A proposed model on MR elastography for predicting postoperative major complications in patients with hepatocellular carcinoma

Objective

To develop a model for predicting post-operative major complications in patients with hepatocellular carcinoma (HCC).

Methods

In all, 186 consecutive patients with pre-operative MR elastography were included. Complications were categorised using Clavien‒Dindo classification, with major complications defined as ≥Grade 3. Liver-stiffness measurement (LSM) values were measured on elastogram. The indocyanine green clearance rate of liver remnant (ICG-Krem) was based on the results of CT volumetry, intraoperative data, and ICG-K value. For an easy application to the prediction model, the continuous variables were converted to categories. Moreover, logistic regression analysis and fivefold cross-validation were performed. The prediction model's discriminative performance was evaluated using the area under the receiver operating characteristic curve (AUC), and the calibration of the model was assessed by the Hosmer‒Lemeshow test.

Results

43 of 186 patients (23.1%) had major complications. The multivariate analysis demonstrated that LSM, albumin-bilirubin (ALBI) score, intraoperative blood loss, and ICG-Krem were significantly associated with major complications. The median AUC of the five validation subsets was 0.878. The Hosmer-Lemeshow test confirmed no evidence of inadequate fit (p = 0.13, 0.19, 0.59, 0.59, and 0.73) on the fivefold cross-validation. The prediction model for major complications was as follows: -2.876 + 2.912 [LSM (>5.3 kPa)]+1.538 [ALBI score (>-2.28)]+0.531 [Intraoperative blood loss (>860 ml)]+0.257 [ICG-Krem (<0.10)].

Conclusion

The proposed prediction model can be used to predict post-operative major complications in patients with HCC.

Advances in knowledge

The proposed prediction model can be used in routine clinical practice to identify post-operative major complications in patients with HCC and to strategise appropriate treatments of HCC.

The hepatic capsular arteries: imaging features and clinical significance

BACKGROUND

Although the anatomical features of the hepatic capsular arteries have been previously reported, the radiological and clinical importance of these arteries has not been well documented.

IMAGING FINDINGS

We injected barium sulfate into the intra- and extra-hepatic arteries in cadavers to investigate the hepatic capsular arteries. The web-like hepatic capsular arteries derived from the capsular branch of the peripheral hepatic arteries are called isolated arteries. There were anastomoses between the intra- and extra-hepatic arteries (inferior phrenic artery, superior falciform ligament artery, and cystic artery) through the hepatic capsular arteries.

CLINICAL SIGNIFICANCE

We reviewed the radiology database and assessed clinical cases. When the hepatic artery is occluded, the collateral vessels, such as the inferior phrenic artery and the superior falciform ligament artery, develop via the hepatic capsular arteries at the right triangular ligament and falciform ligament, respectively. Bleeding from capsular arteries causes extensions of the subcapsular hematoma.

CONCLUSION

The hepatic capsular arteries spread along the hepatic surface and constitute the vascular network throughout the liver. These arteries play an important role in collateral circulation in various clinical situations, as well as subcapsular hematoma.

Isolated Arteries Originating from the Intrahepatic Arteries: Anatomy, Function, and Importance in Intervention

Isolated hepatic arteries are defined as hepatic terminal arterioles that are not accompanied by portal venules or bile ductules and penetrate the liver parenchyma and distribute to the hepatic capsule and intrahepatic hepatic veins. Abundant communications exist between intra- and extrahepatic arteries through isolated arteries and capsular arterial plexus. They play a principal role in the development of subcapsular hemorrhage and arterial collateral formation following transcatheter arterial chemoembolization for liver cancers. The anatomy, function, and clinical importance of isolated hepatic arteries in interventional radiology, especially regarding subcapsular hemorrhage and arterial collateral formation, are highlighted in this article.

The vascular anatomy of the ligaments of the liver: gross anatomy, imaging and clinical applications

The vessels that communicate between the liver and adjacent structures require bridges between them. The bridges comprise the ligaments of the liver as follows: the falciform ligament, right and left coronary ligaments, lesser omentum including the hepatogastric ligament and hepatoduodenal ligament. Each ligament has specific communications between the intrahepatic and extrahapetic vessels. The venous communications called as the portosystemic shunt would become apparent in patients with portal hypertension, intrahepatic portal vein thrombosis and superior vena cava syndrome. The location of the venous communication is related to the pseudolesion or focal enhancement of the liver demonstrated on the CT scan. The arterial communications called collateral vascularization would become apparent in patients with hepatic artery occlusion, especially post-transhepatic arterial embolization, or in patients with the hepatic tumour abutting diaphragm. The knowledge of these collateral arteries is necessary to accomplish the effective transarterial embolization for the hepatic tumours. We reviewed the vessels in these ligaments using contrast-enhanced CT scans and angiography and discussed the clinical applications. Cadaver dissection photos were included as supplementary images for readers to recognize the actual spatial anatomy of the vessel in each ligament.

Spatial anatomy of the round ligament, gallbladder, and intrahepatic vessels in patients with right-sided round ligament of the liver

PURPOSE

To analyze the vascular structure of the liver in patients with a right-sided round ligament.

METHODS

We reviewed 16 patients with a right-sided round ligament and 3 polysplenia and situs inversus patients with a left-sided round ligament who underwent multidetector row CT with contrast media. The patient population consisted of 13 men and 6 women (mean 62 years). We analyzed the axial and volume-rendered images for the location of the round ligament, gallbladder, portal veins, hepatic veins, and hepatic artery. The following imaging findings for the patients with polysplenia and situs inversus were horizontally reversed.

