Typical Computed Tomography Findings Research Articles

Colonoscopy-Induced Acute Diverticulitis

Even though colonoscopy is a common and widely performed procedure, it can cause many complications. If any sign of inflammation is observed, a perforation or postpolypectomy coagulation syndrome should be considered. Diverticulitis, a very rare complication with an incidence of 0.04% to 0.08%, also can occur after the diagnostic and therapeutic procedure. We report a case of acute diverticulitis after colonoscopy, diagnosed with typical computed tomography findings after excluding other complications. The patient was treated in the same manner as for complicated diverticulitis, with bowel rest, hydration, and broad-spectrum antibiotics. Acute diverticulitis as a rare complication can occur following prolonged colonoscopy or colonoscopic polypectomy, especially in those with additional risk factors such as obesity and smoking.

Clinical features of organizing pneumonia associated with rheumatoid arthritis

Objectives: To clarify the clinical features of organizing pneumonia (OP) associated with rheumatoid arthritis (RA) and to determine whether development of OP is related to RA activity.Methods: A cross-sectional study was conducted, in which medical records of 499 consecutive RA patients who visited our hospital during one month were reviewed. OP was diagnosed by pathological findings by trans-bronchial biopsy or by clinical features (typical computed tomography findings, no causative agents, good response to glucocorticoids, and lack of response to antibiotics).Results: Among 499 patients, OP was found in 19 patients and the estimated prevalence was 1.9–4.8%. No differences in clinical features were noted between the OP and non-OP groups. The mean age of OP development was 57.2 years and the period from the onset of RA to OP ranged from −4 to +34 years. Although 14 patients presented OP after the onset of RA, two developed OP before RA and three developed OP simultaneously with RA. Patients receiving tumor necrosis factor inhibitors also developed OP. RA disease activity just before onset of OP was low in 8 of 14 RA cases. At the onset of OP, only two patients showed exacerbations of arthritis, whereas most patients presented with fever and serum C-reactive protein (CRP) elevations. Glucocorticoids were effective for OP in all patients who received them. Relapse occurred in 4 of 19 cases.Conclusions: OP develops in approximately 4% of RA patients, which occurs independently from arthritis activity and at any time in RA patients.

Atypical Presenting Symptoms of Acute Onset Systemic Lupus Erythematosus with Enteritis and Cystitis.

Lupus enteritis and lupus cystitis are relatively rare manifestations of systemic lupus erythematosus. Some patients develop severe complications such as bowel perforation, infarction, obstruction, or irreversible bladder dysfunction. Early diagnosis is critical for management of lupus enteritis and cystitis. We report a 48-year-old Japanese man who presented with initial manifestations of abdominal pain, severe diarrhea, and bloody feces. The diagnosis was delayed due to atypical initial symptoms, resulting in clinical worsening. Physicians should be aware of typical computed tomography findings of lupus enteritis and lupus cystitis.

Changes in Computed Tomography Findings According to the Chronicity of Maxillary Sinus Gossypiboma

The present report describes a case of gossypiboma in the maxillary sinus after treatment for the fracture of the orbital floor with review of the literatures on this interesting disease entity. The suspicion of gossypiboma should be raised when a patient with a history of previous sinonasal surgery, especially Caldwell-Luc approach, presents with chronic recurrent or refractory sinusitis. Because of the rarity of reported cases, typical computed tomography findings of gossypiboma in the sinonasal area have not been established. In the present case, because the gauze was retained for 25 years in the maxillary sinus, computed tomography findings revealed nonspecific findings. Because a foreign body left behind after operation may lead to a serious medicolegal issue, it is worth reemphasizing that the best general approach to retained surgical foreign body is to prevent its occurrence.

Renal tuberculosis and iliopsoas abscess: Two case reports.

