Donor site morbidity after the harvest of microvascular flaps from the medial and lateral femoral condyle region: Objective, radiologic, and patient-reported outcome of a multi-center trial

BACKGROUND

With the experience-based hypothesis of low donor site morbidity (DSM) for free flaps from the distal femur, this cohort study aimed to evaluate the DSM according to objective and reproducible criteria.

METHODS

One hundred and fifty-six patients who had a flap harvest from either the medial or lateral femoral condyle region between 2005 and 2017 were included. A retrospective chart review was performed for all patients. In total, 97 patients were available for a follow-up examination. Outcomes were assessed according to objective (Knee Society Score; Larson Knee Score; OAK Score; 0-100 points), patient-reported (IKDC Score; KOOS Score; 0-100 points), and radiologic criteria (Kellgren and Lawrence Score; MRI Osteoarthritis Knee Score).

RESULTS

The median follow-up time was 1,529 days (range: 248-4,810). The mean Knee Society Score (94.8 ± 10.1), Larson Knee Score (94.5 ± 10.1), and OAK Score (95.5 ± 6.6) showed nearly unimpaired knee function. The overall patient-reported DSM was low (IKDC Score: 86.7 ± 17.4; KOOS Score: 89.3 ± 17.1). Osteochondral (OC) flaps had a significantly higher DSM, regardless of the donor site. Bone flaps did not show any relevant radiologic morbidity in the Kellgren and Lawrence Score. Besides the procedure-associated cartilage lesions at the OC donor sites, MRI Osteoarthritis Knee Score did not show any significant presence of further knee pathologies in the bilateral MRI Scans. The obvious cartilage lesions did not have a relevant impact on the knee function of most patients.

CONCLUSION

The DSM for bone and soft-tissue flaps from the femoral condyle region is negligible. OC flaps are associated with a significantly higher DSM, although a clinically relevant impact on knee function was not evident in the majority of patients.

On-treatment measurements of circulating tumor DNA during FOLFOX therapy in patients with colorectal cancer

We addressed a significant unknown feature of circulating tumor DNA (ctDNA), i.e., how ctDNA levels change during chemotherapy, by serially monitoring ctDNA in patients with colorectal cancer during the 48-h application of FOLFOX. Surprisingly, we did not observe a spike in ctDNA as a sign of a responsive tumor, but instead ctDNA levels initially decreased and remained low in patients with stable disease or partial response. Our observations reveal further insights into cell destruction during chemotherapy with important implications for the management of patients.

Abstract 4295: Early circulating tumor DNA dynamics as a real-time predictor of FOLFOX efficacy in advanced colorectal cancer patients

Background: In recent years, various efforts have been made to identify biomarkers in metastatic colorectal cancer patients (mCRC), all with the goal of improving patients' outcomes, including maximizing therapeutic response and minimizing exposure to ineffective treatments. Nevertheless, there is still no valid biomarker for the early assessment of therapeutic efficacy in the patient management strategy. To address this issue, we aimed to describe the predictive value of circulating tumor DNA (ctDNA) on the efficacy of FOLFOX treatment in mCRC patients.

Patients and methods: A total of 11 patients with mCRC receiving FOLFOX therapy were included in this study. During the 48-hour FOLFOX cycle, we performed serial liquid biopsy-based ctDNA analysis before treatment start (T1) and at eight further time points (T2-T9). Among the 11 patients tested, all patients had detectable variants identified by either tumor tissue genotyping or baseline sample ctDNA sequencing for longitudinal analysis. We assessed genome-wide somatic copy number alterations (SCNAs) and highly sensitive sequencing approaches were utilized to monitor changes in the ctDNA mutant allele frequencies (mAFs) between baseline and on-treatment samples.

Results: We were able to clearly assess different mAF patterns across patients with either stable disease, partial response or progressive disease. However, we invariably observed an early and deep ctDNA mAF decrease in all patients, as comparing the baseline (T1) mAF levels with the mAFs at all time points revealed that the most significant ctDNA drop was 23 hours after treatment start, i.e. at time point T5 (p <0.005). In addition, we observed in patients with stable disease or partial response (n=8) not only a significant decline of mAFs between T5 (p=0.0391) but also at T9 (52 hours after treatment start; p=0.0156) compared to the baseline sample. Conversely, mAFs of patients with progressive disease increased again within the next 29 hours (T9) after the initial ctDNA drop at time point T5, leading to higher ctDNA levels at T9 than the baseline values prior to treatment start.

Conclusion: Our observations clearly demonstrated for the first time that ctDNA dynamics allow real-time, individualized evaluation of treatment response using two early time points, i.e. at T5 and T9. Therefore, our data suggest that sequential ctDNA analysis can contribute to an improved patient treatment strategy. Nevertheless, further studies are clearly required to validate this promising early on-treatment indicator of therapeutic efficacy for CRC patients.

Citation Format: Tina Moser, Julie Waldispuehl-Geigl, Jelena Belic, Samantha Perakis, Sabrina Weber, Qing Zhou, Heinz Sill, Sigurd Lax, Karl Kashofer, Gerald Hoefler, Helmut Schoellnast, Thomas Bauernhofer, Ellen Heitzer, Jochen B. Geigl, Michael R. Speicher. Early circulating tumor DNA dynamics as a real-time predictor of FOLFOX efficacy in advanced colorectal cancer patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4295.

CT perfusion imaging of the liver and the spleen in patients with cirrhosis: Is there a correlation between perfusion and portal venous hypertension?

OBJECTIVES

To correlate hepatic and splenic CT perfusion parameters with hepatic venous pressure gradient (HVPG) measurements in patients with cirrhosis.

METHODS

Twenty-one patients with cirrhosis (males, 17; females, 4; mean ± SD age, 57 ± 7 years) underwent hepatic and splenic perfusion CT on a 320-detector row volume scanner as well as invasive measurement of HVPG. Different CT perfusion algorithms (maximum slope analysis and Patlak plot) were used to measure hepatic arterial flow (HAF), portal venous flow (PVF), hepatic perfusion index (HPI), splenic arterial flow (SAF), splenic blood volume (SBV) and splenic clearance (SCL). Hepatic and splenic perfusion parameters were correlated with HVPG, and sensitivity and specificity for detection of severe portal hypertension (≥12 mmHg) were calculated.

RESULTS

The Spearman correlation coefficient was -0.53 (p < 0.05) between SAF and HVPG, and -0.68 (p < 0.01) between HVPG and SCL. Using a cut-off value of 125 ml/min/100 ml for SCL, sensitivity for detection of a HVPG of ≥12 mmHg was 94%, and specificity 100%. There was no significant correlation between hepatic perfusion parameters and HVPG.

