Nutcracker or left renal vein compression phenomenon: multidetector computed tomography findings and clinical significance

The use of multidetector computed tomography (MDCT) in routine abdominal explorations has increased the detection of the nutcracker phenomenon, defined as left renal vein (LRV) compression by adjacent anatomic structures. The embryology and anatomy of the nutcracker phenomenon are relevant as a background for the nutcracker syndrome, a rare cause of hematuria as well as other symptoms. MDCT examples of collateral renal vein circulation (gonadal, ureteric, azygous, lumbar, capsular) and aortomesenteric (anterior) and retroaortic (posterior) nutcracker phenomena in patients with no urologic complaint are shown as well as studies performed on patients with gross hematuria of uncertain origin. Incidental observation of collateral veins draining the LRV in abdominal MDCT explorations of asymptomatic patients may be a sign of a compensating nutcracker phenomenon. Imbalance between LRV compression and development of collateral circulation may lead to symptomatic nutcracker syndrome.     

Retroaortic left renal vein: an interpretive pitfall on computed tomography

In a patient with retroaortic left renal vein, the anomalous vessel is demonstrated by computed tomography to take a caudal course of several centimeters before crossing in a retroaortic fashion to join with the inferior vena cava. This case differs from previously published reports. Computed tomography provided excellent anatomic details of the vascular anomaly and highlighted the value of postcontrast dynamic computed tomography scanning.     

Retroaortic left renal vein joining the left common iliac vein

Retroaortic left renal vein joining the left common iliac vein is a rare congenital anomaly in the development of the inferior vena cava. To our knowledge, only one case has been reported in the literature; however, its imaging features have never been described. A 27-year-old male presented with a 1-year history of recurrent right flank pain, dysuria, hematuria, and fever (39 °C). Computed tomography and MR venography showed a retroaortic left renal vein joining the left common iliac vein. We present the CT and MR venography findings and discuss their feasibility in showing this congenital anomaly. Received: 18 October 1999; Revised: 11 February 2000; Accepted: 15 February 2000     

Retroaortic left renal vein with renal vein hypertension causing hematuria

We describe a case of retroaortic left renal vein with hematuria. In this case, pullback pressure from the retroaortic left renal vein to the inferior vena cava revealed left renal vein hypertension according to criteria of the “nutcracker phenomenon.” We stress that left renal vein anomaly including retroaortic left renal vein can cause clinical symptoms such as hematuria.     

Retroaortic renal vein with tumor thrombus: MR findings

The magnetic resonance (MR) findings in a case of tumor extension into a retroaortic renal vein from a renal cell carcinoma are reported. The signal characteristics of the tumor thrombus paralleled those of the renal mass, and the preoperative recognition of the anomalous vessel lead to an altered surgical approach.     

Retroaortic renal vein with tumor thrombus: MR findings.

The magnetic resonance (MR) findings in a case of tumor extension into a retroaortic renal vein from a renal cell carcinoma are reported. The signal characteristics of the tumor thrombus paralleled those of the renal mass, and the preoperative recognition of the anomalous vessel lead to an altered surgical approach.     

Median arcuate ligament syndrome: multidetector computed tomography findings

OBJECTIVE: We aimed to describe the clinical and multidetector computed tomography (MDCT) angiography findings of celiac, mesenteric, and renal artery entrapment by the median arcuate ligament. MATERIALS AND METHODS: Patients (n = 453) who underwent MDCT abdominal aorta angiography in a period of 3 years were retrospectively reviewed for vascular compression by median arcuate ligament known as median arcuate ligament syndrome. The MDCT examinations were performed with 16-slice (n = 292) and 64-slice scanners (n = 161). The median arcuate ligament itself and adjacent vascular branches of abdominal aorta were assessed for compression by 2 different radiologists who are experienced on MDCT angiography more than 3 years. Both axial, multiplanar reformatted images and 3-dimensional angiographies were used for interpretation. RESULTS: Twelve patients were found to have clinically significant vessel entrapments by median arcuate ligament; 6 of them with celiac artery, 4 of them with renal artery, and 2 of them with both celiac and mesenteric artery involvement. Patients with celiac and mesenteric vessel entrapments presented with epigastric pain. All patients with renal artery entrapment had resistant hypertension. The MDCT showed the proximal narrowing caused by compression of median arcuate ligament. The proximal portions of renal arteries pulled down and in toward the aorta, with mild to moderate narrowing. CONCLUSIONS: The MDCT exanimation with multiplanar images and 3-dimensional angiography is a noninvasive imaging technique that can be used with high accuracy in the diagnosis of median arcuate ligament syndrome.     

