Comparison of radiation dose and image quality from single-energy and dual-energy CT examinations in the same patients screened for hepatocellular carcinoma.

AIM: To compare radiation dose surrogates [volume CT dose index (CTDIvol), dose-length product (DLP), size-specific dose estimate (SSDE), and effective dose] and image noise in a cohort of patients undergoing hepatocellular carcinoma screening who underwent both single-energy CT (SECT) and dual-energy CT (DECT). MATERIALS AND METHODS: In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study, 74 adults (mean age 59.5 years) underwent 64 section SECT (120 kVp and weight-based reference mAs) and 128 section dual-source DECT (100/Sn 140 kVp and CTDIvol, adjusted to match the CDTIvol of the SECT protocol) on different occasions. Noise levels were measured in the liver, inferior vena cava (IVC), retroperitoneal (RP) fat, and aorta. Generalized linear models were constructed to compare dose and noise, adjusting for effective diameter. RESULTS: The total DLP (1371.11 mGy-cm, SD = 527.91) and effective dose (20.57 mSv, SD = 7.92) with SECT were significantly higher than the DLP (864.84 mGy-cm, SD = 322.10) and effective dose (12.97 mSv, SD = 4.83) with DECT (p < 0.001). The differences between SECT and DECT increased as the patient's effective diameter increased (p < 0.001). Noise levels in the liver (22.4 versus 21.9 HU), IVC (22.3 versus 23.4 HU), and RP fat (23.5 versus 23 HU) were similar for DECT and SECT (p > 0.05) but were significantly lower in the aorta for DECT (25.3 versus 26.4 HU; p = 0.006). CONCLUSION: DECT imaging of the abdomen can achieve noise levels comparable to those seen with SECT imaging without a dose penalty to patients.

Prospective evaluation of fine needle aspiration of small, solid renal masses: accuracy and morbidity.

OBJECTIVES: To determine the accuracy and clinical utility of fine needle aspiration (FNA) of small, solid renal masses. METHODS: A total of 25 patients with small (less than 5.0 cm), solid, clinically localized renal masses were prospectively identified and evaluated with computed tomography guided FNA with analysis for presence of malignant cells and determination of nuclear grade. The final pathologic findings were used for comparison in each case. All patients had renal cell carcinoma and were managed with radical or partial nephrectomy; 3 had low-grade lesions (Fuhrman's grade 1/4), 2 had high-grade lesions (Fuhrman's grade 4/4), and all other patients had intermediate-grade lesions (Fuhrman's grade 2/4 or 3/4) on final histopathologic assessment. RESULTS: Overall, 10 aspirations yielded diagnostic malignant cells, and 9 were read as rare as rare atypical cells suspicious for malignancy. The remainder were negative (n = 6). Correlation with final nuclear grade was observed in eight instances and discordance in two instances. Subcapsular hematomas were observed at the time of surgery in 10 patients, but in no instance was the operation adversely affected. CONCLUSIONS: The diagnostic yield of FNA of small, solid renal masses appears to be too low to justify the potential morbidity of the procedure.

Helical CT and CT angiography for the identification of crossing vessels at the ureteropelvic junction.

In comparison with pyeloplasty, endourologic procedures for the treatment of ureteropelvic junction obstruction offer good success rates with less morbidity and a shorter hospitalization; however, studies have found lower success rates and increased complications in patients with crossing vessels. Conventional diagnostic angiography and intravenous urography have both been used to identify crossing vessels at the UPJ; but, a reliable, less invasive, less costly, and simpler preoperative procedure to identify crossing vessels is needed. Helical CT with CT angiography is a promising noninvasive technique for the identification of crossing vessels at the ureteropelvic junction, which can be used for surgical planning of endourologic treatment of UPJ obstruction.

Contemporary diagnosis of retrocaval ureter.

PURPOSE: We describe a noninvasive radiologic evaluation of a retrocaval ureter using currently available technology. MATERIALS AND METHODS: Three-dimensional volume-rendered CT and diuretic renography were performed for evaluation of a possible retrocaval ureter. RESULTS: The 3D CT scan definitively diagnosed the retrocaval ureter, while diuretic renography showed no evidence of clinically significant obstruction. No invasive procedures were required. CONCLUSION: A 3D volume-rendered CT scan in the excretory phase combined with diuretic renography is the radiologic evaluation of choice for patients with a suspected retrocaval ureter, as it is noninvasive yet highly accurate in its anatomic delineation.