CONCLUSION

CT perfusion in patients with cirrhosis showed a strong correlation between SCL and HVPG and may be used for detection of severe portal hypertension.

KEY POINTS

• SAF and SCL are statistically significantly correlated with HVPG • SCL showed stronger correlation with HVPG than SAF • 125 ml/min/100 ml SCL-cut-off yielded 94 % sensitivity, 100 % specificity for severe PH • HAF, PVF and HPI showed no statistically significant correlation with HVPG.

First pass dual input volume CT-perfusion of lung lesions: The influence of the CT- value range settings on the perfusion values of benign and malignant entities

OBJECTIVE

To assess the influence of the lower threshold for segmentation of the volume of interest on the perfusion values in first-pass dual input volume CT-perfusion of lung lesions.

MATERIALS AND METHODS

Dual input maximum slope volume CT-perfusion was performed in 48 patients (mean age±standard deviation [SD], 68±10years; range, 46-87 years) who underwent subsequent CT-guided biopsy to evaluate a lung lesion. Using commercial perfusion software, a lower and upper threshold was set for determination of the CT-value range, which again determined the volume of interest for perfusion calculation. The pulmonary arterial flow (PAF), bronchial arterial flow (BAF), and perfusion index (PI; PAF/(PAF+BAF)) were calculated at following pre contrast CT value range settings: -80 to 150HU (setting 1), -200 to 150HU (setting 2), -300 to 150HU (setting 3), and -500 to 150HU (setting 4). Perfusion parameters were compared between benign (n, 15) and malignant (n, 33) lesions for each setting. Intraobserver- and interobserver reliability were calculated for setting 4.

RESULTS

Median PAF was significantly higher in malignant lesions than in benign lesions for all settings (53-96 versus 29-62mL/min/100mL, P<0.05). There was no significant difference in BAF between malignant and benign lesions. Median PAF of all lesions was significantly influenced by the CT value range setting (P<0.05), whereas the values increased from setting 1 to 4. Intraobserver analysis as well as interobserver analysis of PAF at setting 4 showed excellent reliability (Cronbach's alpha 0.98 and 0.95, respectively, P<0.01).

CONCLUSION

PAF derived from first-pass dual-input maximum slope volume CT perfusion is statistically significantly higher in malignant than in benign lesion, whereas the measurements are influenced by the lower threshold of the CT value range setting. This has to be considered when using cutoff values provided in the literature for differentiation between benign and malignant lung lesions.

Interstitial laser-induced thermotherapy of the lung: evaluation of the influence of ablation continuity on ablation size in a swine model

The purpose of this study was to assess the relationship between size and the continuity of energy application in interstitial laser-induced thermotherapy. Percutaneous computed tomography-guided laser ablation (30 W, 600 nm diode) of the lung was performed in 7 Yorkshire pigs; a total of 42 ablation zones were created. Twenty ablations were performed using a continuous cycle of 2 min (protocol A) and 22 ablations were performed using 4 intermittent cycles with a duration of 1 min for each cycle interrupted by a 10-s stop between the cycles (protocol B). The lung was harvested immediately after euthanasia for gross pathology and histopathologic evaluation. Statistical analysis was performed using the Student t test and the Spearman correlation coefficient. Laser ablation resulted in complete necrosis of variable size of lung. The mean ablation zone dimensions (±SD) were 1.9 (±0.4) cm × 1.4 (±0.3) cm for protocol A and 2.2 (±0.5) cm × 1.4 (±0.4) cm for protocol B. The size of the necrosis is not significantly different when comparing a continuous 2-min ablation to a 4-cycle intermittent ablation for 1 min each cycle interrupted by a 10-s stop between the cycles (P = 0.98 and 0.53, respectively).

Recurrent non-small cell lung cancer: evaluation of CT-guided radiofrequency ablation as salvage therapy

BACKGROUND

Radiofrequency ablation (RFA) is a potential application as a salvage tool after failure of surgery, chemotherapy, or radiotherapy of non-small cell lung cancer (NSCLC). Although several studies have evaluated the use of RFA in primary NSCLC, there is little literature on its potential application as a salvage tool.

PURPOSE

To evaluate CT-guided RFA employed as a salvage therapy for pulmonary recurrences of NSCLC after prior treatment with chemotherapy, radiation therapy, and/or surgery.

MATERIAL AND METHODS

A retrospective computer database search yielded 33 patients with biopsy proven primary NSCLC who underwent CT-guided RFA of 39 recurrent tumors following surgery, chemotherapy, and/or radiotherapy. Follow-up imaging was performed with CT and PET-CT. The endpoints of interest were progression-free survival (PFS) and time to local progression (TTLP). PFS and TTLP were compared by lesion size (<3 cm, ≥3 cm).

RESULTS

The median PFS was 8 months. For patients with a tumor size <3 cm median PFS was 11 months, whereas the median PFS of patients with a tumor size ≥3 cm was 5 months. The difference did not reach statistical significance (P = 0.09). The median TTLP of all tumors was 14 months. TTLP of ablated tumors <3 cm in size was 24 months, compared to 8 months for ablated tumors ≥3 cm in size. The difference did not reach statistical significance (P = 0.07).

CONCLUSION

RFA of recurrent NSCLC may be a valuable salvage tool to achieve local tumor control, especially in tumors measuring <3 cm in size.

The delayed effects of irreversible electroporation ablation on nerves

OBJECTIVE

To evaluate the delayed effects of irreversible electroporation (IRE) ablation on nerves.

METHODS

The study was approved by the institutional animal care and use committee. CT-guided IRE-ablation (electric field per distance, 1,500 V/cm; pulse length, 70 μs; number of pulses, 90) of 6 sciatic nerves was performed in 6 pigs that were euthanized 2 months after ablation. The sciatic nerves were harvested immediately after euthanasia for histopathological evaluation. Sections from selected specimens were stained with haematoxylin and eosin (H&E), Masson's trichrome (MT) method for collagen, and immunohistochemistry was performed for S100 and neurofilaments (markers for Schwann cells and axons, respectively).

RESULTS

All nerves showed a preserved endoneural architecture and presence of numerous small calibre axons associated with Schwann cell hyperplasia, consistent with axonal regeneration. A fibrous scar was observed in the adjacent muscle tissue, confirming ablation at the site examined.

CONCLUSION

After IRE-ablation of nerves, the preservation of the architecture of the endoneurium and the proliferation of Schwann cells may enable axonal regeneration as demonstrated after 2 months in this study.