Renal cell carcinoma invading the right ovarian vein: multidetector computed tomography and ultrasound Doppler findings

Multidetector computed tomography (MDCT) and Doppler ultrasound findings of a renal cell carcinoma invading the right ovarian vein are presented. An MDCT study performed for evaluation of macroscopic hematuria showed a heterogeneously enhancing malignant thrombus in the right ovarian vein that was in continuity with inferior vena cava and right renal vein thrombi of identical characteristics. Further investigation with Doppler ultrasound confirmed these findings and showed arterial blood flow of low resistance within the ovarian vein and inferior vena cava thrombi. To the authors' knowledge, this is the first report of MDCT and Doppler ultrasound findings of a renal cell carcinoma invading the right ovarian vein.     

Prevalence of significant noncardiac findings on coronary multidetector computed tomography angiography in asymptomatic patients

PURPOSE: The purpose of the present study was to determine the prevalence of significant noncardiac findings in asymptomatic patients undergoing coronary multidetector computed tomography (MDCT) angiography. MATERIALS AND METHODS: A total of 258 consecutive participants, 202 (78.3%) men and 56 (21.7%) women, aged 54.38 +/- 7.9 years (range, 40-86 years), underwent CT of the coronary arteries. All examinations were performed with the 16-slice Brilliance CT scanner (Philips, Cleveland, Ohio) and electrocardiography triggering. Patients were scanned in the supine position twice, first without contrast medium to calculate the calcium score and then with contrast medium. RESULTS: One hundred forty-five patients (56.2%) were found to have a significant noncardiac abnormality on coronary MDCT angiography. Lung abnormalities were detected in 91 patients. Eleven patients had emphysema, 17 with bullae, 3 with interstitial lung disease, 3 with lung mass of more than 10 mm, and 64 with lung nodules. Pericardial abnormalities were identified in 10 patients (3.8%). Liver disease was detected in 12 patients (16.9%), including multiple cysts and echinococcal cyst, and 5 patients had liver mass. Adrenal masses were found in 8 patients (one with 2 masses). Bone abnormalities were found in 3 patients, one with sclerotic lesion in the vertebral body, one with osteolytic lesion in the fifth rib, and one with bilateral cervical rib. CONCLUSIONS: In the present study, 56.2% of asymptomatic patients undergoing coronary MDCT angiography were found to have significant extracardiac pathology requiring additional workup. Therefore it is essential that a radiologist should review the scans for abnormalities in structures other than the coronary arteries.     

Popliteal artery entrapment syndrome with thrombosed popliteal aneurysm: multidetector computed tomography angiography findings of a case

Popliteal artery entrapment syndrome (PAES) is a rare congenital vascular pathology caused by the compression of the popliteal artery by adjacent muscle and tendinous structures. Popliteal artery aneurysm associated with this syndrome is extremely rare. A 45-year-old male suffering from pain at the right lower extremity during exercise was admitted to our hospital. Physical examination and Doppler imaging revealed a weak pulse at the posterior tibial artery and no pulse at dorsalis pedis and anterior tibial arteries. The patient was further evaluated with multidetector computed tomography angiography (MDCTA). MDCTA revealed PAES due to compression of the accessory fibers of the gastrocnemius muscle and related thrombosed popliteal aneurysm.     

Postoperative multidetector computed tomography angiography after aneurysm clipping: comparison with digital subtraction angiography

OBJECTIVES: To evaluate the usefulness of multidetector computed tomography angiography (MDCTA) as a noninvasive diagnostic modality for the detection of aneurysm remnants after clipping of intracranial aneurysms. METHODS: Thirty-eight patients who had aneurysm clipping and had undergone MDCTA and digital subtraction angiography (DSA) were enrolled in this study. In 16 of the 38 patients, MDCTA was performed with 16-channel MDCTA, in 20 patients with 4-channel MDCTA, and in 2 with both. Two neuroradiologists evaluated the image quality of MDCTA with a 3-point rating scale and the presence of the residual aneurysm sac with a 5-point rating scale. Receiver operating characteristic analysis was used to measure the diagnostic performance of MDCTA. RESULTS: Forty-nine surgically clipped aneurysms were evaluated in this study. The overall diagnostic accuracy of MDCTA was 88.1% (95% confidence interval: 0.761-0.954). The ability of 16-channel MDCTA to discriminate between surgical clips and parent vessels was superior to that of 4-channel MDCTA (P=0.005). CONCLUSION: Multidetector computed tomography angiography is a valuable noninvasive diagnostic modality for the assessment of aneurysm remnants in patients after aneurysm clipping.     

