MR imaging of prostate cancer

MR imaging technology is continually evolving and improving. Endorectal MR imaging provides excellent anatomic detail and is the most accurate imaging modality for staging prostate cancer with the ability to affect therapy and cure in many men. Failure to detect microscopic disease and microscopic capsular invasion remain significant weaknesses. MR spectroscopy has great potential for improving the sensitivity and specificity of MR imaging and expanding its diagnostic and staging usefulness.

MR imaging of the thoracoabdominal junction

Recent advances in MR imaging techniques and its multiplanar capability allow for improved detection and characterization of benign and malignant processes occurring in the thoracoabdominal region. It is important to the staging process of patients with known malignancy to correctly diagnose incidental masses in this region, including hepatic or adrenal lesions, which initially may be identified by other imaging modalities. MR imaging provides a complimentary role in lesion detection and diagnosis that may ultimately affect therapeutic management and outcome.

Liver and bone window settings for soft-copy interpretation of chest and abdominal CT

OBJECTIVE

We evaluated whether the use of multiple window and level settings on a soft-copy workstation improves diagnostic accuracy on chest and abdominal CT. We hypothesized that routinely using window and level settings during soft-copy interpretation would beneficially affect the final diagnosis without compromising efficiency.

MATERIALS AND METHODS

Two hundred three randomly selected abdominal and chest CT scans were interpreted by three radiologists using a four-monitor soft-copy workstation (images per screen, nine; resolution, 2K). After the initial interpretations, all scans were reevaluated by the same radiologists using additional liver and bone window and level settings. Differences in conspicuity and characterization of abnormalities were graded on a three-point scale.

RESULTS

Conspicuity and characterization of abnormalities were improved in 67% of abnormal findings (81/121; p = 0.01). Improvement (a finding that substantially affected the final diagnosis) was present in 18% of abnormal findings (22/121; p = 0.04). On average, the evaluation of images at multiple window and level settings required an additional 40 sec per case.

CONCLUSION

The use of multiple window and level settings during soft-copy interpretation resulted in improved lesion detectability and characterization with greater diagnostic efficacy. Using soft-copy workstations, radiologists can evaluate images using multiple settings without compromising efficiency.

Imaging features of posttransplantation lymphoproliferative disorder in pancreas transplant recipients

OBJECTIVE

The purpose of this study was to describe the imaging features of posttransplant lymphoproliferative disorder (PTLD) in pancreas transplant recipients.

CONCLUSION

The prominent image finding of PTLD in pancreas transplant recipients is diffuse allograft enlargement, an appearance that may be indistinguishable from the image findings of acute pancreatitis or transplant rejection. However, failure of response to immunosuppressive therapy, presence of intraallograft or extraallograft focal masses, or organomegaly may suggest the diagnosis of PTLD.

Percutaneous abdominal and pelvic interventional procedures using CT fluoroscopy guidance

OBJECTIVE

The purpose of our study was to assess the use of low-milliamperage CT fluoroscopy guidance for percutaneous abdominopelvic biopsy and therapeutic procedures.

MATERIALS AND METHODS

We reviewed the clinical records and relevant imaging studies of 97 patients who underwent 119 percutaneous CT fluoroscopy-guided abdominal or pelvic procedures: fluid collection aspiration or drainage catheter insertion (n = 59), biopsy (n = 49), hepatocellular carcinoma ethanol ablation (n = 6), chemoneurolysis (n = 4), and brachytherapy catheter insertion (n = 1). These procedures were guided using a helical CT scanner providing real-time fluoroscopy reconstruction at six frames per second. A control panel and video monitor beside the gantry allowed direct operator control during all interventional procedures.

RESULTS

One hundred twelve (94.1%) procedures were successfully performed using either a stand-off needle holder and continuous real-time CT fluoroscopy guidance or incremental manual insertion and intermittent CT fluoroscopy to confirm position. Image quality using low milliamperage was adequate for needle or drainage tube placement in all but two low-contrast liver lesions. Two hematomas were accessed but yielded no fluid on aspiration; one drainage procedure was abandoned after the patient developed endotoxic shock. Imaging of ethanol distribution during injection facilitated tumor ablation and neurolytic procedures. CT fluoroscopy allowed rapid assessment of needle, guidewire, dilator, and catheter placement, especially in nonaxial planes. Average CT fluoroscopy time for biopsy and therapeutic procedures was 133 sec (range, 35-336 sec) and 186 sec (range, 20-660 sec), respectively.