Clinical significance of periportal tracking as an extrarenal manifestation of acute pyelonephritis

PURPOSE

The purpose of this study was to evaluate whether hepatic periportal tracking (PPT) in patients with acute pyelonephritis correlates with the severity of pyelonephritis.

MATERIAL AND METHODS

A database search was conducted of patients with clinically suspected acute pyelonephritis who underwent abdominal computed tomography (CT) between January 2004 and June 2009 for disease evaluation. The final study group consisted of 274 patients (221 women, 53 men) with a mean age of 43 ± 20 years. The abdominal CT studies were retrospectively reviewed by two radiologists by consensus to assess PPT, renal wedge-shaped hypoperfusion areas, and renal abscesses. The laboratory reports obtained on the day of the CT examinations were reviewed for C-reactive protein (CRP), white blood cell count (WBCC), and leukocytes in urine. Presence of PPT was correlated with the presence of renal abscess, extension of renal hypoperfusion areas as well with levels of CRP, leukocytosis, and urine leukocytes using the Fisher's exact Test and the Wilcoxon Test.

RESULTS

All patients showed renal hypoperfusion areas consistent with the clinical diagnosis of acute pyelonephritis. Twenty-nine patients (11%) showed PPT which was significantly associated with the extension of the wedge-shaped renal hypoperfusion areas (P < 0.001), the presence of a renal abscess (P < 0.01), as well as the level of CRP (P < 0.001) and urine leukocytes (P < 0.01). A renal abscess was observed in 36% of patients with PPT compared with 14% of patients without PPT.

CONCLUSION

The PPT should be kept in mind as an extrarenal finding in acute pyelonephritis and may indicate a more serious clinical course of the disease.

Acute and subacute effects of irreversible electroporation on nerves: experimental study in a pig model

PURPOSE

To evaluate whether irreversible electroporation (IRE) has the potential to damage nerves in a porcine model and to compare histopathologic findings after IRE with histopathologic findings after radiofrequency ablation (RFA).

MATERIALS AND METHODS

This study was approved by the institutional animal care and use committee. Computed tomography (CT)-guided IRE of 11 porcine sciatic nerves was performed in nine pigs, and histopathologic analysis was performed on the day of ablation or 3, 6, or 14 days after ablation. In addition, acute RFA of six porcine sciatic nerves was performed in six pigs that were harvested on the day of ablation. All nerves and associated muscles and tissues were assessed for histopathologic findings consistent with athermal or thermal injury, respectively, such as axonal swelling, axonal fragmentation and loss, Wallerian degeneration, inflammatory infiltrates, Schwann cell proliferation, and coagulative necrosis. The percentage of fascicles affected was recorded.

RESULTS

All nerves had an axonal injury. The percentage of affected nerve fascicles after IRE was 50%-100%. Axonal swelling and perineural inflammatory infiltrates were detectable at every time point after ablation. Axonal fragmentation and loss, macrophage infiltration, and Schwann cell proliferation were found 6 and 14 days after ablation. Distal Wallerian axonal degeneration was observed 14 days after ablation. The endoneurium and perineurium architecture remained intact in all cases. RFA specimens at the day of ablation revealed acute coagulative necrosis associated with intense basophilic staining of extracellular matrix, including collagen of the perineurium and epineurium consistent with thermal injury.

CONCLUSION

IRE has the potential to damage nerves and may result in axonal swelling, fragmentation, and distal Wallerian degeneration. However, preservation of endoneurium architecture and proliferation of Schwann cells may suggest the potential for axonal regeneration. In contrast, RFA leads to thermal nerve damage, causing protein denaturation, and suggests a much lower potential for regeneration.

Radiofrequency ablation of non-small-cell carcinoma of the lung under real-time FDG PET CT guidance

Radiofrequency ablation (RFA) is a well-established method in treatment of patients with lung carcinomas who are not candidates for surgical resection. Usually computed tomographic (CT) guidance is used for the procedure, thus enabling needle placement and permitting evaluation of complications such as pneumothorax and bleeding. (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is generally used for tumor activity assessment and is therefore useful in follow-up after tumor treatment. A method that provides real-time image-based monitoring of RFA to ensure complete tumor ablation would be a valuable tool. In this report, we describe the behavior of preinjected FDG during PET CT-guided RFA of a non-small-cell lung carcinoma and discuss the value of FDG as a tool to provide intraprocedure monitor ablation. The size and the form of the activity changed during ablation. Ablation led to increase of the size and blurring and irregularity of the contour compared to pretreatment imaging. The maximal standardized uptake value decreased only slightly during the procedure. Therefore, before RFA, FDG PET can guide initial needle placement, but it does not serve as a monitoring tool to evaluate residual viable tissue during the procedure.

Acute pulmonary embolism: Comparison of standard axial MDCT with paddlewheel technique

PURPOSE

The purpose of this study was to evaluate the ability of rotated paddlewheel reformations for the detection of central and peripheral pulmonary embolism (PE) compared to standard axial multi detector CT (MDCT) images.

MATERIAL AND METHODS

CT scans of 35 patients with PE were reviewed by three independent readers for the detection of pulmonary emboli using standard axial CT scans and reformatted paddlewheel technique. All images were evaluated in random order. MDCT examinations were performed with a collimation of 1.25 mm, a pitch of six and a reconstruction interval of 0.8mm. For each patient MIP were reformatted by using a paddlewheel arrangement with 5mm slab thickness and 5 degrees rotation. Standard of reference for PE was a consensus reading of the axial images by all three readers.

RESULTS

The overall sensitivity for the axial images for the three readers ranged between 91% and 96%; for paddlewheel reformations from 78% to 83%; the specificity for both methods was 98-99%. Inter- and intraobserver agreement was also higher for axial images than for paddlewheel reformations.

CONCLUSION

Comparing standard axial MDCT scans and reformatted paddlewheel images no significant difference for the detection of central PE was found, whereas for the detection of peripheral emboli standard axial images showed a significant higher percentage of detecting PE than paddlewheel reformations.

Diagnostic accuracy of 3D time-of-flight MR angiography compared with digital subtraction angiography for follow-up of coiled intracranial aneurysms: influence of aneurysm size

BACKGROUND AND PURPOSE

3D time-of-flight MR angiography (3D TOF MRA) may be used as noninvasive alternative to digital subtraction angiography (DSA) for the follow-up of patients with intracranial aneurysms treated with Guglielmi detachable coils (GDCs). We aimed to determine the influence of aneurysm size and location on diagnostic accuracy of 3D TOF MRA for follow-up of intracranial aneurysms treated with GDCs.

