[PET/CT with (18F)FDG in the initial staging of a pelvic kidney neoplasm. A case report]. / PET-TAC con (18)F-FDG en la estadificación inicial de una neoplasia de pelvis renal. A propósito de un caso.

We report a case of 58-year-old woman referred to our service for an (18)FFDG PET/CT study of initial staging after being diagnosed of a pelvic kidney mass consistent with malignancy. The FDG-PET showed an abnormal mass in the right kidney, a suspicious metastasis versus a second primary tumor in the cortex of the kidney and lymph node infiltration in the paracaval nodes. The histological analysis verification after exeresis of the lesions confirmed the diagnosis of renal metastases. In this article, we present a brief review of the literature published on the role of PET in the characterization and initial staging of kidney and urinary tract tumors. We also stress the clinical importance of carefully evaluating any low attenuation lesion or focal glucose uptake detected in these structures in a PET/CT study with (18)FFDG.

PET-TAC con 18F-FDG en la estadificación inicial de una neoplasia de pelvis renal. A propósito de un caso / PET/CT with 18FFDG in the initial staging of a pelvic kidney neoplasm. A case report

Presentamos el caso de una mujer de 58 años remitida a nuestro servicio para la realización de un estudio PET-TAC con 18F-FDG de estadificación inicial tras ser diagnosticada de una masa en la pelvis de riñón derecho compatible con un proceso neoproliferativo. La PET-FDG mostró una masa en riñón derecho, una lesión sospechosa de metástasis versus un segundo tumor primario en la cortical del propio riñón y signos de infiltración adenopática tumoral en situación paracaval. El estudio histológico tras la exéresis de las lesiones confirmó dichos hallazgos como metastásicos. En este artículo realizamos un breve repaso de la bibliografía publicada al respecto, valorando la utilidad de la PET en la caracterización y estadificación inicial de las neoplasias de riñón y vías urinarias. Asimismo enfatizamos la importancia de valorar cuidadosamente cualquier imagen hipodensa o depósito de glucosa en riñones y vías urinarias visualizado en un estudio PET-TAC con 18F-FDG(AU)

We report a case of 58-year-old woman referred to our service for an 18FFDG PET/CT study of initial staging after being diagnosed of a pelvic kidney mass consistent with malignancy. The FDG-PET showed an abnormal mass in the right kidney, a suspicious metastasis versus a second primary tumor in the cortex of the kidney and lymph node infiltration in the paracaval nodes. The histological analysis verification after exeresis of the lesions confirmed the diagnosis of renal metastases. In this article, we present a brief review of the literature published on the role of PET in the characterization and initial staging of kidney and urinary tract tumors. We also stress the clinical importance of carefully evaluating any low attenuation lesion or focal glucose uptake detected in these structures in a PET/CT study with 18FFDG(AU)

[Vesicosigmoid fistulas secondary to diverticulitis: helical CT diagnosis]. / Fístulas vesicosigmoideas secundarias a diverticulitis. Diagnóstico mediante tomografía computarizada helicoidal.

Colovesical fistulas are the most common type of vesicointestinal fistula and the most prevalent of these are vesicosigmoid fistulas. In our environment, diverticulitis is the most common cause, accounting for approximately one half of all cases. The literature describes different methods for the diagnosis of colovesical fistula, with computed tomography and cystography being the most useful. We describe two cases of vesicosigmoid fistula secondary to diverticulitis diagnosed at our center using helical computed tomography and review the clinical and radiological findings for this entity.

Fístulas vesicosigmoideas secundarias a diverticulitis. Diagnóstico mediante tomografía computarizada helicoidal / Vesicosigmoid fistulas secondary to diverticulitis: helical CT diagnosis

La fístula colovesical es la más frecuente de las fístulas vesico-intestinales, y dentro de éstas la más prevalente es la vesico-sigmoidea.La diverticulitis es su causa más común en nuestro medio, llegando a ocasionar aproximadamente la mitad de los casos. En la literatura se recogen diversos métodos diagnósticos de fístula colovesical, siendo la tomografía computarizada y la cistoscopia los más rentables. Presentamos la iconografía de dos casos de fístula vesicosigmoidea secundaria a diverticulitis diagnosticados en nuestro hospital mediante tomografíacomputarizada helicoidal, y revisamos los hallazgos clínicos y radiológicos de esta entidad

Colovesical fistulas are the most common type of vesicointestinal fistula and the most prevalent of these are vesicosigmoid fistulas. In our environment, diverticulitis is the most common cause, accounting for approximately one half of all cases. The literature describes different methods for the diagnosis of colovesical fistula, with computed tomography and cystography being the most useful. We describe two casesof vesicosigmoid fistula secondary to diverticulitis diagnosed at our center using helical computed tomography and review the clinical and radiological findings for this entity

Complications of orthotopic liver transplantation: spectrum of findings with helical CT.