CONCLUSION

CT fluoroscopy is a practical clinical tool that facilitates effective performance of percutaneous abdominal and pelvic interventional procedures.

MammoWeb continuing medical education (CME): a web-based breast imaging CME program

The ubiquity of the world-wide web allows unique educational opportunities for continuing medical education (CME). We have designed a comprehensive breast imaging CME curriculum to permit individual physicians in their homes or offices to use personal computers to ease the burden of this process. Category 1 CME credits can be earned off-hours without having the physician travel out of town. In addition, since the course is computer-based, the overall costs to the participant are substantially reduced. The program can be updated on an ongoing basis to include new technology or to provide additional information requested by the users.

Acute pancreatic transplant rejection: evaluation with dynamic contrast-enhanced MR imaging compared with histopathologic analysis

PURPOSE

To evaluate the use of dynamic contrast material-enhanced gradient-recalled-echo MR imaging for the diagnosis of acute pancreatic transplant rejection, as confirmed at histopathologic analysis.

MATERIALS AND METHODS

Thirty MR imaging studies were performed in 25 patients within 3 days of percutaneous biopsy or pancreatectomy. The mean percentage of parenchymal enhancement (MPPE) at dynamic contrast-enhanced MR imaging was calculated.

RESULTS

Biopsy findings were no evidence of rejection (n = 7 [23%]), mild rejection (n = 10 [33%]), moderate (n = 6 [20%]) and severe (n = 2 [7%]) acute rejection, and infarction (n = 5 [17%]). The corresponding MPPEs at 1 minute were 106%, 66%, 62%, 57%, and 3%, respectively. Overlap of cases in the normal and rejection groups occurred; however, using an MPPE cutoff of 100% resulted in a sensitivity of 96%. An MPPE over 120% was seen in the normal group only. The MPPE was significantly greater in the normal group than in the rejection or infarction group (P < .05).

CONCLUSION

Dynamic contrast-enhanced MR imaging is highly sensitive for the detection of acute pancreatic transplant rejection. Because of overlap of cases in the normal and rejection groups, percutaneous biopsy may be needed in some cases. Pancreatic allografts with infarction can be clearly identified.

Evaluation of biopsy needles and prototypic needle guide devices for percutaneous biopsy with CT fluoroscopic guidance in simulated organ tissue

The authors evaluated accuracy and success rates for placement of fine-aspiration, core, and coaxial biopsy needles in pork meat with three needle guide devices and computed tomographic fluoroscopic guidance. Accuracy and reliability with a metallic sponge-forceps needle holder was equal to or greater than those with other devices, and it was preferred by operators due to its lighter weight and single-handed manipulation. All needle holders functioned poorly with thin-walled needles.

MR imaging of the adrenal gland: radiologic-pathologic correlation

Complex physiologic and neoplastic processes affect the adrenal glands. An appreciation of the gross pathologic and histologic correlates of disease aids in understanding the mechanisms by which diagnostic imaging helps characterize adrenal masses. Computed tomographic (CT) densitometry and chemical shift magnetic resonance (MR) imaging would seem to be the most reliable tools in determining whether a given adrenal mass is specifically an adenoma. Such a determination is made on the basis of the presence of substantial amounts of intracytoplasmic lipid. Thus, although a homogeneous mass with a CT attenuation of less than 10 HU or a decrease in signal intensity at opposed-phase MR imaging is diagnostic for adenoma, lesions that do not have these features are indeterminate and may necessitate biopsy. Adrenal myelolipoma also has a distinctive imaging appearance that reflects the presence of macroscopic fat deposits. Diagnosis of adenoma or adrenal myelolipoma is very helpful in the assessment and treatment of asymptomatic patients with adrenal masses and may make biopsy unnecessary. In patients with clinical or biochemical evidence of adrenal disease, MR imaging helps confirm the presence of a mass and allows localization and further characterization of the lesion.

Torsion of intraperitoneal renal transplants: imaging appearances

OBJECTIVE

Torsion of a renal transplant is a rare complication with nonspecific clinical manifestations. Prompt detection is necessary to allow surgical treatment and to preserve renal function. We describe the radiologic appearances of torsion of intraperitoneal renal transplants in patients who have undergone simultaneous renal and pancreatic transplantation or dual renal transplantation.

