Successful Endovascular Management of Pseudoaneurysm following Transarterial Chemoembolization: A Case Report.

Background and Objectives: Transarterial chemoembolization (TACE) is a widely accepted treatment for hepatocellular carcinoma (HCC). Regarding TACE, arterial injuries, such as hepatic artery spasm or dissection, can also occur, although pseudoaneurysms are rare. We report a case of pseudoaneurysm following TACE. Materials and Methods: A 78-year-old man had been undergoing TACE for HCC in segment 8 of the liver for the past 5 years, with the most recent TACE procedure performed approximately 1 month prior. He presented to the emergency department with melena that persisted for 5 days. Computed tomography revealed a pseudoaneurysm in the S8 hepatic artery with hemobilia. Results: the pseudoaneurysm was successfully treated by N-Butyl-cyanoacrylate glue embolization. Conclusions: In patients that have undergone TACE presenting with melena and hemobilia identified on CT, consideration of hepatic artery pseudoaneurysm is crucial. Such cases can be safely and effectively treated with endovascular managements.

Factors associated with increased risk of peritoneal seeding after radiofrequency ablation for hepatocellular carcinoma.

PURPOSE: To evaluate the incidence, risk factors, and prognosis associated with peritoneal seeding after percutaneous radiofrequency ablation (RFA) for HCC, focusing on viable tumors after previous locoregional treatment, including TACE and RFA. METHODS: Exactly 290 patients (mean age, 67.9 years ± 9.74; 223 men) with 383 HCCs (mean size, 15.9 mm ± 5.49) who underwent RFA between June 2012 and December 2019 were included in this retrospective study. Among them, 158 had history of previous treatment (mean number, 1.3 ± 1.8) with 109 viable HCCs. Cumulative seeding after RFA was estimated using the Kaplan-Meier method. Independent factors affecting seeding were investigated using multivariable Cox proportional hazards regression analysis. RESULTS: Median follow-up was 1175 days (range: 28-4116). Seeding incidence was 4.1 (12/290) and 4.7% (17/383) per patient and tumor, respectively. The median time interval between RFA and detection of seeding was 785 days (range: 81-1961). Independent risk factors for seeding included subcapsular tumor location (hazard ratio [HR] 4.2; 95% confidence interval [CI] 1.4, 13.0; p = 0.012) and RFA for viable HCC after previous locoregional treatment (HR 4.5; 95% CI 1.7, 12.3; p = 0.003). Subgroup analysis for viable tumors, revealed no significant difference in cumulative seeding rates between the TACE and RFA groups (p = 0.078). Cumulative overall survival rates differed significantly between patients with and without seeding metastases (p < 0.001). CONCLUSION: Peritoneal seeding after RFA is a rare, delayed complication. Subcapsular-located and viable HCC after previous locoregional treatment are potential risk factors for seeding. Seeding metastases could affect the prognosis of patients who cannot receive local therapy.

Efficacy of single-session 99.5% ethanol sclerotherapy for incidentally found simple renal cysts.

Simple renal cysts are the most common masses in the kidney. Most are asymptomatic and are incidentally detected on imaging examinations performed for other reasons. This study aimed to compare the results of 40 and 120 minutes ethanol sclerotherapies that were performed in a single session to treat incidentally found simple renal cysts. We retrospectively reviewed 63 renal cysts in 62 patients treated by single session percutaneous ethanol sclerotherapy. Thirty-one patients with 32 cysts underwent a 40 minutes sclerotherapy (group A), and 31 patients with 31 cysts underwent a 120 minutes retention technique (group B). Under ultrasonographic and fluoroscopic guidance, cystic fluid was completely aspirated, and 50% of the aspirated volume was replaced with 99.5% ethanol (a maximum of 100 mL). Imaging follow-up of the patients was performed 3 months after sclerotherapy. The technical success rates were 100% in both groups. Eighteen patients (29.0%) were symptomatic (flank pain or discomfort). Indications of the other patients were large cysts (>5 cm; 46%) and an increment in the diameter on serial studies (25.4%). A significant difference between the 2 groups in terms of age, cyst diameter, volume of aspirated fluid, volume of injected ethanol, and percentage of reduction in cyst diameter (P > .05) was not found. After treatment, flank pain or discomfort resolved in 17 of 18 (94.4%) symptomatic patients. One patient complained of persistent flank pain; however, no significant abnormality was detected on post-procedural computed tomography images. There were no other complications after therapy in the 2 groups. Single session ethanol sclerotherapy with a 40 minutes retention technique is an effective, safe, and cost-effective method for the treatment of incidentally found simple renal cysts. Although the procedural time was reduced, there was no significant difference in therapeutic efficacy between the 40 and 120 minutes therapies.

