Anatomical communications of the perirenal space.

There are controversies over the anatomical communications between the perirenal space and the adjacent extraperitoneal spaces. Clinical studies, mainly based on CT, show fluid collections extending into the adjacent space; into the bare area of the liver on the right, into the superior extraperitoneal space on the left, towards the midline from each perirenal space, and into the lower retroperitoneal space of the abdomen and pelvis. There are certain constant anatomical barriers limiting free extension of fluid or pathology. The pattern of fluid collection in the perirenal space and extension into the adjacent extraperitoneal space is relatively consistent although it varies with the amount and nature of the pathological fluid collection. This pictorial review illustrates anatomical barriers and CT findings of perirenal fluid collections and their extension into adjacent extraperitoneal spaces.

Usefulness of MR imaging for diseases of the small intestine: comparison with CT.

OBJECTIVE: To evaluate the usefulness of MR imaging for diseases of the small intestine, emphasizing a comparison with CT. MATERIALS AND METHODS: Thirty-four patients who underwent both CT and MR imaging using FLASH 2D and HASTE sequences were analyzed. All patients had various small bowel diseases with variable association of peritoneal lesions. We compared the detectabilities of CT and MR imaging using different MR pulse sequences. The capability for analyzing the characteristics of small intestinal disease was also compared. RESULTS: MR imaging was nearly equal to CT for detecting intraluminal or peritoneal masses, lesions in the bowel and mesentery, and small bowel obstruction, but was definitely inferior for detecting omental lesions. The most successful MR imaging sequence was HASTE for demonstrating bowel wall thickening, coronal FLASH 2D for mesenteric lesions, and axial FLASH 2D for omental lesions. MR imaging yielded greater information than CT in six of 12 inflammatory bowel diseases, while it was equal to CT in six of seven neoplasms and inferior in five of seven mesenteric ischemia. In determining the primary causes of 15 intestinal obstructions, MR imaging was correct in 11 (73%) and CT in nine (60%) patients. CONCLUSION: MR imaging can serve as an alternative diagnostic tool for patients with suspected inflammatory bowel disease, small intestinal neoplasm or obstruction.

CT and MR diagnoses of intestinal ischemia.

CT and MR imaging have an important role in establishing the diagnosis of mesenteric ischemia. However, without specific signs such as thromboembolism in the mesenteric vessel, intramural or portal venous gas, and the absence of bowel wall enhancement, mesenteric ischemia can be confused with inflammatory or neoplastic gastrointestinal diseases. Arterial or venous occlusion or low-flow state are the main direct causes of mesenteric ischemia. Delayed diagnosis in equivocal cases can be avoided through an understanding of the patholophysiological aspects of mesenteric ischemia as they occur in a variety of other conditions, including: thromboembolism, bowel obstruction, neoplasm, vasculitis, inflammatory diseases, trauma, and drug or radiation therapy.

Computed tomography of the abdomen.

The CT applications described above are based on our experience with an integrated ultrasound-CT approach, tailored to the patient and aimed at reducing radiation and invasive diagnostic procedures. This approach is not presented as the ideal example to be followed by all. Rather, it is only a sample of the many possible uses of CT. Though there may be many disagreements with our approach, there can be no doubt that CT has revolutionized diagnostic abdominal imaging, to the benefit of all concerned.

Right perirenal space. Computed tomography evidence of communication between the bare area of the liver.

Computed tomography (CT) images from one cadaver and 11 patients with perirenal fluid collection were reviewed to study whether the right perirenal space communicates with the bare area of the liver. CT of a cadaver obtained after meticulous right perirenal injection of contrast media showed that contrast media extended superiorly into the bare area of the liver. CT of 11 patients with right perirenal hemorrhage or infection showed that fluid collection within the right perirenal space continued upward, crossing the coronary ligament, extending into the bare area of the liver. The inferior vena cava were completely or partially surrounded by fluid. CT of two patients with bleeding hepatocellular carcinoma showed that blood in the bare area continued extending downward into the perirenal space. We conclude that the right perirenal space is open toward the bare area of the liver and fluid collection within one space may communicate with the other space across the coronary ligament.

CT of carcinoma of the pancreas: different mode of spread according to lesion site.

Thirty-seven patients were evaluated on computed tomography concerning the different modes of spread (peripancreatic vascular invasion and peritoneal implanting) in the pancreatic carcinoma arising in the four anatomic segments. Each was graded from 0 to 3. The median diameter of the adenocarcinomas was 4.5 cm. It was found that high propensity for vascular invasion occurred in the carcinomas of the body and neck, probably due to the anatomical proximity of the these structures, and the high incidence of intraperitoneal seeding in the carcinomas of the tail was found probably because of its intraperitoneal location.

Hepatic arterial color Doppler signals in Caroli's disease.