RESULTS

The prevalence of a right-sided round ligament with and without polysplenia was 75 and 0.11 %, respectively. The gallbladder was located to the right, below, and left of the round ligament in 27.7, 38.8 and 33.3 %, respectively. Independent branching of the right posterior portal vein was noted in 57.8 %. PV4 was difficult to identify in 36.8 %. The middle hepatic vein was located to the left of the round ligament. Two branching patterns for the lateral and medial branches of the right anterior hepatic artery were noted: the common (44.4 %) and separated types (55.5 %). Both of the right anterior hepatic artery and portal vein ramified into two segments; the lateral segment with many branches and the medial segment with a few branches.

CONCLUSIONS

The right-sided round ligament divided the right anterior section into the lateral and medial segments based on the portal vein and hepatic artery anatomy.

An analysis of initial and follow-up CT findings in intramural hematoma, aortic double-lumen dissection, and mixed type lesions

BACKGROUND

Although the clinical presentation of intramural hematoma (IMH) and aortic double-lumen dissection (AD) is similar, the imaging results and subsequent clinical course of the two lesions differ.

PURPOSE

To compare the clinical and radiological findings of IMH, AD, and mixed type lesions.

MATERIAL AND METHODS

Forty-two patients with IMH, 38 with AD, and 10 with mixed type lesions were imaged with post-contrast-enhanced CT. The most proximal ulcer-like lesions and entry tears and the distal ends of the IMH and AD were evaluated. The interval change of the intramural hematoma, ulcer-like lesion, and false lumen was observed. The pathological findings of the aorta were evaluated in 15 patients.

RESULTS

The most proximal ulcer-like lesion and entry tear were located in the arch to the descending aorta in 27 (64.2%) of the 42 patients with IMH and in 24 (63.1%) of the 38 patients with AD. The distal extension was located at the iliac arteries in six (14.3%) patients with IMH and in 31 (81.6%) patients with AD (P < 0.001). The intramural hematomas regressed in 29 (93.5%) of 31 patients, and the ulcer-like lesion progressed in 14 (70%) of 20 patients with IMH. The clinical features of the mixed type lesions resembled those of AD, rather than IMH. The intramural hematoma or dissection was observed within the outer media in all lesion types on histopathology.

CONCLUSION

There is a distinct difference between IMH and AD in distal extension; however, the locations of the lesions are pathologically the same in the media of the aorta.

Secondary cancers after breast-conserving therapy in Tokyo database

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Background: The more patients overcome early breast cancer and become cancer survivors as a result of modern sophisticated approach, the more secondary cancers inevitably arise. The second malignancies after breast conserving therapy (BCT) are well-known sticky dilemma because of additional anxiety and need for medical care for longer-time. However, it is unclear whether secondary cancers negatively affect prognosis of breast cancer survivors. Methods: We performed a retrospective study of long-term cancer survivors after BCT for locoregional invasive or noninvasive breast cancer diagnosed between 1982 and mid-2012. Actuarial rates of overall (OS) and cause-specific survival (CSS) were calculated by using the Kaplan-Meier method. We compared between-group differences using the log-rank test. Results: Eight hundred sixty patients (32%) were followed-up for more than 10 years. At a median follow-up of 90 months, 146 patients had developed a second malignancy. The greatest increases in risk were for leukemia (Standardized incidence ratio (SIR): 4.24 (1.52–8.31)), ovarian cancer (SIR: 4.12 (2.40–6.31)), reno-ureteral cancer (SIR: 3.18 (1.14–6.23)), endometrial cancer (SIR: 2.48 (1.27–4.08)), and pancreatic cancer (SIR: 2.32 (1.11–3.99)). No increased risk was observed for other gastrointestinal and genitourinary cancer, malignant melanoma, lymphoma, thyroid or head and neck cancer. Overall 10-year cumulative incidence of OS without secondary cancer was 93.3%, and 10-year cumulative incidence of OS with secondary cancer was 81.5%. (p<0.001)Overall 10-year cumulative incidence of CSS without secondary cancer was 94.2%, and 10-year cumulative incidence of CSS with secondary cancer was 92.8%. (p=0.749). This likelihood of survival disadvantage is similar to that with ipsilateral breast tumor recurrecnce. Conclusions: Secondary cancers after BCT negatively impact on OS. Given the life-threatening nature to cancer survivors, lifetime caution such as smoking cessation, alcohol intake abstention, weight control, physical activity, and other healthy lifestyle must be paid.

Multidetector CT anatomy of drainage routes of gastric varices: a pictorial review

Most gastric varices arise at hepatofugal collateral pathways and drain into the systemic vein through one or both of two different types of portosystemic collateral drainage systems: the gastroesophageal (azygous) venous system and the gastrophrenic venous system. The gastroesophageal venous system consists of gastric varices contiguous with esophageal varices, paraesophageal varices, and the azygos vein, which terminates into the superior vena cava. Gastric varices draining through the gastroesophageal venous system can be treated with endoscopic techniques or creation of a transjugular intrahepatic portosystemic shunt. The gastrophrenic venous system consists of the gastric varices and the left inferior phrenic vein (IPV), which terminates into the left renal vein or the inferior vena cava. The left IPV has abundant anastomoses with peridiaphragmatic and retroperitoneal veins, and these anastomoses can function as drainage pathways from gastric varices. Balloon-occluded retrograde transvenous obliteration is a preferred treatment option for this type of gastric varix. Occasionally, gastric varices can form at the hepatopetal collateral pathway that develops secondary to localized portal hypertension caused by splenic vein occlusion. Splenectomy is often required for the treatment of this type of gastric varix. Multidetector computed tomography permits comprehensive evaluation of these venous drainage systems. Familiarity with and assessment of these draining routes of gastric varices are important for selecting treatment options and interventional techniques.

Analysis of the caudate artery with three-dimensional imaging

BACKGROUND/PURPOSE

To date there have been only a few radiological studies of the caudate artery. This study aimed to precisely analyze the caudate artery as well as the relationship between the caudate arteries, the arterial plexus at the hilar plate, and the hilar bile duct.