MATERIALS AND METHODS

Two hundred and one 3D TOF MRAs in 127 consecutive patients with 136 aneurysms were compared with DSA as standard of reference. Sensitivity and specificity of 3D TOF MRA for detection of residual or reperfusion of the aneurysms was calculated with regard to aneurysm size and location.

RESULTS

Overall sensitivity and specificity of MRA was 88.5% and 92.9%, respectively. Sensitivity was lower for aneurysms <or=5 mm (72.2%) and <or=3 mm (63.6%). In addition to the small aneurysm size, interpretation of MR angiograms was compromised by susceptibility artifacts at the air-bone interface, arterial overlap, and pulsation-induced artifacts. The small number of disagreements between MRA and DSA hampered reliable interpretation of the possible influence of aneurysm location on MRA accuracy.

CONCLUSION

The sensitivity of 3D TOF MRA for detection of reperfusion or residual perfusion of coiled intracranial aneurysms varies considerably depending on the size of the aneurysms. No conclusions can be drawn regarding a possible influence of aneurysm location on diagnostic accuracy of 3D TOF MRA. These findings may influence the decision about whether to replace DSA by 3D TOF MRA for the follow-up of patients with intracranial aneurysms treated with GDCs.

Endoluminal therapy in patients with peripheral arterial disease: prospective assessment of quality of life in 190 patients

OBJECTIVE

The objective of our study was to assess the impact of endoluminal treatment on health-related quality of life in patients with peripheral arterial disease.

SUBJECTS AND METHODS

Changes in quality of life were prospectively evaluated in 190 patients before and 1, 3, 6, and 12 months after treatment. Physical, emotional, and general health components were determined using the short-form (36 items) health survey (SF-36). Claudicant patients were compared with patients who had critical limb ischemia. The influence of the lesion location (iliac, femoropopliteal, or crural) restenosis, and additional interventions on quality of life were evaluated.

RESULTS

Six- and 12-month follow-up data were available for 136 and 103 patients, respectively. Significant improvements in quality of life were observed in most of the patients after the intervention. Many of the SF-36 scores decreased from the 6- to the 12-month follow-up but remained significantly higher than the score before the intervention. Reduction of bodily pain was the most evident effect of treatment. Claudicant patients seemed to benefit more from treatment than patients with critical limb ischemia. In terms of SF-36 scores, percutaneous transluminal angioplasty of the crural arteries was equally as effective as endoluminal revascularization of the iliac and femoropopliteal arteries and multilevel interventions were as effective as single-level interventions. The occurrence of a restenosis was significantly related to lower SF-36 scores, and restenosis not followed by a second intervention was associated with lower SF-36 scores.

CONCLUSION

Although there were several differences between the groups, significant improvements in quality of life up to 12 months after endoluminal therapy were observed in most patients.

Routine Use of Three-Dimensional Contrast-Enhanced Moving-Table MR Angiography in Patients with Peripheral Arterial Occlusive Disease: Comparison with Selective Digital Subtraction Angiography

PURPOSE

To compare the diagnostic accuracy of contrast-enhanced (CE) three-dimensional (3D) moving-table magnetic resonance (MR) angiography with that of selective digital subtraction angiography (DSA) for routine clinical investigation in patients with peripheral arterial occlusive disease.

METHODS

Thirty-eight patients underwent CE 3D moving-table MR angiography of the pelvic and peripheral arteries. A commercially available large-field-of-view adapter and a dedicated peripheral vascular phased-array coil were used. MR angiograms were evaluated for grade of arterial stenosis, diagnostic quality, and presence of artifacts. MR imaging results for each patient were compared with those of selective DSA.

RESULTS

Two hundred and twenty-six arterial segments in 38 patients were evaluated by both selective DSA and MR angiography. No complications related to MR angiography were observed. There was agreement in stenosis classification in 204 (90.3%) segments; MR angiography overgraded 16 (7%) segments and undergraded 6 (2.7%) segments. Compared with selective DSA, MR angiography provided high sensitivity and specificity and excellent interobserver agreement for detection of severe stenosis (97% and 95%, kappa = 0.9 +/- 0.03) and moderate stenosis (96.5% and 94.3%, kappa = 0.9 +/- 0.03).

CONCLUSION

Compared with selective DSA, moving-table MR angiography proved to be an accurate, noninvasive method for evaluation of peripheral arterial occlusive disease and may thus serve as an alternative to DSA in clinical routine.

MDCT Angiography of the Pulmonary Arteries: Influence of Body Weight, Body Mass Index, and Scan Length on Arterial Enhancement at Different Iodine Flow Rates

OBJECTIVE

The purpose of this study was to assess whether body weight, body mass index, and scan length influence arterial enhancement during CT angiography (CTA) of the pulmonary arteries at different iodine flow rates.

MATERIALS AND METHODS

CTA examinations of the pulmonary arteries performed for routine clinical care of 120 patients between March and December 2003 were retrospectively evaluated. Patients had received either 120 mL of contrast medium with an iodine concentration of 300 mg I/mL (group A) or 90 mL of contrast medium with an iodine concentration of 400 mg I/mL (group B). The iodine dose was 36 g, and the injection rate was 4 mL/s in all examinations. The iodine flow rate was 1.2 g I/s in group A and 1.6 g I/s in group B. Arterial attenuation along the z-axis was measured per patient, and the influence of body weight, body mass index, and scan length on enhancement of the pulmonary arteries in the two groups was assessed.

RESULTS

In group A and in group B, body weight and body mass index correlated significantly with mean enhancement along the z-axis (r = -0.35 and -0.26 for group A and -0.48 and -0.40 for group B). Scan length showed no correlation with pulmonary attenuation. Mean pulmonary artery enhancement was significantly higher in group B with a difference of 51 H compared with group A.

CONCLUSION

Pulmonary artery attenuation in CTA of the pulmonary arteries shows a small but significant correlation with body weight and body mass index independently of the iodine flow rate used. A higher iodine flow rate improves pulmonary artery enhancement.

Psoriatic arthritis and rheumatoid arthritis: findings in contrast-enhanced MRI

OBJECTIVE

Our objective was to define typical MRI findings of the wrist and the hand in patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA).

MATERIALS AND METHODS

Eighteen PsA and 21 RA patients with arthralgia of the wrist or hand joints underwent gadolinium-enhanced MRI of the wrist and hand. Two experienced radiologists interpreted abnormalities in consensus with respect to periarticular soft-tissue swelling, synovitis with or without effusion, periostitis, bone edema, bone erosions, bone cysts, and tenosynovitis. The distribution of the abnormalities also was evaluated.