The urinary system is the second most commonly affected site of extrapulmonary tuberculosis (TB). Due to the diverse and atypical clinical manifestations of urinary TB, the disease is easy to misdiagnose. In the present study, two cases of renal TB are reported, which had completely different clinical manifestations. The first case is a female who presented with loin pain and fever. Purified protein derivative (PPD) and TB antibody tests were negative and computed tomography (CT) scans showed a low density focus in the right kidney with an iliopsoas abscess. The typical CT findings indicated renal tuberculosis. Anti-TB drugs were effective proved the diagnosis. The second case is a male who presented with intermittent gross hematuria. Acid-fast bacilli in urine and TB antibody tests were positive. CT scans revealed a low density focus in the unilateral kidney with a slight expansion of the pelvis, calices and ureter. The patients were treated with the anti-TB drugs and the clinical manifestations disappeared. The diagnosis of urinary TB is challenging in certain cases; when there is no response to the usual antibiotics in patients with fever or gross hematuria, TB should be suspected. CT is the mainstay for investigating possible urinary TB.

Appendicitis in adults with incidental midgut malrotation: CT findings

To report the computed tomography (CT) findings of acute and complicated appendicitis in adults with incidental midgut malrotation. The medical records and CT studies of eight patients with appendicitis and incidental midgut malrotation who presented to two medical centres between 1998 and 2009 were reviewed. All patients presented with 1-5 days of acute abdominal pain, which was diffuse in two, left-sided in two, lower abdominal in two, and in the right lower quadrant in two patients. The inflamed appendix was right-sided in three, left-sided in three, and in the midline in two patients. Three cases were complicated by a peri-appendicular abscess, and one patient also had a small bowel obstruction. All patients had a complete non-rotation with right-sided duodenum and jejunum, and left-sided colon. All eight patients had an abnormal superior mesenteric artery-superior mesenteric vein (SMA/SMV) relationship and a dysplastic uncinate process of the pancreas. Urgent surgery was performed in six patients and the remaining two were treated conservatively. Altered anatomy in malrotation affects the typical clinical and CT findings of acute appendicitis, therefore delaying diagnosis. When CT shows focal inflammation anywhere within the abdomen, along with an abnormal SMA/SMV relationship, the position of the caecum should be ascertained and acute appendicitis ruled out.

Non‐human immunodeficiency virus Pneumocystis jiroveci pneumonia

We read with great interest the recent two studies by Hardak et al. and Enomoto et al. about the diagnosis of Pneumocystis jiroveci pneumonia (PJP) in non-human immunodeficiency virus (HIV)-infected patients.1, 2 Here, we would like to describe a case of PJP and highlight several important issues regarding the diagnosis of this disease in non-HIV-infected patients. A 32-year-old lady, who underwent allogeneic peripheral blood stem cell transplantation for leukaemia 6 months earlier, was admitted to the hospital for high fever, dry cough and progressive dyspnoea for 5 days. Chest radiography showed alveolar opacities in the bilateral lower lungs (Fig. 1a), while thin-section chest computed tomography showed major findings of subpleural consolidation, with peripheral distribution and focal ground glass opacities (GGO) in the bilateral lower lungs (Fig. 1b,c). The results of the microbiology study were inconclusive. To achieve a definitive diagnosis, surgical lung biopsies by thoracoscopy were obtained. Thoracoscopic biopsy of the right middle and lower lungs showed PJP. After a 2-week treatment, there was evolutional change from consolidation to GGO with crazy-paving pattern (Fig. 1d). The lower lung opacities resolved after 4 weeks of sulfamethoxazole-trimethoprim treatment, and she was discharged. (a) Chest radiograph showing alveolar opacities in the bilateral lower lungs and a right-sided port-a catheter; (b and c) computed tomography (CT) imaging revealed subpleural consolidation and focal ground glass opacities (GGO) with a peripheral distribution; (d) compared with the initial chest CT, there was note of evolutionary change from consolidation to GGO with crazy-paving pattern after 2 weeks of treatment. The clinical course of PJP in non-HIV-infected patients is substantially different from those of HIV-infected patients.2, 3 The disease usually presents with a more acute and fulminant course in non-HIV-infected patients.3 In contrast, the presentation is usually indolent in HIV-infected patients. In addition, the mortality rate is higher among non-HIV-infected patients.2, 3 Table 1 summarizes the differences of PJP between HIV-infected and non-HIV-infected patients. Typical computed tomography findings of PJP include diffuse GGO in a mosaic pattern, distributed mostly at the central and upper lungs, with peripheral sparing.4 However, atypical imaging presentation, such as dense consolidation and atypical distribution of the involved lungs, is not unusual in non-HIV-infected patients.3 The greater consolidation and less GGO in chest computed tomography of non-HIV-infected patients may reflect more extensive lung inflammation due to more inflammatory cells and fewer Pneumocystis organisms.5 Therefore, a consolidation-predominant pattern should not preclude a suspicion of PJP. Early diagnosis of PJP usually relies on a high index of suspicion. In non-HIV-infected patients, transplantation and corticosteroid use are two important risk factors. A susceptible host with risk factors presenting with atypical pneumonia should elicit a suspicion of this disease regardless of typical chest imaging presented. Furthermore, the imaging pattern of PJP varies with HIV-infected status and disease stage.3 Evolutionary changes may occur after treatment. In this presented case, the subpleural lesions changed from consolidation to GGO with crazy-paving pattern after 2 weeks of treatment (Fig. 1d). Nevertheless, initial GGO lesions may progress to alveolar consolidation in few days, if no definite treatment is provided. In conclusion, PJP in non-HIV-infected patients has different clinical and radiographical presentations from that in HIV-infected patients. The clinical and radiographical features from HIV-infected patients cannot be totally applied to diagnose PJP in non-HIV-infected patients.