CONCLUSION

Renal transplant torsion should be suspected when a change in renal axis associated with abnormal perfusion occurs in an intraperitoneal kidney.

Frequency of abdominal CT findings in AIDS patients with M. avium complex bacteraemia

BACKGROUND

Use of blood culture studies for early diagnosis of Mycobacterium avium complex (MAC) infection has become important due to the recent development of effective antibiotic therapy for this condition. This study assessed the abdominal computed tomography (CT) findings in patients with AIDS who presented with bacteraemic MAC infection.

METHODS

A retrospective analysis of abdominal CT scans was performed in 24 patients who presented with MAC-positive blood culture. CT images were reviewed specifically to evaluate for lymph node enlargement and attenuation, hepatomegaly, splenomegaly, bowel wall abnormality and for any other pathological changes. Comparison was made to prior reports of the CT findings in this disease process.

RESULT

Enlarged intra-abdominal mesenteric and/or retroperitoneal lymph nodes were found in 10 patients (42%). These nodes were characterized by homogeneous, soft-tissue attenuation in eight of the 10 patients. Hepatomegaly, splenomegaly and small bowel wall thickening were noted in 12 (50%), 11 (46%) and four (14%) patients, respectively. CT findings were evaluated as normal in six (25%) patients.

CONCLUSIONS

Enlarged mesenteric and/or retroperitoneal lymph nodes in AIDS patients with bacteraemic MAC were observed much less frequently on CT than previously reported in AIDS patient populations. Normal abdominal CT findings do not exclude this diagnosis and may reflect a trend towards earlier detection of MAC disease.

Clinical pathway for enhanced parent and preterm infant interaction through parent education

The article discusses the importance of implementing a clinical pathway in the neonatal intensive care unit that emphasizes parent education. Through an extensive literature review, a clinical path was developed that incorporates parent education through an individualized, developmentally supportive model of interaction. The clinical path is designed to be utilized as a teaching tool from birth to discharge from the hospital. The path can serve as a guide for teaching and identifying learning objectives a long a time line as well as for providing consistent documentation.

Comparison of three display methods for evaluating CT angiography data for the vascular assessment of renal donors

In conclusion, CTA display methods are useful when evaluating renal vascular anatomy. Cinematic loop appears to be the most useful display method and is significantly more sensitive, specific, and accurate than the 3D-MIP or stack axial when identifying renal arterial anatomy.

Creating a digital video-based teaching file for interventional procedures using CT fluoroscopy

A computerized radiology education teaching file application, MRW (Multimedia Radiology Workstation), was produced in our department as a collaboration of faculty, fellows and a doctoral student. This inexpensive and flexible system is novice-programmable and is capable of capturing images from multiple modalities (including still and cine image) and organizing them into individual electronic teaching cases. Help and tutorial functions support the main case display functions.

Cytoablative therapy with combined resection and cryosurgery for limited bilobar hepatic colorectal metastases

BACKGROUND

Cryosurgery can be employed in patients with unresectable hepatic metastases when the tumor size and the number of metastases are limited. However, local recurrence can result from incomplete ablation. We proposed a trial of complete cytoablation with a combined approach of cryosurgery and hepatic resection for patients with bilobar hepatic metastases.

METHODS

Seven patients underwent cryosurgery alone (CRYO). Seven additional patients underwent combined resection and cryosurgery (CRYO+RES) for bilobar metastases.

RESULTS

In the CRYO group, 5 of 7 patients had at least one centrally located tumor. All 5 of these patients had early recurrence at the site of ablation. In the CRYO+RES group complete ablation was achieved in 7 of 7. Two (28.6%) of these patients developed local recurrence.

CONCLUSION

Cytoablation of hepatic metastases can be safely achieved with combined hepatic resection and cryosurgery in selected patients. Long-term survival data are necessary before advocating widespread application of this approach.

End stage renal transplant failure: allograft appearances on CT

INTRODUCTION

Failed renal allografts often are left in situ in patients who revert to chronic dialysis therapy or who undergo retransplantation. These patients may be investigated with computed tomography (CT) imaging for allograft-related or other abdominopelvic disease. This study describes the appearances of failed renal transplants on CT.