RESULTS

Erosions were statistically more frequent in patients with RA (p < 0.05). Periostitis was statistically seen more frequently in patients with PsA (p < 0.05). No statistically significant difference was found in the frequency of synovitis, bone marrow edema, bone cysts, and tenosynovitis between the two groups (p > 0.05). The radiocarpal joint, the midcarpal joints, the carpometacarpal joints, and the metacarpophalangeal joints were significantly affected more frequently in patients with RA than in patients with PsA (p < 0.05), whereas the proximal interphalangeal joints were significantly more frequently affected in patients with PsA (p < 0.05).

CONCLUSION

Periostitis and synovitis of the proximal interphalangeal joints are typical MRI findings in patients with PsA, whereas synovitis with erosions of the wrist, the midcarpal joints, the carpometacarpal joints, and the metacarpophalangeal joints are typical findings in patients with RA.

Density histogram analysis of unenhanced hepatic computed tomography in patients with diffuse liver diseases

OBJECTIVE

The aim of the study was to assess the potential of density histogram analysis of unenhanced hepatic computed tomography (CT) in the diagnosis and differentiation of diffuse liver diseases.

METHODS

Twenty-six patients with normal liver parenchyma, 35 patients with diffuse steatosis, 14 patients with acute steatohepatitis, 15 patients with active alcoholic cirrhosis, 23 patients with inactive alcoholic cirrhosis, 15 patients with virus-induced cirrhosis, and 8 patients with hemochromatosis underwent unenhanced hepatic CT. All diffuse liver diseases and the absence of diffuse liver disease were histologically proven. Quantitative analysis of unenhanced liver parenchyma was performed in each patient.

RESULTS

The hepatic density histogram showed no significant differences in kurtosis and skewness between the groups (P > 0.05). Except for steatosis, active alcoholic cirrhosis, and hemochromatosis, diffuse liver diseases led to similar densities of liver parenchyma in unenhanced hepatic CT.

CONCLUSION

A reliable diagnosis and differentiation of diffuse liver diseases on the basis of density histogram analysis is not possible.

Multiphasic multidetector-row CT (MDCT) in detection and staging of transitional cell carcinomas of the upper urinary tract

The aim of this study was to evaluate the potential of multiphasic multidetector-row CT (MDCT) in the detection and staging of transitional cell carcinomas (TCC) of the upper urinary tract. We performed a retrospective chart review of 39 consecutive patients with 41 histologically verified TCC of the renal pelvis and/or the ureter. The urinary tract was examined using MDCT performing unenhanced and contrast-enhanced scans during the corticomedullary (CMP), nephrographic (NP) and pyelographic phase (PP). Tumors were staged according to the TNM classification. MDCT and histopathological findings were correlated. The attenuation of the lesions was documented in Hounsfield units (HU). In MDCT, all 41 TCC--including two multicentric TCC--were detected. TCC confined to the organ (stage 0a-II) was correctly staged in 28/29 tumors (96.6%). Stage III-IV tumors were correctly staged in 8/12 patients (66.6%). Overall, MDCT was accurate in predicting pathologic TNM stage in 36/41 upper urinary tract TCC (87.8%). There was no significant difference of mean attenuation of TCC between CMP, NP and PP (P > 0.05). MDCT with its high spatial and temporal resolution is an accurate tool for detection TCC of the upper urinary tract, with 87.8% accuracy in predicting its stage.

High-Concentration Contrast Media in Multiphasic Abdominal Multidetector-Row Computed Tomography

OBJECTIVE

The purpose of this study was to assess the influence of the iodine flow rate on parenchymal and vascular enhancement during multiphasic abdominal multidetector-row computed tomography (MDCT).

METHODS

Fifteen patients underwent MDCT at an iodine flow rate of 1.2 g/s as well as 1.6 g/s (group A, protocols 1 and 2), and 90 patients underwent MDCT at an iodine flow rate of 1.2 g/s (group B) or 1.6 g/s (group C). Measurements were performed for all groups in the liver, spleen, pancreas, portal vein, inferior vena cava, and abdominal aorta.

RESULTS

Aortal and pancreatic enhancement during the arterial phase was significantly higher with the higher iodine flow rate. The mean difference in aortal enhancement was 60 Hounsfield units (HU) between protocols 1 and 2 of group A, and the mean difference was 70 HU between groups B and C. The mean difference in pancreatic enhancement was 10 HU between protocols 1 and 2 of group A and 17 HU between groups B and C. During the portal and hepatic venous phases, no significant difference in enhancement was observed.

CONCLUSION

A high iodine flow rate in multiphasic abdominal MDCT improves enhancement of the aorta and the pancreas during the arterial phase but does not influence later phases.

MDCT angiography of the pulmonary arteries: influence of iodine flow concentration on vessel attenuation and visualization

OBJECTIVE

Our objective was to assess the influence of iodine flow concentration on attenuation and visualization of the pulmonary arteries in thoracic MDCT angiography.

MATERIALS AND METHODS

One hundred consecutive patients who were referred to our department with suspected acute pulmonary embolism underwent MDCT angiography of the pulmonary arteries either with 120 mL of standard contrast medium (300 mg I/mL) (group A) or with 90 mL of high-concentration contrast medium (400 mg I/mL) (group B). The contrast medium was injected at a flow rate of 4 mL/sec. The scan delay was determined using a semiautomatic bolus-tracking system in all examinations conducted with the same scanning parameters. Quantitative analysis was performed by region-of-interest measurements along the z-axis to compare the attenuation profiles of the two groups. Attenuation of the fourth-, fifth-, and sixth-order arteries was assessed visually for differences between the two groups.

RESULTS

The mean enhancement along the z-axis was 268 +/- 56 H in group A and 344 +/- 108 in group B. The difference of 76 H was statistically significant (p < 0.001). The attenuation profile was similar in both groups. The detection rate of fifth- and sixth-order arteries was significantly higher in group B than in group A (94% compared with 91% and 72% compared with 60%, respectively, p < 0.01).

CONCLUSION

Use of a high flow concentration of iodine in MDCT angiography of the pulmonary arteries significantly increases attenuation of the pulmonary arteries, thereby improving visualization of subsegmental pulmonary arteries.

Adrenocortical carcinomas and adrenal pheochromocytomas: mass and enhancement loss evaluation at delayed contrast-enhanced CT

PURPOSE

To retrospectively measure the adrenal gland attenuation and the percentage loss of adrenal gland enhancement at delayed contrast medium-enhanced computed tomography (CT) in patients with adrenocortical carcinomas and pheochromocytomas and to compare these data with those in patients with adenomas and metastases.