左肾静脉及其属支的MSCTA

目的：探讨左肾静脉及其属支的64层MSCTA技术及其影像表现。方法：分析连续100例患者MSCT增强扫描动脉期和静脉期图像上左肾静脉及其各属支的显示情况。MSCT检查采用64层CT机,0.625mm×64i方式采集,0.625mm层厚回顾性重建,标准或软组织算法;对比剂剂量80～90ml,注射流率3～4ml/s,延迟时间动脉期为25～26s、静脉期50～60s。后处理采用三维正交多平面重组（OMPR）、最大密度投影（MIP）和容积再现（VR）三种方法。结果：MSCTA动脉期和静脉期图像上均完整显示左肾静脉主干,静脉期图像上对其3个属支的显示数量（276支）多于动脉期（217支）。VR图像显示这些血管最好。69%的病例为标准的单支左肾静脉和3个属支（肾上腺静脉、生殖腺静脉和腰静脉）,31%的病例有不同程度的变异,部分病例可清楚显示膈静脉（23例）和肾包膜静脉（27例）的汇入。结论：MSCTA静脉期图像结合三维重组技术可以清晰显示左肾静脉及其属支,其中以VR图像最佳;大部分受试者的左肾静脉及属支为标准的单支型,但变异类型较多。     

Thoracic aortic disease: Spectrum of multidetector computed tomography imaging findings

The clinical presentation of diseases involving the thoracic aorta ranges from a large number of asymptomatic patients with clinically undetectable thoracic aortic aneurysm to patients with symptoms of severe chest pain as a result of acute aortic dissection. Thoracic aortic disease often remains undiagnosed until a life-threatening complication occurs or the disease is discovered serendipitously on imaging studies performed for other purposes. Multidetector row computed tomography (MDCT) imaging of the aorta is used to diagnose various acute and chronic conditions, including aortic aneurysms, aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, traumatic injury, rupture, inflammatory disorders, and congenital malformations. This review illustrates the wide range of MDCT imaging findings of thoracic aortic disease.     

Comparison of different iodine concentrations for multidetector row computed tomography angiography of segmental renal arteries

The aims of this study were (1) to assess the diagnostic performance of multidetector row computed tomography angiography (CTA) on imaging of renal artery branches and (2) to investigate the effect of different iodine concentrations at constant total iodine load and either constant injection rates or constant iodine administration rates. A number of 120 consecutive patients (71±6 years of age) underwent CTA of renal arteries (collimation 4×1 mm) using the nonionic contrast medium iopromide, and were divided into six equal groups: 1: 150 ml, 240 mg/ml at 4 ml/s; 2: 120 ml, 300 mg/ml at 4 ml/s; 3: 97.3 ml, 370 mg/ml at 4 ml/s; 4: 150 ml, 240 mg/ml at 5 ml/s; 5: 120 ml, 300 mg/ml, 60 ml at 6 ml/s, 60 ml at 3 ml/s; 6: 97.3 ml, 370 mg/ml at 3.3 ml/s. The image quality of the main renal arteries (n=240) and their first-order to fourth-order branches was scored as 0 for no visualization, 1 for only visualization, and 2 for diagnostic. All main renal arteries were diagnostic. First-order branches had score 2 in 38/40, 40/40, 37/40, 38/40, 39/40, and 40/40 patients for groups 1–6, respectively (p=0.34). Second-order branches were imaged best in group 2 (p<0.002)). Third-order branches had score 2 in only 1/40, 5/40, 1/40, 2/40, 0/40, and 2/40 renal arteries. Fourth-order branches were not imaged diagnostically. At a constant total iodine load, the main renal arteries and their first-order branches achieved diagnostic image quality at all iodine concentrations in four-channel multidetector row CTA for the protocols tested. Second-order renal artery branches were imaged best at 120 ml contrast medium with an iodine concentration of 300 mg/ml at 4 ml/s.     

Incremental prognostic value of left ventricular function analysis over non-invasive coronary angiography with multidetector computed tomography

Background

The purpose of this study was to determine the prognostic value of computed tomography coronary angiography (CTA)-derived left ventricular (LV) function analysis and to assess its incremental prognostic value over the detection of significant stenosis using CTA.

Methods

In 728 patients (400 males, mean age 55 ± 12 years) with known or suspected CAD, the presence of significant stenosis (≥ 50% stenosis) and LV function were assessed using CTA. LV end-systolic volume (LVESV), LV end-diastolic volume (LVEDV), and LV ejection fraction (LVEF) were calculated. LV function was assessed as a continuous variable and using cutoff values (LVEDV > 215 mL, LVESV > 90 mL, LVEF < 49%). The following events were combined in a composite end-point: all-cause mortality, non-fatal myocardial infarction, and unstable angina pectoris requiring hospitalization.