METHODS

A retrospective study was made of the clinical records and CT findings on 25 studies in 14 patients, 5-156 months (average, 44 months) following allograft failure. CT studies were reviewed for allograft position, size, shape, attenuation value, calcification, cyst formation, related abdominopelvic findings and the presence of other allografts. Correlation was made with clinical findings in all patients and with pathological findings in six.

RESULTS

Global shrinkage was noted in eight failed allografts, all of which were asymptomatic. Enlargement of two failed allografts was due to symptomatic acute infarction of the allograft in one patient and subacute haemorrhagic infarction simulating a tumour mass in another. CT attenuation values in individual allografts varied markedly due to fatty replacement, hydronephrosis, haemorrhage or dense calcification. Both a failed longstanding and a functioning more recently placed renal allograft were present in seven patients, four of whom had acute complications related to the more recently transplanted kidney. Two of six calcified allografts were mistaken for opacified bowel on CT.

CONCLUSION

A wide spectrum in size, shape and attenuation values may be detected in failed renal allografts by CT. These organs may be the site of acute disease despite their lack of physiological function or may be diagnostically confusing findings in patients with acute disease related to more recently transplanted organs.

Evaluation of 14- and 11-gauge directional, vacuum-assisted biopsy probes and 14-gauge biopsy guns in a breast parenchymal model

PURPOSE

To compare commercially available 14-guage core biopsy guns and 11- and 14-gauge, directional, vaccum-assisted biopsy probes for tissue yield and fragmentation.

MATERIALS AND METHODS

One hundred passes were made through fresh turkey breasts by using each of 11 14-gauge, automated biopsy gun-needle combinations and a directional, stereotactic, vacuum-assisted biopsy system equipped with 11- or 14-gauge probes. Specimens were measured for total weight, individual length, diameter, and number of fragments.

RESULTS

Among the handheld devices, the Pro-Mag 2.2 gun (Manan Medical Products, Northbrook, Ill) and 14-gauge Biopsy-Cut needle (Bard, Covington, Ga) had the greatest yield (17.7 mg per core specimen); this combination also produced the greatest percentage of nonfragmented cores (83%). Directional, vacuum-assisted biopsy specimens were significantly larger (P < .001): 36.8 mg per core specimen for the 14-gauge probe and 94.4 mg per core specimen for the 11-gauge probe. Specimens obtained with directional, vacuum-assisted biopsy were more fragmented than those obtained with spring-actuated, two-stage, long-throw, automated biopsy systems.

CONCLUSION

Statistically significant differences with various biopsy devices are seen in the breast tissue yield and in fragmentation.

The adrenal gland: radiologic-pathologic correlation

The adrenal glands are affected by complex physiologic and neoplastic processes. Recently described computed tomography densitometry and chemical shift MR imaging techniques are useful to distinguish between benign and malignant masses. Knowledge of the basic gross pathologic and histologic correlates of adrenal disease helps in applying these new imaging methods and in understanding established cross-sectional studies.

MR imaging evaluation with a transrectal surface coil of local recurrence of prostatic cancer in men who have undergone radical prostatectomy

OBJECTIVE

The objective of this study was to evaluate the ability of transrectal surface coil MR imaging to reveal local recurrence of malignancy in men who have had radical prostatectomy for prostatic adenocarcinoma.

SUBJECTS AND METHODS

We performed prospective analysis of 41 men who had undergone radical prostatectomy (range of time since surgery, 8 months to 5 years; mean, 26 months), 35 of whom had clinical suspicion of recurrent prostatic cancer and the remaining six of whom had no clinical evidence of recurrent prostatic cancer (controls). Our imaging used a transrectal surface coil on a 1.5-T MR scanner. Sagittal and axial fat-saturated T2-weighted fast spin-echo as well as axial T1-weighted unenhanced and gadolinium-enhanced MR images of the prostatic bed were acquired in all patients. Thirty-one of the 35 men with clinical suspicion of recurrent prostatic cancer had elevated prostate-specific antigen (PSA) levels (> or = 0.4 ng/ml), and 22 of these 31 men had a palpable prostatic bed module or induration. The four of 35 men with clinical suspicion of recurrent prostatic cancer who had PSA levels less than 0.4 ng/ml had a palpable prostatic bed nodule or induration. Transrectal biopsy of the prostatic bed was directed by digital palpation or transrectal sonography in all 35 men with clinical suspicion of recurrent malignancy.