Donor kidney volume and outcomes following live donor kidney transplantation.

Pre-donation kidney volume and function may be crucial factors in determining graft outcomes in kidney transplant recipients. We measured living donor kidney volumes by 3D helical computed tomography scanning and glomerular filtration rate (GFR) by (125)I-iothalamate clearances in 119 donors, and correlated these values with graft function and incidence of acute rejection at 2 years post-transplantation. Kidney volume strongly correlated with GFR (Pearson r= 0.71, p < 0.001). Body size and male gender were independent correlates of larger kidney volumes, and body size and age were predictors of kidney function. The effects of transplanted kidney volume on graft outcome were studied in 104 donor-recipient pairs. A transplanted kidney volume greater than 120 cc/1.73 m(2) was independently associated with better estimated GFR at 2 years post-transplant when compared to recipients of lower transplanted kidney volumes (64 +/- 19 vs. 48 +/- 14 mL/min/1.73 m(2), p < 0.001). Moreover, recipients of lower volumes had a higher incidence of acute cellular rejection (16% vs. 3.7%, p = 0.046). In conclusion, kidney volume strongly correlates with function in living kidney donors and is an independent determinant of post-transplant graft outcome. The findings suggest that (1) transplantation of larger kidneys confers an outcome advantage and (2) larger kidneys should be preferred when selecting from otherwise similar living donors.

Imaging guided biopsies of renal masses.

Percutaneous fine-needle aspiration biopsy can be used for the diagnosis of many abdominal masses. It is safe and accurate, and is often all that is necessary to determine treatment. Fine-needle aspiration biopsy is both accurate and cost-effective, comparing favorably with open surgical biopsy. The use of percutaneous biopsy for the diagnosis of renal masses is now more commonplace as urologists and radiologists become familiar with its indications, contraindications, accuracy and complications.

The current role of percutaneous biopsy in the evaluation of renal masses.

Percutaneous biopsy of intraabdominal masses is a safe and accurate means of obtaining a tissue diagnosis without surgical exploration. It is often sufficient to determine treatment plans and in many instances, obviates the need for surgery. Percutaneous biopsy of renal masses has traditionally had a limited role in the United States. However, with a recent increase in the detection of small renal masses because of the widespread use of abdominal computed tomography (CT), there is an increasing role for percutaneous biopsy in the management of renal masses. Percutaneous biopsy of renal masses is indicated to differentiate between a primary renal cell carcinoma and metastatic disease in patients with a known extrarenal primary. Percutaneous biopsy is also indicated to establish a diagnosis of renal lymphoma and abscess. Complications of percutaneous biopsy include bleeding, pneumothorax, and tumor seeding along the needle tract; fortunately, these complications are uncommon. We will review the indications, techniques, complications, sensitivity, and accuracy of CT and ultrasound-guided biopsy of renal masses. Urologists and radiologists should both be familiar with the indications and contraindications of percutaneous biopsy to insure the appropriate management of renal masses.

Cystic artery pseudoaneurysm as a complication of laparoscopic cholecystectomy.

A 39-year-old man presented with a subhepatic fluid collection 3 weeks after undergoing a laparoscopic cholecystectomy. This was mistakenly thought to represent an abscess, and a drainage catheter was placed at an outside institution. Upon transfer, the collection was diagnosed as a pseudoaneurysm by spiral computed tomography (CT) and angiography. This is the first report of a pseudoaneurysm complicating laparoscopic cholecystectomy.

Spiral CT of the abdomen: artifacts and potential pitfalls.

Spiral CT has been advocated as a major advancement in CT technology. Spiral CT scanning is rapid, the volume of IV contrast material can potentially be decreased, and high-quality coronal, sagittal, and three-dimensional reconstruction is possible. However, when compared with dynamic CT, because of the shorter acquisition time of spiral CT, vascular and organ enhancement on spiral CT scans is more dependent on factors that affect the delivery of contrast material into the bloodstream and on the time that scanning begins after the start of injection of contrast material. Additionally, organs other than the liver are scanned earlier than they typically are during a dynamic study, particularly the kidneys and spleen. In our experience to date, these aspects of spiral scanning have led to several difficulties in the interpretation of spiral CT scans. This essay illustrates potential pitfalls in the interpretation of spiral CT scans associated with scanning too soon after injection of contrast material.