Results

On CTA, a significant stenosis was observed in 221 patients (30%). During follow-up [median 765 days, 25-75th percentile: 493-978] an event occurred in 45 patients (6.2%). After multivariate correction for clinical risk factors and CTA, LVEF < 49% and LVESV > 90 mL were independent predictors of events with an incremental prognostic value over clinical risk factors and CTA.

Conclusions

The present results suggest that LV function analysis provides independent and incremental prognostic information beyond anatomic assessment of CAD using CTA.     

Remarkable anatomic anomalies of coronary arteries and their clinical importance: a multidetector computed tomography angiographic study

OBJECTIVE: An anomalous origin and course of the coronary arteries can be benign or life threatening. Recently, because of new advances in computed tomography technology, radiologists have begun to interpret the diseases of coronary arteries. We aimed to demonstrate some remarkable anomalies of coronary arteries, some of which were not shown by multidetector computed tomography (MDCT) coronary angiography previously, and to discuss the clinical importance of these anomalies. MATERIALS AND METHODS: Seven hundred twenty-five consequent patients referred to Florence Nightingale Hospital and Atatürk University Hospital for MDCT coronary angiography were included in this study. The patients were between the ages of 33 and 78 years (mean +/- SD, 59 +/- 13.86 years). Four hundred ninety-seven patients (68.6%) were men, and 228 (31.4%) were women. All the examinations were evaluated by both a radiologist and a cardiologist. RESULTS: The incidence of anomalous anatomical origin and course of the coronaries found in our study group was 5.79% (n = 42). The anomalies found in our study are absence of the right coronary artery (RCA; n = 1, 0.13%), ectopic origin of RCA from the left anterior descending (LAD) artery (n = 1, 0.13%), absence of the left main coronary artery (n = 4, 0.52%), ectopic origin of the left main coronary artery from the right sinus of Valsalva (n = 1, 0.13%), double LAD and ectopic origin of LAD from RCA (n = 1, 0.13%), ectopic origin of the left circumflex artery from the right sinus of Valsalva (n = 3, 0.39%), ectopic origin of the left circumflex artery from RCA (n = 2, 0.26%), and myocardial bridging (n = 29, 4%). CONCLUSIONS: An anomalous origin of the coronary anatomy must be present in the interpretations because of its importance for patients, cardiologists, and surgeons. As a conclusion, our study showed that MDCT, especially volume rendering and maximum intensity projection techniques, may be useful for assessment of complex variations, when the conventional angiography may not be sufficient.     

The importance of end-systole for optimal reconstruction protocol of coronary angiography with 16-slice multidetector computed tomography

OBJECTIVES: Multidetector-row computed tomography coronary images are usually analyzed in mid-diastole (MD). Because of slow coronary motion also in end-systole (ES), we evaluated the impact on image quality of including ES images and defined an efficient reconstruction protocol. MATERIAL AND METHODS: In 50 coronary multidetector-row computed tomography studies, 9 reconstructions (at 10% increments of the RR interval) were graded for image quality. Multiple combinations of reconstructions were compared. RESULTS: MD (60-70% of the RR interval) offered the best image quality. In 44% patients, the best reconstruction for >or=1 coronary was found in ES (20-30%). Their heart rate was higher (68.2+/-9.9 bpm vs. 59.2+/-8.8 bpm, P=0.0014). Combining ES and MD consistently offered superior image quality and less nonevaluable vessels than even larger numbers of diastolic reconstructions alone. A combination of 2-3 reconstructions was most efficient. Adding more reconstructions did not significantly improve results. CONCLUSIONS: Combining ES and MD reconstructions reduces nonevaluable coronary arteries, particularly with higher heart rates. A protocol including 2-3 reconstructions is the most efficient.     

Right top pulmonary vein: evaluation with 64 section multidetector computed tomography

PURPOSE: To evaluate the incidence and anatomic features of the rare variant of the pulmonary veins named "right top pulmonary vein" as depicted with 64 section multidetector computed tomography (MDCT). MATERIALS AND METHODS: MDCT of 610 patients obtained over 12 months period for diagnosis of suspected thoracic or cardiac pathology were routinely reviewed in transverse and 3D images. The frequency of right top pulmonary vein (RTPV) was determined and anatomic features were also documented. RESULTS: Right top pulmonary vein (RTPV) is a supernumerary vein arising from the roof of the right part of the left atrium separately from the orifice of the right superior pulmonary vein. It crosses behind the intermediate bronchus and drains mainly posterior segment of the right upper lobe but also receives few subsegmental branches of superior segment of the right lower lobe. It was detected in 2.2% of patients (14/610). The mean diameter of RTPV was 5.1 mm. CONCLUSION: The RTPV is a rare venous drainage variation of pulmonary veins. It is important to be aware of this anatomic pattern for avoiding misinterpretation of pulmonary venographic findings, inadvertent ablation of pulmonary vein and perioperative bleeding during video assisted thorocoscopic lobectomy.     

