Gadoteridol-enhanced MR imaging of malignant hepatic tumors: effects of triple versus standard doses on lesion-liver contrast

OBJECTIVE

The purpose of this study was to compare liver signal-to-noise ratio (SNR), lesion SNR, and lesion-liver contrast-to-noise-ratio (CNR) in patients with malignant liver lesions after the administration of a standard dose (0.1 mmol/kg of body weight) or a triple dose (0.3 mmol/kg) of a gadolinium chelate (gadoteridol). We hypothesized that the higher dose would produce a higher lesion-liver CNR and therefore increase the conspicuity of hepatic lesions.

MATERIALS AND METHODS

A total of 85 patients with malignant hepatic masses (61 metastases, 22 hepatocellular carcinomas, and two lymphomas) proved by histologic or follow-up studies underwent MR imaging at 1.5 T. T1-weighted spin-echo imaging and gradient-echo imaging were done before and within 1 min after (gradient echo) as well as 5 (spin echo) and 15 (spin echo) min after the injection of 0.1 or 0.3 mmol of gadoteridol per kg, randomized before the start of the study (39 patients received the standard dose, and 46 received the triple dose). The signal intensities of the liver and lesions and the SD of background noise were measured by use of regions of interest to calculate the SNR of the liver and malignant lesions and the lesion-liver CNR.

RESULTS

The lesion-liver CNR was increased significantly at 5 and 15 min after the administration of gadoteridol. No significant differences in the liver SNR, lesion SNR, and lesion-liver CNR (after 1 min: standard dose, -5 +/- 8, and triple dose, -4 +/- 14; after 5 min: standard dose, -1 +/- 5, and triple dose, 2 +/- 8; and after 15 min: standard dose, 1 +/- 5, and triple dose, 6 +/- 20) were found between the doses at all time points.

CONCLUSION

Triple-dose gadoteridol does not improve the lesion-liver contrast of malignant hepatic lesions over that provided by the standard dose and is not warranted for liver MR imaging.

Extended lymph node dissection (D2 resection) should now be performed routinely in the curative surgical treatment of gastric carcinoma

Gastric cancer has a dismal prognosis in the Western world. In contrast, in Japan where extended lymphadenectomy is the rule in curative gastric cancer surgery, the prognosis is much better. The arguments for and against the adoption of this procedure in the West are presented. This procedure is safe in the hands of experienced surgeons and by improving locoregional control, may improve survival. However, in the absence of controlled data supporting a survival advantage, the excess morbidity and mortality of this extended procedure in the West may not be justified.

Tuberculosis of the pancreas

Tuberculosis of the pancreas is extremely rare. We report a case which demonstrates the diagnostic confusion which may arise in this condition. A 55-year-old alcoholic caucasian man presented with loss of weight and obstructive jaundice. Ultrasonography, endoscopic retrograde cholangiopancreatography and computed tomography showed a mass lesion in the head of the pancreas, diagnosed as probably malignant. He underwent a Whipple's pancreatoduodencetomy and made a good recovery. Histological examination showed typical features of tuberculosis. In the absence of other foci of active disease chemotherapy was not given. He remains well 12 months after operation.

Abdominal mass in a patient with Crohn's disease

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"Research" and "science" in the first half of the chiropractic century

In the first 50 years of the chiropractic profession, a variety of unorthodox meanings for the terms "research," "science" and related words were in evidence. In harmony with popular conceptions of the day, science was constructed as a relatively static body of knowledge and was thought to reflect the will of God. Research was an ill-defined activity, and acquisition of new knowledge did not involve the experimental methodology that increasingly took hold in biology and medicine in the twentieth century. Chiropractors often viewed science and research as marketing strategies. Clinical data collection, when it occurred at all, was not described in sufficient detail to permit replication. Results were enthusiastically interpreted as indisputable proof of investigators' a priori assumptions about the effectiveness of chiropractic methods. A few in the profession recognized the general lack of understanding of the scientific method and sought reform from within. However, the colleges were unwilling to introduce coursework in research methods. At the end of World War II, the broad-scope national association of chiropractors in the United States established a nonprofit foundation for the purpose of raising funds for chiropractic research and education. Research plans were poorly conceived and grandiose: the first major initiative of the Chiropractic Research Foundation involved a nationwide publicity and fund-raising campaign modeled after the March of Dimes. When these efforts failed and the possibility of establishing free-standing research centers collapsed, the Foundation sought to shift responsibility for research to the schools. The poverty-stricken chiropractic colleges lacked the research sophistication for this task. Several more decades would pass before a sustained research effort and interest in clinical experimentation would become evident in chiropractic.