Evaluation of renal masses detected by excretory urography: cost-effectiveness of sonography versus CT.

OBJECTIVE: The purpose of this study was to compare the cost-effectiveness of sonography and CT for the evaluation of renal masses discovered at excretory urography. MATERIALS AND METHODS: The records of 225 patients with a renal mass shown by urography who then had either sonography or CT within 3 months were reviewed retrospectively. The number, location, and size of lesions; initial and subsequent imaging tests; and final diagnoses were determined. Using the current Medicare reimbursements for sonography and CT, we calculated the economic implications of using sonography or CT as the initial examination. Any effect of the location or size of the lesion on the most cost-effective examination was also determined. RESULTS: Twenty-one percent of patients had both initial sonography and follow-up CT because of indeterminate findings or detection of a solid mass that required further staging. When CT was done first, CT findings were equivocal in 12%, necessitating follow-up sonography. At the prevailing charges, CT would have to be needed in 70% of patients initially imaged with sonography to justify the use of CT as the initial examination. The location and size of the lesion did not affect the need for CT at a rate (greater than 70%) that would economically justify use of CT as the first imaging test. Eighty-six percent of patients with a mass detected by urography had either a simple cyst or no evidence of a mass on sonography or CT. CONCLUSION: Sonography is the most cost-effective imaging method for the workup of a renal mass detected at urography. The number of sonographic examinations in which findings are indeterminate or positive (for a solid mass) is not sufficiently high to warrant replacement of sonography by CT, regardless of the size and location of the lesion. CT should be reserved for a limited number of specific indications.

Determination of spiral CT slice sensitivity profiles using a point response phantom.

OBJECTIVE: This study was done to compare the slice sensitivity profiles (SSP) for combinations of collimation, pitch, and table speed for spiral CT using a point response phantom. The goal was to determine the optimal combination of parameters to reduce partial volume averaging without compromising z-axis coverage. MATERIALS AND METHODS: A copper ball bearing measuring 0.4 mm was embedded in a closed-cell air-foam background to create a point response input phantom. The phantom was scanned at pitches from 0.1 to 2.0 for collimations of 5, 8, and 10 mm. The full width half maximums (FWHMs) and full width tenth maximums (FWTMs) were estimated from SSP curves generated by plotting the maximum pixel value in HU for each reconstructed image against table position. FWHMs and FWTMs were compared separately for constant collimation and increasing table speed and for constant table speed and decreasing collimation using either a two-tailed z-test or chi-square test. RESULTS: Differences between FWHMs and between FWTMs for comparisons made between different collimations at constant table speeds of 8 and 10 mm/s were significantly different (p < or = 0.0001). Differences between FWHMs and between FWTMs showed a linear trend, increasing with increasing pitch for constant collimation (p < or = 0.0013). CONCLUSION: Scanning at narrower collimation but higher pitch provides a narrower SSP when scanning at equivalent table speeds without compromising z-axis coverage.

Use of contrast material for spiral CT of the abdomen: comparison of hepatic enhancement and vascular attenuation for three different contrast media at two different delay times.

OBJECTIVE: The purpose of this study was to determine the relative effects of delay time, contrast agent concentration, and contrast agent volume on hepatic enhancement and on aortic and portal vein attenuation for contrast-enhanced spiral CT of the abdomen. The effect of delay time was evaluated by comparing two different delay times for each of three IV contrast media. Three different media were tested to identify whether the effects were different with different iodine concentrations and doses or with different volumes of contrast medium. SUBJECTS AND METHODS: A total of 169 patients who underwent contrast-enhanced CT of the abdomen with spiral CT imaging were evaluated for enhancement of the liver parenchyma and for postenhancement attenuation of the aorta and portal vein. Total iodine doses of 30 g as 100 ml of iohexol 300 or 125 ml of ioversol 240 and of 40 g as 125 ml of ioversol 320 were evaluated at delay times of 45 and 60 sec and with a low-flow monophasic injection at a rate of 2 ml/sec. RESULTS: For each contrast medium tested, a 60-sec delay provided greater hepatic enhancement than did a 45-sec delay (43 vs 32 H for iohexol 300, 37 vs 28 H for ioversol 240, and 50 vs 39 H for ioversol 320; all comparisons, p < or = .0001). The aortic attenuation achieved in the abdomen after contrast medium administration was significantly greater with a 45-sec delay than with a 60-sec delay for iohexol 300 (p = .0290) but not for the other contrast media. The portal vein attenuation achieved after contrast medium administration was significantly greater with a 60-sec delay than with a 45-sec delay for all three contrast media (p = .0051). CONCLUSION: When IV contrast material was injected with a low-flow-rate monophasic bolus, a delay time of 60 sec, longer than that typically used for dynamic incremental scanning, provided greater hepatic enhancement in spiral CT. This result was significant for the three contrast media tested. Aortic attenuation was significantly greater at shorter delay times when a smaller volume of contrast material was injected. Portal vein attenuation was greater at longer delay times, suggesting that the optimal delay time may be longer than 60 sec. Further work to determine the optimal scanning window for hepatic enhancement in spiral CT by use of time-density curves is indicated.