Diagnostic Strategy for Differentiating Autoimmune Pancreatitis From Pancreatic Cancer

OBJECTIVES: The purpose of this study was to determine whether the choice for performance of endoscopic retrograde pancreatography (ERP) could be tailored to findings on computed tomography (CT) in patients with suspected autoimmune pancreatitis (AIP). METHODS: Eighty-four AIP patients and 73 pathology-proven pancreatic cancer patients from a prospectively maintained database were retrospectively included. Computed tomography and ERP images were reviewed in consensus by 2 blinded radiologists. The diagnostic performance of CT alone and combined use of CT and ERP (CT-ERP) were compared. RESULTS: The area under the receiver operating characteristic curve of CT-ERP was significantly greater than that of CT alone (0.97 vs 0.87, P < 0.001). When patients with AIP were divided into 2 subgroups according to CT features (typical vs atypical), 24 (69%) of 35 AIP patients with atypical CT findings were correctly diagnosed with AIP at CT-ERP and received benefits from additional ERP. Endoscopic retrograde pancreatography had little added benefit in patients with typical CT findings for AIP (n = 49), because no alternative diagnoses were established after ERP. CONCLUSIONS: In patients with suspected AIP, the decision to perform ERP could be tailored to findings on CT.

Noninvasive diagnostic criteria for hepatocellular carcinoma in hepatic masses &gt;2 cm in a hepatitis B virus‐endemic area

Noninvasive criteria for diagnosing hepatocellular carcinoma (HCC) suggested by the American Association for the Study of Liver Diseases (AASLD) in 2005 consisted of serum α-fetoprotein (AFP) level >200 ng/ml or a typical enhancement pattern (arterial enhancement and portal/delayed washed out) on dynamic imaging of hepatic mass(es) >2 cm in a cirrhotic liver. To validate these criteria in a Korean population and to evaluate whether these criteria are applicable to patients without cirrhosis at a high risk of developing HCC. We prospectively investigated 206 consecutive patients with hepatic mass(es) >2 cm who underwent biopsy or surgical resection. Patients were evaluated by four-phase dynamic computed tomography (CT) and by assays of serum AFP concentrations at baseline. Patients were classified according to the presence of risk factors or cirrhosis, and the diagnostic accuracy of each test was determined. The positive predictive values (PPV) of typical CT findings or serum AFP >200 ng/ml were 97.8% in cirrhotic patients, 89.6% in high-risk patients without cirrhosis and 82.4% in low-risk patients. The PPVs of typical CT findings alone in these groups were 98.8, 97.6 and 87.5% respectively. In high-risk patients without cirrhosis, the addition of serum AFP levels to typical CT findings minimally increased the diagnostic sensitivity from 81.6 to 87.8% but reduced the PPV from 97.6 to 89.6%. Serum AFP concentration is not a suitable diagnostic criterion for HCC. Typical CT findings can be used to diagnose HCC >2 cm both in cirrhotic patients and in high-risk patients without cirrhosis.