METHODS

Reconstructed three-dimensional (3D) computed tomography images from 50 patients during hepatic arteriography were analyzed. The caudate arteries were classified as right branches (Irs) or left branches (Ils). The communicating artery (CA) was defined as the artery connecting the right, left, segmental, and common hepatic arteries.

RESULTS

The caudate artery was divided into 3 types: an independent branch (Type 1); the common tract formed by Ir and Il (Type 2); and an arterial branch from the CA (Type 3). The CA was recognized in 25 of 50 patients. There was a total of 65 arteries to the hilar bile duct observed in 40 patients, and 24 (37 %) of these 65 arteries to the hilar bile duct originated from the caudate artery or CA.

CONCLUSION

The caudate artery plays an important role not only in connecting the blood supply of the right and left livers but in the blood supply to the hilar bile duct.

Anatomy of right superior septal artery demonstrated on the coronary CT scan

BACKGROUND

A coronary CT scan allows for non-invasive visualization of the anatomy of a coronary artery in three dimensions compared to the two dimensions afforded by conventional angiography. The septal artery, the main blood source of the interventricular septum, is usually derived from the left anterior descending artery; however, it is occasionally derived from the right coronary artery.

PURPOSE

To analyze the prevalence, origin, diameter, and length of the right superior septal artery (RSSA) demonstrated on a coronary CT scan.

MATERIAL AND METHODS

The right superior septal artery was retrospectively reviewed on the reconstructed axial scan images (0.5-mm thickness, 0.25-mm interval) in 1290 consecutive patients who underwent coronary CT scans. All patients were scanned on a 320-row CT scanner. The images were transferred to a workstation to trace the vessel to analyze the origin, diameter, and length. We also compared the length of the RSSA between patients with and without coronary artery stenosis.

RESULTS

The RSSA was identified in 51 (3.9%) of 1290 patients. The origin was the proximal portion of the right coronary artery (n = 40) or the right sinus of Valsalva (n = 11). The artery co-existed with the conus artery in 15 (29%) of 51 patients. The length was 16-62 mm (mean 31.2 mm ± 10.5), and the diameter was 0.8-2.0 mm (mean 1.3 mm ± 0.2). Longer RSSAs tended to be demonstrated in the patients with coronary artery stenosis rather than with normal coronary arteries (P < 0.05).

CONCLUSION

The right superior septal artery and its anatomical variant could be analyzed with a coronary CT scan. The ability to demonstrate this artery on the coronary CT scan was the same as with coronary angiography. The recognition of this vessel is useful for physicians managing with the diagnosis and treatment of the coronary artery disease.

Spatial relationship between intrahepatic artery and portal vein based on the fusion image of CT-arterial portography (CTAP) and CT-angiography (CTA): new classification for hepatic artery at hepatic hilum and the segmentation of right anterior section of the liver

PURPOSE

To clarify the variations of the intrahepatic artery and portal vein and to verify the proper segmentation for the right anterior section of the liver.

MATERIALS AND METHODS

CT during arterial portography and CT angiography were performed on 64-slice multi detector row CT in 147 patients. All images were transferred to a workstation for analysis using multi-image-fusion mode. We investigated the spatial relationship between hepatic artery and portal vein in the right hemiliver and the segmentation of the right anterior hepatic artery and portal vein.

RESULTS

The spatial anatomy of right hepatic arteries and portal vein was (1) anterior and posterior hepatic artery run superior and inferior to anterior portal vein, respectively (47.6%), (2) one anterior hepatic artery runs superior to and another one runs inferior to anterior portal vein (15%), (3) anterior and posterior hepatic arteries run superior to anterior portal vein (11.6%), (4) anterior and posterior hepatic arteries run inferior to anterior portal vein (7.5%), and (5) one posterior hepatic artery runs superior to and another one runs inferior to anterior portal vein (6.8%). The combined anatomy of right anterior artery and portal vein with regard to segmentation was classified as (1) dorso-ventral (26.5%), (2) dorso-ventral and inferior (10.9%), (3) multiple (18.4%), and (4) superior and inferior segments (1.4%).

CONCLUSION

There are various types of spatial anatomy of intrahepatic artery and portal vein. The hepatic arteries as well as portal veins of right anterior section of the liver could be divided into dorsal and ventral, not superior and inferior.

Evaluation of skin exposure during cerebral CT perfusion studies on a phantom

OBJECTIVES

To evaluate the skin dose during cerebral CT perfusion on a phantom, and estimate the weighted CT dose index (CTDIw) to maximum skin dose conversion factors for four types of CT scanners.

STUDY DESIGN

We evaluated the relationship between surface dose during cerebral CT perfusion and distance from the scan center in the x-y plane using a 64-multidetector row CT scanner. Skin doses were also assessed with 4 different 64-multidetector CT scanners.

RESULTS

The surface doses decreased with the distance from the scan center in the x-y plane. The surface doses at the points 6 cm and 10 cm from the scan center in the x-y plane were different from the dose at the point 8 cm by about 15%. CTDIw and skin doses differed among the CT scanners (CTDIw, 143-590 mGy; averaged temporal skin dose, 126-590 mGy). For all the four types of CT scanner, the doses increased in the following order: occipital point<frontal point<temporal points. The ratios of the maximum skin dose (averaged temporal skin dose) to CTDIw differed among the CT scanners (64-100%).

CONCLUSIONS

The maximum skin dose during cerebral CT perfusion and the dose to CTDIw ratios differs among CT scanners. The CTDIw is useful for estimation of the maximum skin dose during cerebral CT perfusion using a proper conversion factor specific to each type of CT scanner.

Lens exposure during brain scans using multidetector row CT scanners: methods for estimation of lens dose

BACKGROUND AND PURPOSE

Some recent studies on radiation lens injuries have indicated much lower dose thresholds than specified by the current radiation protection guidelines. The purpose of this research was to measure the lens dose during brain CT scans with multidetector row CT and to assess methods for estimating the lens dose.

