seen significantly more frequently when the lesion is ≤3.1 cm.

Key Points

? CEUS yields confident diagnoses of FNHs ≤3.1 cm ? The larger the FNH, the lower the diagnostic sensitivity of CEUS ? Final diagnosis of FNHs >3.1 cm should be obtained with MRI not CEUS     

Evaluation of 11C-choline PET/CT for primary diagnosis and staging of urothelial carcinoma of the upper urinary tract: a pilot study

Purpose

We conducted a pilot study to prospectively evaluate the efficacy of PET/CT with ¹¹C-choline (choline PET/CT) for primary diagnosis and staging of urothelial carcinoma of the upper urinary tract (UUT-UC).

Methods

Enrolled in this study were 16 patients (9 men, 7 women; age range 51 – 83 years, mean?±?SD 69?±?10.8 years) with suspected UUT-UC. The patients were examined by choline PET/CT, and 13 underwent laparoscopic nephroureterectomy and partial cystectomy. Lymphadenectomy and chemotherapy were also performed as necessary in some of the patients. Of the 16 patients, 12 were confirmed to have UUT-UC (7 renal pelvis carcinoma and 5 ureteral carcinoma), 1 had malignant lymphoma (ureter), 1 had IgG4-related disease (ureter), and 2 had other benign diseases (ureter).

Results

Of the 16 study patients, 13 showed definite choline uptake in urothelial lesions, and of these, 11 had UUT-UC, 1 had malignant lymphoma, and 1 had IgG4-related disease. Three patients without choline uptake comprised one with UUT-UC and two with benign diseases. Of the 12 patients with UUT-UC, 3 had distant metastases, 2 had metastases only in the regional lymph nodes, and 7 had no metastases. Distant metastases and metastases in the regional lymph nodes showed definite choline uptake. The outcome in patients with UUT-UC, which was evaluated 592 – 1,530 days after surgery, corresponded to the patient classification based on the presence or absence of metastases and locoregional or distant metastases. Choline uptake determined as SUVmax 10 min after administration was significantly higher than at 20 min in metastatic tumours of UUT-UC (p?Conclusion This study suggests that choline PET/CT is a promising tool for the primary diagnosis and staging of UUT-UC.     

Assessment of hepatic functional regeneration after hepatectomy using 99mTc-GSA SPECT/CT fused imaging

Background

The liver itself regenerates after hepatectomy but little is known about how much hepatic function recovers during the regeneration. The liver uptake value (LUV), calculated from Tc-99m-labeled galactosyl-human-serum-albumin (^99mTc-GSA) SPECT/CT fused images, is reliable and useful for evaluating hepatic function. In this study, we evaluated the clinical usefulness of LUV for estimating hepatic functional regeneration after hepatectomy.

Methods

We enrolled 95 patients who had undergone ^99mTc-GSA SPECT/CT tests before/on days 30 and 90 after hepatectomy. We determined the LUV from the ^99mTc-GSA SPECT/CT images and calculated the %LUV (postoperative LUV/preoperative LUV × 100). Based on surgical procedures and histopathological damage, we divided the study population into patients with severe (n = 12) or non-severe fibrosis (n = 33) who had undergone minor hepatectomy, and patients with severe (n = 14) or non-severe fibrosis (n = 36) having major hepatectomy. On the 90th post-hepatectomy day, five patients manifested liver failure; in these patients, we analyzed the co-relation between liver failure and the results of the liver function tests performed on day 30 after surgery.

Results

Although the %LUV reached 95.4 ± 12.2 % in 30 days, in patients with severe fibrosis after major hepatectomy it remained below 90 %. Patients having low %LUV (<75 %) and high serum bilirubin (>2.0 mg/dl) at 30 days showed a relative risk of liver failure of 12.0 and 4.5 (p < 0.001 and p < 0.001), respectively.

Conclusions

Although the %LUV recovered to about 95 % in all patients within 30 days after the hepatectomy, in patients with severe fibrosis having major hepatectomy, the process of recovery was delayed. The %LUV corresponded to the quality of the liver function which emerged in a later post-hepatectomy phase.     

Cross-sectional imaging of idiopathic solitary renal vein varix: Report of two cases

Two cases of solitary renal vein varices are reported which presented as incidental findings on abdominal computed tomography (CT) and were initially thought to represent retroperitoneal lymph nodes. Contrast-enhanced CT, magnetic resonance imaging (MRI), and Doppler ultrasound (US), all demonstrated the vascular nature of these masses suggesting the correct diagnosis. When a rounded soft tissue density mass is seen on noncontrast-enhanced CT either in or contiguous to the renal hilum, a renal vein varix must be excluded. Doppler US, MRI, or dynamic contrast-enhanced CT should be done to exclude a renal varix as the cause.