Clinical features of clinically diagnosed eosinophilic liver abscesses

Eosinophilic liver abscesses (ELAs) are frequently encountered in the clinical field based on typical computed tomography (CT) findings and the presence of peripheral eosinophilia. In this study, the authors evaluated the clinical features and natural course of CT diagnosed ELAs. The medical records of patients that underwent abdominal CT from July 2004 to February 2008 at Seoul National University Hospital were retrospectively evaluated. ELA was clinically diagnosed by the presence of peripheral eosinophilia (≥500μL(-1)) and typical CT findings. The presumptive causes of clinically diagnosed ELA were divided into three categories, namely, parasitic infections, malignancies, and unidentified etiologies. Clinical courses and responses to treatment were evaluated. Clinically diagnosed ELAs were identified in 164 patients and the incidence of ELA was 0.68%. Of these patients, 118 (71.9%) showed radiologic resolution of clinically diagnosed ELA at a median 6.2 (0.2-33.1)months. In addition, 79 (48.2%) patients also achieved normalization of peripheral eosinophilia with radiologic resolution of clinically diagnosed ELA. In patients without identified etiologies, mean time to radiologic resolution was significantly shorter for patients treated empirically with an anti-parasitic drug than for those not treated [4.4 (0.9-26.3) vs. 12.2 (1.5-33.2) months, median (range), P=0.001]. Clinically diagnosed ELA adopts a relatively benign course. Empirical anti-parasitic treatment in patients without an identified etiology may shorten the duration of clinically diagnosed ELA.

Gallbladder Tuberculosis: CT Findings with Histopathologic Correlation

ObjectiveWe wanted to describe the computed tomography (CT) findings of gallbladder tuberculosis (TB) and to correlate them with pathologic findings.Materials and MethodsThere were seven patients (M:F = 3:4; mean age, 46.3 years; age range, 32 to 78 years) in whom gallbladder TB was eventually diagnosed. All of them underwent cross-sectional imaging with CT, a pathologic examination and a retrospective review. CT imaging evaluation was done in each case, including the findings of a mass versus nodule, wall thickening (uniform or irregular) and the enhancement patterns (homogeneous or heterogeneous).ResultsAll the cases of gallbladder TB revealed the following three different CT findings: micronodular lesion of the gallbladder wall (n = 1), a thickened wall (n = 4) and a gallbladder mass (n = 2). There were three cases of homogeneous enhancement of the lesions, including homogeneous enhancement with nodular lesion, homogeneous uniform thickness enhancement and homogeneous thickness enhancement in one case each, and these cases pathology showed tuberculous granuloma with a little caseating necrosis in one case and tuberculous granuloma with rich fibrous tissue, but little or no evident caseating necrosis in two cases. Four cases of heterogeneous enhancement of the lesions, including heterogeneous uniform-thickness enhancement in two cases, heterogeneous enhancement with a local mass lesion in one case and heterogeneous enhancement with a mass that replaced the gallbladder in one case; in these cases, pathology showed tuberculous granuloma with marked caseation or liquefaction necrosis in three cases and tuberculous granuloma by fibrous and calcifications accompanied by caseating necrosis in one case. Among the seven cases of gallbladder TB, six cases were accompanied by abdominal extra-gallbladder TB, including abdominal lymph node TB in five cases and hepatic TB in four cases.ConclusionGallbladder TB has various CT manifestations, and the enhanced CT findings are well matched with pathological features. An irregularly thickened gallbladder wall or a gallbladder wall mass with multiple-focus necrosis or calcifications accompanied by the typical CT findings of abdominal extra-gallbladder TB should suggest the diagnosis of gallbladder TB.