MATERIALS AND METHODS

With 8 types of multidetector row CT scanners, both axial and helical scans were obtained for the head part of a human-shaped phantom by using normal clinical settings with the orbitomeatal line as the baseline. We measured the doses on both eyelids by using an RPLGD during whole-brain scans including the orbit with the starting point at the level of the inferior orbital rim. To assess the effect of the starting points on the lens doses, we measured the lens doses by using 2 other starting points for scanning (the orbitomeatal line and the superior orbital rim).

RESULTS

The CTDIvols and the lens doses during whole-brain CT including the orbit were 50.9-113.3 mGy and 42.6-103.5 mGy, respectively. The ratios of lens dose to CTDIvol were 80.6%-103.4%. The lens doses decreased as the starting points were set more superiorly. The lens doses during scans from the superior orbital rim were 11.8%-20.9% of the doses during the scans from the inferior orbital rim.

CONCLUSIONS

CTDIvol can be used to estimate the lens dose during whole-brain CT when the orbit is included in the scanning range.

The left inferior phrenic artery arising from left hepatic artery or left gastric artery: radiological and anatomical correlation in clinical cases and cadaver dissection

BACKGROUND

The purpose of this study is to assess angiographic and CT appearance of left inferior phrenic artery (LIPA) arising from left hepatic or left gastric artery and to recognize its specific anatomical location with the help of cadaver dissection.

METHODS

We retrospectively reviewed 761 abdominal angiographies and found 13 patients (1.7%) with LIPA arising from left hepatic or left gastric artery. We classified those origins and assessed radiological features. We also presented a cadaver dissection to identify anatomical location of LIPA arising from left hepatic artery.

RESULTS

The origin of the LIPA was classified as follows: (a) left hepatic artery: four, (b) accessory left gastric artery: one, (c) accessory left hepatic artery: three, and (d) left gastric artery: five patients. The proximal portion was located in gastrohepatic ligament and its distal portion was located in front of esophageal hiatus. In a cadaver dissection, the proximal portion ascends along ligamentum venosum and distal portion courses along superior aspect of left hemi diaphragm in front of esophagus.

CONCLUSION

The LIPA rarely arises from left hepatic or left gastric artery. The proximal portion was located in gastrohepatic ligament and the distal portion runs in front of the esophageal hiatus.

Balloon-occluded retrograde transvenous obliteration (BRTO) for a direct shunt between the inferior mesenteric vein and the inferior vena cava in a patient with hepatic encephalopathy

A direct shunt between the inferior mesenteric vein and the inferior vena cava was detected in a patient with hepatic encephalopathy. The authors performed balloon-occluded retrograde transvenous obliteration (BRTO) for this shunt. Before the obliteration, the shunt was occluded by using a balloon catheter and it was confirmed that the portal venous flow was redirected to the liver. The encephalopathy disappeared immediately after BRTO. The improvement of the liver function, the disappearance of the shunt, and the increase in the size of the portal vein and liver volume were confirmed at computed tomography performed 5 months after treatment.

Prevalence and sonographic detection of Chilaiditi's sign in cirrhotic patients without ascites

OBJECTIVE

Although Chilaiditi's sign is uncommon, its recognition is mandatory to avoid intestinal injury during percutaneous transhepatic procedures. Our purpose was to investigate the prevalence of Chilaiditi's sign in cirrhotic patients without ascites and to review the diagnostic ability of sonography to detect this rare abnormality.

CONCLUSION

The prevalence of Chilaiditi's sign was much higher in cirrhotic patients without ascites than in the general population. A precise diagnosis of Chilaiditi's sign was possible using sonography. Percutaneous transhepatic procedures can be performed safely if a route that avoids the intestine is found.

Signal Flare Phenomenon as Active Bleeding in Retroperitoneal Hematoma With Hematocrit Effect on Dynamic CT Scan

The contrast medium was observed as a thin line indicating active bleeding in the cellular component and stayed at the boundary between the plasma and cellular components in liquefied hematomas. We could also reproduce the same phenomenon in an experimental study using human blood. The characteristic dynamic motion of the contrast medium demonstrated in the liquefied hematoma, which we have called the "signal flare" phenomenon, is a significant sign indicating active bleeding.

Noncardiac findings in cardiac imaging with multidetector computed tomography

OBJECTIVES

We investigated the frequency of the noncardiac findings in cardiac imaging with multidetector computed tomography (MDCT).

BACKGROUND

Multidetector computed tomography is an accepted new tool to evaluate the heart. In cardiac MDCT scans, organs other than the heart are also irradiated, but usually not assessed.

METHODS

A total of 503 patients underwent cardiac imaging with 16- or 64-slice MDCT. Cardiologists assessed the heart, while radiologists reviewed the other organs.

RESULTS

A total of 346 new, noncardiac findings were identified in 292 patients (58.1%). A total of 114 patients (22.7%) had clinically significant findings including 4 cases of malignancy (0.8%).

CONCLUSIONS

There were a significant number of noncardiac findings in cardiac MDCT. To avoid missing clinically important findings, physicians who analyze cardiac MDCT scan--either radiologists or cardiologists--should carefully evaluate all the organs irradiated in the scan.

Phlebosclerotic colitis with deep circumferential ulceration: three-year endoscopic follow-up. Report of a case

We report a case of phlebosclerotic colitis with deep circumferential ulceration in which the characteristic findings were observed radiologically and endoscopically. Previously, the patient was diagnosed with colitis of unknown etiology in 1999 when a colonoscopy showed small erosions, ulcers, and dark purple mucosa in the right colon. As a result of parenteral nutrition treatment, his symptoms and ulcerations disappeared; however, the dark purple mucosa remained unchanged for three years on the annual endoscopic follow-up. Recurrent colitis associated with circumferential ulceration was diagnosed in 2002. The patient was treated again with only parenteral nutrition and his symptoms improved after a few days; the ulceration completely disappeared within seven months. This case emphasizes the benefit of nonsurgical treatment for phlebosclerotic colitis even in cases of deep circumferential ulceration.