MATERIALS AND METHODS

The study protocol was approved by the ethics committee, which waived informed consent. Eleven patients with proved adrenocortical carcinoma, 17 with proved pheochromocytoma, 23 with adrenal adenoma, and 16 with metastasis to the adrenal gland underwent helical CT. Nonenhanced CT was followed by contrast-enhanced CT 1 minute and 10 minutes later. Attenuation and enhancement loss values were calculated.

RESULTS

The mean attenuation of adenomas (8 HU +/- 18 [standard deviation]) was significantly lower than those of adrenocortical carcinomas (39 HU +/- 14), pheochromocytomas (44 HU +/- 11), and metastases (34 HU +/- 11) on nonenhanced CT scans (P < .001). Although the mean attenuation values for nonadenomas (ie, adrenocortical carcinomas, pheochromocytomas, and metastases) were significantly higher than the value for adenomas on the 1-minute contrast-enhanced CT scans (P < .001), there was more overlap in attenuation between adenomas and nonadenomas on contrast-enhanced scans than on nonenhanced scans. On the 10-minute delayed contrast-enhanced scans, the mean attenuation of adenomas (32 HU +/- 17) was significantly lower than the mean attenuations of carcinomas (72 HU +/- 15), pheochromocytomas (83 HU +/- 14), and metastases (66 HU +/- 13) (P < .001). At optimal threshold values of 50% for absolute percentage of enhancement loss and 40% for relative percentage of enhancement loss at 10 minutes, both the sensitivity and the specificity for the diagnosis of adenoma were 100% when adenomas were compared with carcinomas, pheochromocytomas, and metastases.

CONCLUSION

The enhancement loss in adrenocortical carcinomas and pheochromocytomas is similar to that in adrenal metastases but significantly less than that in adrenal adenomas. The percentage change in contrast material washout is a useful adjunct to absolute CT attenuation values in differentiating adrenal adenomas from adrenocortical carcinomas and pheochromocytomas.

Frequency and Significance of Lumbar and Inferior Mesenteric Artery Perfusion After Endovascular Repair of Abdominal Aortic Aneurysms

PURPOSE

To evaluate the frequency and influence of perfused side branches (lumbar arteries [LA] and inferior mesenteric artery trunks) on development of type II endoleaks (EL-II) and on volume changes of abdominal aortic aneurysms (AAA) after endovascular repair.

METHODS

Of 114 patients undergoing EVR of AAA, 89 patients (83 men; mean age 72+/-7.5 years, range 51-88) with >6 months' follow-up and no type I endoleaks were retrospectively analyzed to determine any relationships between retrograde perfusion, endoleaks, and sac volume. Data were derived from computed tomographic angiographic (CTA) scans taken before and after intervention, at discharge, and at 1, 3, 6, and semi-annually thereafter in follow-up. Two groups were identified and compared based on their status at 6 months post EVR: without perfused side branches (group 1) and with perfused collaterals (group 2); group 2 was further divided according to the absence (2a) or presence (2b) of endoleak.

RESULTS

Median follow-up was 24 months (range 6-36). Based on a total of 582 CTAs analyzed, 17 (19%) patients developed type II endoleaks (EL-II) during follow-up. There was a significant difference in the number of perfused LAs prior to EVR between groups 1 (n=44) and the 45 patients with postprocedural patent collateral arteries in group 2 (p<0.05); there was no significant difference between groups 2a and 2b (p=0.88) relative to the number of pre-existing patent collaterals. The number of pLAs preoperatively and the rate of type II endoleak were significantly correlated (p<0.05). No type II endoleak was seen in patients without perfused side branches (p=0.01). No significant differences in mean volumes were found between groups 1 and 2a (no EL-II), but significant differences between groups 1 and 2b were seen in later follow-up.

CONCLUSIONS

A larger number of patent LAs before EVR was associated with a significantly higher rate of type II endoleak. Patent collateral vessels were common after aneurysm repair, but the frequency decreased during follow-up. Persistent side branch perfusion was associated with increased type II endoleak after endovascular AAA repair. Significant differences in volume changes in later follow-up were seen between patients with or without type II endoleak.

Sonographic diagnosis of urethral anomalies in infants: value of perineal sonography

OBJECTIVE

To assess the value of urethral sonography including a perineal approach in evaluating urethral anomalies in infants.

METHODS

A radiology database review identified 88 patients (mean age +/- SD, 64 +/- 84 days) who underwent voiding cystourethrography (VCUG) and urethral sonography as part of extended sonography of the urinary tract. Sonographic and VCUG images and reports were reviewed to assess agreement between both modalities for detection of urethral anomalies.

RESULTS

Sonography facilitated the correct diagnosis of all 3 posterior urethral valves. The only urethral diverticulum, the only ectopic ureteric insertion into the urethra, the only urogenital sinus, and the only urethrovaginal fistula were also shown on sonography. In 73 (94%) of 78 cases, sonography correctly showed the absence of anomalies. In 5 infants, sonography could not reliably assess the urethra and showed indirect signs of urethral anomalies; however, these patients had normal urethras on VCUG.

CONCLUSIONS

Our data show that sonography of the urethra is a valuable tool for diagnosis of urethral anomalies. Especially, negative findings on sonography are highly suggestive of the absence of urethral anomalies. Positive or equivocal sonographic findings should indicate VCUG.

Multislice spiral CT angiography in peripheral arterial occlusive disease: a valuable tool in detecting significant arterial lumen narrowing?