RESULTS

Thirty-one of the 35 men who had clinical suspicion of local recurrence of prostatic cancer had a soft-tissue nodule revealed in the prostatic bed by transrectal surface coil MR imaging. Compared with the adjacent muscle, all nodules were isointense on the T1-weighted images, hyperintense on the T2-weighted images, and enhanced with gadolinium administration. The 22 patients who had an abnormal MR scan and a palpable nodule or induration and the nine patients with elevated PSA levels, no palpable abnormality, and an abnormality revealed by MR imaging underwent transrectal biopsy; all had recurrent prostatic cancer proven by histology in the four patients with a palpable prostatic bed nodule or induration and normal PSA levels, MR imaging showed no distinct soft-tissue nodule or area of enhancement in the prostatic bed; transrectal biopsy of the palpable nodule or induration yielded fibrosis but no malignancy in all four patients. In the six control patients with no clinical evidence of local recurrence, MR imaging revealed no evidence of recurrent malignancy; all six control patients continue to have no clinical evidence of recurrent prostatic cancer with a minimum follow-up of 22 months. Thus, the sensitivity of MR imaging in revealing local recurrence of prostatic cancer was 100% (95% confidence interval = 89-100%), and the specificity also was 100% (95% confidence interval = 69-100%). The kappa coefficient was 1.0 (p < .001).

CONCLUSION

MR imaging with a transrectal surface coil is a useful imaging tool to evaluate men who have undergone radical prostatectomy and are suspected of having local recurrence of malignancy in the prostatic bed.

Quality assurance for abdominal CT: a rapid, computer-assisted technique

OBJECTIVE

Maintaining high standards in a large CT imaging department with multiple scanners, a large technical and clerical staff, and a rotating staff of radiologists is an ongoing challenge. We undertook a project to design and implement a simple, rapidly performed computer-assisted system of quality assurance (QA) for use in abdominal CT. In our project, we also analyzed the results of that QA system.

MATERIALS AND METHODS

We graded 1810 abdominal CT studies done in a 50-week period, using a three-point scale to indicate the quality of the following five parameters of technical quality: IV contrast enhancement, oral contrast opacification, window settings and artifacts, conformity to radiologists' protocol, and completeness and accuracy of header and scout data. In addition, a parameter reflecting performance of the film library and clerical staff was similarly graded. To provide a measure of peer review for radiologists, any disagreements with prior CT study reports were recorded when comparison studies were reviewed in the process of CT interpretation. A commercially available spreadsheet and database software program was tailored to allow rapid, easily performed data entry and analysis. Tables and graphs showing performance of technologists and film library and clerical staff were generated. This customized program was made available on the radiology department computer network. Results generated by the program were further analyzed with linear regression models.

RESULTS

Our QA system was successfully integrated into the routine operation of the abdominal CT division. During the first 11.5 months of operation, the system reflected improvement in each of the technical parameters with a statistically significant improvement in the combined average technical score (from 1.15 to 1.68 on a scale of 0-2; p < .0001). The "Throughout Speed/Old Exams" parameter for performance of the film library and clerical staff, which was analyzed separately from the technical parameters, also improved significantly (from 1.3 to 1.8; p < .02). Improvements were statistically significant, even when we controlled for potential variations in quality among different CT scanners and variations among the radiologists who rated the quality of the examination. Thirty-eight disagreements with previous scan interpretations (5% of all scan comparisons) were recorded for evaluation at peer review conferences.

CONCLUSION

The ability to monitor performance continuously using a rapid, computer-assisted system has effected measurable improvement in our CT service. Technologist and film library and clerical staff performance improved for all parameters studied. Deficiencies were revealed and trends demonstrated. The QA system allowed us to identify disagreements in interpretation of CT examinations for subsequent peer review by radiologists. Our QA software program has been made available on the Internet as freeware to licensed Excel users via anonymous file transfer protocol at Internet Protocol 134.192.6.110.

Nonbiliary laparoscopic gastrointestinal surgery: role of CT in diagnosis and management of complication

OBJECTIVE

Laparoscopic techniques are evolving for a wide range of surgical procedures outside the biliary tree. We describe the CT findings of important complications detected after nonbiliary laparoscopic gastrointestinal surgery and the role of CT in their management.