High-attenuation lymphadenopathy in AIDS patients: significance of findings at CT.

A retrospective evaluation was performed of the location and attenuation characteristics of abdominal and pelvic lymphadenopathy, identified at dynamic sequential bolus computed tomography (CT) in 69 patients with acquired immunodeficiency syndrome (AIDS). Lymph node appearance at CT was characterized as hyperattenuating, isoattenuating, or hypoattenuating relative to the iliopsoas muscle. The significance of finding hyperattenuating adenopathy in the patient population was evaluated. Thirty-three patients had hyperattenuating adenopathy, including 26 with the epidemic form of Kaposi sarcoma (KS). Of 38 patients with epidemic KS, 26 had hyperattenuating, 11 had isoattenuating, and one had hypoattenuating lymphadenopathy. The positive predictive value of hyperattenuating adenopathy for epidemic KS was 79%. These findings were statistically significant at the 95% confidence interval (P < .005). Hyperattenuating lymphadenopathy, identified on dynamic sequential bolus CT scans in AIDS patients, was seen with disseminated KS in approximately 80% of cases.

Pelvic computed tomography of breast carcinoma patients. Should it routinely be added to abdominal computed tomography?

BACKGROUND: This study was conducted to determine if pelvic computed tomography (CT) should routinely be appended to abdominal CT in the workup of patients with breast carcinoma. METHODS: The abdominal-pelvic CTs of 139 breast carcinoma patients (195 exams) were reviewed. Scans were grouped by indication and whether pelvic pathology was known before CT. Pelvic CT results were correlated with their effect on patient management. RESULTS: Among the 119 patients without pre-CT evidence of pelvic disease, a nonosseous pelvic metastasis was identified in only 1; this patient also had liver metastases and management was not changed. No unsuspected pelvic CT finding altered therapy for breast carcinoma. However, three patients underwent surgery for asymptomatic masses discovered on pelvic CT; all were benign. CONCLUSIONS: Pelvic CT is unlikely to affect the management of patients with breast carcinoma by detecting occult metastatic disease.

Preoperative use of 3D volume rendering to demonstrate renal tumors and renal anatomy.

With increased use of computed tomography (CT) and abdominal ultrasonography, the indications for nephron-sparing surgery are also increasing. Triphasic helical CT and three-dimensional (3D) volume rendering can be combined into a single noninvasive test to delineate renal tumors and normal and complex renal anatomy prior to nephron-sparing surgery. This combination technique has proved accurate and very useful for both preoperative and intraoperative planning by demonstrating renal position, tumor location and depth of tumor extension into the kidney, relationship of the tumor to the collecting system, and renal vascular anatomy. Knowledge of the position of the kidney relative to the lower rib cage, iliac crest, and spine helps in planning the initial surgical incision. By depicting tumor location and depth of extension, helical CT with 3D volume rendering helps ensure complete tumor excision and conservation of adjacent normal renal parenchyma. Depiction of the relationship of the tumor to the collecting system helps anticipate further tumor extension and minimize postoperative complications. Identification of normal renal vasculature and anatomic variants can help minimize ischemic injury and intraoperative bleeding. Radiologists should be familiar with current indications for nephron-sparing surgery and understand what information is required prior to surgery.

Prospective, blinded comparison of laparoscopic ultrasonography vs. contrast-enhanced computerized tomography for liver assessment in patients undergoing colorectal carcinoma surgery.