Orthotopic liver transplantation has become the treatment of choice for patients with end-stage nonmalignant liver disease. The surgical techniques and immunosuppressive therapy for this procedure have improved considerably. Nevertheless, there are still significant complications, particularly those of vascular origin, which can lead to graft failure and require retransplantation unless prompt treatment is instituted. These complications include arterial and venous thrombosis and stenosis; arterial pseudoaneurysm; biliary leakage, stricture, and obstruction; liver ischemia, infarction, and abscess; fluid collections and hematomas; lymphoproliferative disorders; recurrent tumors; hepatitis C virus infection; and splenic infarction. Since the clinical presentation of posttransplantation complications is frequently nonspecific and varies widely, imaging studies are critical for early diagnosis. Helical computed tomography (CT) is a valuable complement to ultrasonography (US) in the postoperative period and is a safe, accurate, and noninvasive method of demonstrating hepatic vessels (hepatic artery, portal vein, hepatic veins, and inferior vena cava) and evaluating nonvascular complications (in the hepatic parenchyma and bile duct abnormalities) and extrahepatic tissues. Knowledge and early recognition of these complications is essential for graft salvage, and CT can provide valuable information, particularly for patients with indeterminate US results or in whom US examination is difficult.

[Computerized tomography angiography of the renal vessels]. / Angiografía por tomografía computarizada de los vasos renales.

OBJECTIVE: To present the findings and discuss the diagnostic possibilities of helical CT angiography and digital substraction angiography, and to compare their capabilities to depict renal vascular anatomy (arterial and venous) and the pathological changes. METHODS: The findings obtained by the different imaging modalities of CT angiography were compared with those of digital substraction angiography in more than 2000 studies performed at our hospital. RESULTS: Agreement and correlation between CT angiography and digital substraction angiography, the gold standard, were found in the vast majority of the cases. In conjunction, various image post-processing possibilities of CT angiography achieved almost 100% sensitivity and specificity. CONCLUSION: CT angiography is capable of obtaining results that overlap with those of optimum quality digital substraction angiography and is a less invasive and less costly procedure. The time required is shorter and the radiation dose exposure is markedly lower for patient and staff. Helical CT is a minimal invasive technique with an increasing role in the evaluation of the renal vessels. Although its field of applications has not yet been completely established, it is less invasive, less costly, radiation exposure of patient and staff performing the procedure is lower, and has had a considerable impact in the diagnosis and management of vascular disorders. CT angiography is applicable to a number of indications of conventional angiography and has permitted vascular screening studies where one would be reluctant to indicate catheter arteriography. This imaging procedure is mainly used for 1) screening of patients that may have renovascular hypertension that may be amenable to surgical or intraluminal treatment; 2) follow-up of treated patients; 3) preoperative assessment of kidney donors; 4) evaluation of renal artery aneurysms (uncommon), aneurysms extending to the renal arteries or dissection of the aorta. It is also effective, but only slightly superior to conventional CT, in depicting thrombosis or tumor invasion of renal veins, although it is highly effective in evaluating anatomical variations and renal vein anomalies. In inflammatory vascular disease it is similar to catheter angiography, although its impact is not considerable due to the low prevalence of inflammatory vascular disease in our setting.

Hemoperitoneum as a first manifestation of hepatocellular carcinoma in western patients with liver cirrhosis: effectiveness of emergency treatment with transcatheter arterial embolization.

Hemoperitoneum is a well-known form of hepatocellular carcinoma presentation and represents a frequent complication in countries with a high incidence of hepatocellular carcinoma, but it is rarely seen in Western countries. Our aim was to report the results and describe the arteriographic and CT-scan characteristics in a series of seven consecutive patients. They were admitted to our hospital because of hemoperitoneum due to ruptured tumor as a first manifestation of hepatocellular carcinoma, and the rupture was effectively controlled by transcatheter arterial embolization. From April 1989 to April 1998, 440 consecutive patients were admitted to our liver unit with the diagnosis of hepatocellular carcinoma and liver cirrhosis. Fourteen patients (3%) presented with acute hemoperitoneum due to tumor rupture as a first manifestation of hepatocellular carcinoma. We here report our experience in the group of patients treated by transcatheter arterial embolization. Mean age was 67.1+/-5 years (range, 61-73). All patients presented with sudden abdominal pain, abdominal distension, and four patients had symptoms of acute anemia. In all cases the ruptured tumor was subcapsular. The procedure was effective in the control of bleeding in all cases, without significant impairment in liver function or treatment-related deaths. In six of the seven patients, a self-limited postembolization syndrome was observed. Mean survival time was 273+/-488.7 days (range: 15-1290). Three patients survived more than six months but at the time of evaluation, only one patient was alive. In conclusion, the present results confirm that transcatheter arterial embolization is an effective and well-tolerated treatment in the management of hemoperitoneum due to ruptured hepatocellular carcinoma in patients with liver cirrhosis.