Radiologic placement of Hickman catheters using intravenous sedation in pediatric patients under 20 kg.

ABSTRACT: Surgeons generally perform Hickman catheter insertion in children under general anesthesia. At times, it is difficult to perform procedures with an anesthesiologist for an interventional radiologist. Several diagnostic and therapeutic procedures are efficiently and safely conducted using intravenous (IV) sedation in children with a pediatrician. This study aims to evaluate the efficacy and safety of radiologically placed Hickman catheters using IV sedation in children under 20 kg.Fifty-nine catheters were inserted in 45 children under IV sedation. With continuous monitoring of vital signs, IV midazolam and ketamine were slowly infused by a pediatrician. Mean age and body weights were 3.2 years and 15.2 kg, respectively. Acute leukemia was the most common disease for the procedure (72.9%). The location of the catheter tip was evaluated by measuring the height of the thoracic vertebra.Technical success rate was 100%, and IV sedation-related complications did not occur. The right internal jugular vein was accessed for 51 catheters (86.4%), and the mean procedure time was 21.5 minutes. The 2 vertebral body units below the carina were the cavoatrial junction on a fluoroscopy image. Mean catheter life was 285 days, and catheters were removed post-treatment (35.6%). During follow-up, complications occurred in 29 cases (1.72 per 1000 catheter-days). Catheter-related infections were suspected in 4 patients (6.8%), with 1 positive result.Radiological Hickman catheter placement in children under 20 kg using IV sedation by pediatricians is effective and safe, with minimal complications. The carina is a landmark to estimate the cavoatrial junction in pediatric patients.

Stent graft treatment of an ilioenteric fistula secondary to radiotherapy: a case report.

Fistulas between the arteries and the gastrointestinal tract are rare but can be fatal. We present a case of an ilioenteric fistula between the left external iliac artery and sigmoid colon caused by radiotherapy for cervical cancer, which was treated with endovascular management using a stent graft. A 38-year-old woman underwent concurrent chemoradiotherapy for cervical cancer recurrence. Approximately 9 months later, the patient suddenly developed hematochezia. On her first visit to the emergency room of our hospital, computed tomography (CT) images did not reveal extravasation of contrast media. However, 8 hours later, she revisited the emergency room because of massive hematochezia with a blood pressure of 40/20 mmHg and a heart rate of 150 beats per minute. At that time, CT images showed the presence of contrast media in almost the entire colon. The patient was referred to the angiography room at our hospital for emergency angiography. Inferior mesenteric arteriography did not reveal any source of bleeding. Pelvic arteriography showed contrast media extravasation from the left external iliac artery to the sigmoid colon; this was diagnosed as an ilioenteric fistula and treated with a stent graft. When the bleeding focus is not detected on visceral angiography despite massive arterial bleeding, pelvic arteriography is recommended, especially in patients with a history of pelvic surgery or radiotherapy.

Plug-assisted retrograde transvenous obliteration via gastrocaval shunt for the gastric variceal bleeding: A case report.