PURPOSE: To prospectively and blindly compare intraoperative laparoscopic ultrasonography to preoperative contrast-enhanced computerized tomography in detecting liver lesions in colorectal cancer patients. Additionally, we compared conventional (open) intraoperative ultrasonography with bimanual liver palpation to contrast-enhanced computerized tomography in a subset of patients. METHODS: From December 1995 to March 1998, 77 consecutive patients underwent curative (n = 63) or palliative (n = 14) resections for colorectal cancer. All patients undergoing curative resections were randomized to either laparoscopic (n = 34) or conventional (n = 29) surgery after informed consent. All patients underwent contrast-enhanced computerized tomography, diagnostic laparoscopy, and laparoscopic ultrasonography before resection. In those patients who had conventional procedures, intraoperative ultrasonography with bimanual liver palpation was also done. All laparoscopic ultrasonography and intraoperative ultrasonography evaluations were performed by one of two radiologists who were blinded to the CT results. All hepatic segments were scanned using a standardized method. The yield of each modality was calculated using the number of lesions identified by each imaging modality divided by the total number of lesions identified. RESULTS: In 43 of the 77 patients, both the laparoscopic ultrasonography and CT scan were negative for any liver lesions. In 34 patients, a total of 130 lesions were detected by laparoscopic ultrasonography, CT, or both. When compared with laparoscopic ultrasonography, intraoperative ultrasonography with bimanual liver palpation identified one additional metastatic lesion and no additional benign lesions. laparoscopic ultrasonography identified two patients with mets who had negative preoperative contrast-enhanced computerized tomography. CONCLUSIONS: Laparoscopic ultrasonography of the liver at the time of primary resection of colorectal cancer yields more lesions than preoperative contrast-enhanced computerized tomography and should be considered for routine use during laparoscopic oncologic colorectal surgery.

3-dimensional volume rendered computerized tomography for preoperative evaluation and intraoperative treatment of patients undergoing nephron sparing surgery.

PURPOSE: Computerized tomography (CT) is the diagnostic and staging modality of choice for renal neoplasms. Existing imaging modalities are limited by a 2-dimensional (D) format. Recent advances in computer technology now allow the production of high quality 3-D images from helical CT. Nephron sparing surgery requires a detailed understanding of renal anatomy. Preoperative evaluation must delineate the relationship of the tumor to adjacent normal structures and demonstrate the vascular supply to the tumor for the surgeon to conserve as much normal parenchyma as possible. We propose that helical CT combined with 3-D volume rendering provides all of the information required for preoperative evaluation and intraoperative management of nephron sparing surgery cases. We prospectively evaluated the role of 3-D volume rendering CT in 60 patients undergoing nephron sparing surgery for renal cell carcinoma at the Cleveland Clinic Foundation. MATERIALS AND METHODS: Triphasic spiral CT was performed preoperatively in 60 consecutive patients undergoing nephron sparing surgery for renal neoplasms. A 3 to 5-minute videotape was prepared using volume rendering software which demonstrated the position of the kidney, location and depth of extension of the tumor(s), renal artery(ies) and vein(s), and relationship of the tumor to the collecting system. These videotapes were viewed by a radiologist and urologist in the operating room at surgery, and immediately correlated with surgical findings. Corresponding renal arteriograms of 19 patients were retrospectively compared to 3-D volume rendering CT and operative findings. RESULTS: A total of 97 renal masses were identified in 60 cases evaluated with 3-D volume rendering CT before nephron sparing surgery. There were no complications related to the 3-D protocol and 3-D rendering was successful in all patients. The number and location of lesions identified by 3-D volume rendering CT were accurate in all cases, while enhancement and diagnostic characteristics were consistent with pathological findings in 95 of 97 tumors (98%). Of 77 renal arteries identified at surgery 74 were detected by 3-D volume rendering CT (96%). Helical CT missed 3 small accessory arteries, including 1 in a cross fused ectopic kidney. All major venous branches and anomalies were identified, including 3 circumaortic left renal veins. Of 69 renal veins identified at surgery 64 were detected by 3-D volume rendering CT (93%). All 5 renal veins missed by CT were small, short, duplicated right branches of the main renal vein. Renal fusion and malrotation anomalies were correctly identified in all 4 patients. CONCLUSIONS: The 3-D volume rendering CT accurately depicts the renal parenchymal and vascular anatomy in a format familiar to most surgeons. The data integrate essential information from angiography, venography, excretory urography and conventional 2-D CT into a single imaging modality, and can obviate the need for more invasive imaging. Additionally, the use of videotape in an intraoperative setting provides concise, accurate and immediate 3-D information to the surgeon, and it has become the preferred means of data display for these procedures at our center.