The aim of this study was to evaluate the potential of multislice CT angiography (CTA) in detecting hemodynamically significant (> or =70%) lesions of lower extremity inflow and runoff arteries. Fifty patients (42 men, 8 women; mean age 68 years) with peripheral arterial occlusive disease underwent multislice spiral CTA and digital subtraction angiography (DSA) from the infrarenal aorta to the supramalleolar region. CT parameters were 4x2.5-mm collimation, 15-mm table increment/rotation (pitch 6), and 1.25-mm reconstruction increment. Semitransparent volume rendering technique (STVR) images with semitransparent display of the arterial lumen (opacity: 50%) and vascular calcifications (opacity: 20%), as well as maximum intensity projection (MIP), and MIP together with axial CT studies were independently reviewed for hemodynamically significant lesions (> or =70% cross-sectional area reduction). DSA was the standard of reference. In 46 patients, 260 lesions were found (95 stenoses, 165 occlusions). For detecting > or =70% lesions in all vessel regions, sensitivity and specificity were 84% and 78% (STVR), 89% and 74% (MIP), and 92% and 83% (MIP+axial CT), respectively, with a significantly lower sensitivity of STVR ( p<0.05) and a significantly lower specificity of MIP studies ( p<0.01). Sensitivity and specificity were, respectively, 81% and 93% (STVR), 88% and 75% (MIP). and 92% and 95% (MIP+axial CT) at aortoiliac arteries, 92% and 73% (STVR), 95% and 70% (MIP) and 98% and 70% (MIP+axial CT) at femoropopliteal arteries, as well as 82% and 64% (STVR), 86% and 74% (MIP), and 90% and 74% (MIP+axial CT) at infrapopliteal arteries. Specificity of MIP-CTA was significantly lower in the aortoiliac region ( p<0.01), whereas STVR revealed significantly lower specificity at infrapopliteal arteries ( p<0.05). In the infrapopliteal region, the particular CTA imaging modalities led to misinterpretation regarding stenoses and occlusions in 39-45 cases, whereas only 0-6 significant aortoiliac and femoropopliteal lesions were misinterpreted. Multislice CTA is helpful in detecting hemodynamically significant lesions in peripheral arterial occlusive disease. Since axial CT studies yielded the most correct results, they should always be reviewed additionally. In the infrapopliteal region, exact lesion assessment remains problematic due to small vessel diameters.

Aortoiliac enhancement during computed tomography angiography with reduced contrast material dose and saline solution flush: influence on magnitude and uniformity of the contrast column

RATIONALE AND OBJECTIVES

To compare the magnitude and uniformity of aortoiliac contrast enhancement obtained from uniphasic contrast material injections versus contrast material injections with reduced iodine dose followed by a saline flush in aortoiliac multislice CT angiography (CTA).

METHODS

Twenty-nine patients with abdominal aortic aneurysms underwent aortoiliac CTA using protocols A and B. With protocol A, 120 mL contrast material (300 mgI/mL), and with protocol B, 100 mL contrast material followed by a 40-mL saline solution flush were administered at a flow rate of 4 mL/s. Quantitative analysis was performed by calculating mean aortoiliac attenuation, mean plateau deviation, and mean difference between maximum and minimum attenuation value for both groups. Qualitative analysis was performed by visual assessment of vascular enhancement using 2-dimensional and 3-dimensional postprocessing techniques.

RESULTS

The mean aortoiliac attenuation with protocol A was 291 +/- 62 HU, and with protocol B it was 285 +/- 61 HU. The difference of 6 HU was not statistically significant (P = 0.27). Mean plateau deviation was significantly smaller using protocol A than protocol B (16 +/- 9 HU vs. 20 +/- 10 HU, P = 0.03). In addition, the mean difference between maximum and minimum attenuation value was significantly smaller with protocol A than with protocol B (59 +/- 29 HU vs. 72 +/- 32 HU, P = 0.01). Visual analysis showed no difference in contrast material magnitude and homogeneity between the protocols.

CONCLUSIONS

In aortoiliac CTA, a saline solution flush after contrast material bolus allows an iodine dose reduction of approximately 20 mL without impairing the magnitude of contrast enhancement but degrades the uniformity of the contrast column. However, the degradation does not affect visual analysis.

Non-small cell lung cancer: evaluation of pleural abnormalities on CT scans with 18F FDG PET

PURPOSE

To evaluate the accuracy of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in differentiation of pleural malignancy and cancer-unrelated pleural disease in patients with non-small cell lung cancer (NSCLC) and pleural abnormalities at computed tomography (CT).

MATERIALS AND METHODS

In 92 patients, pleural abnormalities were detected at contrast material-enhanced thoracic CT, which was performed for newly diagnosed NSCLC (n = 41) or restaging (n = 51). CT findings were negative for pleural malignancy when pleural effusion with attenuation of 10 HU or less and/or rib fractures with no evidence of pathologic fracture were present; findings were indeterminate when pleural effusion with attenuation greater than 10 HU and/or solid pleural abnormalities without osseous destruction of the chest wall were present; and findings were positive if any osseous destruction of the chest wall adjacent to a pleural mass was present. All patients underwent FDG PET. Findings were negative for pleural malignancy if pleural activity was absent, equal to, or less than mediastinal background activity; findings were positive if pleural activity was higher than mediastinal background activity. Reading of CT and FDG PET scans was first performed separately and then was combined. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPP), and accuracy were calculated for CT and FDG PET separately and for CT and FDG PET combined, with cytologic and/or histologic analysis as standard of reference.

RESULTS

In detection of pleural malignancies, CT findings were indeterminate in 65 (71%) patients and true-negative in 27 (29%). Respective sensitivity, specificity, PPV, NPV, and accuracy of FDG PET in detection of pleural malignancies were 100%, 71%, 63%, 100%, and 80%; and those of CT and FDG PET combined, 100%, 76%, 67%, 100%, and 84%.

CONCLUSION

Findings suggest that a negative FDG PET scan for indeterminate pleural abnormalities at CT indicates a benign character, while positive findings on an FDG PET scan are sensitive for malignancy.

Abdominal multidetector row computed tomography: reduction of cost and contrast material dose using saline flush

OBJECTIVE

To evaluate the potential of a saline solution flush after the contrast material bolus in abdominal multidetector row CT (MDCT) in contrast material dose and cost reduction.

METHODS

Abdominal MDCT was performed in 78 patients who were assigned randomly to 2 groups receiving 120 mL nonionic contrast material (300 mgI/mL) alone or 100 mL of the same contrast material pushed with 40 mL of saline solution. Mean attenuation values for both groups were measured in the liver, the spleen, the pancreas, the portal vein, the inferior vena cava, and the abdominal aorta. Cost analyses were performed for both groups.

RESULTS

There was no significant difference in parenchymal and vascular enhancement between both groups. The difference of the enhancement was 2 HU for the liver (P = 0.11), 2 HU for the spleen (P = 0.44), 3 HU for the pancreas (P = 0.38), 9 HU for the portal vein (P = 0.11), 3 HU for the inferior vena cava (P = 0.55), and 10 HU for the aorta (P = 0.06). Taking the costs of contrast material, saline solution, and disposal material into account, 7.30 dollars was saved by the patient using a saline solution flush.

CONCLUSIONS

Using a saline flush after the contrast material bolus in abdominal MDCT allows an iodine dose reduction of approximately 6 g, or 17%, without impairing mean parenchymal and vascular enhancement and a cost reduction of 7.30 dollars per patient.