Improved diagnosis of hepatic perfusion disorders: value of hepatic arterial phase imaging during helical CT.

The liver has a unique dual blood supply, which makes helical computed tomography (CT) a highly suitable technique for hepatic imaging. Helical CT allows single breath-hold scanning without motion artifacts. Because of rapid image acquisition, two-phase (hepatic arterial phase and portal venous phase) evaluation of the hepatic parenchyma is possible, improving tumor detection and tumor characterization in a single CT study. The arterial and portal venous supplies to the liver are not independent systems. There are several communications between the vessels, including transsinusoidal, transvasal, and transplexal routes. When vascular compromise occurs, there are often changes in the volume of blood flow in individual vessels and even in the direction of blood flow. These perfusion disorders can be detected with helical CT and are generally seen as an area of high attenuation on hepatic arterial phase images that returns to normal on portal venous phase images; this finding reflects increased arterial blood flow and arterioportal shunting in most cases. Familiarity with the helical CT appearances of these perfusion disorders will result in more accurate diagnosis. By recognizing these perfusion disorders, false-positive diagnosis (hypervascular tumors) or overestimation of the size of liver tumors (eg, hepatocellular carcinoma) can be avoided.

Portomesenteric vein gas: pathologic mechanisms, CT findings, and prognosis.

Portomesenteric vein gas is a rare condition whose pathogenesis is not fully understood. Portomesenteric vein gas is most commonly caused by mesenteric ischemia but may have a variety of other causes. The primary factors that favor the development of this pathologic entity are intestinal wall alterations, bowel distention, and sepsis. Portomesenteric vein gas is idiopathic in approximately 15% of cases. Advanced imaging techniques such as computed tomography (CT) have increased the sensitivity for detection of portomesenteric vein gas. At CT, portal vein gas appears as tubular areas of decreased attenuation in the liver, predominantly in the left lobe. Gas in the great mesenteric veins can easily be demonstrated with contrast material-enhanced CT, whereas gas in the small mesenteric veins appears as tubular or branched areas of decreased attenuation in the mesenteric border of the bowel. Findings of portomesenteric vein gas at CT should be carefully evaluated in the context of clinical findings. In the majority of cases, the prognosis is favorable and surgery is not required. However, when CT demonstrates portomesenteric vein gas and clinical findings suggest the presence of mesenteric ischemia, surgery is mandatory.

Accuracy of helical computed tomographic angiography for the diagnosis of colonic angiodysplasia.

BACKGROUND & AIMS: The diagnosis of colonic angiodysplasia is often challenging and relies on endoscopy or catheter angiography. We investigated whether computed tomographic angiography (CTA) contributes to the diagnosis of colonic angiodysplasia. METHODS: Twenty-eight patients with suspected bleeding from colonic angiodysplasia were prospectively evaluated. Gastrointestinal bleeding was investigated by colonoscopy plus visceral angiography and by CTA. The level of agreement between CTA and the former procedures was determined. RESULTS: CTA images of diagnostic quality were obtained in 26 patients. Eighteen patients were diagnosed with colonic angiodysplasia by colonoscopy plus visceral angiography, and 14 by CTA (kappa = 0.68; P < 0.001). Sensitivity, specificity, and positive predictive values of CTA for detection of colonic angiodysplasia were 70%, 100%, and 100%, respectively. CTA signs including accumulation of vessels in the colonic wall, early filling vein, and supplying enlarged artery were present in 55%, 50%, and 22% of cases, respectively. None of these signs were present in the 8 patients with obscure gastrointestinal bleeding and negative diagnostic investigation of the digestive tract. CONCLUSIONS: CTA is a sensitive, specific, well-tolerated, and minimally invasive tool for the diagnosis of colonic angiodysplasia.

Arteriovenous fistula secondary to iliac mycotic aneurysm: helical CT findings.