RATIONALE: Most gastric varices at the fundus drain into the left renal vein via the gastrorenal shunt (80-85% of cases) or the inferior vena cava via the gastrocaval shunt (10-15%). Therefore, plug-assisted retrograde transvenous obliteration (PARTO) is usually performed via a gastrorenal shunt. Here, we report a case of gastric varix treated with PARTO via a gastrocaval shunt. PATIENT CONCERNS: A 46-year-old woman with hepatitis B virus and liver cirrhosis visited the emergency room in our hospital with the main symptom of hematemesis and hematochezia. DIAGNOSES: Endoscopy and computed tomography (CT) revealed a gastric varix and thrombotic-occluded transjugular intrahepatic portosystemic shunt (TIPS) stent. INTERVENTIONS: The patient underwent PARTO via a gastrocaval shunt to manage gastric variceal bleeding after failed TIPS revision. OUTCOMES: On CT, the gastric varix completely disappeared. The patient did not experience any additional bleeding events. LESSONS: PARTO via a gastrocaval shunt is safe and effective.

Safety, Efficacy, and Patient Satisfaction with Initial Peripherally Inserted Central Catheters Compared with Usual Intravenous Access in Terminally Ill Cancer Patients: A Randomized Phase II Study.

PURPOSE: The purpose of this study was to investigate whether routine insertion of peripherally inserted central catheter (PICC) at admission to a hospice-palliative care (HPC) unit is acceptable in terms of safety and efficacy and whether it results in superior patient satisfaction compared to usual intravenous (IV) access. MATERIALS AND METHODS: Terminally ill cancer patients were randomly assigned to two arms: routine PICC access and usual IV access arm. The primary endpoint was IV maintenance success rate, defined as the rate of functional IV maintenance until the intended time (discharge, transfer, or death). RESULTS: A total of 66 terminally ill cancer patients were enrolled and randomized to study arms. Among them, 57 patients (routine PICC, 29; usual IV, 28) were analyzed. In the routine PICC arm, mean time to PICC was 0.84 days (range, 0 to 3 days), 27 patients maintained PICC with function until the intended time. In the usual IV arm, 11 patients maintained peripheral IV access until the intended time, and 15 patients underwent PICC insertion. The IV maintenance success rate in the routine PICC arm (27/29, 93.1%) was similar to that in the usual IV arm (26/28, 92.8%, p=0.958). Patient satisfaction at day 5 was better in the routine PICC arm (97%, 'a little comfort' or 'much comfort') compared with the usual IV arm (21%) (p <0.001). CONCLUSION: Routine PICC insertion in terminally ill cancer patients was comparable in safety and efficacy and resulted in superior satisfaction compared with usual IV access. Thus, routine PICC insertion could be considered at admission to the HPC unit.

Neutrophil-lymphocyte ratio predicts the therapeutic benefit of neoadjuvant transarterial chemoembolization in patients with resectable hepatocellular carcinoma.

BACKGROUND AND AIMS: All published meta-analyses failed to demonstrate that preoperative transarterial chemoembolization improves the clinical outcomes of patients with resectable hepatocellular carcinoma. The present study aimed to investigate the utility of systemic inflammatory cells as a tumor biology marker predicting therapeutic benefit of neoadjuvant transarterial chemoembolization in patients with resectable hepatocellular carcinoma. MATERIALS AND METHODS: We retrospectively investigated 441 hepatocellular carcinoma patients who underwent curative resection. Among 441 patients, 73 patients underwent preoperative transarterial chemoembolization, and 368 patients did not. We compared recurrence-free survival and overall survival between transarterial chemoembolization plus sequential resection group and resection only group. We analyzed whether pretreatment neutrophil-lymphocyte ratio demonstrates survival benefit in each groups. RESULTS: No significant difference was observed in recurrence-free or overall survival between both groups. In the transarterial chemoembolization plus sequential resection group, the 5-year overall survival in patients with high neutrophil-lymphocyte ratio (≥1.6) was significantly lower than that in patients with low neutrophil-lymphocyte ratio (78.4% and 100%, P = 0.027). High neutrophil-lymphocyte ratio was associated with vascular invasion (P = 0.033). CONCLUSION: Neutrophil-lymphocyte ratio can be considered as a predictive factor of long-term survival and used to identify patients with resectable hepatocellular carcinoma who benefit from neoadjuvant transarterial chemoembolization.