Anatomical variants of the lateral femoral circumflex artery: an angiographic study

The descending branch of the lateral femoral circumflex artery (LFCA) has found recent use as a new arterial graft for coronary artery bypass grafting (CABG). Anatomical variants of the LFCA were assessed on femoral arteriograms obtained before CABG in 131 adult patients. The most common pattern, found in 78.6% of extremities, consisted of the LFCA arising from the deep femoral artery, and the arterial graft was selected from this pattern in 92.3% of patients in whom the descending branch of the LFCA was used for CABG.

CT-guided transthoracic core biopsy for pulmonary tuberculosis: diagnostic value of the histopathological findings in the specimen

We evaluated the value of CT-guided transthoracic core biopsy for the diagnosis of mycobacterial pulmonary nodules. The 30 subjects in this study had pulmonary nodules that had been either diagnosed histopathologically as tuberculosis or were suspected as tuberculosis based on a specimen obtained by CT-guided transthoracic core biopsy. The histopathological findings, the existence of acid-fast bacilli in the biopsy specimens, and the clinical course of the patients after the biopsy were reviewed retrospectively. Two of the three histological findings for tuberculosis that included epithelioid cells, multinucleated giant cells and caseous necrosis were observed in 21 of the nodules which were therefore diagnosed as histological tuberculosis. Six of these 21 nodules were positive for acid-fast bacilli, confirming the diagnosis of tuberculosis. Thirteen of the 21 nodules did not contain acid-fast bacilli but decreased in size in response to antituberculous treatment and were therefore diagnosed as clinical tuberculosis. Seven nodules with only caseous necrosis were diagnosed as suspected tuberculosis, with a final diagnosis of tuberculosis being made in 4 of the nodules and a diagnosis of old tuberculosis in 2 nodules. Two nodules with only multinucleated giant cells were diagnosed as suspected tuberculosis with 1 of these nodules being diagnosed finally as tuberculosis and the other nodule as a nonspecific granuloma. When any two of the three following histopathological findings--epithelioid cells, multinucleated giant cells or caseous necrosis--are observed in a specimen obtained by CT-guided transthoracic core biopsy, the diagnosis of tuberculosis can be established without the detection of acid-fast bacilli or Mycobacterium tuberculosis.

Collateral Venous Pathways in the Transverse Mesocolon and Greater Omentum in Patients with Pancreatic Disease

OBJECTIVE

The purpose of this study was to describe the radiologic findings of the collateral venous pathways in the transverse mesocolon and the greater omentum associated with pancreatic diseases and to correlate these venous pathways and the accompanying arterial anatomy.

CONCLUSION

The collateral pathway in the transverse mesocolon consists of the inferior mesenteric vein, left transverse colic vein, marginal vein of the transverse colon, and middle colic vein. The pathway in the greater omentum consists of anastomosis of the left and right epiploic veins deriving from the gastroepiploic vein. The former pathway is the vena comitans of Riolan's arch and the latter is the vena comitans of the arch of Barkow.

Vascular anatomy of the pancreas and clinical applications

The development of recent technology, especially the helical computed tomography (CT) scan, allows us to observe small peripancreatic vessels which previously could be demonstrated only by angiography (1), and therefore make three-dimensional (3-D) volume rendered CT angiographic reconstruction possible (2). The neighboring structures as well as the pancreatic vessels are clearly visualized on the axial CT scan. Therefore, it is necessary to define the peripancreatic vessels on the axial images, as well as on angiography to make an accurate diagnosis of pancreatic disease so that we can also estimate the dynamic flow of the peripancreatic vessels. In this chapter, I would like to use the cadaver dissections of pancreatic vessels to explain each pancreatic vessel based on previous anatomic and radiologic references and finally demonstrate the clinical cases in terms of the pancreatic vessels. The pancreatic arteries and veins are explained based on the anatomic and radiologic references. Principal pancreatic vessels are demonstrated on cadaver dissection. The pancreas head is supplied by the anterior and posterior pancreaticoduodenal arteries forming arcades in the pancreaticoduodenal sulcus and is drained by the pancreaticoduodenal veins. The pancreas body and tail are supplied by the dorsal, inferior, and caudate pancreatic arteries, and are drained by the inferior and left pancreatic veins. Clinical applications in terms of the pancreatic vessels such as basis for interpretation of the angiography and the CT scan, treatment of pancreatitis and pancreatic cancer, detection of small insulinoma are stated.

The congenital anastomoses between hepatic arteries: angiographic appearance

The purpose of this study was to evaluate congenital anastomoses between hepatic arteries demonstrated on angiography in ten patients and to correlate the anastomosis with types of hepatic arterial anatomy. We evaluated the types of the hepatic arterial anatomy based on Michels' classification for 720 patients and compared the anatomic types between the patients with the anastomoses (ten patients) and without the anastomoses (710 patients). The diameter of the anastomoses ranged from 1.5 to 3.0 mm (mean, 2.4 mm). Five anastomoses were classified as tortuous type and five as straight type. Based on Michels' classification for types of hepatic arterial anatomy, eight (80%) of ten patients with the congenital anastomoses were classified as type III (replaced right hepatic artery from superior mesenteric artery). The remaining two patients were classified as type IV (replaced right hepatic artery from superior mesenteric artery and replaced left hepatic artery from left gastric artery) and type VIIIa (replaced right hepatic artery from superior mesenteric artery and accessory left hepatic artery from left gastric artery). Eight (16%) of 48 patients who were classified as type III have the anastomoses. In conclusion, the congenital anastomoses were observed especially in patients with replaced right hepatic artery from superior mesenteric artery.

The subclavius posticus muscle: a factor in arterial, venous or brachial plexus compression?