Emphysematous Aortitis

Emphysematous Aortitis

Kidney packed with fat, pus and stone-xanthogranulomatous pyelonephritis

A 60-year-old woman presented with intermittent low-grade fever and chills for 1 month accompanied by right flank soreness, poor appetite and marked body weight loss (12 kg within 1 month). Leukocytosis (WBC = 17.75 × 109/l), normocytic anaemia (haemoglobin 6.6 g/dl) and pyuria were noted. Abdominal computed tomography (CT) showed an enlarged right kidney with dilated collecting system filled with hypodense substance (pus) and staghorn stones, which are typical CT findings for xanthogranulomatous pyelonephritis (Figure ​(Figure1A).1A). She received CT-guided drainage immediately, and total amount of 300 ml brown-bloody pus was drained out. However, serial urine and pus cultures did not yield any pathogen. After a 4-week antibiotic therapy, she underwent right nephrectomy (Figure ​(Figure1B).1B). Microscopic examination disclosed that renal parenchyma was replaced by lipid-laden macrophage (Figure ​(Figure1C),1C), which is a typical feature of xanthogranulomatous pyelonephritis. Fig. 1 (A) Contrast-enhanced abdomen CT showed an enlarged nonfunctioning right kidney and staghorn calculi, with distention of the collecting system. (B) The coronal section of the right kidney revealed that the dilating collecting system was filled with pus ... Xanthogranulomatous pyelonephritis is a variant of chronic pyelonephritis characterized by the destruction of the renal parenchyma and the presence of granulomas, abscesses and foam cells. Most of the cases occur in the presence of chronic obstruction due to renal calculi. It is usually a unilateral disease and more frequently affects middle-aged women. The most common associated pathogens are Escherichia coli and Proteus mirabilis. Treatment of choice is nephrectomy that yields excellent outcome as this patient. Conflict of interest statement. None declared.

A Rare Ileal Intussusception Caused by a Lipoma of the Ileum

Adult intussusception is a rare disease and it differs from childhood intussusception in its presentation, cause and treatment. Most of the cases have an underlying lesion within the intussusception that requires surgical resection. Making the diagnosis can be delayed because of the nonspecific and chronic symptoms, and many cases are diagnosed during performance of emergency laparotomy for treating the obstructive symptoms. A computed tomography (CT) scan is most useful for making the diagnosis of adult intussusception and is helpful in revealing the underlying lesion, although a barium enema can help to diagnose colonic intussusceptions. Surgical resection remains the recommended treatment for nearly all cases, but there is controversy about whether or not the intussusception should be initially reduced before resection. Gastrointestinal lipomas are rare benign tumors that can occur anywhere along the gut, and the small bowel is the second most common site for gastrointestinal lipomas after the colon. Intussusception of the ileum by a lipoma is very rare. We report here on a case of ileo-ileal intussusception that was caused by a lipoma of the ileum in a 35-year-old man who complained of abdominal pain of one week duration. The diagnosis of an ileo-ileal intussusception caused by a lipoma of the ileum was suspected preoperatively according to the typical CT findings, so we tried to initially reduce the intussusception during laparotomy. But manual reduction was impossible due to the edema of the lesion, and an ileum of some length had to be resected.

Accumulation of gallium-67 within mature and immature teratoma in pediatric patients: investigation for the uptake mechanism

We encountered cases of mature and immature teratoma with positive uptake of (67)Ga. The objective of this study is to investigate the mechanism of (67)Ga accumulation within mature and immature teratomas by comparing the findings of gallium scan, computed tomography (CT), and autoradiography of surgical specimens with the pathological findings. The subjects comprised 14 children who underwent surgical resection for intra-abdominal mature and immature teratomas, which were histologically proved to be of the mature and immature subtype. Their age ranged from 24 days to 14 years. The origins of the mature teratomas consisted of seven ovaries including one bilateral case, two retroperitoneal, and two sacrococcygeal regions. The origins of the immature teratomas were retroperitoneum in two cases, an ovary and a sacrococcygeal region. Complete surgical excision was feasible in all children. They underwent both gallium scan and CT prior to surgery. Single-photon emission computed tomography was added in some cases. For two gallium-positive cases, radiography and scintigraphy (autoradiography) of the resected specimen were performed. Of the 14 children, 5 (one with immature and four with mature subtype) showed positive (67)Ga uptake within tumors, which originated from the retroperitoneum in the 3 boys, and from the ovary in the 2 girls. All had typical CT findings of teratoma, including calcifications, fat components, cystic areas, and solid parts. (67)Ga accumulation in the four mature teratomas appeared discretely strong, and was considered to correspond with intralesional calcifications. However, in the remaining one immature teratoma, the gallium distribution was diffuse within the tumor. The comparison between radiography and autoradiography of the resected mature teratomas confirmed the correlation between the intralesional calcifications and areas of (67)Ga accumulation. A high-uptake ratio of (67)Ga in benign teratoma was indicated. A close correlation between gallium scan and CT helps to ascertain whether (67)Ga uptake results from malignant and/or immature elements, or mature tissue components.