Two-layer repair of the transversalis fascia is sufficient for inguinal hernia repair

The Shouldice four-layer repair is considered to be the gold standard procedure for repair of inguinal hernia with low recurrence rates around 1%. Tension-free two-layer repair of the transversalis fascia may be all that is required to avoid recurrence. We compared the early recurrence rate after two-layer repair of the transversalis fascia or the standard four-layer Shouldice technique in a randomised study of elective inguinal herniorrhaphy. In 48 patients (53 repairs) who had a two-layer transversalis fascia repair, there was one recurrence (2%) in the first 12 months after operation, though there was one more recurrence within 36 months (total 4%). In 39 patients who had a four-layer Shouldice repair (42 repairs), there was no recurrence at 12 months but at 36 months two recurrences (5%) were found. We conclude that a two-layer repair of the transversalis fascia is anatomically correct, physiologically sound and can provide equivalent results to the standard Shouldice repair for inguinal hernia.

Abdominal manifestations of sarcoidosis in CT studies

OBJECTIVE

The purpose of this study is to demonstrate the spectrum of abdominal CT findings in patients with tissue proved sarcoidosis, estimate their prevalence, and correlate abdominal findings with stage of thoracic disease.

MATERIALS AND METHODS

Between 1987 and 1993, 140 patients with tissue proved sarcoidosis underwent abdominal or chest CT at our institution. After exclusions, 49 patients remained. Abdominal CT was retrospectively reviewed and the findings arrived at by consensus. Chest radiography within 1 month of CT was available for 46 patients. Chest radiography was retrospectively reviewed and stage of thoracic disease arrived at by consensus.

RESULTS

Splenic abnormalities consisted of splenomegaly, low density lesions, and punctate calcifications. Hepatic sarcoidosis manifested as hypovascular lesions, hepatomegaly, and punctate calcifications. Lymphatic abnormalities consisted of lymphadenopathy, most commonly between 1 and 2 cm, and an increased number of normal sized lymph nodes.

CONCLUSION

Sarcoidosis produces splenic abnormalities in 53% of patients, liver abnormalities in 16%, and lymphatic findings in 43%. No correlation was demonstrated between the abdominal findings and stage of thoracic sarcoidosis.

MR imaging of the abdomen with a phased-array multicoil: prospective clinical evaluation

PURPOSE

To prospectively compare use of a phased-array multicoil and a conventional body coil in abdominal MR imaging.

MATERIALS AND METHODS

Thirteen patients (seven men, six women; mean age, 55 years) underwent imaging with a phased-array multicoil and with a conventional body coil. Four pulse sequences were used: T2-weighted spin echo (SE), magnetization-prepared gradient-recalled echo (GRE), breath-hold fast SE, and echo planar (EP).

RESULTS

Lesion detection improved the most on fast SE, multicoil-acquired images. Signal-to-noise ratio (S/N) increased 64% with fast SE (P = .0005) and EP (P < .0109) sequences. Contrast-to-noise ratio (C/N) doubled (P < .05) with T2-weighted SE sequences. Lesion conspicuity improved on multicoil-acquired images with all fast sequences (magnetization-prepared GRE, P = .015; fast SE, P = .002; EP imaging, P = .013). There was little difference in respiratory and vascular artifact. Depiction of most abdominal structures improved (P < .01).

CONCLUSION

Use of the phased-array multicoil provides better MR images of the abdomen than does use of a conventional body coil.

Caenorhabditis elegans mutants resistant to inhibitors of acetylcholinesterase

We characterized 18 genes from Caenorhabditis elegans that, when mutated, confer recessive resistance to inhibitors of acetylcholinesterase. These include previously described genes as well as newly identified genes; they encode essential as well as nonessential functions. In the absence of acetylcholinesterase inhibitors, the different mutants display a wide range of behavioral deficits, from mild uncoordination to almost complete paralysis. Measurements of acetylcholine levels in these mutants suggest that some of the genes are involved in presynaptic functions.

Management of ductal carcinoma in situ of the breast

The advent of mammographic breast screening has increased the detection of ductal carcinoma in situ (DCIS), which now accounts for 15-20% of all breast cancer. While symptomatic DCIS has been treated satisfactorily by mastectomy, this may be an overtreatment of smaller screen-detected lesions. Although local excision, with or without radiotherapy, is associated with a significant risk of local recurrence of DCIS or invasive cancer, salvage surgery is usually successful. The long-term breast-specific mortality rate of treatment by mastectomy and local excision are similar. Whereas mastectomy is still appropriate for women with lesions > 30 mm in diameter or centrally placed and for those women who demand the best possible disease-free survival, local surgery should otherwise be considered.