MATERIALS AND METHODS

Over a 3-year period, 209 patients had nonbiliary gastrointestinal laparoscopic procedures (partial or total colectomy, splenectomy, Nissen fundoplication, lymph-node dissection, herniorrhaphy, appendectomy, and exploratory laparoscopy). Thirty-seven abdominopelvic CT studies were performed on 18 (9%) of these patients for complications after surgery. In all cases CT findings were reviewed and correlated with follow-up surgical, clinical, or interventional radiologic findings.

RESULTS

Fourteen major complications were detected on CT in 12 of 18 (67%) patients who had undergone partial or total colectomy (6/25, 24%), splenectomy (4/41, 10%), appendectomy (1/15, 7%), or lymph-node dissection (1/43, 2%). These complications included seven abscesses (three of the splenic bed, two of the pelvis, one of the liver, and one of the abdominal wall). The remaining complications were four hematomas (two in the abdominal wall caused by trocar site bleeding, one intraperitoneal, and one retroperitoneal), one case of colon perforation, one case of pancreatitis, and one case of splenic infarction. Percutaneous abscess drainage was performed successfully in seven patients, using CT guidance in six. Six patients had negative CT studies.

CONCLUSION

Major complications may occur after complex nonbiliary laparoscopic procedures and are probably related to lack of experience with new surgical techniques. In this study, such complications occurred most often after laparoscopic colectomy and splenectomy. CT valuable in their diagnosis and in the management of abscess collections.

Large-core biopsy guns: comparison for yield of breast tissue

PURPOSE

To compare seven large-core, long-throw, 14-gauge biopsy guns for yield and quality of breast tissue obtained.

MATERIALS AND METHODS

A two-phase, randomized and blinded study was performed. In the first phase, four fully automated 14-gauge biopsy guns (BIP, Manan, Biopsy, and ASAP) and one semiautomated device (Temno) were used to obtain breast cores from a cadaver. Samples were assessed for volume, number of fragments, and crush artifact. In the second phase, seven biopsy guns (previously mentioned guns plus Monopty and Ultra-Cut guns) were used to obtain cores from a breast parenchyma model. These cores were then evaluated for weight, volume, and number of fragments.

RESULTS

The mean specimen volume of cadaveric breast tissue obtained was 17.9 mm3 for the BIP gun, 17.8 for the Manan gun, 14.9 for the Biopsy gun, 14.1 for the ASAP gun, and 9.9 for the Temno gun. The Temno gun obtained statistically significantly smaller volumes than all other guns. For the breast parenchyma model, mean obtained volumes were 24.5, 24.1, 16.2, 21.7, 17.5, 20.0, and 15.2 mm3, respectively. The BIP and Manan guns yielded statistically significantly larger cores than all other guns except the ASAP.

CONCLUSION

Yields of breast tissue provided by each biopsy device differed statistically significantly. BIP and Manan biopsy guns yielded the greatest volume of core tissue, which may facilitate histopathologic diagnosis from breast biopsies performed with imaging guidance.

Sonographic evaluation of acute pancreatic transplant rejection: morphology-Doppler analysis versus guided percutaneous biopsy

OBJECTIVE

Despite the increasing success of pancreatic transplantation for diabetes, rejection remains the most common cause of graft loss. The purpose of this study was to correlate gray-scale sonographic morphology and Doppler resistive index (RI) with acute pancreatic transplant rejection as determined by percutaneous, sonographically guided biopsy of the pancreas.

SUBJECTS AND METHODS

Fifty-one sonograms of 36 patients were correlated with sonographically guided biopsies performed for clinically suspected acute rejection. Sonographic studies consisted of gray-scale morphologic assessment of gland size, texture, marginal definition, peripancreatic fluid, and duct dilatation as well as measurement of the average Doppler RI. Biopsies were performed within 48 hr of sonography. After localization by sonography, we performed percutaneous biopsy with an 18-gauge automated biopsy device.

RESULTS

Biopsy findings were acute rejection (n = 40, 78%), chronic rejection (n = 2, 4%), and no evidence of rejection (n = 9, 18%). Procedure-related hemorrhage occurred in one patient and resolved spontaneously. Gray-scale sonographic abnormalities were present in 37 studies (73%). The most common abnormality was pancreatic enlargement (n = 23) with a sensitivity and specificity of 58% and 100%, respectively, for acute rejection. Loss of marginal definition occurred in nine studies with a sensitivity and specificity of 15% and 73%, respectively, for acute rejection. An RI > or = 0.7 was found in 11 studies (22%) with a sensitivity of 20% and a specificity of 73% for acute rejection.