Improvement of parenchymal and vascular enhancement using saline flush and power injection for multiple-detector-row abdominal CT

The aim of this study was to determine if a saline solution flush following low dose contrast material bolus improves parenchymal and vascular enhancement during abdominal multiple detector-row computed tomography (MDCT). Forty-one patients (24 men and 17 women; mean age 49 years, age range 27-86 years) underwent abdominal MDCT (collimation 4x5 mm, 15-mm table increment, reconstruction interval 5 mm, gantry rotation period 0.8 s) with a single- as well as with a double syringe power injector. Indication for examination were benign and malignant tumors and inflammatory diseases. Patients received 100 ml nonionic contrast material (300 mgI/ml) alone or pushed with 20 ml saline solution. Mean enhancement values for both protocols were measured in the liver, the spleen, the pancreas, the renal cortex, the portal vein, the inferior vena cava and the abdominal aorta. Double syringe power-injector protocol led to significantly higher parenchymal and vascular enhancement than single syringe power-injector protocol (p<0.05). The improvement in mean enhancement of the liver was 9 +/- 9 HU, of the spleen 8 +/- 10 HU, of the pancreas 7 +/- 9 HU, and of the renal cortex 8 +/- 20 HU. The improvement in mean enhancement of the portal vein was 10 +/- 17 HU of the inferior vena cava 8 +/- 13 HU and of the abdominal aorta 10 +/- 17 HU. The use of a double syringe power injector with saline flush following contrast material bolus significantly improves parenchymal and vascular enhancement during contrast-enhanced abdominal MDCT with low iodine doses.

Semitransparent volume-rendering CT angiography for lesion display in aortoiliac arteriosclerotic disease

PURPOSE

The potential of semitransparent volume-rendering (STVR) computed tomographic (CT) angiography was evaluated for the assessment of hemodynamically significant stenoses in aortoiliac arteriosclerotic disease.

MATERIALS AND METHODS

In a prospective study, 76 patients (57 men, 19 women; mean age, 70 years) underwent single-detector (n = 26) or multidetector (n = 50) CT angiography of the aortoiliac region. Intraarterial digital subtraction angiography (DSA) was performed in each patient. STVR images with semitransparent display of arterial lumen (opacity, 50%) and vascular calcifications (opacity, 20%), as well as maximum-intensity projection (MIP), frontal/sagittal curved planar reformation (CPR), and MIP/axial studies were independently reviewed for hemodynamically significant lesions (> or =70% cross-sectional area reduction). DSA combined with invasive pressure measurement was used as the standard of reference. Vessel wall calcifications were classified according to a four-point scale (0, not calcified; 1, mildly calcified; 2, moderately calcified; 3, severely calcified).

RESULTS

Of the 380 reviewed vessel sections, 28 represented 70%-99% stenoses and 14 represented occlusions. For detecting >/==" BORDER="0">70% lesions, STVR as well as CPR and MIP/axial studies revealed significantly higher specificity (91%-94%), positive predictive value (PPV; 0.62-0.72), and accuracy (90%-94%) than MIP (specificity, 59%; PPV, 0.27; accuracy, 64%; P <.001) in moderately or severely calcified vessel sections. In noncalcified or mildly calcified sections, the specificity of MIP was comparable with the other rendering techniques (96%-98%; P values ranging from.34 to.77). No significant sensitivity differences were noticed among the CT angiography modalities: STVR, 79%; MIP, 88%; CPR, 83%; and MIP/axial, 93% (P values ranging from.12 to.78). Negative predictive values ranged from 0.97 to 0.99 (P values ranging from.14 to 1). Median calcification scores in sections with overestimated lumen narrowings were significantly higher (3, severely calcified) than in sections with correctly graded lumen width (1, mildly calcified) with all CT angiography modalities (P <.05).

CONCLUSION

With use of STVR, visualization of vascular lumen can be improved by rendering highly transparent mural calcifications. Hence, for three-dimensional presentation of aortoiliac arteriosclerotic disease, STVR studies should be preferred to MIPs as supplements to review of axial-source images.

Helical CT angiography with maximum intensity projection in the assessment of aortic coarctation after surgery

OBJECTIVE

The value of CT angiography and three-dimensional (3D) reconstructions was investigated in the postoperative care after surgical repair of aortic coarctation and compared with conventional angiography.

SUBJECTS AND METHODS

Twenty-five patients referred because of suspicion of stenosis in the area of former coarctation were prospectively studied with CT angiography and catheter angiography. We determined the morphometric and morphologic findings such as aortic diameter, stenosis, aneurysm, intimal flaps, circumscribed pouch, or arteriosclerotic plaques with 3D reconstructions, using maximum-intensity-projection (MIP) technique and catheter angiography. The results of both techniques were compared. The ratio of the narrowest diameters of the former coarctation and the descending aorta was correlated with the systolic pullback blood pressure gradient in all patients.

RESULTS

The former coarctation was normal in 11 patients, (44%), group A; narrowed in 12 children (48%), group B; and dilated in two children (8%), group C. An intimal flap and a circumscribed pouch were delineated in four subjects. MIP reconstructions and catheter angiography revealed identical results regarding the classification into groups A, B, C; intimal flaps; and circumscribed pouches. Statistical analysis revealed good correlation between the narrowest aortic diameters measured on MIP reconstructions and catheter angiography, whereas no correlation between the systolic pullback blood pressure gradient and the diameter ratio of the former coarctation and the descending aorta was found.

CONCLUSION

CT angiography and 3D reconstructions using MIP represent a reliable noninvasive technique to replace diagnostic catheter angiography in the postoperative care of patients with coarctation and provide the clinician with valuable information concerning further invasive procedures.

Digital image fusion of CT and PET data sets--clinical value in abdominal/pelvic malignancies

PURPOSE

We investigated the clinical relevance of digital image fusion of CT and 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) positron emission tomography (PET) studies in patients with suspected abdominal and/or pelvic metastasis.

METHOD

Nineteen patients with suspected residual/recurrent malignancies underwent CT and [18F]FDG PET studies of the abdomen and/or pelvis. The data sets of both modalities were fused on a digital workstation by automatic adaptation of the pixel size and the slice thickness. Different body positions were corrected by semiautomatic adaptation of the body axes. The fused images were reconstructed in sagittal, coronal, and axial planes.

RESULTS

Good spatial correlation between both modalities was achieved in all patients. Image fusion improved the spatial allocation of pathologically increased [18F]FDG uptake in 7 of 35 lesions (20%).

CONCLUSION

This work suggests that digital image fusion of CT and [18F]FDG PET data sets improves the anatomical localization of foci with increased [18F]FDG enhancement of the retroperitoneum and the abdominal/pelvic wall, respectively.