During dissection practice in 1993 and 1995 to 1999, we found an aberrant muscle which connected the first costal cartilage and the superior margin of the scapula in 12 sides (4.8%) of 11 cadavers (8.9%) among 248 sides of 124 cadavers. The muscle originated from the cranial surface of the sternal end of the first rib, ran laterodorsally, and inserted into the superior margin of the scapula. According to the origin and insertion, the aberrant muscle was considered to be the subclavius posticus (Rosenmüller, 1800). We also examined the supraclavicular region of a living subject by MR imaging to estimate the course of such an aberrant muscle. It is thought that the aberrant muscle runs on the anterior surface of the subclavian vein and crosses over the brachial plexus. Such a muscle could be considered as a possible factor causing the Paget-von Schrötter syndrome which is recognized as spontaneous or effort-related thrombosis of the axillo-subclavian vein. It is recommended to take into account the possible existence of such an aberrant muscle during the examination of patients with thoracic outlet syndrome, especially in those with symptoms of venous compression.

Balloon-occluded retrograde transvenous obliteration of gastric varix draining via the left inferior phrenic vein into the left hepatic vein

We encountered a patient with gastric varix draining not via the usual left suprarenal vein but via the left inferior phrenic vein joining the left hepatic vein. Transfemoral balloon-occluded retrograde transvenous obliteration (BRTO) of the varix was performed under balloon occlusion of the left inferior phrenic vein via the left hepatic vein and retrograde injection of the sclerosing agent (5% of ethanolamine oleate) into the gastric varix. Disappearance of the gastric varix was confirmed on endoscopic examination 2 months later.

Precaval draining vein from paraesophageal varices: radiologic-anatomic correlation

OBJECTIVE

The purpose of this study was to describe the CT features of the precaval draining vein from paraesophageal varices in six patients with liver cirrhosis. We also assessed the anatomic nature of the vein.

CONCLUSION

The precaval vein courses anteriorly to the inferior vena cava and drains into the right anterior aspect of the inferior vena cava. The diameter of the precaval vein ranged from 3 to 13 mm (mean, 6.5 mm). The precaval vein is anatomically identical to the anastomosis between the right and left inferior phrenic veins.

Hepatic falciform ligament artery: angiographic anatomy and clinical importance

The hepatic falciform ligament artery (HFLA) was evaluated by angiography and also by dissections. Based on the findings, the mechanism of the post-chemoembolization skin rash was studied. A total of 340 liver cirrhosis patients who underwent hepatic artery chemoembolization for hepatocellular carcinoma were reviewed in terms of the angiographic incidence of the HFLA, variations in its origin, and the incidence of skin rash. The HFLA was demonstrated in 26 (7.6%) of the 340 patients on angiography. Two HFLAs were observed in one patient. The origin was the middle hepatic artery (A4) in 16 cases, the superior branch of the middle hepatic artery in three, the inferior branch of the middle hepatic artery in two, the inferior branch of the left hepatic artery (A3) in three, and the confluence of A3 and A4 in three cases. There were no patients who developed post-chemoembolization skin rash. Two cadavers were dissected to investigate the anastomosis between the HFLA and the subcutaneous artery. Two different anastomoses were found: (1) direct and (2) via the ensiform branch of the internal thoracic artery. These were located at the lower and upper part of the falciform ligament, respectively. The distribution of a chemotherapeutic agent through these anastomoses is the likely cause of post-chemoembolization skin rash. If prophylactic embolization of the proximal portion of the HFLA using a metallic coil is performed, the skin rash will be prevented.

Veins of Retzius at CT during arterial portography: anatomy and clinical importance

PURPOSE

To classify the veins of Retzius demonstrated at computed tomography (CT) during arterial portography (CTAP) on the basis of anatomic location and to evaluate the relationship between the frequency of CT visualization and associated disease.

MATERIALS AND METHODS

The authors reviewed axial CTAP scans from 130 patients. Patients were classified into one of two groups: patients with liver cirrhosis (group 1 [n = 81]) and patients without liver cirrhosis (group 2 [n = 49]).

RESULTS

The pathways of the veins of Retzius were classified as follows: (a) The ileocolic vein drained into the inferior vena cava (IVC) or the right renal vein through the right gonadal vein (n = 61); (b) the pancreaticoduodenal vein drained into the IVC (n = 8); (c) the proximal branches of the superior mesenteric vein drained into the left gonadal vein (n = 6); and (d) the ileocolic vein drained directly into the IVC (n = 5). The veins of Retzius were demonstrated in 41 (51%) of the 81 patients in group 1 and 26 (53%) of the 49 patients in group 2. There was no statistically significant difference between the two groups.

CONCLUSION

The veins of Retzius were demonstrated at CTAP in approximately 50% of patients with and 50% of patients without liver cirrhosis.

Preaortic esophageal veins: CT appearance

OBJECTIVE

The purpose of this study was to describe the CT imaging features of preaortic esophageal veins in 10 patients with liver cirrhosis.

CONCLUSION

Preaortic esophageal veins deriving from the paraesophageal varices course anterior to the descending aorta and drain into the hemiazygos vein. Preaortic esophageal veins are anatomically identical to extrinsic esophageal veins. The diameter of the veins we studied ranged from 1 to 8 mm (mean, 3.1 mm). Two preaortic esophageal veins were noted in each of two patients.

Wedge-shaped lesion in the liver seen on postoperative CT. Probable thromboembolic phenomenon in the portal venous system

PURPOSE

To demonstrate CT findings of a wedge-shaped lesion (WSL) in the liver following abdominopelvic surgery and to determine the etiology and incidence of WSL.

MATERIAL AND METHODS

Retrospective review of teaching files in our institution revealed 18 cases showing postoperative WSL in the liver. We also retrospectively reviewed CT images of the liver in 104 patients with a recent history of abdominopelvic surgery performed during a period of 12 months, as well as in 102 patients with no history of surgery during the same period to be used as control. Three additional patients with WSL were found in the postoperative group and none in the control group. Liver CT images from the 21 patients showing WSL, along with their clinical data and follow-up CT where available, were retrospectively analyzed.