We describe the case of a 59-year-old man who presented a mycotic aneurysm of the common right iliac artery due to Streptococcus agalactiae and developed an arteriovenous fistula within the inferior vena cava secondary to spontaneous rupture of the aneurysm. The clinical syndrome, helical computed tomographic, and angiographic findings are described and discussed.

Intrahepatic arterioportal shunt: helical CT findings.

The purpose of this study was to characterize the appearance of intrahepatic arterioportal shunts (APS) on two-phase helical CT, with emphasis on the importance of the hepatic arterial-dominant phase (HAP) to demonstrate perfusion disorders. We review eight cases of APS diagnosed by helical CT in our institution from January 1996 to March 1997 and describe the CT findings that established diagnosis. Five of them were confirmed by angiography. In seven (87. 5 %) cases of APS we found early enhancement of the peripheral portal branches during the HAP of helical CT, whereas the superior mesenteric and splenic veins remained unenhanced. In five (62.5 %) cases of APS, transient, peripheral, triangular parenchymal enhancement was depicted during the HAP of helical CT; in four of these cases there was associated early enhancement of the portal branches. Helical CT can show perfusion alterations that might remain undiagnosed with conventional CT. An understanding of the hemodynamic changes that occur in APS can help in the interpretation of focal transient hepatic parenchymal enhancement and to differentiate APS from hypervascular tumors. We believe that the helical CT findings described herein are characteristic enough to suggest the diagnosis of APS.

Renal trauma in occult ureteropelvic junction obstruction: CT findings.

The aim of this study was to present CT findings of occult ureteropelvic junction obstruction in patients with renal trauma and to describe the clinical signs and singular CT features that are characteristically observed with trauma and are relevant to management of these patients. We retrospectively reviewed 82 helical CT studies in patients with renal trauma referred to our institution. We found 13 cases of occult preexisting renal pathology, six of which were occult ureteropelvic junction obstructions. The clinical presentation, radiologic findings of trauma according to the Federle classification, and CT findings of obstructed ureteropelvic junction are presented. We found three category-I lesions (one in horseshoe kidney), two of them treated with nephrostomy because of increased ureteropelvic junction obstruction due to pelvic clots; two category-II lesions (parenchymal and renal pelvis lacerations) that had presented only with microhematuria; and one category-IV lesion (pelvic laceration alone). Pelvic extension was demonstrated in all the cases with perirenal collections. The CT studies in all the cases with suspected ureteropelvic junction obstruction showed decreased parenchymal thickness and enhancement, and dilatation of the renal pelvis and calyx, with a normal ureter. Computed tomography can provide information to confidently diagnose underlying ureteropelvic junction obstruction in renal trauma, categorize the traumatic injury (at times clinically silent) and facilitate proper management according to the singularities observed, such us rupture of the renal pelvis alone (Federle category IV) and increasing ureteropelvic obstruction due to clots which can be decompressed by nephrostomy.

Aortic dissection: diagnosis and follow-up with helical CT.

Acute aortic dissection is a cardiovascular emergency that requires prompt diagnosis and treatment. Helical computed tomography (CT) allows diagnosis of acute aortic dissection with a sensitivity and specificity of nearly 100%. With helical CT, a dissection involving the ascending aorta (type A in the Stanford classification) can be differentiated from one distal to the left subclavian artery (type B). Helical CT can also be used to identify atypical forms of aortic dissection such as intramural hematoma, penetrating atherosclerotic ulcer, ruptured type B dissection, and atypical configurations of the intimal flap. Helical CT is useful in follow-up of aortic dissection by allowing assessment of early and late changes after surgery or medical treatment. Such changes include postoperative complications of type A dissection, healing of intramural hematoma, progression of intramural hematoma, and aneurysms of the true or false lumen. Helical CT can also be used to monitor potentially life-threatening ischemic complications of abdominal branch vessels.

Small bowel obstruction secondary to bezoar: CT diagnosis.

Two cases of small bowel obstruction secondary to phytobezoar diagnosed by computed tomography (CT) and confirmed at surgery are presented. CT findings were dilated intestinal loops and an intraluminal mass with air bubbles retained in its interstices, resulting in a mottled appearance. We propose that definite diagnosis of small bowel bezoar can be made on the basis of these CT findings.

Duodenal schwannoma causing gastrointestinal bleeding: helical CT findings.