Preclinical safety evaluation of hepatic arterial infusion of oncolytic poxvirus.

PURPOSE: Oncolytic poxvirus has shown promise in treating various solid tumors, such as liver cancer, and administration of oncolytic poxvirus via the hepatic artery may provide more survival benefits than other routes of administration. However, there is a lack of safety information to guide the application of hepatic arterial infusion (HAI) of oncolytic poxvirus in human studies. To investigate the acute and chronic toxicity of HAI administration of oncolytic poxvirus in animals and provide safety information for future human studies. METHODS: VVtk-, a vaccinia poxvirus with inactivated thymidine kinase gene, was administered via HAI to rabbits with normal liver function under angiography (1×108 or 1×109 pfu), and rats with N-nitrosomorpholine-induced precancerous liver cirrhosis under open surgery (1×108 pfu). Body weights and survival were monitored and blood samples were collected for hematological and biochemical tests. Distribution of A56 (a specific marker for poxvirus infection) in rabbit organs was evaluated using immunofluorescence assays. RESULTS: HAI of high doses of VVtk- did not cause any acute or chronic changes in body weight, survival or in biochemical, hematological tests in the 2 animal models, and none of the changes showed dose dependency (in rabbit study), or were influenced by liver cirrhosis (in rat study). A56 was not detected in any of the major rabbit organs. CONCLUSION: HAI may provide a safe alternative route of oncolytic poxvirus administration for human studies.

Therapeutic efficacy and stent patency of transhepatic portal vein stenting after surgery.

AIM: To evaluate portal vein (PV) stenosis and stent patency after hepatobiliary and pancreatic surgery, using abdominal computed tomography (CT). METHODS: Percutaneous portal venous stenting was attempted in 22 patients with significant PV stenosis (> 50%) - after hepatobiliary or pancreatic surgery - diagnosed by abdominal CT. Stents were placed in various stenotic lesions after percutaneous transhepatic portography. Pressure gradient across the stenotic segment was measured in 14 patients. Stents were placed when the pressure gradient across the stenotic segment was > 5 mmHg or PV stenosis was > 50%, as observed on transhepatic portography. Patients underwent follow-up abdominal CT and technical and clinical success, complications, and stent patency were evaluated. RESULTS: Stent placement was successful in 21 patients (technical success rate: 95.5%). Stents were positioned through the main PV and superior mesenteric vein (n = 13), main PV (n = 2), right and main PV (n = 1), left and main PV (n = 4), or main PV and splenic vein (n = 1). Patients showed no complications after stent placement. The time between procedure and final follow-up CT was 41-761 d (mean: 374.5 d). Twenty stents remained patent during the entire follow-up. Stent obstruction - caused by invasion of the PV stent by a recurrent tumor - was observed in 1 patient in a follow-up CT performed after 155 d after the procedure. The cumulative stent patency rate was 95.7%. Small in-stent low-density areas were found in 11 (55%) patients; however, during successive follow-up CT, the extent of these areas had decreased. CONCLUSION: Percutaneous transhepatic stent placement can be safe and effective in cases of PV stenosis after hepatobiliary and pancreatic surgery. Stents show excellent patency in follow-up abdominal CT, despite development of small in-stent low-density areas.

Duodenal stump fistula after gastrectomy for gastric cancer: risk factors, prevention, and management.