CONCLUSION

For the diagnosis of acute pancreatic rejection, sonographically guided percutaneous biopsy is superior to gray-scale and spectral Doppler sonography. Sonographically guided percutaneous biopsy is a safe technique with a high success rate. Gray-scale and spectral Doppler sonography lack sensitivity, and a normal RI should not delay biopsy.

Surgical transfer of the sartorius muscle to the groin after lymphadenectomy or debridement: CT findings

OBJECTIVE

We describe the CT findings of medial transfer of a sartorius muscle flap, which is done to protect the femoral blood vessels after radical inguinal lymphadenectomy for cancer or surgical debridement of infected femoral vascular grafts.

MATERIALS AND METHODS

We reviewed the appearances and initial interpretations of 33 CT studies in 17 patients who underwent medial sartorius flap transfer after either (1) inguinal lymphadenectomy for melanoma or penile cancer or (2) debridement of infected groin wounds complicating vascular reconstruction of the femoral arteries. Muscle flap transfer was defined by the surgical record as either complete or incomplete. In complete sartorius muscle transfer, the proximal end of the muscle is dissected from the anterior superior iliac spine, rotated along its long axis, and sutured medially to the inguinal ligament. In incomplete transfer, the muscle it mobilized and stretched medially, and its medial border is fixed to the inguinal ligament and deep tissues. Clinical correlation and follow-up examinations were done for all patients, and CT reevaluation at intervals was done in nine patients.

RESULTS

Complete sartorius flap transfer resulted in a mass anterolateral or anterior to the femoral vessels on postoperative CT scans in 20 studies; five of these masses were misinterpreted initially as possible recurrent metastatic lymphadenopathy, infection, or hematoma. Incomplete sartorius flap transfer resulted in bandlike stretching of the muscle over the femoral vessels in 13 studies.

CONCLUSION

Medial transfer of the sartorius muscle causes a variable appearance of the groin on CT scans. The findings on CT scans after complete sartorius flap transfer should be distinguished from recurrent lymphadenopathy and from postoperative phlegmon or hematoma.

Vascular complications of pancreatic transplantation: MR evaluation

PURPOSE

To determine the value of magnetic resonance (MR) angiography and MR imaging with dynamic gadopentetate dimeglumine-enhanced gradient-echo (Gd-GRE) sequences in detection of vascular complications of pancreatic transplantation.

MATERIALS AND METHODS

Three radiologists evaluated findings of 32 MR examinations in 20 adult patients who underwent pancreatic transplantation. The images were obtained with a surface coil and T1-weighted and T2-weighted fast spin-echo sequences, Gd-GRE sequences, and MR angiography. Vascular abnormality was confirmed at surgery or biopsy, and vascular patency with clinical correlation.

RESULTS

Absence of flow was found in six of 32 studies (19%): acute vascular thrombosis of the vascular pedicle and/or branch vessels in four studies (three patients) and chronic pancreatic rejection in two studies (one patient). Gd-GRE images helped identify infarction in two patients. The sensitivity of MR angiography for detection of acute vascular compromise was 100%, and the specificity was 93%.

CONCLUSION

MR angiography and MR imaging with Gd-GRE sequences allow detection of vascular complications of pancreatic transplantation.

Emphysematous gastritis in an immunocompromised host

Emphysematous gastritis is a rare, often lethal condition of gastric mural inflammation and gaseous dissection. Infection with gas-forming organisms is the most frequently cited cause. In all previously reported patients, the clinical presentation was dramatic. We report on an immunocompromised host who had a surprisingly subtle clinical presentation.

Complications after laparoscopic pelvic lymphadenectomy: CT diagnosis

OBJECTIVE

Laparoscopic dissection of pelvic lymph nodes has become an accepted alternative to open lymphadenectomy for staging of genitourinary tumors. This study reviews the CT findings in patients with major complications detected after laparoscopic dissection.