Fibrolamellar hepatocellular carcinoma: stage at presentation and results of aggressive surgical management

OBJECTIVE

The purpose of this study was to report the stage of fibrolamellar carcinoma at presentation and the imaging findings of postoperative recurrent tumor in an aggressively managed population and to assess the implications of those findings relative to the patients' management.

MATERIALS AND METHODS

Imaging studies in 10 patients with pathologically proved fibrolamellar carcinoma were reviewed. Preoperative studies included CT (n = 10), sonography (n = 8), and MR imaging (n = 2). Postoperative studies included CT (n = 9), sonography (n = 4), and MR imaging (n = 1). Imaging findings were correlated with clinical and surgical follow-up data. Patients were followed up for 2-75 months (median, 26 months).

RESULTS

At presentation, seven (70%) of 10 patients had metastatic lymphadenopathy. Seven patients (70%), including four with lymph node metastasis, had tumor resections with intent to cure. Postoperative imaging studies revealed recurrent tumor in all seven of these patients, including six patients (86%) who had intrahepatic recurrence with or without lymph node metastasis after 6-18 months, and one patient (14%) who had distant metastases 66 months postoperatively. Recurrent lesions were subsequently resected in three (43%) of seven patients, who were disease-free at a mean of 8 months after their second resection. Five patients died after 9 months mean survival, and two patients were alive with residual tumor after 3 months mean follow-up.

CONCLUSION

Fibrolamellar carcinomas are often of advanced stage at diagnosis. Recurrence after resection with intent to cure is common. Early and frequent follow-up imaging is necessary for optimizing surgical management in patients with fibrolamellar carcinoma.

A large necrotic defect secondary to a cutaneous sinus tract of odontogenic origin: a case report

This article reviews the case of a patient with a periapical dental abscess that drained inferior and posterior to the angle of the jaw and created a large purulent cutaneous defect. Both the diagnosis and treatment issues are discussed.

Upper abdominal phase-contrast MR angiography: comparison of cine and non-cine techniques

PURPOSE

To evaluate image quality, vessel conspicuity, and signal-to-noise ratio (S/N) of four two-dimensional magnetic resonance (MR) phase-contrast techniques: cine phase-contrast with respiratory compensation (CPC-R), cine phase-contrast without respiratory compensation (CPC), phase-contrast with two signals acquired (PC-2), and phase-contrast with eight signals acquired (PC-8).

MATERIALS AND METHODS

MR angiographic images of the portal vein were obtained in 14 patients.

RESULTS

Overall image quality was rated excellent in 10 of 14 patients (CPC-R), in one of 14 patients (CPC), in none of 14 patients (PC-2), and in one of 14 patients (PC-8). Views of 10 upper abdominal vessels were evaluated with each technique. The mean (+/- standard deviation) number of well-imaged vessels was 6 +/- 2 (CPC-R), 3 +/- 2 (CPC), 2 +/- 2 (PC-2), and 3 +/- 2 (PC-8). CPC-R images were significantly better in overall image quality and number of vessels seen (P < .01). Mean S/Ns were 10.8 +/- 3.4 (CPC-R), 6.8 +/- 2.7 (CPC), 4.5 +/- 1.7 (PC-2), and 6.4 +/- 2.1 (PC-8). S/N with CPC-R was significantly greater than with CPC, PC-2, or PC-8.

CONCLUSION

CPC-R provided consistently higher quality angiographic images than were obtained with the other sequences studied.

Distinction between cavernous hemangiomas of the liver and hepatic metastases on CT: value of contrast enhancement patterns

OBJECTIVE

Differentiating between cavernous hemangiomas of the liver and hepatic metastases on the basis of single-pass, contrast-enhanced CT is a significant and frequently encountered diagnostic challenge. Recognition of characteristic enhancement features of cavernous hemangiomas can aid in effectively distinguishing between these lesions. The purpose of this study was to determine sensitivity and specificity of dense, globular enhancement for differentiating cavernos hemangiomas and metastases during single-pass, contrast-enhanced CT.