PURPOSE: A duodenal stump fistula is one of the most severe complications after gastrectomy for gastric cancer. We aimed to analyze the risk factors for this problem, and to identify the methods used for its prevention and management. METHODS: We retrospectively reviewed the clinical data of 716 consecutive patients who underwent curative gastrectomy with a duodenal stump for gastric cancer between 2008 and 2013. RESULTS: A duodenal stump fistula occurred in 16 patients (2.2%) and there were 2 deaths in this group. Univariate analysis revealed age >60 years (odds ratio [OR], 3.09; 95% confidence interval [CI], 0.99-9.66), multiple comorbidities (OR, 4.23; 95% CI, 1.50-11.92), clinical T stage (OR, 2.91; 95% CI, 1.045-8.10), and gastric outlet obstruction (OR, 8.64; 95% CI, 2.61-28.61) to be significant factors for developing a duodenal stump fistula. Multivariate analysis identified multiple comorbidities (OR, 3.92; 95% CI, 1.30-11.80) and gastric outlet obstruction (OR, 5.62; 95% CI, 1.45-21.71) as predictors of this complication. CONCLUSION: Multiple comorbidities and gastric outlet obstruction were the main risk factors for a duodenal stump fistula. Therefore, preventive methods and aggressive management should be applied for patients at high risk.

Comparison of diameters of ipsilateral and contralateral internal mammary arteries by breast MRI in patients with unilateral breast cancer.

PURPOSE: We compared maximal diameters of ipsilateral (IMA) and contralateral (IMA) internal mammary arteries in patients with unilateral breast cancer and analyze the implications of enlargements of ipsilateral or contralateral IMAs in relation to histopathologic factors. MATERIALS AND METHODS: Of 568 women who underwent breast magnetic resonance imaging (MRI) examinations from January 2009 to May 2012, 196 had unilateral, histologically proven breast cancer. In 156 women, maximal IMA diameters in the second intercostal space were measured by two blinded radiologists in left and right sides using nonenhanced axial T2-weighted turbo spin-echo sequence images. RESULTS: In the 156 study patients, mean maximal diameter of ipsilateral IMAs (2.37 ± 0.60 mm) was significantly larger than that of contralateral IMAs (2.03 ± 0.58 mm) (p = 0.00). Ipsilateral IMA enlargement was present in 66.7 % of the patients (104 of 156). Furthermore, ipsilateral IMA enlargement was found to be significantly associated with human epidermal growth factor receptor-2 (HER-2) expression (p = 0.039). CONCLUSIONS: Maximal IMA diameter was significantly greater in ipsilateral sides in breast cancer patients. Findings suggest ipsilateral IMA enlargement detected by MRI might be a useful additional predictor of HER-2 expression in unilateral breast cancer.

Diagnostic performance and radiation dose of lower extremity CT angiography using a 128-slice dual source CT at 80 kVp and high pitch.

BACKGROUND: Multi-detector computed tomography (MDCT) angiography is now used for the diagnosing patients with peripheral arterial disease. The dose of radiation is related to variable factors, such as tube current, tube voltage, and helical pitch. PURPOSE: To assess the diagnostic performance and radiation dose of lower extremity CT angiography (CTA) using a 128-slice dual source CT at 80 kVp and high pitch in patients with critical limb ischemia (CLI). MATERIAL AND METHODS: Twenty-eight patients (mean, 64.1 years; range, 39-80 years) with CLI were enrolled in this retrospective study and underwent CTA using a 128-slice dual source CT at 80 kVp and high pitch and subsequent intra-arterial digital subtraction angiography (DSA), which was used as a reference standard for assessing diagnostic performance. RESULTS: For arterial segments with significant disease (>50% stenosis), overall sensitivity, specificity, and accuracy of lower extremity CTA were 94.8% (95% CI, 91.7-98.0%), 91.5% (95% CI, 87.7-95.2%), and 93.1% (95% CI, 90.6-95.6%), respectively, and its positive and negative predictive values were 91.0% (95% CI, 87.1-95.0%), and 95.1% (95% CI, 92.1-98.1%), respectively. Mean radiation dose delivered to lower extremities was 266.6 mGy.cm. CONCLUSION: Lower extremity CTA using a 128-slice dual source CT at 80 kVp and high pitch was found to have good diagnostic performance for the assessment of patients with CLI using an extremely low radiation dose.