MATERIALS AND METHODS

Of 85 patients who had laparoscopic dissection of pelvic lymph nodes at our institutions during a 3-year period, complications developed in 12 patients (14%), and eight of these had abdominopelvic CT studies done. CT findings and initial interpretations were correlated with follow-up surgical, clinical, or interventional radiologic findings in all cases.

RESULTS

Complications of laparoscopic dissection detected with CT included small-bowel obstruction due to herniation through the trocar site in the abdominal wall (n = 2), extensive hematoma of the abdominal wall or retroperitoneum (n = 2), urinary ascites or multiple urinomas due to ureteral laceration or transection (n = 2), and lymphocele compressing the bladder where the peritoneum was sealed after lymphadenectomy (n = 1). In one case, CT showed pneumoperitoneum but failed to show a perforation of the sigmoid colon.

CONCLUSION

Major complications occurred after laparoscopic dissection of pelvic lymph nodes and were diagnosed on the basis of CT findings in seven of eight patients. Recognition of the CT appearances of hernia or hematoma at the insertion sites of the trocars or the laparoscope is important, as is detection of injury to bladder, ureter, bowel, or blood vessels. Symptomatic lymphoceles were infrequently detected, probably because of the use of free drainage into the peritoneal cavity after laparoscopic dissection.

Fine-needle biopsy: prospective comparison of aspiration versus nonaspiration techniques in the abdomen

A prospective study was designed to compare the aspiration (suction method) and nonaspiration (nonsuction method) techniques of fine-needle biopsy (FNB) in 50 consecutive patients with abdominal pathologic conditions. Sites of biopsy included liver (n = 24), retroperitoneum (n = 9), adrenal gland (n = 5), pancreas (n = 4), omentum (n = 4), and miscellaneous sites (n = 4). Aspiration and nonaspiration FNBs were performed in each lesion with 22-gauge needles, and results were interpreted by a single cytopathologist. Cytologic specimens obtained with each technique were analyzed for diagnostic accuracy, total number of cell clusters per biopsy (graded 0-10, 10-20, 20-30, and > 30), presence of crush artifact, and amount of blood present (graded from 0 to +3). No significant differences were seen between the aspiration and nonaspiration techniques with regard to number of cell clusters per biopsy (44 of 50 specimens vs 42 of 50) (P < .0003), amount of blood present (grade 2.3 vs 2.2) (P < .0003), and amount of crush artifact. The positive predictive value for the aspiration technique was 91.5% versus 74% for the nonaspiration technique. The aspiration technique of FNB appears superior to the nonaspiration technique in the abdomen.

Palliation of malignant bile duct obstruction with metallic biliary endoprostheses: technique, results, and complications

Expandable metallic stents were placed in 34 patients with pathologically proved malignant bile duct obstruction to determine ease of insertion, benefits of a one-stage insertion, and cost-effectiveness relative to conventional plastic stents. Thirty-eight strictures, ranging in length from 1 to 7 cm (mean, 3.2 cm), were present in the 34 patients. Strictures were located in the lower common bile duct (n = 22), middle of the common bile duct (n = 6), and hilar confluence (n = 10). In 13 patients (38%) metallic stents were placed at the time of initial biliary drainage (one-stage procedure), while the remaining patients underwent stent placement within 1-7 days of biliary drainage (two-stage procedure). Biliary obstruction was relieved in 31 of 34 patients (91%). Three patients died within 14 days of stent insertion of unrelated causes, without any change in biliary status. Mean duration of follow-up for all patients was 5.3 months (range, 0.5-14 months). Four episodes of stent occlusion occurred in three patients (12% occlusion rate); each episode was treated successfully. The average length of hospital stay for patients who underwent a one-stage procedure was 13 days (range, 3-33 days) and was 20 days (range, 9-42 days) for patients who underwent a two-stage procedure. The facility of one-step insertion, low occlusion rate, and the many strategies available for treatment of occluded stents make metallic stents an attractive alternative to conventional plastic stents in palliating patients with malignant biliary obstruction.

Colonic perforation: complication of automatic implantable cardioverter defibrillator placement

Massive pneumoperitoneum developed 3 days after placement of an automatic implantable cardioverter defibrillator in a 75-year-old man. A subsequent computed tomographic examination revealed generator wires passing through the subxiphoid colon. Partial colectomy was performed, the generator was removed, and the wires were moved. The postoperative course was uneventful.