MATERIALS AND METHODS

CT appearance of 133 lesions in 91 patients with cavernous hemangiomas (44 patients) or metastases (47 patients) was retrospectively evaluated in a blinded review. CT examinations were performed with nonhelical technique following injection of 150 ml of contrast material. All patients with metastases had pathologic proof (n = 47). Patients with cavernous hemangiomas were clinically stable for at least 2 years after CT (n = 43) or had tissue proof (n = 1). All lesions were evaluated based on the following criteria: (1) Type of enhancement: globular, linear, diffuse and homogeneous, or diffuse and heterogeneous. (Globular enhancement was considered to be present when enhancing nodules less than 1 cm in diameter were seen within lesions.) (2) Continuity of enhancing tissue: continuous or noncontinuous. (Uninterrupted collections of contrast material within at least 50% of a lesion were considered continuous. Multiple, separate collections of contrast material were considered noncontinuous.) (3) Degree of enhancement: hypo-, iso-, or hyperdense relative to the aorta. (4) Distribution of enhancement: peripheral, central, or mixed.

RESULTS

Seventy-six percent of cavernous hemangiomas had globular enhancement, compared to 10% of metastases (p < .001). Seventy-two percent of cavernous hemangiomas had enhancement isodense with the aorta, and 96% of metastases were hypodense (p < .001). Sixty-seven percent of cavernous hemangiomas had peripheral enhancement, compared to 38% of metastases (p < .001). The combined finding of globular, isodense enhancement was seen in 67% of cavernous hemangiomas and none of the metastases. Only 10% of cavernous hemangiomas had nonglobular, hypodense enhancement, compared with 90% of metastases. Combining all criteria, reviewers correctly classified 122 (92%) of the lesions. Presence of globular enhancement, isodense with the aorta, was 67% sensitive and 100% specific in differentiating cavernous hemangiomas from hepatic metastases.

CONCLUSION

In most cases, differentiation of cavernous hemangiomas from hepatic metastases can confidently be made with single-pass, contrast-enhanced CT. Globular enhancement, isodense with the aorta, is 67% sensitive and 100% specific in differentiating cavernous hemangiomas and hepatic metastases.

MR measurements of mesenteric venous flow: prospective evaluation in healthy volunteers and patients with suspected chronic mesenteric ischemia

PURPOSE

To quantify portal vein (PV) and superior mesenteric vein (SMV) flow before and after a standardized meal in healthy volunteers and to prospectively evaluate patients with a clinical suspicion of chronic mesenteric ischemia on the basis of magnetic resonance (MR) measurement of flow in the mesenteric venous system in volunteers.

MATERIALS AND METHODS

Cine phase-contrast flow measurements were acquired in 10 asymptomatic volunteers and in 10 patients.

RESULTS

In volunteers, the difference between the fasting and post-prandial flows in the SMV and PV was significant (P < .001), with a peak flow augmentation of 245% +/- 74 and 70% +/- 29, respectively. Postprandial augmentation of peak flow in the SMV was significantly less in patients with mesenteric ischemia compared with volunteers (64% +/- 28; P = .02). SMV flow augmentation in patients without mesenteric ischemia did not differ significantly from that in volunteers (206% +/- 36; P = .31).

CONCLUSION

Measurement of postprandial flow augmentation in the SMV with MR imaging shows promise as a noninvasive screening test for chronic mesenteric ischemia.

Controversial issues in the management of pancreatic cancer: Part one. A debate held at St Mary's Hospital, London on 18 November 1993

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Pancreatic enzyme supplementation in acute pancreatitis

This study evaluates the effect of oral pancreatic enzyme supplements on pain, analgesic requirement and the incidence of complications in patients with acute pancreatitis. This double blind, prospectively randomised placebo controlled study included 23 patients. Pain was monitored using a visual analogue scale; the analgesic requirement was assessed with a numerical score. No significant differences were noted between the median (range) pain scores of patients who received placebo: 22 (17.1-58) and those who received enzymes: 23 (11.3-63). Hospital stay was 7 (5-10) days in patients on placebo and 8 (6-24) days in the enzyme group (p = 0.069). Analgesic requirements were: placebo 20 (6-60) and enzymes: 16 (0-63) (p = 0.56). This study has shown no beneficial effect of oral pancreatic enzyme supplements in the initial management of patients with acute pancreatitis.

Palliative resection of pancreatic adenocarcinoma. A survey of British surgeons

A survey was carried out by postal questionnaire of the attitudes of British surgeons to pancreatic resection as palliation for ductal adenocarcinoma of the pancreas. Replies from 24 surgeons related to experience in over 700 resections. The incidence of estimated residual local disease after resection was median 12.5 percent, range 0-35 percent. Half (12) of the surgeons felt that pancreatic resection with residual macroscopic disease was justified. Only 3 (12.5 percent) surgeons accepted that palliative resection in the presence of liver metastases was sometimes justifiable. Further evidence is required of improved quality of life after resection before the majority of surgeons will accept palliative resection in the management of pancreatic ductal adenocarcinoma.