A Case of Post-Traumatic Pseudocyst in the Spleen Successfully Treated with Alcohol Sclerotherapy.

This report details a case of post-traumatic pseudocyst in the spleen that was successfully treated with sclerotherapy using ethanol. A sixteen-year-old boy visited our hospital for a follow-up examination of a splenic cyst. He had experienced blunt trauma to the abdomen three years prior to presentation. An abdominal computed tomography scan revealed a large cyst of the lower pole of the spleen. The cyst was 6.8×9.5×7.0 cm and conservative management was tried. A follow-up ultrasonographic examination three years later revealed that the size of the cyst was unchanged and another treatment was needed to prevent complications. One session of sclerosis with ethanol (90 mL of 99% ethanol) percutaneously was applied to the cyst. A follow-up after four months revealed that the cyst had completely resolved.

Retroperitoneal fibromatosis presenting as a presacral mass.

Aggressive fibromatosis arising from the retroperitoneum is extremely rare. It may occur in association with previous trauma, abdominal surgery, drugs, Gardner's syndrome, or familial adenomatous polyposis. We report a case of retroperitoneal fibromatosis presenting as a presacral mass with an infiltrating nature, relatively intense enhancement on enhanced computed tomography scanning, and low-signal intensity on T2-weighted magnetic resonance imaging in a patient with no significant medical or surgical history.

Image quality and radiation dose of 128-slice dual-source CT venography using low kilovoltage combined with high-pitch scanning and automatic tube current modulation.

To compare vascular enhancement, image quality, and radiation dose of 128-slice dual-source CT venography (CTV) between an imaging setting of 120 kVp with low pitch, and a setting of 100 kVp combined with high pitch and automatic tube current modulation. A total of 100 patients with suspected deep vein thrombosis and varicose veins were divided into two groups: Group 1 [50 patients, 120 kVp, low pitch (0.6), and fixed 120 mA) and Group 2 (50 patients, 100 kVp, high pitch (3.0), and automatic tube current modulation]. Two radiologists, who were blinded to the image protocol, assessed vascular enhancement and image noise in the inferior vena cava (IVC), femoral vein, and popliteal vein. They also assigned an image quality score independently using a 5-point visual scale. Effective dose was estimated using the dose-length product (DLP). Group demographics, radiation dose, vascular enhancement, image noise, and image quality in the two groups were analyzed. Mean vascular enhancement of the IVC, femoral vein, and popliteal vein was significantly higher in group 2 than in group 1, and images in group 2 had significantly higher image noise. However, there were no significant differences in subjective image quality score of the IVC, femoral vein, and popliteal vein. The mean DLP in group 2 (402.10 ± 94.29 mGy cm) was significantly lower than that in group 1 (973.36 ± 63.20 mGy cm) (P < 0.001). Lower extremity CTV using 100 kVp, high pitch (3.0), and automatic tube current modulation improved vascular enhancement with acceptable image quality and low radiation dose.

Plasma cell type of Castleman's disease involving renal parenchyma and sinus with cardiac tamponade: case report and literature review.

Castleman's disease is an uncommon disorder characterized by benign proliferation of the lymphoid tissue that occurs most commonly in the mediastinum. Although unusual locations and manifestations have been reported, involvement of the renal parenchyma and sinus, and moreover, manifestations as cardiac tamponade are extremely rare. Here, we present a rare case of Castleman's disease in the renal parenchyma and sinus that also accompanied cardiac tamponade.

The washout rate on the delayed CT image as a diagnostic tool for adrenal adenoma verified by pathology: a multicenter study.