Neurogenic tumors of the small intestine are extremely rare and represent an unusual cause of gastrointestinal hemorrhage. We present a case of schwannoma of the fourth portion of the duodenum demonstrated by helical computed tomography. Multiplanar reconstructions showed a hypervascular tumor arising from the inferior wall of the duodenum. The use of water as oral contrast agent instead of iodinated contrast permitted a better visualization of the intact mucosa and differentiated a hypervascular tumor from hypodense gastrointestinal content.

CT evaluation of underlying cause in spontaneous subcapsular and perirenal hemorrhage.

We evaluated the CT scans of 13 patients with spontaneous subcapsular or perinephric hemorrhage (SPH) associated with these underlying causes: 4 angiomyolipomas, 2 renal cell carcinomas, 1 renal metastatic malignant melanoma, 1 ruptured renal artery aneurysm, 1 adrenal myelolipoma, 1 ruptured renal abscess, 2 ruptured hemorrhagic cysts, and 1 patient with undiagnosed coagulation disorder. Our objective was to ascertain whether an underlying cause of SPH was identifiable by CT, and to determine the extension of the hematomas. Computed tomography identified the hematoma in all 13 cases (sensitivity 100 %). In all 12 cases in which there was a renal or adrenal anatomic lesion, the underlying cause was identified with CT (100 %), with correct diagnosis in 11 cases (91.6 %). The case in which no lesion was identified was the undiagnosed coagulation disorder. We conclude that CT is a useful technique for the initial evaluation of SPH, permitting diagnosis of hemorrhage and identification of the underlying cause.

Spontaneous aortocaval fistula: CT findings with pathologic correlation.

We present a case of aortocaval fistula (ACF) secondary to spontaneous rupture of an atherosclerotic infrarenal aortic aneurysm into the inferior vena cava that was initially diagnosed with computed tomography (CT). This is believed to be the first report of this condition with CT demonstration of the exact site of fistula and CT-pathologic correlation. We retrospectively reviewed the CT findings of another two cases of ACF and the previous literature.

[The percutaneous dissolution treatment of gallstones. Our initial experience]. / Tratamiento disolutivo percutáneo de la litiasis vesicular. Experiencia inicial.

OBJECTIVE: To describe our initial experience in direct contact dissolution of cholesterol gallstones with methyl-tert-butyl ether, a non surgical approach for high risk patients. PATIENTS: Twenty symptomatic patients were preselected. They all had radiolucent stones in functioning gallbladders. Patients rejected elective surgery or were considered to be of high risk for anesthesia. Computerized tomography scan was performed to evaluate stone calcium content and liver-gallbladder anatomy. In selected patients, contact stone dissolution was carried out after transhepatic gallbladder catheterization. RESULTS: Ten patients were excluded due to poor gallbladder contact to the liver (two patients) or stone density greater than 70 Hounsfield Units. Percutaneous transhepatic positioning of the catheter into the gallbladder was achieved in seven patients. Stone dissolution was complete in five patients and partial in one. Mean perfusion time was 6.15 hours (3.45-7.5); however, mean hospitalization stay was 7 days (4-10) mainly due to inexperienced management coordination. While on treatment, all patients experienced nausea, burning or abdominal discomfort that were easily controlled. Complications were related to catheter placement (intraperitoneal biliary leakage, external fistula) and in five patients to the dissolution procedure (severe abdominal pain, biliary colic, cholecystopancreatitis). Complications were all handled with non surgical treatment. CONCLUSIONS: Percutaneous gallstone dissolution with methyl-tert-butyl ether is a rapid and efficacious procedure that can, nevertheless, induce relevant secondary effects and complications.

Scintigraphy, angiography and computed tomography in unilateral hyperlucent lung due to obliterative bronchiolitis.

This study examines the value of different imaging methods in assessing the anatomic structures of unilateral hyperlucent lung due to obliterative bronchiolitis. We studied 9 patients, 5 males and 4 females, suffering from UHL (mean age 49 years). Ventilation-perfusion scan (VPS) and computed tomography (CT) of the chest were performed in all, and conventional angiography or digital substraction angiography (DSA) in 7 patients. The VPS showed the characteristic pattern of a matched ventilation-perfusion defect and considerable air trapping during the washout phase. Conventional angiography and DSA displayed a smaller pulmonary artery on the affected side, with a poor peripheral vasculature. CT displayed a loss of lung volume in all cases, with diminished mean attenuation values, a markedly diminished vasculature and integrity of the main airways. In contrast to other imaging modalities, CT imaged bronchiectasis, which was the cause of the patients' clinical symptoms of bronchorrhea and hemoptysis. We conclude that CT of the chest is the most valuable imaging method for evaluating unilateral hyperlucent lung, particularly in symptomatic patients.