Diagnostic performance of multidetector computed tomography for detecting aorto-ostial lesions compared with catheter coronary angiography: multidetector computed tomography coronary angiography is superior to catheter angiography in detection of aorto-ostial lesions

PURPOSE: In this study, our goal is to determine the use of multidetector computed tomography (MDCT) in detection of aorto-ostial lesions. MATERIALS AND METHODS: Thirty-three patients suspected to have aorto-ostial lesion by either catheter angiography (CA) or MDCT coronary angiography comprised our study population. In 19 patients (group 1), aorto-ostial lesion was suspected based on CA, then MDCT coronary angiography was performed. In the remaining 14 patients (group 2), aorto-ostial lesion diagnosis was made by MDCT coronary angiography, and then afterward, CA was performed. A cardiologist and a radiologist reevaluated both the CA and MDCT coronary angiography recordings of all patients and their consensus formed the diagnosis. We accepted this consensus diagnosis as our criterion standard because a universal criterion standard to compare CA and MDCT findings with is not available. Then, the previous diagnoses by CA and MDCT coronary angiography were compared with the consensus diagnoses. RESULTS: Finally, 26 patients were diagnosed with aorto-ostial lesion, whereas 5 patients were found not to have aorto-ostial lesions. Two patients were diagnosed with abnormal origination of a coronary artery. When the results were evaluated in terms of the presence of aorto-ostial lesion, MDCT coronary angiography correctly diagnosed all 26 patients, and in the 5 patients with normal ostium, MDCT coronary angiography finding was also normal. However, 7 of 26 patients with aorto-ostial lesion were reported to be normal by CA, and also 5 patients with normal ostia were reported to have aorto-ostial lesion by CA. That is, 12 of 33 patients were misdiagnosed by CA. Moreover, CA missed the abnormal origination of the coronary arteries in 2 patients. When the results were evaluated in terms of the degree of stenosis in 26 patients with aorto-ostial lesion; MDCT coronary angiography predicted the final diagnosis in all 26 patients correctly. However, CA predicted the final degree of stenosis only in 12 patients. Catheter angiography underestimated the degree of the stenosis in 2 patients, overestimated in 5 patients and missed the lesion in 7 patients. CONCLUSIONS: Our findings suggest that MDCT is a reliable tool for diagnosing the presence and severity of aorto-ostial lesions. In addition, MDCT might be useful in preventing the false diagnosis due to the catheter-induced spasms in patients who were diagnosed with aorto-ostial lesion by CA. Moreover, if MDCT coronary angiography detects a lesion in aorto-ostial region, there is no need to perform CA to merely verify this pathology.     

Multislice computed tomography angiography of the abdominal arteries: comparison between computed tomography angiography and digital subtraction angiography findings in 52 cases

Since the introduction of multislice CT scanners, CT angiography (CTA) has become a powerful tool for imaging the vascular system. We compare conventional angiography to CTA in the diagnosis of morphological changes in the abdominal aorta and its branches. A retrospective analysis of 52 patients who underwent both multislice CT angiography (MSCTA) and digital subtraction angiography before surgical treatment is presented. All CT examinations were performed after administration of 100 mL contrast medium with a collimation of 4 x 1 mm and a pitch of 7. A standardized evaluation of the axial, multiplanar and 3D reconstructions was performed by two experienced radiologists. Stenoses were classified as high-grade and low-grade, and aneurysms, occlusions and arteriosclerosis were evaluated. The CTA findings were compared with conventional angiography. All aneurysms, occlusions, stenoses and calcifications were diagnosed correctly by CTA in axial and multiplanar projections (sensitivity 1.0; specificity 1.0). The degree of stenosis was overestimated in three cases when using axial projections. Three-dimensional volume-rendered CTA showed a sensitivity of 0.91 for aneurysms, 0.82 for stenoses, 0.75 for occlusions and 0.77 for calcifications. The specificity was 1.0 in all cases. Multislice CT angiography seems to be similar to conventional digital subtraction angiography for abdominal vessels if multiplanar projections are used.