RESULTS

I.v. contrast-enhanced CT showed homogeneous higher attenuation of WSL than the surrounding liver in all cases; unenhanced CT showed low density in 5 patients, isodensity in 7 patients, and high density in 5 patients as compared with the surrounding liver. Density on unenhanced CT was significantly correlated with the presence or grade of fatty liver (p<0.01). In 5 cases CT demonstrated clots in the portal vein branch within the area of WSL and in 2 cases portal perfusion defects were observed on arterial portal CT, corresponding to the areas of WSL. Follow-up CT examinations were available on 15 patients: WSL became less prominent, or atrophic, or showed no change in 10, 2 and 3 patients respectively. Follow-up CT showed development of liver metastasis in only 3 cases. Only 2 of the 21 patients were clinically symptomatic; one had postoperative ileus and the other obstructive jaundice.

CONCLUSION

Postoperative WSL may represent a thromboembolic phenomenon at the peripheral intrahepatic branch of the portal venous system during or after abdominopelvic surgery, resulting in a compensatory increase in the hepatic arterial flow that appears as wedge-shaped enhancement on CT. This is a clinically asymptomatic and uncommon phenomenon (occurring in 3% of abdominopelvic surgeries). It is important that this phenomenon is not confused with liver metastasis.

Peripancreatic veins on thin-section (3 mm) helical CT

OBJECTIVE

The purpose of this study was to evaluate thin-section helical CT for the frequency of visualization of the peripancreatic veins, the venous anatomy at the head of the pancreas, and variations of the venous anatomy.

SUBJECTS AND METHODS

We performed 30-sec helical CT of the pancreas with one breath-hold and a 3-mm scanning collimation in 50 patients. The scan was started 60 sec after injection of an i.v. contrast medium at the rate of 2 ml/sec (total amount of contrast medium, 100 ml). The axial scan data were reviewed for the following information: the frequency of CT visualization of the peripancreatic veins (anterior superior pancreaticoduodenal vein, first jejunal vein, gastrocolic trunk, inferior mesenteric vein, left gastric vein, middle colic vein, posterior superior pancreaticoduodenal vein, right colic vein, and right gastroepipolic vein) and the anatomic relationship between the large portal venous system (portal vein, superior mesenteric vein, and splenic vein) and its tributaries.

RESULTS

The frequency of visualization on CT of each vessel was gastrocolic trunk, 100%; right gastroepiploic vein, 100%; first jejunal vein, 96%; inferior mesenteric vein, 88%; left gastric vein, 80%; posterior superior pancreaticoduodenal vein, 72%; middle colic vein, 72%; right colic vein, 64%; and anterior superior pancreaticoduodenal vein, 50%. The anatomic relationship between the large portal venous system and its tributaries was as follows: The left gastric vein drained into the splenic vein-portal vein confluence (46%), into the splenic vein (32%), and into the portal vein (22%); the inferior mesenteric vein drained into the splenic vein (46%), the splenic vein-superior mesenteric vein confluence (25%), and the superior mesenteric vein (29%). The posterior superior pancreaticoduodenal vein drained into the portal vein above the splenic vein-portal vein confluence (mean distance, 0.3 cm). The middle colic vein, gastrocolic trunk, and first jejunal vein drained into the superior mesenteric vein below the splenic vein-portal vein confluence (mean distances of 2.4 cm, 3.0 cm, and 3.7 cm, respectively).

CONCLUSION

Thin-section helical CT scans provide good visualization of the peripancreatic veins.

Helical CT angiography with multiplanar reformation: techniques and clinical applications

The technique and potential clinical applications of multiplanar reformation (MPR) of imaging data from helical computed tomography (CT) to display images of the blood vessels in the abdomen and the thorax are described. Helical CT was performed following bolus intravenous contrast material enhancement in patients with suspected tumor involvement of vessels in various regions of the body. The axial images were stacked to form a volume of imaging data from which a plane could be selected to display the desired vascular image in a two-dimensional format. Various techniques were used to change the image plane so that different vessels in different regions of the body could be displayed, including the splanchnic vessels around the pancreas, the portal veins and hepatic artery in the porta hepatis, the renal vessels, and the venae cavae and aorta. Rotation from a coronal or sagittal plane was necessary to display most vessels. The technique is practical and reproducible, but it requires that the operator be knowledgeable about vascular anatomy. Helical CT angiography with MPR has the potential to display vascular images that are similar to angiograms.

Repeat embolization of the side branch of the internal mammary artery graft by gelatin sponge particles and micro coils

The internal mammary artery (IMA) is increasingly used as a coronary bypass conduit because of better long-term patency and improved prognosis as compared with venous grafts. Previous investigators have suggested that the "steal" of blood flow of the IMA graft via the subclavian artery or a persistent large side branch of the graft may lead to its thinning. However, only a few reports have described the embolization of a large side branch using a transcatheter procedure. We present a case of repeated embolization of a large lateral costal side branch of the left internal mammary arterial graft applying gelatin sponge particles and micro coils, as well as angioplasty to the graft conduit, with resulting easing of chest pain.

Embolization with steel coils using a saline flush technique

A method using saline flush to push Gianturco steel coils through catheters is described, and has been successfully used in 45 patients. The saline flush technique requires no precise matching of coils and catheters, solves problems associated with the conventional method and simplifies the coil embolization procedure.