Three siblings with congenital dilatation of the intrahepatic bile ducts (Caroli's disease) are presented. Bile duct pathology was associated with congenital hepatic fibrosis and polycystic renal disease in all three patients. On color Doppler imaging (CD imaging), multiple small color Doppler signals were observed in the vascular radicles within the dilated bile ducts or in the center of the lumen apart from the vascular radicles, as well as in other well-known sonographic findings such as bile duct dilatations and bilary calculi. Doppler frequency spectral analysis confirmed all these color signals as arterial in origin in all patients, revealing pulsatile wave patterns. In spite of the fact that portal venous radicles have been well described on conventional sonograms or computed tomography (CT), continuous wave patterns of venous flow on spectral analysis were not detected in all patients. Identification of such less emphasized arterial flow may add another clue in the diagnosis and pathogenesis of this rare disease entity. In conclusion, color Doppler signals of arterial wave pattern within the dilated bile ducts are another helpful diagnostic criteria in previously reported sonographic findings, and these color signals are easily depicted on sonograms with color mapping.

Color Doppler flow imaging of hepatocellular carcinomas. Comparison with metastatic tumors and hemangiomas by three-step grading for color hues.

The role of color Doppler imaging was evaluated in differentiating hepatocellular carcinomas (HCCs) from metastases and hemangiomas by the amount of tumoral color signals. Intratumoral and peritumoral color signals were analyzed by a three-step grading system (grade 1 to 3) in 51 patients (32 HCCs, seven metastases, and 12 hemangiomas). Correlation of grading scores for intratumoral and peritumoral color signals was evaluated with the size of the tumors as well. HCCs demonstrated a higher grade of intratumoral color signals than did metastases or hemangiomas in all (p < 0.05) and biopsy-proved lesions (p = 0.0084); there was no significant difference in the degree of peritumoral color signals in all (p > 0.05) or 17 biopsy-proved HCCs (p = 0.2078) from the other tumor groups. In addition, the grade of both intratumoral and peritumoral color signals was not related with the tumor size in all groups (p > 0.05). In conclusion, color Doppler imaging provided a valuable role in the diagnosis of HCCs based on the qualitative analysis of the intratumoral color signals.

Pelioid-type hepatocellular carcinoma masquerading as a hepatic hemangioma on technetium-99m red blood cell scintigraphy.

Technetium-99m red blood cell (RBC) scintigraphy is a very specific method to differentiate a hemangioma from other hepatic masses. The authors report a case of hepatocellular carcinoma that showed a focal area of increased uptake on Tc-99m RBC SPECT in a 60-year-old man. Dynamic computed tomography and angiography revealed features of both hemangioma and hepatocellular carcinoma. Pathologic examination showed that the portion of the hepatocellular carcinoma that showed increased uptake on Tc-99m RBC scintigraphy had peliosis, which is the likely cause of the radiotracer avidity.

Early gastric cancer: virtual gastroscopy.

Gastric cancer is one of the most common cancers and one of the most frequent causes of cancer-related deaths worldwide. Early detection and accurate preoperative staging of early gastric cancer (ECG) offers the best prognosis and is essential for planning optimal therapy such as endoscopic mucosal resection or gastric resection. Recent advances in computed tomographic technology and three-dimensional imaging software have enabled more accurate gastric imaging. Virtual gastroscopy (VG) is helpful in the detection and evaluation of EGC in the same way as gastroscopy. VG has a wider field of view than conventional gastroscopy, the angle of the virtual cancer can be adjusted omnidirectionally, and it has no blind point because retrospective reconstruction is available. Thus, VG is a promising method for evaluating gastric lesions despite its limitations. This report describes the clinical usefulness of VG with multidetector row computed tomography for EGC and axial computed tomography.

Milk of calcium in a pancreatic pseudocyst.

A 46-year-old man with a history of chronic alcohol use was found to have milk of calcium that had developed in a pancreatic pseudocyst. This was found incidentally on abdominal computed tomography during a workup for abnormal liver enzymes. Milk of calcium in the pancreas has been described only twice in the literature using plain abdominal radiographs and computed tomography. To our knowledge, this case report is the first to describe magnetic resonance findings of this entity.

CT gastrography.

The rapid dissemination of multidetector-row computed tomographic (CT) technology will make faster and more accurate gastric imagining available. Two-dimensional multiplanar reconstruction and CT gastrography including virtual gastroscopy and transparency rendering using volume rendering are types of interactive two- and three-dimensional medical imaging tools. It provides multiplanar cross-sectional imaging, gastroscopic viewing, and upper gastrointestinal series imaging in the same data acquisition. Two-dimensional multiplanar reconstruction provides accurate staging of gastric cancer and extraluminal information such as lymphadenopathy and distant metastasis. Virtual gastroscopy detects subtle mucosal changes and differentiates them from submucosal lesions in the same way as gastroscopy. Transparency rendering provides global orientation of the focal findings in the stomach in the same way as upper gastrointestinal series findings and provides useful information for preoperative mapping. Thus, CT gastrography is a promising method for evaluating gastric lesion despite its limitations.

Hepatocellular carcinoma presenting only as portal venous tumor thrombosis: CT demonstration.