Spectrum of CT Findings after Radiofrequency Ablation of Hepatic Tumors

Image-guided radiofrequency (RF) ablation has been used to treat both resectable and nonresectable hepatic tumors. A precise imaging assessment of the therapeutic response and of any complications is mandatory after ablation. Contrast material-enhanced ultrasonography, computed tomography (CT), and magnetic resonance imaging all may be useful for this assessment. At most institutions, a three-phase contrast-enhanced CT examination is performed immediately or within 1 month after RF ablation to assess the technical success of treatment. If ablation was technically successful, three-phase CT may be repeated at 3-month intervals for evaluation of tumor recurrence. The typical CT finding in the zone subjected to RF ablation is an area of low attenuation that encompasses the tumor and an ablative margin. However, the appearance of the ablative zone may vary greatly, depending on the success of treatment and the time elapsed after the procedure. Ringlike enhancement representing benign reactive hyperemia around the ablation zone, central high-attenuation areas representing greater cellular disruption, and tiny air bubbles frequently are seen at immediate follow-up CT but usually have disappeared by the first or second follow-up examination. The successfully ablated zone gradually involutes. The appearance of the zone differs when residual tumor tissue or local tumor progression is present. Immediate or delayed complications also may be seen at follow-up CT. Radiologists must be familiar with both typical and atypical CT findings and their clinical significance. (c) RSNA, 2008.

Lymphoplasmacytic Sclerosing Pancreatitis (Autoimmune Pancreatitis): Evaluation with Multidetector CT

Lymphoplasmacytic sclerosing pancreatitis is a form of chronic pancreatitis characterized by a mixed inflammatory infiltrate that centers on the pancreatic ducts. It is a cause of benign pancreatic disease that can clinically mimic pancreatic cancer. Preoperative detection of lymphoplasmacytic sclerosing pancreatitis is important because patients usually respond to steroid therapy. Patients with lymphoplasmacytic sclerosing pancreatitis are often referred for computed tomography (CT) when they are suspected of having a pancreatic or biliary neoplasm; therefore, it is important to search for potential findings suggestive of lymphoplasmacytic sclerosing pancreatitis when typical findings of a pancreatic or biliary neoplasm are not found. Typical CT findings include diffuse or focal enlargement of the pancreas without dilatation of the main pancreatic duct. Focal enlargement is most commonly seen in the head of the pancreas, and the involved pancreas on contrast material-enhanced CT images may be iso-attenuating relative to the rest of the pancreas, or hypo-attenuating, especially during the early postcontrast phase. Thickening and contrast enhancement of the wall of the common bile duct and gallbladder may reflect inflammatory infiltrate and fibrosis associated with lymphoplasmacytic sclerosing pancreatitis. There are several features seen at CT that may help to differentiate lymphoplasmacytic sclerosing pancreatitis from pancreatic cancer, such as diffuse enlargement of the pancreas with minimal peripancreatic stranding in patients with obstructive jaundice, an absence of significant pancreatic atrophy, and an absence of significant main pancreatic duct dilatation. When these findings are encountered, clinical, other imaging, and serologic data should be evaluated.