OBJECTIVES: To establish the undisputed the value of washout rate for adrenal adenoma using delayed enhanced CT, we evaluated diagnostic performance of cut-off value and delayed time of washout rate by final pathologic diagnosis in a multicenter study. METHODS: We reviewed the pathologic and clinical records of 244 patients underwent adrenalectomies at 5 university hospitals between 2005 and 2009. We calculated the mean Housfield units (HU) of adrenal lesion at non-enhancing CT, and early and delayed enhanced CT using the region of interest. We used ROC curves to determine the specificity and sensitivity of non-enhanced CT scans and the washout rate according to the various cut-off for adrenal adenomas. RESULTS: We divided the patients into adrenal adenoma group (n = 138) and non-adrenal adenoma group (n = 106) based on final pathologic report. Using the unenhanced images with a threshold of 10 HU, the sensitivity was 45.7 %, and the specificity was 97.1 %. Using the 15-min-washout rate with a threshold of 55 %, the sensitivity was 93.9 %, and the specificity was 95.8 %. CONCLUSIONS: Regardless of various CT machines and protocols, a washout rate of 15-min-delayed CT was most useful in the diagnosis of adrenal adenomas due to the early inflow and outflow of contrast media in the tissues of adrenal adenomas.

Hepatocellular carcinoma supplied from the short gastric artery: treatment with chemoembolization.

We report a case of transcatheter arterial chemoembolization (TACE) to treat hepatocellular carcinoma (HCC) that was supplied by the short gastric artery. A 67-year-old woman with two nodular HCCs underwent repeated TACE. One of the nodules was supplied by the short gastric artery.

Step-and-shoot prospectively ECG-gated versus retrospectively ECG-gated with tube current modulation coronary CT angiography using the 128-slice MDCT: comparison of image quality and radiation dose.

BACKGROUND: Little is known regarding image quality and the required radiation dose for step-and-shoot and retrospective coronary computed tomography angiography (CCTA) with tube current modulation (TCM) in 128-slice multidetector CT (MDCT) coronary angiography. PURPOSE: To compare image quality and radiation dose in patients who underwent 128-slice MDCT by the step-and-shoot method with those in patients who underwent 128-slice MDCT with retrospective CCTA with TCM. MATERIAL AND METHODS: CCTA obtained with 128-slice MDCT was retrospectively evaluated in 160 patients. Two independent reviewers separately scored the subjective image quality of the coronary artery segments (1, excellent; 4, poor) for step-and-shoot (68, mean heart rate [HR]: 59.3 ± 6.8) and retrospective CCTA with TCM (77, mean HR: 59.1 ± 9.8). Interobserver variability was calculated. Effective radiation doses of both scan techniques were calculated with dose-length product. RESULTS: There was good agreement for quality scores of coronary artery segment images between the independent reviewers (κ = 0.72). The number of coronary artery segments that could not be evaluated was 2.85% (27 of 947) in the step-and-shoot and 1.87% (20 of 1071) in retrospective CCTA with TCM. Image quality scores were not significantly different (P > .05). Mean patient radiation dose was 63% lower for step-and-shoot (1.94 ± 0.70 mSv) than for retrospective CCTA with TCM (4.51 ± 1.18 mSv) (P < 0.0001). For patients who underwent step-and-shoot or retrospective CCTA with TCM, an average HR of 63.5 beats per minute was identified as the threshold for the prediction of non-diagnostic image quality for both protocols. There were no significant differences in the image quality of both methods between obese (body mass index [BMI] ≥ 25) and non-obese patients (BMI < 25), but radiation doses were higher in the obesity group than in the non-obesity group for both methods. CONCLUSION: Both step-and-shoot and retrospective CCTA with TCM using 128-slice MDCT had similar subjective image quality scores, but step-and-shoot required a lower radiation dose than retrospective CCTA with TCM.