Hepatic inferior vena cava obstruction: treatment of two types with Gianturco expandable metallic stents

Gianturco expandable metallic stents were used for treating six patients with inferior vena cava (IVC) obstruction due to compression by large hepatic tumors and three patients with idiopathic obstruction of the hepatic IVC and Budd-Chiari syndrome who showed reocclusion or stenosis 3-21 months after previously performed percutaneous transluminal angioplasty (PTA). In all six patients with compression by hepatic tumors, stents dilated the IVC and debilitating edema of the lower body disappeared. In the three patients with idiopathic obstruction, stents were placed after repeat dilation of the lesions and Budd-Chiari syndrome did not recur during a follow-up period of 7-10 months. In two of the three, cavograms obtained 8 months after placement showed the channels to be open with minimal intimal thickening. Gianturco expandable metallic stents can correct IVC obstruction due to compression by hepatic tumors and are useful in preventing reocclusion of the IVC after PTA for the treatment of idiopathic obstruction. The authors recommend using tanem stents connected by at least two struts.

[Lipiodol-CT for the detection of small hypovascular HCC]

To evaluate the diagnostic value of Lipiodol-CT for small hypovascular HCC, we injected 3 ml or less Lipiodol into the hepatic artery of patients with chronic liver disease and small SOL in the liver detected on echogram but not on angiogram. About seven days after injection CT was used to check for accumulation of Lipiodol in the liver SOL. We found that the sensitivity of this method for detection of hypovascular HCC is only 25%. We assume that Lipiodol does not accumulate in small hypovascular HCC lesions because they have little vascular stroma. Lipiodol-CT has high diagnostic value for the detection of small hypervascular daughter HCC lesions, but this method should not be relied on for the detection of small hypovascular HCC.

[Usefulness of dynamic thin section CT in detecting lymph node metastasis of lung cancer]

The diagnosis for metastatic lymph nodes of lung cancer by the conventional CT is done only by the size of nodes, therefore, its diagnostic accuracy is questionable. For the purpose of more qualitative diagnosis in order to elevate accuracy of metastatic nodes, we studied a new CT image (Dynamic Thin Section CT) by combining the Thin Section CT with the Dynamic CT, and reviewed on the image of histopathological positive nodes. Firstly, for the preoperative cases of lung cancer, the conventional CT was performed for the whole chest with 10 mm-thickness and 10 mm-interval. Secondary, among them, the Dynamic CT by bolus-injection at the sites of detected hilar and mediastinal lymph nodes was performed. For this method, the Thin Section CT with 2 mm-thickness was used, and the image-detected nodes were isolated by surgery. We studied 25 cases whose images were compared with the histological findings. By the conventional CT sensitivity were 35.7%, specificity 54.5%, and accuracy 44.0%, in regarding the shorter diameter over 1 cm as positive nodes, then under diagnosis were 36%, over diagnosis 20%. Morphological features were reviewed on the image of metastatic lymph nodes in the Dynamic Thin Section CT, and were (1) lump-like lymph nodes, (2) disappearance of the fatty plane around the lymph nodes or uneven and irregular margins, (3) irregular internal structures of enhanced lymph nodes. Moreover, small lymph nodes were clearly detected, and the size was exactly measured.(ABSTRACT TRUNCATED AT 250 WORDS)

[Preoperative evaluation of digital subtraction pulmonary angiography in primary lung cancer]

The preoperative evaluation of the resectability for primary lung cancer was studied by using digital subtraction pulmonary angiography (DSA-PAG). Thirty operative cases with primary lung cancer performed DSA-PAG as preoperative test at random for 3 years from June 1985 were subjected in this study. The apparatus used is DSA device (Angiotoron) of a product of Siemens Co., Ltd. The findings obtained by DSA-PAG were retrospectively studied according to the surgical findings, operative modes and postoperative histopathological findings. Moreover, at the same time, usefulness of DSA-PAG was evaluated comparing its findings with preoperative enhanced CT interpretation. The useful findings were obtained in 10 cases of 30 cases (33%). Its contents were 2 cases with invasion of the left atrium, 2 cases with invasion of superior and inferior pulmonary vein, 5 cases with invasion of truncus pulmonary artery and 1 case with interlobar invasion. The findings in all cases were superior to those obtained by the enhanced CT. The decision of operative modes confirming invasion of tumor or metastatic lymph node is one of the important aims of the preoperative test. DSA-PAG can be carried out simply and safely on out-patient basis, additionally, favorable result can be especially obtained in invasion lesions of blood vessels of hilus regions. From the result, informations of regions unknown by preoperative CT were accurately obtained. As a rule, DSA-PAG should be performed by the preoperative routine test of primary lung cancer.

Hypovascular hepatocellular carcinoma undetected at angiography and CT with iodized oil

Eighteen patients with 22 hepatocellular carcinoma (HCC) lesions less than 2 cm in diameter were examined with conventional angiography, digital subtraction angiography (DSA), and computed tomography (CT) after intraarterial injection of iodized oil (Lipiodol CT). Eight lesions detected at ultrasound examination of eight patients were not identified at conventional angiography, DSA, or Lipiodol CT. At histologic examination, all eight lesions were found to consist of well-differentiated carcinoma of grade I or II on the Edmondson-Steiner scale, and four had fatty change in cancer cells. Percutaneous tissue-core biopsy was indispensable in the diagnosis of well-differentiated HCC lesions that could not be diagnosed with conventional angiography, DSA, and Lipiodol CT.

A case of gallbladder cancer manifesting chylous ascites and chylothorax

A case of gallbladder cancer manifesting both chylous ascites and chylothorax was reported. A 66-year-old man was hospitalized with milky ascites. The patient was diagnosed as having gallbladder cancer based on findings of endoscopic retrograde cholangiopancreatography (ERCP) and celiac angiography. The diagnosis of chylous ascites was confirmed by the presence of microscopically visible free fat and the biochemical analysis of the fluid. The patient also gradually developed chylous thoracic effusion. Autopsy revealed lymphogenous metastasis in multiple retroperitoneal and mediastinal nodes. Chylothorax and chyloperitoneum are relatively rare. Only five cases have been reported in Japan that manifested both conditions.