CT and MR Imaging after Imaging-guided Thermal Ablation of Renal Neoplasms

In recent years, thermal tumor ablation techniques such as percutaneous radiofrequency (RF) ablation and cryoablation have assumed an important role in the management of renal tumors, particularly in patients who may be suboptimal candidates for more invasive surgical techniques. Postablation computed tomography (CT) and magnetic resonance (MR) imaging play an important part in evaluation of the ablation zone, surveillance for residual or recurrent tumor, and identification of procedure-related complications. The appearance of the ablation zone may vary depending on the ablation technique used, initial tumor size, and tumor location and composition. Most ablated tumors demonstrate a gradual decrease in size over time once the acute changes have resolved, although tumor involution is more evident after cryoablation than after RF ablation. Exophytic tumor ablation zones typically have a "bull's-eye" appearance on CT scans and MR images obtained after RF ablation, with a visible mass often persisting in the absence of viable tumor. Residual or recurrent tumor often manifests as a focus of nodular or crescentic enhancement on postablation contrast material-enhanced CT scans and MR images, although a thin peripheral rim of enhancement often persists for several months following cryoablation. Complications following renal tumor ablation are usually minor but may include hemorrhage, ureteral stricture, urine leak, colonic perforation and colonephric fistula, and pneumothorax. As more patients undergo renal ablation procedures, it will become increasingly important that radiologists be able to recognize typical postablation CT and MR imaging findings to prevent confusing them with other pathologic processes.

The Role of Late-Phase Pulse Inversion Harmonic Imaging in the Detection of Occult Hepatic Metastases

The purpose of this study was to investigate the efficacy of late-phase pulse inversion harmonic imaging (PIHI) in detecting occult metastases and to compare the results with helical computed tomography (CT) in a group of patients whose fundamental liver sonographic results were normal. Thirty-two patients (21 women and 11 men; age range, 20-87 years) with a known primary malignancy were enrolled in the study. The patients were evaluated with conventional sonography, unenhanced PIHI, and PIHI 3 minutes after the injection of Levovist (SH U 508A; Schering AG, Berlin, Germany). All patients also underwent triphasic helical CT within 1 week after sonography. In 1 patient, mangafodipir-enhanced magnetic resonance imaging was performed as part of the clinical workup. After Levovist injection, in 4 (12.5%) of 32 patients, at least 1 hypoechoic lesion was detected by PIHI; multiple lesions were shown in 1 patient. The mean diameter of newly detected lesions was 12 mm. Triphasic helical CT also showed all of the lesions that were detected by PIHI. The diagnoses were confirmed by biopsy and CT findings in 2 patients and by the typical CT and magnetic resonance imaging findings in 1 patient. For the fourth patient, the diagnosis was confirmed by follow-up and CT. Conclusions. Late-phase PIHI is comparable to helical CT for detecting occult hepatic metastases, but it protects patients from the potentially hazardous effects of radiation and iodinated contrast agents. Further series involving a larger number of patients are needed to determine its place in the evaluation of cancer staging and treatment planning.

Nontraumatic emergent abdominal vascular conditions: advantages of multi-detector row CT and three-dimensional imaging.

In the past decade, great strides have been made in the development of helical computed tomography (CT) that have led to shorter scanning time and higher spatial resolution. A wide range of traumatic and nontraumatic emergent conditions may be quickly and accurately diagnosed with multi-detector row CT. Multi-detector row CT angiography is the preferred method for imaging in emergent abdominal vascular conditions because it enables the acquisition of high-spatial-resolution volumetric image data during a single breath hold. Unlike catheter angiography, multi-detector row CT angiography not only depicts the vessels but also allows assessment of perfusion in adjacent organs. To make the most effective diagnostic use of multi-detector row CT angiography and three-dimensional image postprocessing, radiologists must be familiar with the optimal CT angiographic protocols and with the typical CT findings in various emergent vascular conditions. This article describes the protocols used in 11 patients with conditions including ruptured abdominal aortic aneurysm, secondary aortoduodenal fistula, splanchnic segmental arterial mediolysis, and Wegener-type vasculitis with visceral involvement. All of the diagnoses in these 11 cases were made in the emergency department, and the delay between imaging and diagnosis was decreased considerably by avoiding the transfer of patients for catheter angiography.