Power injection of intravenous contrast material through central venous catheters for CT: in vitro evaluation.

PURPOSE: To determine the feasibility of use of a power injector to deliver contrast material through central venous catheters for computed tomographic (CT) examinations. MATERIALS AND METHODS: Ioversol 240 and iothalamate meglumine 43% were separately injected through three 9.6-F Hickman catheters and three 10.0-F Leonard catheters with a power injector in an in vitro study. Flow rates of 1.0, 1.5, 2.0, and 2.5 mL/sec were tested. Peak pressures were mechanically recorded from two sites. A 95% prediction interval was calculated for each peak pressure, and the upper limits at the prediction interval were evaluated to determine if it was less than the recommended limit of 25 psi (175 kPa). RESULTS: Contrast medium, flow rate, and catheter type each statistically significantly affected the measured peak pressures (P = .0001). For each flow rate tested, the upper limits of the prediction interval for the peak pressure at the connection between the coiled tubing and the catheter were below the manufacturer's specified peak pressure. CONCLUSION: In vitro analysis demonstrates that power injection of intravenous contrast medium through central venous catheters does not exceed the pressure limits of these catheters at the flow rates tested. In vivo testing to evaluate the safety and efficacy of power injection through central venous catheters is necessary.

Triphasic helical CT of the kidneys: contribution of vascular phase scanning in patients before urologic surgery.

OBJECTIVE: The purpose of this study was to evaluate the potential benefits of performing vascular phase scanning of the kidneys in addition to unenhanced and parenchymal phase contrast-enhanced CT in patients being examined for urologic surgery. MATERIALS AND METHODS: Parenchymal and vascular phase images from triphasic renal helical CT of 50 patients were sequentially evaluated in a randomized, retrospective fashion by two independent observers. The number of renal arteries and veins and the presence of vein or collecting system anomalies were recorded for each scan phase along with a subjective 10-point-scale score of the visibility of the vasculature and collecting system. Correlation of these findings was made with surgical or angiographic findings in 67 of the 87 kidneys and was made by consensus review in the remaining 20 kidneys. RESULTS: Accessory renal arteries were seen significantly more often (p < .05, chi-square test) on the vascular phase scans. The subjective scores for the visibility of the renal arteries and renal veins were significantly higher on the vascular phase scans (p < .0001, Wilcoxon's rank sum test). The subjective scores for the visibility of the filling of the collecting system and renal pelvis were significantly higher for the parenchymal phase scans, despite the use of a small contrast bolus before each scan (p < .0001, Wilcoxon's rank sum test). CONCLUSION; Triphasic renal CT better reveals the artery and vein anatomy of the kidney than does parenchymal phase imaging only. Triphasic helical CT is indicated in patients undergoing planning for urologic surgery when vascular anatomy is clinically important.

Power injection of contrast media using central venous catheters: feasibility, safety, and efficacy.

OBJECTIVE: This study evaluates the feasibility, safety, and efficacy of power-injecting IV contrast media through central venous catheters for CT examinations. SUBJECTS AND METHODS: Two hundred ninety-five CT examinations were performed during an 18-month period in 225 patients with indwelling central venous catheters. Patients were randomized to power injection either through peripheral IV catheter or through central venous catheter. Feasibility was defined as the percentage of patients with contrast material injected successfully through the randomized access route. Safety was evaluated by comparing patients with complications. Efficacy was evaluated by comparing contrast enhancement of the thoracic aorta, pulmonary artery, abdominal aorta, and liver. RESULTS: Two hundred nine patients had randomization data recorded. One hundred three (94%) of 109 patients were successfully injected through their indwelling catheter compared with 42 (42%) of 100 through a peripherally placed IV catheter (p < 0.001). After reassignment for unsuccessful access, 174 patients underwent central venous catheter injection, and 51, peripheral IV catheter injection. No statistically significant difference was noted in the complications between the central venous catheter and peripheral IV catheter groups. Enhancement was greater in the thoracic aorta, pulmonary artery, and liver for the peripheral IV catheter group (p < 0.03). CONCLUSION: Power injection of contrast media through central venous catheters for CT examinations is feasible and safe when set hospital guidelines and injection protocols are followed. This technique provides an acceptable alternative in patients without adequate peripheral IV access when bolus contrast enhancement is desired.