We describe two cases of hepatocellular carcinoma initially presenting with portal vein tumor thrombi but with no demonstrable tumor in the liver parenchyma outside the portal vein. Both patients had cirrhosis of the liver and had tumor thrombi in the main portal vein and its branches. The tumor thrombi were demonstrated on ultrasonography, CT, angiography as expanding intraluminal masses.

CT diagnosis of acquired tracheoesophageal fistula in adults.

Two cases of acquired tracheoesophageal fistula (TEF) diagnosed by CT are presented. In one case TEF was clinically suspected; in the other it was incidentally discovered. Because of its noninvasive nature and because it can be performed without discomfort to the patient, CT should be a preferred diagnostic method for demonstration of TEF.

The excessively small ventricle on cranial computed tomography: clinical correlation in 75 patients.

Excessively small ventricle (ESV) was demonstrated in 75 (8.3%) of 9,000 patients over 15 years of age examined by cranial computed tomography (CT). The patients had no other CT abnormality except for ESV. Detailed retrospective analysis of clinical records of these 75 patients revealed four major groups of patients: 1) those with seizures (24%); 2) those with headaches (24%); 3) those with acute non-penetrating head trauma (21.5%); and 4) those with benign increased intracranial pressure (8%). The remaining patients (22.5%) had a variety of cerebral derangements.

Vesicouterine fistula associated with placenta percreta.

Vesicouterine fistulas are uncommon acquired urogenital fistulas. A case of a vesicouterine fistula associated with placenta percreta is presented.

Adrenal hemangioma: a case report.

Adrenal hemangioma is a very rare tumor. Presented is the 18th case proved by autopsy or surgery reported in world literature. The tumor was incidentally discovered at autopsy. Unless this tumor has characteristic calcifications, phlebolith or phlebolithlike, its computed tomography appearance is nonspecific. Therefore, by computed tomography this tumor cannot be differentiated from other primary or secondary adrenal tumors.

Membranous obstruction of the inferior vena cava: comparison of findings at sonography, CT, and venography.

OBJECTIVE: Membranous or segmental obstruction of the inferior vena cava is one of the common causes of chronic Budd-Chiari syndrome. In this study, the venographic findings are compared with the results of sonography and CT in order to ascertain their role in the management of these cases. MATERIALS AND METHODS: Fifteen patients with membranous (n = 8) or segmental (n = 7) obstruction of the inferior vena cava who had been examined with sonography and CT were studied retrospectively. Diagnosis was made at surgery (n = 3) or by venacavography (n = 12). Sonographic findings were analyzed on the basis of the initial report, and CT findings were reviewed retrospectively with knowledge of the sonographic findings. RESULTS: Sonography showed membranous obstruction (n = 5), segmental cordlike obstruction (n = 3), and unspecified obstruction (n = 5) of the inferior vena cava, while CT showed a flap of the membrane (n = 1) and segmental narrowing or obstruction of the inferior vena cava (n = 7). In the remaining cases, the inferior vena cava either appeared normal (n = 6) or was not visualized (n = 1) on CT or was not described in the sonographic report (n = 2). In nine cases, CT showed one or several tiny calcific foci in the inferior vena cava. Sonography showed obliteration of at least one hepatic vein (n = 8) and of intrahepatic collateral vessels (n = 12), whereas CT was less sensitive in evaluating obliteration of intrahepatic veins (n = 4) and collateral vessels (n = 7). Sonography and CT both showed hepatic masses (n = 6), evidence of liver cirrhosis and portal hypertension (n = 14), hepatomegaly (n = 14), enlargement of the caudate lobe (n = 9), and intraabdominal (n = 11) and abdominal wall (n = 15) collateral vessels. CONCLUSION: Sonography was superior to CT in delineating pathologic venous anatomy of the inferior vena cava and hepatic veins whereas CT was better in evaluating hepatic cirrhosis and tumor. We believe that these techniques are useful complements to venography in the diagnosis and management of these cases.

Continuation of gas from the right perirenal space into the bare area of the liver.

PURPOSE: It is difficult to explain some CT findings pertaining the anatomic relationship between the bare area of the liver and the right retroperitoneal space on the basis of the traditional three compartment concept of retroperitoneal anatomy. The purpose of this article is to ascertain and illustrate possible communication between the bare area of the liver and the right perirenal space in patients with gas-forming retroperitoneal infection. METHOD: We reviewed CT findings in 24 cases with retroperitoneal gas-forming condition with particular emphasis on the extent of the infection and resultant distribution of gas. RESULTS: CT images showed gas within the right perirenal space extended upward directly into the bare area of the liver in six cases. CONCLUSION: The right perirenal space is considered open toward the bare area of the liver. Therefore, gas within the perirenal space may communicate directly with the bare area of the liver.

Sonographic findings in myoglobinuric renal failure and their clinical implications.

Myoglobinuria, which occurs more frequently than previously believed, may lead to acute tubular necrosis and renal failure. It may be recurrent and can result in permanent renal damage. Three cases of myoglobinuria with acute renal failure and abnormal sonograms are reported.